By Eben van Tonder
24 August 2020
Meat products fall in the following three categories.
Pure Meat Products is where every ingredient except the spices come from an animal carcass.
Meat Analogues are starches and soy, grains and cereals which are made so that it tastes like meat but contains no part of an animal carcass. The question comes up as to why would a vegan, for example, who does not want to eat meat, buy a product disguised as meat, but which, in reality, contains no meat? Pure meat and meat analogues are therefore two opposing and extreme ends of the spectrum.
Meat Hybrids is the middle of the two and combines meat and plant-based protein, essential for the purpose of achieving a cheaper product. There is something deceptive about this class of products since it is often designed to mislead as to the real nature of the products (I say this, despite the label declaration, which is often still enigmatic to consumers). They think it’s meat, but it contains a percentage of non-meat fillers. This is almost always done to reduce the price of the product, which, in a country like South Africa, is not necessarily a bad thing. Affordable food, where “affordable” is relative to the income level of the consumer, is a very important consideration. It must also be stated that for the most part, large producers of this kind of products do not add as fillers and extenders, anything except high quality, acceptable and healthy products such as soy in the meat to extend it.
My personal preference is clear. I prefer pure meat products mainly based on taste and, to a lesser extent, on matters such as allergy which relate to health in that some of the fillers may be allergens. Taste of pure meat products can, in my personal opinion, not be matched in taste, firmness, mouthfeel, or any other organoleptic characteristics (the aspects of the end-product that create an individual experience via the senses—including taste, sight and smell).
Meat Hybrids I can understand, living in Africa where there is a long tradition of honouring every scrap of meat. My main issue is with meat analogues.
It was with this background that I was intrigued by Denny Mushroom’s range of meat substitute products they recently launched. When I saw it being advertised at our local Spar I immediately went looking for it, but due to its popularity, only the mince was left. My wife and I decided to compare it to soy mince.
In order to do any evaluation worth its salt, we find it best to pare it against a competitor. Here is our evaluation:
We chose the same basic method of preparation and ingredients.
Denny Beef Style Mince
Mushrooms (75%), Oats, Onion, Seasoning (Yeast Extract [Garlic, Sugar], Salt, Dextrose, Caramel colour, Silicon dioxide, Herbs & spices), Maize, Vegetable fat (Sunflower seed, Palm kernel, THBQ, Sodium alginate, Calcium sulphate, Dextrose, Phosphate, Modified Starch), Psyllium husk, Beetroot, Ascorbic acid, Flavouring, Guar gum, Potassium sorbate.
Phrases like “meat alternative” and “100% Vegan Superfood” removes all doubt – it contains no meat.
The product looks like mince and it is obvious where the name comes from. I have a bit of an issue with the “Beef Style” part of the name since it creates an expectation that it will taste like beef. The ingredients list makes it clear that there is no beef in the product.
At first, I am disappointed by the “Beef Style Mince” when I realise that it does not taste like meat at all. My problem with it was, however short-lived when I took my second bite! The taste is “refreshing!” It is unlike anything I had before and is delicious! It stands on its own as a well-formulated product! Sure, it tastes nothing like mince, but it still is exceptional!
Minette and I both noticed that it binds well, meaning that it mushes into a meatball (well, not a meatball 🙈🙈🙈 but you get my point) 🤣 This characteristic opens up a world of possibilities for the chef and is also distinctly different from minced meat.
The manager at Spar told me that the mince is not selling as well as the rest of the range. In my personal opinion it will be a pity if, for commercial reasons, the line is killed.
I understand why they would never go there, but is ripe for inclusion in a food hybrid formulation. A thought for the future as a different brand name with a unique positioning will do well with it. It scores a well deserved 8 out of 10 for a refreshing taste, its originality and the overall product formulation! Hats off to the development team!
Veggie Mince of Frey’s
The product comes in an inner pack with gravy, but right from the start, one can see that it looks far less appealing than Denny’s product. The ingredients are:
Vegetable Protein (Soya, Wheat (Gluten)), Flavourings (Onion, Pepper, Maize Starch, Anti-caking Agent (E551), Savory Flavour), Vegetable Oil (Sunflower Seed), Wheat (Gluten) Flour, Potato Starch, Plant Fibre, Maize Starch, Thickener (Methyl Cellulose), Ground Coriander (Sulphites), Salt, Onion, Mustard, Colourant: Caramel IV
Similarly to Denny’s, it positions itself squarely for the vegetarian market with no meat. The taste was unfortunately such that I could not take a second bite. We threw it all into a bag and in the dustbin. It scores a disappointing 2 out of 10.
In contrast to this, I got up at 2:00 a.m. this morning and sneaked into the kitchen to finish the leftovers of the Denny product!
I understand why marketers link non-meat products to meat. They believe a meat point of reference will aid them in selling the product. Life may very well prove them right. Still, it is a pity, particularly in the case of Denny who produced a unique and exceptional product which should be able to stand on its own two feet, apart from the simile to meat. Why not call it Mushroom Style Mince? or Denny Style Mince? Whatever you call it, it is a brilliant product!
– Frey’s is a well-respected producer and there are many of its products which I love and regularly buy. The Mince is only one of them which I will rather give a miss.
– The views expressed are purely my own. The products were prepared in an unscientific way and no blind test or other evaluation was performed besides merely my first impressions upon tasting it. I advise consumers to be their own judge if they agree with me or not.
– I refer to myself as doing the evaluations for the sake of not making my amazing wife complicit in my comparisons! 🙂 Reality is that I am a very poor cook and she is in a league of her own. Her sister and she practice cooking as an art and not a way to get food in one’s stomach! Minette, therefore, prepares all the meals – exceptionally well. I only enjoy and judge them with her!
Please email me on email@example.com for comments or suggestions. Feel free to comment at the bottom of this blog post!
Poultry MDM: Notes on Composition and Functionality
by Eben van Tonder
5 July 2020
The mechanical deboning of meat has its origins from the late 1940s in Japan when it was applied to the bones of filleted fish. In the late 1950s, the mechanical recovery of poultry meat from necks, backs and other bones with attached flesh started. (EFSA, 2013) A newspaper report from the Ithaca Journal, Wed, 30 Dec 1964 is the earliest reference I can find on Mechanically Deboned Meat (MDM) in America. It reports on research done at Cornell State College of Agriculture in an article entitled, “New Egg Package, Chicken Products Are Among 1964 Research Results.” It reports that “mechanically deboned chicken meat was put to use for the first time, and improvements were in new types of harvesting machines.”
It claims that MDM based products would be available from 1964. “Late in 1964 Cornwell researchers began preparing experimental chicken products from this meat, which resembles finely ground hamburger.” It said that the new chunky type chicken bologna, was introduced in three forms: Chicken Chunk Roll, which is half chunk meat, and Chicken Chunkalona, which is 25 per cent chunks and 75 per cent emulsion.”By 1969, several American universities were working on these products, including the University of Wisconsin.
By the early 1970s, the removal of beef and pork from irregularly shaped bones was introduced. Originally, the aim of MDM was to reduce the rate of repetitive strain injury (RSI) of workers caused by short cyclic boning work in cutting rooms of meat operations. A press was developed to accommodate this. The success of the approach resulted in a rapid acceptance of the principles and an incorporation of the technology across Europe and the USA.
As is the case with meat processing technology in general, despite recent developments of the process, the basic approach is still the same as the first machines that was built. Initially primitive presses derived from other types of industries were used to separate the meat from the bones, using pressures of up to 200 bar. A fine textured meat paste was the end-product, suitable for use in cooked sausages. Gradual technological improvements and pre-selection of the different types of flesh bearing bones pressed at much lower pressure (up to 20 bar) produced a coarse texture of higher quality meat that could no longer be distinguished from traditional minced meat (so called 3 mm or Baader meat).
Today, a wide variety of different products are available on the market from many different suppliers of every imaginable animal protein source. Legislation differs widely between different countries on the definition of MDM. They name and classify it differently and the astute entrepreneur will find opportunities in studying every aspect of this fascinating industry closely, especially in the maize of ever evolving legislation related to it around the world. As one country restricts its use on one front, other countries will be able to buy a particular grade or type at better rates and this will in turn open up opportunities in the buying-country’s market for new ways to use raw material which becomes available for it due to a drop in the price.
My own foray into this world took place during a year when Woody’s gave me the opportunity to spend almost a year working with companies in England. The project I worked on was high injection pork. During this time there were changes to legislation related to ground pork. I witnessed UK prices plummet on a commodity which, in retrospect, we should have pounced on, but I knew far too little about the sausage market to exploit the opportunity. My business partner in the company we founded and where neither of us are involved in any longer will certainly have a good chuckle remembering those days!
Between 10 May and 8 June 2012, at the Tulip plant in Bristol, England, we extended ground pork with 100% brine which was designed by a friend from Denmark. Brine was tumbled into the meat, heat set, chilled, frozen and sliced. Re-looking at the texture of the final product from photos I took, almost 8 years later to the day, I realise that we should have used it to create a fine emulsion for a sausage or loaves. Looking at the result of the 100% extension below, we could easily have targeted 150% or even higher. We could have landed the raw material at a very competitive price in SA if we created a fine emulsion base, extended 150% with rind emulsion added (instead of rusk) and used it as the basis for a number of fine emulsion based products at our factory in Cape Town. Evaluating what we did in Bristol, the heat setting, even in our course loaf-like product, was inadequate for proper gelation, which is clearly seen in the photos below.
All the photos related to these trails can be seen at: https://photos.app.goo.gl/LX6uZheqeBeUa1mWA
The lesson for me is that in order to exploit these realities, one must grasp the functional value of the raw material, which in our consideration here is MDM, but must most certainly include other similar products not necessarily classified as MDM, MRM or MSM such as ground meat or something similar. This will lead to an appreciation of the differences between various grades of MDM and related products, which will allow processors to develop new products and increase its bottom line / reduce selling prices of others as new MDM products become available and countries adjust its legislation to regulate its use. It all begins by understanding the basic principles at work in this immense and fascinating world. We begin by looking at the basics of poultry MDM.
I use the work of JM Jones as the basis for these considerations as was published in the work edited by Hudson, B. J. F.. Related to the functional characteristics, I rely on the work of Abdullah and Al‐Najdawi (2005). They set up to investigate the eﬀects of either manual or mechanical deboning on the functional properties of the resultant meat and any changes that might occur in quality attributes, as measured by sensory testing. They also considered the effects of frozen storage. In their study, they compared 4 treatments: treatment 1: manual deboning of whole carcasses; treatment 2: manual deboning of skinned carcasses; treatment 3: mechanical deboning of whole carcasses; treatment 4: mechanical deboning of skinned carcasses. We will refer to these 4 treatments during our discussion below.
Production Methods, Meat Quality and Nomenclature
The process of mechanical deboning involves crushing the bones and mixing with meat and skin before the bone is separated out. Inevitably, crushing of the material leads to changes in the chemical, physical, sensory and functional properties of the meat, and meat colour is a case in point. This is one of the most important meat-quality characteristics, with a strong inﬂuence on consumer acceptance of the retail product.
Groves and Knight refer to EU Regulation (EC) No 853/2004 which defines “mechanically separated meat (MSM) as the product from mechanical separation of residual flesh from bones where there has been loss or modification of the muscle fibre structure. MSM cannot count towards the meat content of products for the purposes of Quantitative Ingredient Declaration (QUID) requirements in EU Food Labelling legislation.”
Today, MDM production take place in two forms. With high pressure and with low pressure. Low pressure MSM was previously called desinewed meat (DSM or 3mm meat) in the UK and it was shown that it has a considerable amount of intact muscle fibre structure similar to some meat preparations (made from hand deboned meat or HDM) and was very different to high pressure MSM. Based on this research and analytical evidence in the literature, DSM was considered in the UK to fall within the definition of ‘meat preparations’ in EU food law rather than that of MSM. By itself, this shows the major difference between High Pressure and Low Pressure MDM.
Groves and Knight reported that “an audit by the Food and Veterinary Office of the European Commission (FVO) was conducted in March 2012 and led to a change in UK policy to align with the Commission’s interpretation that DSM was treated in all respects as MSM, including for the purposes of QUID. This has significant economic implications as the value of the low pressure MSM is considerably reduced. It is accepted that there is no evidence of any increased food safety risks associated with low pressure MSM (DSM).” It is this classification change that I refer to my own England experience in 2012 and is my case in point of focus for the international MDM trade and opportunities created by a change in legislation.
Regulation (EC) No. 853/2004 further defines different rules for MSM produced by techniques that do not alter the structure of the bones and those that do. This is based on whether the product has a calcium content that is not significantly higher than that of minced meat, for which a limit is set down in Regulation (EC) No. 2074/2005. Calcium content is therefore a method of determining if high or low pressure meat recovery is used as opposed to the health issue, which was the case, early on in its introduction on the world stage.
Their report is very educational in terms of various production methods and serves as an excellent introduction into our study. An evidence-based review MSM vs DMS For now, it is enough to identify two main classes of equipment for producing MDM, High Pressure MDM and Low Pressure MDM machines. Even though Abdullah and Al‐Najdawi (2005) do not say if the MDM used in their study was produced with HP or LP, my guess is that it is Low Pressure MDM produced in Jordan. I mailed the author to get clarity on the point since it will have a direct impact on the points of application. For now, I will assume that Low Pressure was used.
Viuda-Martos (2012), generalises more in their definition of these products. Like many authors, they see mechanically deboned meat (MDM), mechanically recovered meat (MRM) or mechanically separated meat (MSM) as synonyms to mark material, obtained by application of mechanical force (pressure and/or shear) to animal bones (sheep, goat, pork, beef) or poultry carcasses (chicken, duck, turkey) from which the bulk of meat has been manually removed (Püssa and others 2009). They state that the deboning process can be applied to whole carcasses, necks, backs and, in particular, to residual meat left on the bones after the completion of manual deboning operations.
Importantly, they highlight some of the key challenges with this class of products in that the mechanical process of removing meat from the bone causes cell breakage, protein denaturation and an increase in lipids and haem groups and poorer mechanical properties. MDM is therefore characterised by a pasty texture of various consistencies, depending on a wide range of factors. The past texture is generally due to the high proportion of pulverised muscle fibre residue, and the presence of a significant quantity of partly destructured muscle fibres. The term used by these and other authors for this loss or modification of muscle fibre structure is ‘‘destructuration”. Recovered meat is generally considered to be of poor nutritional and microbiological quality and is strictly regulated in its use as a binding agent or as a source of meat proteins in minced meat products. (Viuda-Martos, 2012)
MDM is, therefore, used in the formulation of comminuted meat products and in the creation of fine emulsion sausages due to its fine consistency and relatively low cost. It is an important raw material in underdeveloped countries, due to its price. (Viuda-Martos, 2012) Groves and Knight remind us how important the naming of a substance is and how difficult it is in the case of this class of products. It would be a mistake to see MDM, MRM, MSM or any of the other synonyms as homogeneous product names and that without delving into the details of its production, we cannot fully know its functional qualities. Each individual product, from each different supplier, at different times (depending on input raw material, which is never consistent), must be looked at carefully and evaluated on its own.
There are, however, general observations that can be made related to the overall product class. If nothing else, what follows will give us a list of questions to ask and reasons why it is important. It will further give us an appreciation of the complexity of its evaluation and manipulation and the impact it can have on the final product produced from it.
Poultry MDM Stability
In general, poultry MDM has been shown to have more constant composition compared with pork, veal and beef MDM. Considerable variations in fat and protein content occur in poultry MDM. The amount of back, wing, neck, rack, skin (or no skin) or the ratio of starting material used and type of deboning machine and settings play a major part in final product composition. Deboner head pressure was increased x 3 to increase the yield from 45 to 82%; fat content significantly reduced and moisture content increased. (Hudson, 1994) This is an interesting observation. What could have caused the decrease in fat and increase in moisture? The decrease in fat was probably due to an increase in other components such as connective tissue and the increase in moisture probably refers to unbound water, which resulted as a result of the higher pressure and bone marrow. The addition of bone marrow under higher pressure was therefore less than the increase of connective tissues.
Rancidity problems stem from the method of production. Air with increased iron because of bone marrow are the major reasons. Additional fat stems from bone marrow and skin. Phospholipid fraction, as a percentage of total lipid content, is only at about 1 – 2% in poultry MRM. Over 60% of this may be unsaturated, oleic, linoleic, arachidonic acid. These acids decrease in concentration during freezing or frozen storage of turkey meats or nuggets made from chicken MDM. This (the decrease in polyunsaturated fatty acids) may be explained by reports that chicken muscle homogenates to contain enzymes capable of oxidizing both linoleic and arachidonic acids and one was found to be stable during frozen storage, being 15-lipoxygenase. (Hudson, 1994)
Iron in MDM acts as a catalyst in lipid oxidation is well known, but -> is it haem or non heam iron that plays the dominant role in poultry? Lee et al. say that haem protein, (50% of total iron) is the dominant catalyst for lipid oxidation in poultry MDM. Igene et al. claim that “warmed over flavour” of cooked chicken meat (whole muscle) is due to non-haem iron release during heating, which is the catalyst for oxidation. Kanner et al. say that one reason why haem protein effects lipid oxidation only after heating was that catalase activity was inhibited and this allowed H2O2-activated mayoglobin to initiate peroxidation. Related to uncooked meat, these authors report an iron-redox cycle initiated peroxidation and the soluble fraction of turkey muscle contained reducing substances which stimulated the reaction. Free iron in white and red meats of chicken and turkey increases in concentration with storage time and is capable of catalyzing lipid oxidation. (Hudson, 1994)
Decker and Schanus used gel formation to separate an extract of chicken leg muscle into three protein fractions. One catalysed over 92% of the observed total linoleate oxidation. Iron-exchange chromatography of this active fraction revealed three proteins capable of oxidising linoleate. Haemoglobin was responsible for 30% of total oxidation while two components (according to Soret absorbance) were non-heam proteins and responsible for 60%. (Hudson, 1994)
“Metal ions from the deboning machinery itself and calcium and phosphorus ions from bone may act as catalysts for haem oxidation (Field, 1988).” Also, mechanical deboning of material containing skin leads to a release of subcutaneous fat that tends to dilute the haem pigments present, producing meat of a lighter colour. The same is true for fat released from bone marrow during crushing.” (Abdullah and Al‐Najdawi, 2005)
Related to the effect of the production process on myoglobin, it has been proved that manufacturing MDM “has no eﬀect on the myoglobin contents, although it may inﬂuence the form of that pigment, thereby causing colour changes (Froning, 1981).” (Abdullah and Al‐Najdawi, 2005) Much work in this area remains.
Modification of Poultry MDM and Functional Characteristics
The paste-like nature of poultry MDM limits its use. Early investigations focused on ways to “texturise” it. This can be done by adding plant protein or by various heat treatments. Sensory properties are not always what is desired. (Hudson, 1994)
One method of producing MDM products is to use a twin-screw extrusion cooker. (Extrusion Cooking) Treatment of poultry MDM alone gives unsatisfactory results. The fat content of the material is too high. Satisfactory products similar to meat loaf or luncheon meat were achieved if, as binding or gelling agents, cereal flours, corn starch, egg white concentrate or soy protein isolate were combined with the MDM. (Hudson, 1994) This begs the question as to the gelling temperature of these products.
Alvarez et al. found that chicken extruded with 10 or 15% corn starch, lipid oxidation decreased as extrusion temperature rose from 71 to 115.5 deg C. They suggest that antioxidants were produced with increasing temperature. Hsieh et al. reported that a mixture of turkey MDM (40 parts) and corn flour (60 parts) increased in susceptibility to lipid oxidation above 110°C. The antioxidant BHA (butylated hydroxyanisole) was added to the raw materials before extrusion. (Hudson, 1994)
-> Haem Removal
Haem pigments in the product impacts on product stability and in poultry MDM it has a tendency to create a dark colour in the final products. Much effort is expended to remove these pigments and so extend the range of products in which the MDM may be used. (Hudson, 1994)
Froning and Johnson showed that centrifuging poultry MDM would remove haem pigments. Washing procedures was first developed in Japan to remove haem proteins, enzymes and fats from fish during the production of the myofibrillar protein concentrate, surimi. A lot of work has been done to extend the same procedure to washing MDM. However, there are several reasons why surimi technology might not be applied directly to poultry MRM, viz:
1. Surimi is prepared from whole muscle while poultry MDM is isolated from bones after most muscle tissue is removed.
2. Poultry MDM can have considerable quantities of connective tissue in the final product, e.g. histochemical investigations have shown the connective tissue: muscle ratio of chicken MRM to be 1 : 1.2.
3. Fish mince is frequently washed during preparation, but water washing is not an efficient means of removing haem pigments from MRM.
4. Lee suggested the size of perforations in the deboner drum of fish deboners ranges from 1 to 5 mm, with orifices of 3 to 4 mm giving the best quality and yield of surimi. Poultry deboners seem to have a pore size below 1 mm and thus the particle size of the products will differ. Since the term ‘surimi’ has long been associated with the product isolated from fish muscle, it is perhaps debatable as to whether the term should be applied to the material prepared from poultry MRM.
Other terms used are:
‘Washed mechanically deboned chicken meat’, ‘myofibrillar protein isolate’, (MPI), ‘isolate of myofibrillar protein, (IMP). The acronym IMP is problematic since it is widely accepted as an abbreviation for inosine monophosphate. Clearly some rationalization of nomenclature is required and perhaps a term such as ‘poultry myofibrillar protein extract’ would be more appropriate. (Hudson, 1994)
One of the earliest studies of poultry, turkey neck MDM, considered to be the darkest poultry MDM, was washed either three times in water or once in 0.04 M phosphate at various pH values, followed by two water washes. Then, the mixtures were pressed through cheesecloth to remove as much moisture as possible. The yield of paste from water-washed MRM was higher than that which had been treated with phosphate, but it had a darker colour. The researchers concluded that washing with 0.04 M phosphate at pH 8.0 provided the most efficient means of removing red pigment from turkey MDM. Froning and Niemann reported that extraction of chicken MDM with 0.1 M NaCI significantly reduced fat concentration and colour, and increased protein concentration. Others, using different washing techniques, particularly the use of bicarbonate as the washing medium, have found that either the protein content of the washed material was similar to that of the starting material, or was up to 7% lower. However, all agreed that washing drastically reduced the fat level of the recovered material. (Hudson, 1994)
Washing with bicarbonate appears to be the most efficient way of removing pigment from poultry MDM, probably due to the fact that the pH value of the slurry makes the blood proteins more soluble, there may be other factors at work to influence the final colour of the washed product. For example, Trziszka et al. found that if, following bicarbonate extraction, water washing was carried out at pH 5.5, the product was lighter than at pH 6.0, while the variable amounts of connective tissue present in the washed residue can influence the appearance of the material, as shown by Kijowski et al., who found that removal of connective tissue by sieving increased both the darkness and redness of water-washed chicken MRM. (Hudson, 1994)
The yield after washing range was 13.5 to over 62% of the starting material. Reasons for this variety may be the result of a number of factors such as source material for MRM, grinding of MRM before washing, nature of washing medium, washing time, adjustment of pH, number of washes, ratio of MDM to extractant and centrifugal force applied during separation of ‘meat’ and extractant. (Hudson, 1994)
Cryoprotectants, such as mixtures of sugars and/or phosphates, must be added for the washed material to retain its gelling and water-holding abilities during frozen storage. Washing improved the functional properties of the material – after cooking the washed MDM was more chewy, less cohesive and had increased stress values but the cooking losses from washed material were higher, probably due to the fact that ‘free’ water was absorbed during washing. The best indication of the success of the washing procedure is probably in practical terms measured by the performance of the myofibrillar complex in products. There have been a few studies who looked at this. Frozen-thawed, bicarbonate washed turkey MDM at a level of 10% reduced the fat level of frankfurters, while increasing the expressible moisture content and resistance to shear compared with control frankfurters. Scanning electron microscopy did not reveal any obvious structural differences between controls and frankfurters containing 10% washed MDM. Hernandez et al. reported – the protein paste from washed turkey MDM could be incorporated into patties at levels up to 20% without adversely affecting sensory quality. Trziszka et al. reported that up to 50% of the ground chicken meat in hamburgers could be replaced by carbonate-washed turkey MRM without reducing the acceptability of the product. A sensory panel gave slightly lower flavour scores to hamburgers containing the protein extract, although whether this was due to the ‘soapy’ taste reported by Dawson et al. is not clear. (Hudson, 1994)
-> Improving Emulsification and Gelation
“Since MDM is used in the manufacture of emulsion products, emulsifying capacity (EC) is an important property of the raw material (Froning, 1981; Field, 1988). EC has been deﬁned as the amount of oil that can be emulsiﬁed by the material prior to the reversion or collapse of the emulsion (Swift et al., 1961; Ivey et al., 1970; Kato et al. , 1985). Factors aﬀecting the emulsifying properties of a protein are: protein concentration, medium pH, oil temperature, mechanical force and rate of oil-addition during emulsiﬁcation “(Galluzzo & Regenstein, 1978; Wang & Zayas, 1992; Zorba et al., 1993 as quoted by Abdullah and Al‐Najdawi, 2005.
Although the protein complex isolated from washed MDM could be of use in altering textural properties of poultry products, further possibilities of effecting such changes exist. For instance, Smith and Brekke found that limited acid proteolysis improved the emulsifying capacity of actomyosin isolated from fowl MDM, as well as improving the quality of heat-set gels. Kurth used a model system to demonstrate the crosslinking of myosin and casein by a Ca-dependent acyltransfer reaction catalysed by transglutaminase (EC 22.214.171.124; R-glutaminyl peptide amine gamma-glutamyl transferase). Application of the technique to actomyosin prepared from turkey MDM showed that actin did not polymerize, but that the disappearance of myosin monomer was accompanied by a concomitant increase in polymer content and that the gel strength of enzyme-treated protein was greater. The polymerization could occur at temperatures as low as 4°C, thus opening up possibilities for the manufacture of new products. (Hudson, 1994)
“Mean EC values are presented in Table 1 and show signiﬁcantly higher values for both kinds of deboned meat without skin (treatment 2: manual deboning of skinned carcasses; treatment 4: mechanical deboning of skinned carcasses.). The presence of skin in MDM is considered detrimental to EC, because of its collagen content, and this view is supported by the signiﬁcantly lower EC value obtained for MDM prepared from whole carcases (treatment 3: mechanical deboning of whole carcasses), in comparison with that from skinned carcasses (treatment 4: mechanical deboning of skinned carcasses). Deboning of skinned carcasses by hand (Treatment 2: manual deboning of skinned carcasses) signiﬁcantly increased the proportion of insoluble protein in the meat (Table 1), which can have an adverse eﬀect on EC. However, this would be counterbalanced, to some extent, by the relatively low pH of the material that would increase protein solubility. Increased levels of insoluble protein could lead to protein enveloping the added oil droplets, thereby reducing the total amount of oil that is available to be emulsiﬁed (Swift, et al., 1961). The concentration of protein is also critical in relation to its own stability. When the concentration is suﬃciently low, the protein structure unfolds to a degree that favours stability (Ivey et al., 1970).” (Abdullah and Al‐Najdawi, 2005)
“It is clear from Table 2, that EC values increased signiﬁcantly during frozen storage of manually deboned meat, but declined in the case of MDM obtained from skinned carcasses (Treatment 4: mechanical deboning of skinned carcasses). These changes occurred exclusively during months 1 and 2, with no signiﬁcant eﬀect subsequently for any treatment group. The initial decline in EC values for Treatment 4 may be attributable to the partial denaturation of protein. Accordingly, the corresponding increase in EC for manually-deboned meat is likely to reﬂect the absence of any mechanical damage to the structure of the meat. In this state, the protein would remain largely intact.” (Abdullah and Al‐Najdawi, 2005)
Poultry MDM: Water Holding Capacity
“Another important property of meat used for product manufacture is water-holding capacity (WHC). Like other meats, poultry contains approximately 70% water in the raw state, much of which is not tightly bound and is known as ‘free water’ (Baker & Bruce, 1989). The WHC of muscle foods has been used as an index of palatability, microbial quality and manufacturing potential (Dagbjartsson & Solberg, 1972). It is highly important in the formulation, processing, cooking and freezing of meat products, because it relates to weight loss and ultimate quality of the ﬁnished product (Field, 1988). Factors aﬀecting WHC are pH value, presence of iron, copper, calcium and magnesium from bone, content of skin and collagen, and the processes of cooking and freezing.” (Abdullah and Al‐Najdawi, 2005)
The pH values “obtained from mechanically deboned material (mechanical deboning of whole carcasses and mechanical deboning of skinned carcasses) were signiﬁcantly higher than the values for manually-deboned meat (manual deboning of whole carcasses and manual deboning of skinned carcasses). This may be explained by the unavoidable incorporation of bone marrow in the MDM, which therefore had a higher pH. Crushing of the bones also would have released mineral substances capable of contributing to the increase in pH (Zorba et al., 1993), as well as raising the protein content and concentration of free amino acids. At higher pH values, protein solubility would be increased, limiting any possible improvement in the functional properties of the meat.” (Abdullah and Al‐Najdawi, 2005)
“There were no signiﬁcant diﬀerences between treatment groups in relation to WHC (Table 3). Thus, neither the presence of skin nor the method of deboning inﬂuenced WHC values. The absence of a skin eﬀect is in agreement with Field (1988), and the collagen content of MDM may have been too low. However, while mechanical deboning could have aﬀected WHC, because of the higher pH values obtained (Table 1), this was not the case (cf. Demos & Mandigo, 1995).” (Abdullah and Al‐Najdawi, 2005)
“Table 4 shows that frozen storage only aﬀected the meat from skinned carcasses, whether manually- or mechanically-deboned. WHC values declined signiﬁcantly over the 3-month period, possibly because of the lower fat content and therefore greater rate of protein denaturation.” (Abdullah and Al‐Najdawi, 2005)
Poultry MDM and Pigment Concentration
“Table 5 shows the diﬀerences between the experimental treatments for pigment concentration, which would have included both haemoglobin and myoglobin. It is evident that the mean value was signiﬁcantly higher for MDM without skin (Treatment 4: mechanical deboning of skinned carcasses) and lowest in meat from manually deboned, whole carcasses (Treatment 1: manual deboning of whole carcasses). Pigment concentrations in meat obtained by either method of deboning were clearly inﬂuenced by the presence of skin, and were lower when skin was present, possibly because of a dilution eﬀect. However, diﬀerences in this respect between whole and skinned carcasses were less for those that had been deboned mechanically. The higher values obtained are consistent with a release of haemoglobin from bone marrow during mechanical deboning.” (Abdullah and Al‐Najdawi, 2005)
“Meat colour was not measured instrumentally in this study, but some variation in colour was apparent. It may have involved the conversion of myoglobin to oxymyoglobin in MDM and binding of ions from the metal surface of the deboner to the haem pigment (Froning, 1981; Demos & Mandigo, 1995). Possible pH eﬀects in MDM, resulting from the release of bone marrow, could have led to changes in the structure of myoﬁbrillar protein and may have increased the amount of myoglobin extracted. Also, pH is known to be capable of inﬂuencing the porphyrin ring-structure of meat pigments through its eﬀect on iron.” (Abdullah and Al‐Najdawi, 2005)
“Changes in pigment concentration during frozen storage are shown in Table 6. Results indicate that pigment levels either remained static or diminished over time. For manually-deboned carcasses, there was a signiﬁcant decline when skin and its associated fat were absent, but not when skin was present, suggesting a possible protective eﬀect in limiting pigment oxidation (Field, 1988). No such eﬀect was observed for mechanical deboning, where oxidation of pigment would be more likely, because of the release of potentially oxidising substances.” (Abdullah and Al‐Najdawi, 2005)
Poultry MDM: Sensory Evaluation
“Initially, there were no signiﬁcant diﬀerences between treatments with respect to aroma, colour, texture or overall acceptability of the meat, as judged by the sensory panel. After storage for up to 12 weeks (Table 7), aroma values showed little or no change for hand-deboned meat, but MDM from whole carcasses (Treatment 3: mechanical deboning of whole carcasses) showed a signiﬁcant reduction in score that was indicative of deterioration. This change could be attributed to the higher fat content of the meat and therefore greater susceptibility to oxidation.” (Abdullah and Al‐Najdawi, 2005)
“In relation to meat colour, manually-deboned meat stored for 6 weeks was more acceptable than either kind of MDM, presumably because of the lower haemoglobin content of the former. After 12 weeks, only hand-deboned meat from skinned carcasses (Treatment 2: manual deboning of skinned carcasses) was signiﬁcantly diﬀerent and more acceptable to the panel, although the reason for this is unclear.” (Abdullah and Al‐Najdawi, 2005)
“Meat texture was less aﬀected by carcass treatment during storage in the frozen state for 6 weeks, and no signiﬁcant diﬀerences were observed. After 12 weeks, however, signiﬁcantly lower scores were obtained for both kinds of MDM. Thus, freezing may have further damaged meat structure and the presence of trace amounts of bone (Al-Najdawi & Abdullah, 2002) could have contributed to the lower panel rating. Overall acceptance scores were clearly better for the manually-deboned meat, both at 6 and 12 weeks of frozen storage.” (Abdullah and Al‐Najdawi, 2005)
Conclusion by Abdullah and Al‐Najdawi
“This study has conﬁrmed the role of skin content in deboned meat as a factor aﬀecting EC, but has found no eﬀect of deboning method or incorporating skin on WHC, despite diﬀerences between manually- and mechanically-deboned meat with respect to pH. On the other hand, the inﬂuence of skin on pigment concentration appears to be mainly a dilution eﬀect. Although higher pigment levels in MDM could be attributed to the release of bone marrow during the deboning process, assessment by a sensory panel showed no diﬀerences initially between the experimental treatments in relation to aroma, colour, texture or overall acceptability of the meat. Only after frozen storage for up to 12 weeks, were diﬀerences apparent in both functional and sensory properties, and the study has highlighted the superior keeping-quality of manually-deboned poultry meat, according to a sensory assessment.” (Abdullah and Al‐Najdawi, 2005)
This is a work-in progress. As I expand the functional value of different MDM or related products, I will add it to this document. It is an adventure in discovery!
Abdullah, B. and Al‐Najdawi, R. (2005), Functional and sensory properties of chicken meat from spent‐hen carcasses deboned manually or mechanically in Jordan. International Journal of Food Science & Technology, 40: 537-543. doi:10.1111/j.1365-2621.2005.00969.
EFSA Panel on Biological Hazards (BIOHAZ). 2013. Scientific Opinion on the public health risks related to mechanically separated meat (MSM) derived from poultry and swine; European Food Safety Authority (EFSA), Parma, Italy; EFSA Journal 2013;11(3) : 3137.
Groves, K and Knight, A. An evidence-based review of the state of knowledge on methods for distinguishing mechanically separated meat (MSM) from desinewed meat (DSM). Food Standards Agency & DEFRA
Viuda-Martos, M; Fernández-López, J.; Pérez-Álvarez, J. A., Hui, YH (Editor) Mechanical Deboning, January 2012, DOI: 10.1201/b11479-30, In book: Handbook of Meat and Meat Processing, Chapter: Mechanical Deboning, Publisher: CRC Press; Taylor & Francis Inc.
Notes on Proteins used in Fine Emulsion Sausages
by Eben van Tonder
24 May 2020
I am interested in understanding the ability of gel formation of different meat proteins, their water holding capacity and the relative protein content of various ingredients used in making fine emulsion sausages. This is important, especially in South Africa where there is a heavy reliance on MDM/ MRD in emulation sausages. What can be added to increase its water holding capacity and firmness and can a pure but economical sausage be produced?
Different Meat Related Classes of Products
In making sense of this approach, it is beneficial to understand that we deal with three classes of meat-related products. I call it the pure, the deceptive and the dishonest, thus revealing my personal bias. Pure Meat products which, in my use of the term, means products where every ingredient except the spices come from an animal carcass.
Meat Analogues are starches and soyas, grains and cereals which are made so that it tastes like meat, but contains no part of an animal carcass. This is the dishonest or hypocritical class of products. Why would a vegan, for example, who does not want to eat meat, buy a product disguised as meat, but which, in reality, contains no meat? Pure meat and meat analogues are therefore two opposing and extreme ends of the spectrum.
Meat Hybrids is the middle of the two and combines meat and plant-based protein, essentially for the purpose of achieving a cheaper product. I call it deceptive because the consumer is most often misled as to the real nature of the products they buy (I say this, despite the label declaration, which is often still enigmatic to consumers). They think it’s meat, but it contains a percentage of non-meat fillers. This is almost always done to reduce the price of the product, which, in a country like South Africa, is not necessarily a bad thing. Affordable food, where “affordable” is relative to the income level of the consumer, is a very important consideration. It must also be stated that for the most part, large producers of this kind of products do not add as fillers and extenders, anything except high quality, acceptable and healthy products such as soya in the meat to extend it.
My personal preference for pure meat products is mainly based on taste and, to a lesser extent, on matters such as allergy which relate to health in that some of the fillers may be allergens. Taste of pure meat products can, in my personal opinion, not be matched in taste, firmness, mouth feel, or any other organoleptic characteristics (the aspects of the end-product that create an individual experience via the senses—including taste, sight and smell).
I am therefore interested here to learn more about the functional value of various animal proteins and fats and fillers and extenders, customarily used in producing fine emulsion sausages.
The Cost of Protein
In evaluating the options for a producer, one must first understand the real cost of protein. In the table below, you can see the relative cost per kg of protein sources, expressed in South African Rand. The buying prices per kg obviously change and you can use the following spreadsheet to recalculate it with the current prices. More importantly than the cost of the protein source is the inclusion ratio of protein in the different sources and the real cost of the protein.
Protein options in formulating recipes (source – Mellett, who happens to be the same Dr. Mellett, who co-authored the Mapanda study, 2015)
|Protein Source||Rand Price in SA||% Protein||Rand / kg Protein|
|Soya / TVP||14.00||48%||29.17|
So, taking the prices above, skin was, at the time of writing, the cheapest protein source, followed by soy TVP, then soy isolates, followed by offal and then chicken MDM. For knack, you need collagen.
Starch is an interesting ingredient. Tapioca Starch contains 6.67% protein (66.7g per kg) (eatthismuch) At the writing of this article, it is R12.00 per kg, which is R179,91 per kg of protein making it more expensive than MDM, but at an inclusion rate of around 4%, and with soya isolate at R39.00 per kg
The convention in SA became to use the cheapest protein source available, which is normally seen as MDM/ MRM. Add soy for better binding and pork rind, made of collagen protein, for even greater binding and gel formation. (Mapanda et al., 2015) In reality, it is done to make the products cheaper for the consumer.
The Extremities of Formulating a Sausage
There are at least three sets of characteristics normally taken into account when formulating a sausage.
-> Total Meat Equivalent (TME)
In South Africa, the minimum Total Meat Equivalent (TME) for different classes of meat products is laid down in legislation. Let’s review briefly the important equations which will be applied to the table of possible ingredients with protein percentages above.
The Dutch chemist Gerard Mulder (1802–1880) had published a paper in a Dutch journal in 1838 and this was reprinted in 1839 in the Journal für praktische Chemie. Mulder had examined a series of nitrogen-rich organic compounds, including fibrin, egg albumin, gluten, etc., and had concluded that they all contained a basic nitrogenous component (~16%) to which he gave the name of “protein” (Munro and Allison, 1964) from a Greek term implying that it was the primary material of the animal kingdom.
The term protein was coined by Jöns Jacob Berzelius, and suggested it to Mulder, who was the first one to use it in a published article. (Bulletin des Sciences Physiques et Naturelles en Néerlande (1838); Hartley, Harold (1951) “Ueber die Zusammensetzung einiger thierischen Substanzen” 1839). Berzelius suggested the word to Mulder in a letter from Stockholm on 10 July 1838. (Vickery, H, B, 1950)
Total protein % can therefore be derived from an analysis of the nitrogen content of a meat product. The following equation is used and is derived from the fact that proteins contain around 16% nitrogen.
% N by analysis x 6.25 = % Protein (since 100/16 = 6.25)
An example is if nitrogen, by analysis, is 1.85%, then the % protein is 1.85 x 6.25 = 11.5% (protein).
The protein content in lean meat is also known to be around 21%. The factor to convert protein % to lean meat is therefore 100/21 = 4.8 if we take the lean meat as 100% and divide it by 21. So, in our example, 11.5% x 4.8 = 52.2% lean meat. The equation is:
% Protein x 4.8 = % lean
We can combine these two factors to give us a way to go from % nitrogen directly to the lean meat %. 6.25 x 4.8 = 30 and % N x 30 = % lean.
A good summary of the thinking early in the late 1800s and early 1900s on the subject exists in the South African Food, Drugs and Disinfectants Act No. 13 of 1929 (See note 1). As an important historical document, it sets out the determination of total meat content. It essentially remained unchanged (apart from minor updates).
The calculations of total meat content are defined in subparagraph 4 (iv) which reads as follows: “In all cases where it is necessary to calculate total meat under regulations 14 (1), (2), (3) and (4), the formula used shall be:—
Percentage Lean Meat = (Percentage Protein Nitrogen × 30 ).
Percentage Total Meat = (Percentage Lean Meat + Percentage Fat).”
-> Water Holding Capacity (WHC)
Non-meat binders are often added to meat. Such binders and extenders commonly include flour, starch, breadcrumb, cereal binders, TVP and rusk. Often these are used to hold and bind large amounts of water to reduce product cost.
There are legal limits that must be adhered to in terms of protein content for a sausage to be called a meat sausage. When fillers and extenders are used such as these, it is, however, not a pure meat product, and hybrids are created which contains both plant and animal components.
Here there is a major misconception. All animal proteins have the ability to form gels and to hold water. The functional ability of various animal proteins to do this, however, differs significantly. A thorough knowledge of these abilities of various components of the carcass is required to determine which proteins will be best to achieve what result in any particular sausage formulation.
My suspicion is that these differences were discovered as soups and meat stews were developed by early humans, which was probably motivated by the desire to soften various parts of the carcass for consumption. There is evidence that a centre of these developments emerged on the Russian Steppe. It is interesting that Russia also became the world leader in fine emulsion meat technology and the creation of hybrid meat products.
-> Taste and Texture
Taste and texture differ considerably between pure meat products and hybrids, which leads to my personal preference of the former. The meat industry employs spices as one of the major resources of making hybrid products more “acceptable”.
Animal Protein and Gel Formation
There are three functional characteristics of meat, important to our study, namely gelation, emulsification and water holding ability. It relates to meat particle binding and adhesion ability. Processed foods are the result of the combination of several protein functionalities. In mathematics we will represent it with a polynomial function. An example of this is a Russian sausage with its firm texture and juiciness which is the result of a composite protein network system which in turn is created by protein-protein interaction (gelation), protein-fat interaction or fat encapsulation (emulsification) and protein-water interaction (water binding). Even a slight change in ingredient composition and processing conditions are enough to alter the final texture materially. (Yada, 2004)
Yada (2004) summarises the functional properties of muscle proteins as follows:
Yada (2004) defines gelation as “viscoelastic entity comprised of strands or chains cross-linked into a continuous network structure capable of immobilizing a large amount of water. The process of forming a gel, i.e. gelation, occurs in muscle foods as a result of unfolding and subsequent association of extracted proteins, usually in the presence of salt and sometimes also phosphates. The rate of structural change, i.e. denaturation, is critically important. A slow unfolding process, which typically occurs with a mild heating condition, allows polypeptides to align in an ordered manner into a cohesive structured network capable of holding both indigenous and extraneous water.” (Yada, 2004) When producing boneless hams, the gel formed at the junction of the meat chunks is responsible for the adhesion and is responsible for the integrity of the product.
Cheapest Meat Product: Structure and Characteristics
The key ingredient used in South Africa in producing fine emulsion sausages is MDM/ MRM. It is the cheapest meat product, most often used as the basis for meat hybrids. (see MDM – Not all are created equal!) MDM is a source of meat protein which is “complete, containing all the nine essential amino acids.” (Mapanda et al., 2015) MDM is, however, mostly compromised due to the way it is manufactured. It also contains the least amount of protein on our table of proteins containing raw materials listed above.
The proteins and fibres are denatured / damaged to such an extent that even the protein that it contains is retarded in terms of its ability to form a gel and hold water. Non-meat extenders, fillers and emulsifiers are, therefore, often used to compensate for this. Such plant products often include soy isolate and soy concentrate. Animal products are also often used such as milk powder, whey powder and egg white. Pork skin or rind emulations provide firmness. Fillers are usually carbohydrate materials such as carrageenan and various starch materials (Mapanda et al., 2015) depending on the price point that the formulator is targeting. Low cost sausages can contain as much as 15% such fillers and extenders.
In the Mapanda study, polony was considered as an emulation type sausage. “Polony is formed by changing coarse heterogeneous meat into a homogeneous meat mass consisting of dispersed water, fat and protein, which during heating is transformed into a gel. Polony is regarded as a fully cooked emulsified sausage product” (Mapanda et al., 2015).
Skins or skin emulsions are added to provide firmness and knack, but soya and starch are customarily added to reduce the cost. Inspired by trends from Russia, there has been a trend from around 1946 (following World War 2) in the USA to employ various serials and starches in meat processing as a way to extend the meat. As such, soy protein has been commonly used. Large manufacturers of soy products aggressively targeted the meat industry to continue the use of soy as a meat extender. Spice companies became the preferred method of distribution and large amounts of money was spent on developing recipes that would include soy and starch. The industry preached that this inclusion was “beneficial” from an economic perspective and is healthy. They proclaim that soy is a good “replacer of meat due to its essential amino acids, whose composition (though slightly lower in quantity) is no different from that of meat.” Functionally, they pointed to the fact that soy functions as a binder of fine emulsion type sausages such as polony where it contributes to the water holding capacity and the emulsification of fat in the gel. The real benefit is that it’s cheaper and easier to work than meat, and by itself, this argument is without question a valid one.
POLONY: An Example of a Meat Hybrid
Let’s now look in greater detail at how different fillers, emulsifiers and extenders are used along with MDM to create a low cost meat hybrid. We follow work done by Mapanda, et al. (2015) where they investigated “varying quantities of chicken mechanically recovered meat (MRM), soy flour (S) and pork rind (R)” were used to manufacture South African polony. For the full article, see Effect of Pork Rind and Soy Protein on Polony Sensory Attributes.
Preparation of Meat
In the Mapanda study (2015) the meat components were prepared as follows.
Rind Emulation: “Pork rind is quite tough in texture. To soften it, it was precooked before use. 7.5 kg of rind was cooked in 7.5 kg (litres) of water. The cooking time varied from 4 to 5 h for the three batches of pork rind prepared. After cooking, the pork rind and water mixture was re-weighed and water added to make up the 15 kg before chopping the mixture in the bowl cutter until a fine, sticky homogenous mass called rind emulsion was formed. The rind emulsion was then allowed to cool to room temperature prior to weighing and vacuum packaging. The rind emulsion was subsequently stored at -18°C until chemically analysed or used in polony processing.” (Mapanda et al., 2015)
MDM/ MRM: “The only preparation done on the frozen MRM involved cutting it into smaller blocks for the purpose of easily fitting into the bowl cutter. The cut blocks of MRM were vacuum sealed and frozen until polony processing commenced.” (Mapanda et al., 2015)
Sausage Formulation and Analysis
In the Mapanda study (2015) the meat components were blended as follows with the following functionals added, resulting in the analysis as given.
“All nine treatments were formulated to contain 10% protein (equivalent to 48% LME). MRM, soy flour and pork rind all vary in quantities to maintain a 10% protein in the respective treatments. The percentage of water added also varied to maintain a constant product weight, while the percentage of additives was kept constant. Additives added were 8% tapioca starch, 1.8% salt, 0.016% nitrite, 0.3% phosphate, 0.05% ascorbic acid, 0.02% erythrosine dye, 0.1% each for black pepper and cayenne pepper, 0.03% ginger, 0.2% garlic, and 0.05% each for nutmeg and coriander. Each polony sample was designed to weigh 1.5 kg. Since 10 polony units were produced for each treatment, the total mixture of polony emulsion (meat and all ingredients added for emulsification in a bowl cutter) was 15 kg. ” (Mapanda et al., 2015)
“Order of adding the ingredients was the same, i.e. ingredients were added when the bowl cutter was running at low speed. After that, the speed was increased for the final chopping phase. The MRM was added and chopped first, followed by adding the salt, nitrite, the phosphate and one third of the water. This was followed by adding the rind emulsion. After that, soy flour was added into the bowl cutter and chopped for 2 min before adding spices and another third of the water. The tapioca starch was then added, after which the ascorbic acid and the last third of the water was added.” (Mapanda et al., 2015)
“The end temperatures after chopping the polony emulsion varied between 12°C
and 17°C.” (Mapanda et al., 2015)
“The polonies were cooked in a steam bath for about 2 h to an internal temperature
of 80°C as measured by a thermocouple. The cooked polony was then cooled in clean running water prior to storage at 4°C until chemical, instrumental and sensory analyses were done on the respective samples.” (Mapanda et al., 2015)
Effect on Colour
“The redness decreased, in the Mapanda study (2015), “with an increase in both rind and soy proteins. Chicken MRM contains red pigments of blood (myoglobin and haemoglobin). The replacement of MRM with white proteins (rind and soy) reduced the red colour of the polony treatments.” (Mapanda et al., 2015)
“The present findings for pink colour are consistent with Abiola and Adegbaju, who reported that, when pork back fat was replaced with rind levels of 0, 33, 66 and 100%, the colour of pork sausages decreased correspondingly. The negative effect of MRM replacement with rind and soy on the pink colour of polony can be counteracted by adding more dye during the emulsification stage. In South Africa, dyes such as erythrosine BS can be added to enhance the pink colour of polony up to the maximum level of 30 mg/ kg of the product, Department of Health.” (Mapanda et al., 2015)
“In the treatments where rind was added, white spots were observed. The white spots were actual pieces of rind which resulted from incomplete emulsification of the pork rind emulsion by the bowl cutter. This negative attribute could be rectified by extensive chopping of the raw batter of the treatments containing pork rind.” (Mapanda et al., 2015)
“The replacement of MRM with rind levels of up to 8% and soy levels of up to 4% increased the hardness (firmness) of the polony treatments, while treatments with 8% soy were softer at all levels of rind. Similar results were obtained for gumminess (Figure 5). These results show that good quality polony with acceptable hardness can be obtained with up to 4% soy and 8% rind. Beyond 4% of soy flour, the products become softer and sticky. According to Chambers and Bowers, hardness is the most important attribute to consumers because it determines the commercial value of the processed meat products. Approximately 60% of consumers will be willing to buy a sausage with a hardness of 47.3 N and higher (Dingstad). However, higher values for the parameter do not necessarily mean better quality. There is a cut-off point above which the texture of comminuted meat products would be unacceptable.” (Mapanda et al., 2015)
Related to cohesiveness, the Mapanda (2015) study found that “the addition of binding aids such as soy and rind improves cohesiveness, as long as too much is not used (Trock). Chin  established that the use of incremental levels of soy protein below 3% decreased the cohesiveness of low-fat meat products. The current results disagree with the findings of Chin as some of the treatments of polony in which only soy protein was used, for instance at the level of 4%, showed that cohesiveness increased. A possible explanation might be the difference in the fat content of the products used in their study and in the current study.” (Mapanda et al., 2015)
“For sensory texture, the attributes analysed were firmness, pastiness and fatty mouth feel. All treatments decreased in sensory firmness due to an increase of soy and rind proteins. For both pastiness and fatty mouth feel, the mean scores for these two texture attributes increased in all samples compared to that of the control treatment. Feiner highlighted that the replacing of lean meat with soy protein and water, as was done in the present study, affects texture and firmness because the replaced meat proteins contribute positively to the named parameters. It can clearly be seen that an increased replacement of chicken MRM with pork rind and soy flour reduced firmness and increased the sensory textural attributes of pastiness and fatty mouth feel in all the polony treatments, except for the control sample.” (Mapanda et al., 2015)
Pure Meat Products at the Same Low Cost
The question now comes up, if a pure meat product can be produced at the same low cost as is done in the Mapanda study. The Yada (2004) study and the table of various functional values of different animal proteins is the first clue.
I again present this article as a “work in progress” study, as I did with other investigations. Results will be reported on unless a proprietary benefit can be derived. Any suggestions and comments can be mailed to me at firstname.lastname@example.org. All results of relevant investigations will be listed below and the controlling principle will be: “Why think, if we can test?” I embark on this voyage with great excitement!
-> Counting Nitrogen Atoms – The History of Determining Total Meat Content Before we get down to business, I examine the history of the development of the concept of Total Meat Equivalent and the equations which are laid down in legislation.
-> Protein Functionality: The Bind Index and the Early History of Meat Extenders in America The first consideration is the fact that different meat sources, and different parts of the carcass, have different binding functionalities. Here I also develop the history of binders, fillers and meat extenders in America and the birth of the analog product.
-> Hot Boning in America First step towards a better understanding of the binding of proteins to each other and water.
-> Emulsifiers in Sausages – Introduction. Understanding the role and chemistry of non-meat emulsifiers, extenders and fillers is currently widely used in South Africa.
-> MDM – Not all are created equal! Starting to understand the base meat material used in fine emulsion sausages in South Africa.
-> Soy or Pea Protein and what in the world is TVP? Here we start to learn about the functional properties brought to the fine emulsion by soy, pea protein and TVP by first understanding exactly what they are and how they are produced.
-> Poultry MDM: Notes on Composition and Functionality Here we start our detailed consideration of chicken MDM.
Feiner, G. 2006. Meat Products Handbook: Practical Science and Technology, Woodhead Publishing.
Mapanda, C., Hoffman, L. C., Mellett, F. D., Muller, N. Effect of Pork Rind and Soy Protein on Polony Sensory Attributes. J Food Process Technol 2015, 6:2 DOI: 10.4172/2157-7110.1000417
Yada, Y. (Editor). 2004. Proteins in Food Processing. Woodhead Publishing. CRC Press.
by Eben van Tonder
26 May 2020
I came across this Anglo-Boer War photo of medical staff in the Bloemfontein Concentration Camp posted online by Elria Wessels. For those who are not familiar with the history, between 11 October 1899 – 31 May 1902, England fought a war against two independent Boer republics in Southern Africa to gain control of the lucrative gold and diamond fields of the Johannesburg and Kimberly areas. Unable to win the war against a determined foe, they placed the women and children in over a 100 concentration camps while they enforced a scorched earth policy and burned down the farmhouses of the Boers. This provides the background for the photo.
I was struck by the prominence of the Bovril poster in the photo, appearing very deliberate and staged. Further investigation revealed a fascinating history.
The Name: Bovril
The name, Bovril, comes from the Latin bovīnus, meaning “ox”. The inventor, Johnston, added the suffix, -vril, from a contemporary popular novel by Edward Bulwer-Lytton, The Coming Race (1870). It is a story of a superior race of people, the Vril-ya. They derived their power from an electromagnetic substance named “Vril”. Bovril is therefore great strength obtained from an ox. (Phillips, 1920) The essence of the meaning of the name is given in an advertisement in 1899 where it is claimed that it is “the vital principle of prime ox beef.” (Western Mail (Cardiff, South Glamorgan, Wales) 24 January 1899)
The Inventor: John Lawson Johnston
Johnston was born in 1839 in Roslin near Edinburgh where he was also educated. He studied dietetics. It was said that he pursued the discipline with a “thoroughness and pertinacity” with such “good purpose that, when, after the close of the Franco-German war, the French Government determined to thoroughly investigate the question of food concentration and preservation, he was chosen, as its Commissioner, to proceed to Canada, and make a thorough investigation of the subject. ” (The Isle of Man Weekly Times, 1900)
He was successful in the task given to him and “the French Government conferred on him the Fellowship of the Red Cross Society of France”. It is said that he realised the dream of Liebig to develop a beef concentrate “that should contain not only the stimulative extracts but also the nourishing fibrine and albumen of the beef.” (The Isle of Man Weekly Times, 1900)
“Returning to England he enlisted the cooperation of Lord Playfair, the friend and assistant of Liebig; Sir Edmund Franklin, Dr. Farquharson, and other leading scientists were quick to perceive the great value of Mr. Johnston’s invention. With their powerful endorsement and Mr. Johnston’s determined assiduity, Bovril soon became recognised as the embodiment of the latest scientific ideas on the subject of dietetics.” (The Isle of Man Weekly Times, 1900)
From the beginning, the invention had military applications as a prime objective and the British army became an important consumer of the new invention. The Marker: The British Army during the Anglo-Boer War and British Run Camps in South Africa. With a wide application in war theatres around the world, the South African War created a hungry market both from the perspective of supplying the British forces, including their hospitals and the concentration camps housing the Boer women and children. I am sure it would have included the many POW camps set up in Ceylon, India, Bermuda, St. Helena and in South Africa such as the Sea Point camp. It is here where our interest began because of the Bloemfontein photo of Elria Wessels.
I did some digging and found advertisements in British newspapers at that time, referencing its application in this war.
The Key Differentiator: What Makes it Different from Beef Extract
The following advertisement makes it clear what sets Bovril apart from all other beef extracts.
Chapter 17: The Boers (Our Lives and Wars)
The Afrikaner Nation and Boers feature prominently in my story of bacon. The first and second Anglo-Boer war shaped our land and provided the motivation for setting up the bacon company. Here are photos from the time immediately before and after the second Anglo-Boer War (ABW). It allows the reader to visualise the context better. I dedicate this section to my friends who bring to life the Afrikaner, referred to as Boers, the Brits, and the black and coloured South Africans who fought in these wars and lived through these times.
Australians in the ABW
Black Refugees, soldiers and ordinary people
Solomon Tshekisho Plaatje (1876-1932) Historical Papers Research Archive, University of the Witwatersrand, South Africa; Sol Plaatje during his visit to England. The driver of the car is Henry Carsle, an Estate agent from Sussex, and next to him his wife Louise. Also in the car are their children Mary, the oldest of their daughters, Eleanor, Faith and Brock.
Martin Plaut writes about the role of ‘black Boers’, as they refer to black people fighting for the Boer nations, and says that the role of these ‘black Boers’ is captured in this British ditty:
‘Tommy, Tommy, watch your back
There are dusky wolves in cunning Piet’s pack
Sometimes nowhere to be seen
Sometimes up and shooting clean
They’re steathy lads, stealthy and brave
In darkness they’re awake
Duck, Duck, that bullet isn’t fake.
Chris Pretorius posted a quote about Plaatjies: “In 1932, Solomon Tshekisho (Sol) Plaatje, intellectual, journalist, linguist, politician, translator and writer, born at Doornfontein near Boshof, OFS in 1876, passed away in Soweto at the age of 56. He was (amongst others) court translator for the British during the Siege of Mafeking and diarized his experiences, which was published posthumously.”
Brandwater Basin (Where my great Grandfather surrendered to the British – ABW)
Bermuda, Hawkins Island
Children, Concentration Camps and War
Crossing the River
Genl. De Wet, Christiaan.
The newspaper article is from a 1950’s Sunday Times article. Who is the “Pieter” referred to in the article? There was a Pieter de Villiers Graaff who was known as the Cape Rebel (Kaapse Rebel). He was a cousin of Sir David de Villiers Graaff, who is featured prominently in my work on bacon. Pieter participated in 25 battles in the ABW against the English and on 24 March 1901 he was captured and sent to India as a POW where he remained for the duration of the war. I doubt if the Sunday Times article refers to him. He did, however, have a son, also named Pieter de Villiers Graaff. He was born on December 16, 1911 and passed away on July 11, 1988. He was 76.
Diyatalawa and Ragama, Ceylon (Diyatalawa is where my great grandfather was a POW – ABW)
Dirk Marais writes about the Diyatalawa Garrison:
The Diyatalawa Garrison is a common name used for collection of military bases of the Sri Lanka Army located in and around the garrison town Diyatalawa in the Uva Province. Sometimes it is referred to as the Diyatalawa Cantonment. It is one of the oldest military garrisons in Sri Lanka. It is home to the several training centers of the army, including the Sri Lanka Military Academy and has a detachment of the Gemunu Watch. The Sri Lanka Army Medical Corps maintains a base hospital in Diyatalawa. SLAF Diyatalawa is situated in close proximity.
It is not exactly known as to when Diyatalawa became a training station for troops, but available records show that it was selected around 1885, when the British Army first established a garrison at Diyatalawa. At that time training was conducted at the Imperial Camp, which is presently occupied by the Gemunu Watch troops. In 1900, the British War Office constructed a concentration camp in Diyatalawa to house Boer prisoners captured in the Second Boer War. Initially constructed to house 2500 prisoners and 1000 guards and staff, the number of prisoners increased to 5000. During World War I an internment camp for enemy aliens was set up.
Early in World War II the camp was reopened and German nationals resident in Hong Kong and Singapore, as well as many sailors, like those removed from the Asama Maru in violation of international law, were housed here. Also imprisoned were Buddhist monks of German extraction like Nyanaponika and Govinda Anagarika who had acquired British citizenship. In June 1941 most of the sailors were transferred to Canada. The section for Germans was sensibly divided in a pro- and anti-Nazi wing. There was also a section set up to house Italian POWs. After the Japanese started bombing the island, inmates were on 23 February 1942 transferred to camps on the mainland. Males usually went to Dehradun.
After independence the facilities of the British Army were taken over by the newly established Ceylon Army, and Diyatalawa became the primary training grounds for the young army with the establishment in 1950 the Army Recruit Training Depot later renamed at the Army Training Centre. Several of the army’s regiments were resided here, 1st Field Squadron, Ceylon Engineers (1951), Sri Lanka Sinha Regiment (1956), Gemunu Watch (1962).
The Royal Navy had a rest camp, HMS Uva, which was situated at Diyatalawa with recreational facilities; this was later taken over by the Royal Ceylon Navy in 1956, commissioning it as HMCYS Rangalla and established its training center there. They had to move out in 1962 and it was taken over by the Gemunu Watch.
On 14 March 2013, the Security Forces Headquarters – Central the youngest of the seven commands of the Sri Lanka Army was formed at Diyatalawa. Prior to this Diyatalawa served as an Area Headquarters.
Howick British Concentration Camp for Boer Women and Children
Indigenous Houses (Used by Boers in the ABW)
Northern Cape ABW
The Royal Irish Regiment recruited from the counties of Tipperary, Waterford, Wexford and Kilkenny. It served in South Africa with General Hart’s Irish Brigade. Around 30,000 Irishmen saw service with the British Army in South Africa.
Iain Hayter writes, “There were a number of instances where Irish fought Irish in the ABW and many poems poems were written, the Irish being so lyrical………
We are leaving dear old Dublin
The gallant famous fifth;
We’re going to the Transvaal
Where the Boers we mean to shift.
We are the sons of Erin’s Isle –
The famous Fifth Battalion
Of the Dublin Fusiliers.
Let this conflict be a warning
To all Britannia’s foes;
Not to tease her ftirious lion
As on his way he goes.
For if they do, they’ll fmd they’re wrong
And won’t get volunteers
To stand in the face of a Regiment
Like the Dublin Fusiliers
On the mountain side the battle raged, there was no stop or stay;
Mackin captured Private Burke and Ensign Michael Shea,
Fitzgerald got Fitzpatrick, Brannigan found O ’Rourke,
Firmigan took a man named Fay – and a couple of lads from Cork.
Sudden they heard McManus shout, ‘Hands up or I’ll run you through’.
He thought it was a Yorkshire ‘Tyke’ – ’twas Corporal Donaghue!
McGany took O ’Leary, O ’Brien got McNamee,
That’s how the ’English fought the Dutch’ at the Battle of Dundee.
The sun was sinking slowly, the battle rolled along;
The man that Murphy ‘handed in’, was a cousin of Maud Gonne,
Then Flanagan dropped his rifle, shook hands with Bill McGuire,
For both had carried a piece of turf to light the schooh-oom fire …
Dicey brought a lad named Welsh; Dooley got McGurk;
Gilligan turned in Fahey’s boy – for his father he used to work.
They had marched to fight the English – but Irish were all they could see –
That’s how the ‘English fought the Dutch’ at the Battle of Dundee.
Russians in the ABW
Simons Town POW’s
St Helena, Broadbottom Camp, Deadwood Camp.
Treaty of Vereeniging, signed on 31 May 1902 (end of ABW2)
Gideon Jacobus van Tonder was born in 1864 in Uitenhage, Eastern Cape (then the Cape Colony). He passed away in 1924 in the Free State. He is buried at the Rustfontein Dam, which is located on the Modder River near Thaba ‘Nchu. He was the owner of the farm Brakfontein in that area. He also resided at 21 Hill Street, Bloemfontein. From 1894 to 1900 he was minister of Agriculture in the Orange Free State Government. Giel Venter from Fauresmith gave me this information. Giel is one of his descendants. If Gideon was still alive we would have spent many days talking about farming and animal husbandry and of course, bacon curing!
When President Steyn was out of the country or on leave, he acted as State President on numerous occasions. When the ABW broke out, he resigned from government after his son, Hansie, was killed at the battle of Magersfontein. Genl. De Wet wrote about it in his book, Three Years’ War.
De Wet wrote: “I can only remember three instances of anyone being hurt by the shells. A young burgher, while riding behind a ridge and thus quite hidden from the enemy, was hit by a bomb, and both he and his horse were blown to atoms. This youth was a son of Mr. Gideon van Tonder, a member of the Executive Council.”
I am planning a visit to Giel, as soon as it is permitted and will update this section with much more information.
Vredefort Concentration Camp ABW
Yunnan Xuanwei Ham (宣威火腿/xuān wēi huó tuǐ)
Eben van Tonder
10 May 2020
Yunnan is one of China’s premium food regions known for exquisite tastes. One of the major cities in this picturesque region is Xuanwei, where one of the world famous Chinese hams are produced, the others being Jinhua Ham from Zhejiang province and Rugao Ham from Jiangsu province. Yunnan Xuanwei Ham is known for its fragrance, appearance, and out-of-the-world taste. Through the ages, there have been many references in literature to the health benefits associated with the hams. In order to produce these hams, there are at least two ingredients without which the hams can not be produced. The first ingredient is salt.
The Industrialisation of Ham
Early references to Xuanwei hams go back to 1766. “Old chronicles recorded the Qing emperor Yong Zheng five years (the year 1727) located XuanWei (a city of YunNan province, China), so it is called XuanWei ham. (China on the Way) In 1909, Zhuo Lin’s (Deng Xiaoping’s third wife) father Pu Zai Ting, a businessman, mass-produced it for the first time. He established Xuanhe Ham Industry Company Limited. His company sent food technicians to Shanghai, Guangzhou (formerly Canton), and Japan to learn advanced food processing technology.
One example of the excellence pursued in Guangzhou relates to the cultivation of rice. Rice breeding began in China in 1906. However, by 1919, systematic and well-targeted breeding using rigorous methodologies was started at Nanjing Higher Agricultural School and Guangzhou Agricultural Specialized School. Between 1919 and 1949, 100 different rice varieties were bred and released. (Mew, et al., 2003) For a riveting look at the trade in Guangzhou, see the work by Dr. Peter C. Perdue, Professor of History, Yale University, Canton Trade.
By all accounts, Pu Zaiting was successful in creating a world famous ham (at least by probably standardising and industrialising the process). In 1915 Xuanwei ham won a Gold Medal at Panama International Fair. The ham, which, in the Qing and Ming Dynasties, was a necessary gift for friends and guests and which, during the gourmet festival, became the main ingredient to create different delicious dishes achieved international acclaim. (chinadaily.com)
The Xuanhe Canned Ham Industry Company Limited was established on the back of canning equipment bought from the United States of America to produce canned ham. Most of what it produced were exported overseas. In 1923 Sun Yat-sen tasted the ham at the National Food Exhibition held in Guangzhou. Sun famously wrote of the ham, “yin he shi de” translating as “eat well for a sound mind!” By 1934, four companies were producing the canned ham. (Kristbergsson and Oliveira, 2016)
Xuanwei Ham expanded greatly under the People’s Republic of China, established in 1949. Supporting industries started to develop. A factory was created to supply the cans used by the Municipal Authority of Kunming City. (Kristbergsson and Oliveira, 2016)
Production of Xuanwei hams rose by 1999 to 13 000 tonnes, made by 38 large producers. In 2001 it got the status of a regional brand, protected by the People’s Republic of China. A Chinese standard, GB 18357-2003 was subsequently issued. By 2004 production rose to 20,750 tonnes with technology in manufacturing and packaging improving continuously. (Kristbergsson and Oliveira, 2016)
Apart from a rich and competitive environment, an entrepreneur, as the proverb goes, worth his salt, was needed to bring discipline to the production process and to establish this ham among the finest on earth. In achieving this status, three elements were required, namely salt, the right meat and a solid production technique to yield this culinary masterpiece on an industrial scale.
Yunnan – Centre of Culinary Excellence
The first requirement for competitiveness is an environment of excellence and innovation. The environment where this exquisite ham is produced testifies to culinary excellence. Like Prague, which produced the ham press, nitrite curing and the famous Prague hams, the Yunnan hams likewise hail from an area replete with food and cooking innovations. Yunnan is located on what was known as the Southern Silk Road and its culinary excellence is seen, among other things, in the equipment used in preparing their foods. Joseph Needham, et al. reports that in restaurants in the cities of Yunnan, a very special dish is found “in which chicken, ham, meat balls and the like have been cooked in water just condensed from steam. This is done by means of an apparatus called chhi kuo (or formerly yang li kuo) made especially at Chien-shui near Kochiu. It consists simply of a red earthenware pot with a domical cover, the bottom of the pot being pierced by a tapering chimney so formed as to leave on all sides an annular trough (figure 1490). The chhi kuo once placed on a saucepan of boiling water, steam enters from below and is condensed so as to fall upon and cook the viands of the trough, resulting thus after due process in something much better than either a soup or a stew in the ordinary sense. Since the chimney tapers to a small hole at its tip no natural volatile substances are lost from the food, hence the name of the object and the purpose of its existence. The chhi kuo must claim to be regarded as a distant descendant of the Babylonian rim-pot (for it has and needs no Hellenistic side-tube) with the ancient rim expanded to form a trough, compressing the ‘still’-body to a narrow chimney. But how the idea found its way through the ages, and from Mesopotamia to Yunnan, might admit of a wide conjecture.” (Needham, et al.,1980)
The second essential ingredient for a salt-cured ham is salt. Salt is something that China has been specialising in for thousands of years and which became the backbone of the creation of this legend.
Salt in China
Flad, et al. (2005) showed that salt production was taking place in China on an industrial scale as early as the first millennium BCE at Zhongba. “Zhongba is located in the Zhong Xian County, Chongqing Municipality, approximately 200 km down-river along the Yangzi from Chongqing City in central China. Researchers concluded that “the homogeneity of the ceramic assemblage” found at this site “suggests that salt production may already have been significant in this area throughout the second millennium B.C..” Significantly, “the Zhongba data represent the oldest confirmed example of pottery-based salt production yet found in China.” (Flad, et al.; 2005)
Salt-cured Chinese hams have been in production since the Tang Dynasty (618-907AD). First records appeared in the book Supplement to Chinese Materia Medica by Tang Dynasty doctor Chen Zangqi, who claimed ham from Jinhua was the best. Pork legs were commonly salted by soldiers in Jinhua to take on long journeys during wartime, and it was imperial scholar Zong Ze who introduced it to Song Dynasty Emperor Gaozong. Gaozong was so enamored with the ham’s intense flavour and red colour he named it huo tui, or ‘fire leg’. (SBS) An earlier record of ham than Jinhua-ham is Anfu ham from the Qin dynasty (221 to 206 BCE).
In the middle ages, Marco Polo is said to have encountered salt curing of hams in China on his presumed 13th-century trip. Impressed with the culture and customs he saw on his travels, he claims that he returned to Venice with Chinese porcelain, paper money, spices, and silks to introduce to his home country. He claims that it was from his time in Jinhua, a city in eastern Zheijiang province, where he found salt-cured ham. Whether one can accept these claims from Marco Polo is, however, a different question.
Salt Production In and Around Yunnan
When it comes to salt, only a very particular variety is called on to create this legend.
Around the Yunnan-Guizhou plateau are three salt producing areas which took advantage of the expansion of China towards the west in the early modern era. “Szechwan with a slow but steady advance; Yunnan with the speed and initiative characteristic of a developing mining area; Mongolia with a sudden, temporary eruption.” (Adshead, 1988) As fascinating as Szechwan and Mongolia are, we leave this for a future consideration and hone in on Yunnan.
Szechwan not only supplied its own requirements for salt, but also that of Kweichow, Yunnan (trade started in 1726) and western Hupei. Despite the fact that Yunnan imported salt from Szechwan and possibly from Kwangtung, this was mainly to supply its eastern regions of the escarpment. On the plateau it had salt resources of its own. By 1800, it is estimated that it produced 375 000 cwt (hundredweight).”These salines formed three groups: Pei-ching in the west near Tali the old indigenous capital; the Mo-hei-ching or Shihi-koa ching in the south near Szemao close to Laotian and Burmese borders; Hei-ching in the east near the provincial capital Kunming. (Adshead, 1988) It is this last group that captures our imagination due to the connection with the Yunnan hams.
Although known as ching or wells, many of the Yunnan salines, especially those in the Mo-hei-ching group, were in the nature of shafts or mines, though the low grade rock salt was generally turned into brine and evaporated over wood fires. The growth of the Yunnan salines in the Ch’ing period was the product of two forces. First, Chinese mining enterprise, often Chinese Muslim enterprise, which in the 18th century was turning Yunnan into China’s major source of base materials – copper, tin and zinc. Second, the extension of direct Chinese rule into the area, the so-called kai-t’u kuei-liu, initiated particularly by the Machu governor-general O-er-t’ai between 1725 and 1732. (Adshead, 1988)
The distant past of Heijin comes to us, courtesy of Yunnan Adventure Travel, who writes that “the unearthed relics of stones, potteries, and bronze wares have proved that as early as 3,200 years ago, ancestors of some minority groups already worked and multiplied on this land. It’s recorded in the “Annals of Heijin” that, a local farmer lost his cattle when grazing on the mountain, he finally found his black cattle near a well; but to his surprise, when it lipped the soil around the well, salt appeared; thus in order to memorize the black well, the place was nicknamed as “Heiniu Yanjin” which means the black cattle and the salt well. It’s shortly referred to as Heijin afterwards.” (www.yunnanadventure.com) Some accounts of the story have it that it was a Yi girl who was looking for her missing oxen when she came upon them licking salt from the black well.
Who better to take us on a tour of the old town than a seasoned traveller! We meet such a wanderer in the old city of Heijin in the person of Christy Huang. She takes us on an epic adventure, discovering the old salt kingdom of Hei-ching. She posted it on Monday, November 30th, 2015 and she called her post “
Christy writes that “the quite fameless Old Town of Heijing (黑井古镇) – today one of the nicest in Yunnan – used to be famous for the high-quality salt which was produced there since hundreds of years. The once most important town of Yunnan is hidden at the banks of Longchuan River in Lufeng County of Chuxiong Prefecture of Yunnan.
Salt production in bigger scale began in the Tang Dynasty (618-907) and peaked during the Ming (1368–1644) and Qing (1644–1912) Dynasties. Besides the overall beautiful picture of Hejing and its surroundings, there are a couple of scenic spots worth mentioning:
- Courtyard of Family Wu,
- Ancient Salt Workshop,
- Dalong Shrine, as well as,
- Heiniu Salt Well.
The Courtyard of Family Wu used to be the residence of former salt tycoon of Heijing Old Town. The mansion was built during 21 years in mid 19th century and is formed in the shape of the Chinese character wang (王), which means king. It has 108 rooms, which have been left more or less unchanged. Today it serves as an (expensive) hotel for Heijing visitors.
The Ancient Salt Workshop was Heijing’s core place and fortune fountain. The remaining huge water wheels and stages for making salt testify the great prosperity of the bygone times. The salt produced in Heijing is as white as snow. It was and is used for preserving Yunnan’s well-known Xuanwei Ham.” (Christy Huang, 2015)
The third ingredient in the production of Yunnan Xuanwei Ham is the pigs. Traditionally, the rear legs of the Wujin pig breed are used. The breed is known for its high-fat content, muscle quality and thin skin (chinadaily.com).
The breed is usually kept outdoors and is typical in the Xuanwei region. They are normally fed on corn flour, soybean, horse bean, potato, carrot, and buckwheat. They are slow growers, but their meat is of superb quality.
Li Yingqing and Guo Anfei (China Daily) wrote a great article about these pigs for the Yunnan China Daily entitled “Yunnan’s little black pig by the Angry River.”
They write that “there is a quiet little revolution taking place by the banks of Nujiang River, the “angry river”, the upper stretch of the famous Mekong as it passes the narrow gorges near Lijiang. Here, little black pigs wander freely by steep meadows, grazing on wild herbs and foraging as freely as wild animals. They are relatively small, compared to their bigger cousins bred in farms. These sturdy little animals are reared for about two to three years before they are slaughtered and made into the region’s organic hams – called black hams for their deep-colored crusts.” (Yingqing and Anfei)
Li Yingqing and Guo Anfei report on “Wang Yingwen, a 47-year-old farmer who has raised the black pigs for more than 30 years, says the pigs are fed spring water and they live on wild fruits, mushrooms and ants on mountains, an all-organic diet if there was one. (Yingqing and Anfei)
With increased industrialisation came the demand for a faster growing animal. Wujin pigs were being crossed with Duroc (USA), Landrace (Denmark), and York (UK) to achieve faster growth. Wujin x Duroc were crossbred. Other crossbreeds are York x (Wujin x Duroc) and DLY (Duroc x (Landrace x York). Yang and Lu (1987) found that the cross itself does not materially influence the quality of the ham as long as the breed contains 25% Wujin blood. (Kristbergsson and Oliveira, 2016)
In Xuanwei City, pig production is big business! In 2004, the city loaned 120 million yuan to breeders. By this date, the city had 31 breeding facilities each yielding 3000 pigs annually. There were an additional 9600 small breeding facilities. 356 Animal hospitals support the breeding and husbandry operations. In Xuanwei City, 1.2 million pigs were sold in that year. (Kristbergsson and Oliveira, 2016)
Consumers want a great product (consistency, despite volumes offered by industrialised processes) and a great story (focussing on the ancient history of the process and ham itself). Work to accomplish this was funded by the Yunnan Scientific Department, the Yunnan Education Department and Xuanwei City Local Government who all promoted the continued development of the Yunnan Xuanwei Ham (宣威火腿/xuān wēi huó tuǐ). (Kristbergsson and Oliveira, 2016) Modern processing methods moved away from seasonal production and embraced modern processing technology, but the great legends of the past remain as well as tailor-made production techniques catering for year-round production.
Processing Yunnan Xuanwei Ham
The Xuanwei climate explains the production methods used, as is the case with all the great hams around the world. Xuanwei City is located on a low-latitude plateau mansoon climatic area where the north sub-torrid zone, the southern temperature zone, and the mid-temperature zone coexist. Winter lasts from November to January and spring occurs from February to April. February, March, April is sunny and clear and this leads to a low relative humidity during these months. From March to September it is overcast and rainy, and the relative humidity is comparatively high. Winter is the best time to salt the hams according to the old methods to limit microactivity till salt dehydrates the meat and reduces the water activity. The rainy season is best for fermenting the ham. (Kristbergsson and Oliveira, 2016)
As in all meat processing, making the hams start with good meat selection. The process starts in the winter. The animal is killed and all the blood pressed out by hand. Animals are between 90 and 130 kg (live weight) when slaughtered.
A simple flow chart is given by Kristbergsson and Oliveira (2016).
Slaughtering and Trimming
Traditionally Xuanwei people kill the pigs usually before the last frost. They add boiling water to a wok and scrape the pig’s hair. Some people refer to killing the pig as washing the pig. For villagers, the killing of the pig is a sacred ceremony. (China on the Way)
The hind leg is trimmed into an oval shape in the form of a Chinese musical instrument, the pipa. The legs of small pigs are cut in the form of a leaf. The legs cut off along the last lumbar vertebra. After the blood is pressed out, the meat is held for ripening in a cold room at a temperature of 4 to 8 deg C, relative humidity of 75% for 24 hours. Ripened legs are known as green hams. (Kristbergsson and Oliveira, 2016) This step is an enigma to me since I am not sure what is accomplished in such a short period of time. My guess is that it is not technically ripening, but rather allowing any excess fluids to drain out. I will keep interrogating the processing steps to ensure that my sources have the right information.
The green hams are then salted. The salt is a mixture of table salt (25g/kg of leg) and sodium nitrite (0.1g/kg leg). (Kristbergsson and Oliveira, 2016) The inclusion of sodium nitrite is without question a modern development since nitrite curing of meat only became popular after World War I. My instinct tells me that they originally only used salt and later, possibly, sodium nitrate, the production of which has been done for very long in Chinese history.
The salt is rubbed into the hams by hand massaging for around 5 minutes. “The salted hams are then stacked in pallets and held in a cold room at 4 to 8 deg C, 75 to 85% relative humidity for 2 days. Salting procedure is then repeated.” The salt ratios are this time changed to table salt of 30g/kg ham and sodium nitrite is kept at 0.1g/kg leg. The meat is rested for a further 3 days in the chiller after which another salting is done. The ratio of this salting is 15g of table salt per kg of ham and again, sodium nitrite is kept at 0.1g per kg ham. (Kristbergsson and Oliveira, 2016)
According to Li Yingqing and Guo Anfei, “traditionally made hams are cured with half the salt used in factories. Instead, they are allowed to dry-cure for at least eight months to about three years, so the meat has time to mellow and mature.” “The longer the ham is cured, the better the quality and the most popular product now is the three-year-old cured ham.”
The hams are then hung in the drying room with a temperature of 10 to 15 deg C and relative humidity of between 50 and 60%. (Kristbergsson and Oliveira, 2016) Note how the temperature is increased and the relative humidity decreases to facilitate drying from the inside, out.
The excess salt is brushed away and the hams are dried for 40 days. Windows are kept open to facilitate air movement to air drying. Screens are placed in front of openings to prevent flies, other insects and birds from entering. If drying is too fast, a crust will form on the outside of the ham and if it is done too quick, the inside will not be dried and will spoil. If drying is done too long, the meat will be too dry to accommodate the lactic acid bacteria which will be involved in the fermentation process.
Li Yingqing and Guo Anfei reports on the traditional way that drying was done. “If you visit the villages by Nujiang, you may chance upon a strange sight in winter, when the hams are hoisted high on trees so they can catch the best of the drying winds. These trees with hocks of ham hanging from them seem to bear strange fruit indeed.”
After drying, the temperature is raised to 25 deg C. Relative humidity is pushed up to 70% and ideal conditions are created for fermentation. This process lasts for 180 days. Apart from creating an ideal condition for microbes, raising the temperature and humidity favours enzymatic activity, which is important in flavour development due to the partial decomposition of lipids (fat) and proteins. (Kristbergsson and Oliveira, 2016)
“Xuanwei ham is like good wine: the older the better. A ham that’s been aged at least 3 years can be eaten raw like prosciutto di parma.”
Control of Pests
During the curing and drying stages, flies pose a major risk. During fermentation and storage ham moths and mites (eg. tyrophagus putrescentiae) are the major danger. Relative humidity of over 80% attracts flies such as Piophila casei, Dermestes carnivorus beetle and mites. “There has been considerable work done in controlling mite infestation. Microorganisms such as the Streptomyces strain s-368 help prevent and treat mite investigation.” (Kristbergsson and Oliveira, 2016)
Xuanwei hams are evaluated by sensory evaluation. The odor is absorbed by a bamboo stick, used for the evaluation. This is the most traditional absorption method to classify different ham grades. For a detailed discussion and evaluation of this method, see Xia, et. al (2017), Categorization of Chinese Dry-Cured Ham Based on Three Sticks Method by Multiple Sensory Techniques
Storage is done under ambient conditions and the hams can be stored between 2 and 3 years.
“The physical and chemical properties of dry-cured ham are important determinants of its quality (Jiang et al. 1990 ; Careri et al. 1993 ). The lean portion of Xuanwei ham contains 30.4 % protein, 10.9 % fat, 10.3 % amino acids, 42.2 % moisture, and 8.8 % salt (Jiang et al. 1990 ). The whole ham contains 17.6 % protein, 29.1 % fat, 5.6 % amino acids, 24.8 % moisture, and 3.3 % salt (Jiang et al. 1990 ). Many essential elements are present in the ham as are some vitamins. The ham is particularly rich in vitamin E (45 mg/100 g). The characteristic bright red color of Xuanwei ham is mainly attributed to oxymyoglobin and myoglobin. The flavor and taste are associated with the presence of various amino acids and volatile organic compounds . The volatile substances present in Xuanwei ham have been extensively studied (Qiao and Ma 2004 ; Yao et al. 2004 ). Seventy-five compounds were tentatively identified in the volatile fraction. The compounds identified included hydrocarbons, alcohols, aldehydes, ketones, organic acids, esters, and other unspecified compounds.” (Kristbergsson and Oliveira, 2016)
The dominant microorganism on the surface of dry cured hams is mold, which affects quality. During the ripening stage, molds play an important and positive role in flavour and appearance. A study of Iberian dry-cured hams showed that yeasts are predominant during the end of the maturing phase of production whereas Staphylococcus and Micrococcus are absent. This surface yeast population has been shown to be useful for estimating the progress of maturation. Its contribution to curing is suggested to be their proteolytic or lipolytic activity. (Kristbergsson and Oliveira, 2016)
In Xuanwei hams, researchers have shown Streptomyces bacteria to dominate and account for almost half of the Actinomycetes. Aspergilli and Penicillia are common on the surface of Xuanwei hams during June to August. They found 8 species of Aspergillus. A. fumigatus was found to be dominant and accounts for one third of Aspergilli. Generally speaking, a high relative humidity encourages mold development on the surface of the hams. (Kristbergsson and Oliveira, 2016)
The dominant fungi found on Xuanwei hams is yeast. Yeast can be 50% of the total microorganisms found on mature dry-cured hams. Proteolytic and lipolytic activity of yeast is desirable. Towards the end of maturation, yeast dominates on dry-cured hams. (Kristbergsson and Oliveira, 2016)
Which species to be found during the different stages of production depends on temperature and relative humidity. In the Xuanwei region, humidity and temperature are highest during the rainy season. Molds occur almost exclusively on the surface of the hams. Aspergilli and Penicillia occur mostly during May when relative humidity and temperature are high. These fungi peak in July and August. Molds begin to grow in May and are well established by June. Spores are formed in August and September. The quantity of spores falls off gradually in September. (Kristbergsson and Oliveira, 2016)
“The growth of bacteria and Actinomycetes does not seem to be dependent on humidity in the curing room. Levels of bacteria are generally lower than levels of yeast. According to Wang, et al. (2006) yeast on ham multiplies exponentially from the beginning of the salting stage to reach a peak in April, and then the numbers drop and stabilise to around 2 x 107 cfu/g.Yeast levels within the ham show similar variation as the surface yeast. According to Wang et al. (2006) yeast accounts for 60 to 70% of the total microbial population on the surface of the ham. In some cases, no molds have been found growing on the surface of good-quality ham; therefore, some researchers believe that molds do not play a direct role in determining the quality of dry-cured ham, but an opposing view also prevails.” (Kristbergsson and Oliveira, 2016)
“According to the traditional view, high quality Xuanwei ham must have “green growth” (i.e. molds) on it. However, fungi such as Penicillia , Fusarium , and Aspergilli are known to produce mycotoxin in foods such as dry-cured Iberian ham (Núñez et al. 1996 ; Cvetnić and Pepeljnjak 1997 ; Brera et al. 1998 ; Erdogan et al. 2003 ). More than 15 % of the mold strains examined were found to produce mycotoxins in Xuanwei ham (Wang et al. 2006 ). The toxins penetrated to a depth of 0.6 cm in the ham muscle. Because most of the fungi that occur on ham have not been examined for producing mycotoxins , contamination with toxins might be more prevalent than is realized.” (Kristbergsson and Oliveira, 2016)
“The ham must be flame burned and washed before eating, in order to remove the rancid taste.” (China on the Way.)
There are an infinite variety of ways to serve the ham. It can be steamed, boiled, fried, or used as accessories. Old legs can be eaten raw. When cooking, cook either the whole ham or large cuts on a slow fire or slow boil it to retain the flavour.
Traditional Foods, Kristbergsson, K., Oliveira
Adshead, S. A. M.. 1992. Salt and Civilization. Palgrave.
chinadaily.com Updated: June 26, 2019
China on the Way, XuanWei Ham
Flad, R., Zhu, J., Wang, C., Chen, P., von Falkenhausen, L., Sun, Z., & Li, S. (2005). Archaeological and chemical evidence for early salt production in China. Proceedings of the National Academy of Sciences of the United States of America, 102(35), 12618–12622. http://doi.org/10.1073/pnas.0502985102
Huang, Christy. 2015.
Kristbergsson, K., Oliveira, J. (Editors). 2016. Traditional Foods: General and Consumer Aspects. Springer.
Mew, T. W., Brar, D. S., Peng, S., Dawe, D., Hardy. B. (Editors). 2003. Rice Science: Innovations and Impact for Livelihood. International Rice Institute (IRRI).
Needham, J., Ping-Yu, H., Gwei-Djen, L.. 1980. Sivin, N.. Science and Civilisation in China: Volume 5, Chemistry and Chemical Technology. Cambridge University Press.
Xia, D., Zhang, D. N., Gao, S. T., Cheng, L., Li, N., Zheng, F. P., Liu, Y.. 2017. Categorization of Chinese Dry-Cured Ham Based on Three Sticks Method by Multiple Sensory Techniques Volume 2017, ID 1701756 https://doi.org/10.1155/2017/1701756
Hot Boning In America
By Eben van Tonder
20 April 2020
When we formulate recipes, we formulate for:
- Protein content (according to legislation);
- Functionality of protein sources and gelling properties;
- Water Holding Capacity (which speaks to affordability);
- Mouth-feel, bite and firmness / tenderness;
- Freeze/ thaw stability where required;
- Visual appeal;
- Shelf life;
- Emulsion stability.
Hot boning is a technique where practitioners claim that water holding capacity is high, without the need to use phosphates. In emulsions made from such meat there is no need for non-meat extenders, emulsifiers and stabilisers. The processing is also achieved without the need for expensive and unnecessary refrigeration. It can have a material impact on shelf life by extending it and renders the end product firmer with a better visual appearance. It is therefore worth a proper consideration.
Hot boning is when bones and fat are removed from the animal carcass within a few hours after slaughter, before chilling. Some researchers distinguish between hot and warm boning. We will get into these differences at a later stage.
A short and clear description of hot boning is given by Dr. Lynn Knipe, who is, amongst other things, responsible for the processed meats extension programs at Ohio State University and conducts research related to the quality and safety of processed meat products.
Dr. Knipe writes that “the fresh, “bloom” color of meat is enhanced with rapid chilling (using CO2) of pre-rigor meat, as soon after hot boning as possible. This improvement in color can be reflected in a sharper particle definition (less smeared look), as well as a leaner appearance. While there are other functional advantages to hot boning of meat, currently, the main commercial reason for pre-rigor boning of pork is to extend the shelf life (time until the lean loses color) of the fresh color. Other advantages to pre-rigor processing include a firmer texture to the final cooked sausage, with less cooking loss.” (Knipe)
Schematically, the difference between hot-boning and cold-boning is represented as follows:
A German friend who is a 3rd generation Master Butcher tells me that his dad never used emulsifiers or stabilisers in his fine meat emulsion, and his secret was hot boning. Well, it was not really a secret – it was practiced throughout Germany.
Let’s briefly look at the ingredients normally used in sausage production. We will consider them by listing protein content and the relative price of the different proteins. This will show that when formulating products, a proper evaluation of the different ingredients is required.
In the table below I give the relative protein %’s of different functional ingredients and the Rand price as it was in April 2020. The links attached to this paragraph title and title below in the table are live and you can download the spreadsheet and insert the price of these protein sources in your own currency. You can also adjust the protein % of the particular product you use. The manufacturer must be consulted to get this information. The final protein % will depend on the particular product blend and the production method used.
|Protein options in formulating recipes (Mellett)|
|Protein Source||Price in SA (Rand)||% Protein||Rand/ kg Protein|
|Soya / TVP||14.00||48%||29.17|
If you do not know that pork loin typically contains 20.85g of protein per 100g of meat (20.85%), you can calculate it as 0.8kg of lean meat (in a 80/20 trim ratio) to get to the % lean that is 0.8 (% lean) / 4.8 = 16.7% protein. It follows from the formulas below.
-> Remember the key equations:
%N x 6.25 = % Protein
% Protein x 4.8 = % lean
6.25 x 4.8 = 30
So, %N x 30 = % lean (Mellett)
The red and blue raw materials show the difference between high and low-end products.
-> High-End and Low-End Products in South Africa
Local food legislation invariably calls for a minimum protein percentage and usually specifies what the source of the proteins must be. The hybrid meat formulations in South Africa usually contain a mixture of the ingredients listed in blue. High quality sausages or loaves or hams are produced in South Africa from either primal cuts (whole muscle) or from the ingredients listed in red. The question is if hot boning is used and all the costs are taken into account, including labour, energy (refrigeration and cooking), is it possible to come close to the price point when low-end products are produced, again, taking every input cost into account.
-> Hot Boning – A way to Make High-End Products Affordable
Hot boning is of interest for its Water Holding Capacity and its ability to form stable emulsions without the need to add non-meat fillers, stabilisers and extenders and the firmer texture and visual appeal. Due to the availability of data from the USA, it makes it easier to trace the history of the development of the technique from there.
Early work on Hot Boning in America
The Des Moines Register reported in 1974 on the work of Dr. R. L. Henrickson of the Oklahoma Agricultural Experimental Station where he had been working on hot boned meat since 1965. His initial work was on pork, and later he included beef in his research. Henrickson says that the concept was conceived by his research team in 1957. He is quoted as saying that pork from this process is “equal or better” in quality compared to conventional methods. It is interesting when he says that “we are fast approaching a time when social and economic pressures will force the implementation of new meat processing procedures.” (Des Moines Register, 1974) Such conditions have existed in many parts of the world for a long time.
Status of Hot Processing of Meat in the United States
Arguably one of the foremost authorities on hot boning, Dr. Henrickson writes that “there appears to be very little direct industry application of hot processing of primal cuts in the United States, even though most research evidence points to many advantages for the various available processing systems.” In contrast to this, “the success of the pork sausage industry can be attributed directly to the short processing period from slaughter to the chilled or frozen package. The system makes raw seasoned sausage available to the consumer in less than 90 minutes after slaughter. This process not only takes advantage of economics in processing and chilling, but provides the consumer with a sanitary, longer shelf-life product. The major bulk of the raw pork sausage industry now uses pre-rigor pork.” (Henrickson, 1983)
“The raw pork sausage industry uses young sows with the proper ratio of fat to lean. This careful selection of the animal makes it possible to blend a product without a great amount of excess fat.” If sausages are made, the following steps are followed.
-> Sausage Production
- Separate the lean meat and fat from the bone;
- Chopped into uniform pieces;
- Cool it, partially;
- Add spices / seasoning;
- Stuff into one and two pound grease-proof casings.
- Cool down “using an ethylene glycol bath system.
- Another option is to extrude the pork sausage links with or without casing directly onto a liquid nitrogen enclosed endless belt. “By the time each link reaches the end of the belt it has absorbed sufficient refrigeration to be case frozen.”
- Packaged and tempered to 0 deg F / -18 deg C for marketing.
-> If Not All the Meat is Used Immediately
Pork tissue (lean and fat) which can not all be used for sausage production immediately are handled as follows.
- Salted (2-4 percent) during the following procedure of . . .
- Coarse chopping of the meat
- Place in 50-60 pound / 20-25kg boxes and freeze.
- The pre-salted meat is used in sausage manufacture because of its ability to yield myosin for binding.
There is a variation on the above system which is commercially appealing, namely to produce the slabs of coarse chopped meat with spices and fat or rind emulsion already blended in. I have seen this widely in use in India and Nepal and my intention is to test these methods and create a product which can be exported to small scale butchers who lack the equipment or experience to create the emulsions.
Hot Boning and Some Chilling
Pre-rigor pork has been demonstrated to have many benefits. In America it is a matter of preference. Dr. Henrickson writes that “the prospect of cutting hog carcasses directly from the dressing line prior to chilling makes the average packing house worker shudder. The reason most often given is that one cannot trim hot cuts to presentable standards of appearance.”
Dr. Henrickson argues that the attitude in the US against hot-boning due to appearance is invalid “since most of the primal cuts do not require a high standard appearance value. All pork cuts except the loin and spare rib are subjected to some manner of forming either by can, package, stockinette, casing or press. Therefore, the only primal cut which may require some form of smoothness is the loin. Smoothness of the loin can even be attained by leaving the back fat intact, conveyorizing the loin through a blast chill and then trimming. A few minutes in a blast chill at -50°F / -45 deg C should provide ample firmness for the necessary trim. An alternative would be to market a completely boneless loin, since the consumer is now discriminating against fat and bone. The whole concept of hot processing not only requires converting practices of plant and market, but the thinking of personnel.” (Henrickson, 1983)
Henrickson reports that there has been progress during the past thirty years and expresses the hope that the process will be widely adapted in the future. He says that “even though the pork industry has been reluctant to adopt hot processing for primal cuts, it has reduced the period from kill to package. High volume (880 hogs per hour) ham production (kill to can in three days) has been practiced since 1965. Pickle solution is automatically injected into the meat and the cure is equalized in a matter of hours. A flexible vacuum wrapper makes the product ready for shipment and distribution in less than three days. Hot processing could reduce this time by an additional day.” (Henrickson, 1983)
There is a widely held belief that microbial problems are a major drawback to the system of hot boning. There is evidence that hot processing could provide a more sanitary products. (Henrickson, 1983)
These claims were further investigated by Fung, et al. (1981) who found that if “hot-boned meat is chilled adequately (from carcass temperature to 21 C with 9 h) during the first 24 h, the hot-boned meat is acceptable in color and odor and bacterial quality after 14 days of storage and 3 additional days of display. When meat is not chilled adequately (from carcass temperature to 21 C at 12 h), the shelf-life and storage life will not be acceptable.”
Their research showed the need for adequate chilling after boning the hot meat “at a rate sufficient to produce a bacteriologically acceptable product.” Boxing the meat before chilling is, according to their data, doable, but should be approached with great care. They caution against too-rapid cooling rates of hot-boned meat which can lead to cold-induced muscle shortening, which, in turn, causes toughening of the meat. (Fung, 1981)
They claim that faster chilling rates of up to 3-9 h after fabrication can be used as an additional insurance for better microbial quality and still the processor will be able to avoid cold-induced toughening. They also add that electrical stimulation can very successfully be used in conjunction with hot-boning, as an extra measure to prevent muscle toughening. They therefore recommend “chilling hot-boned meat to 21 C within 3-9 h after fabrication, and with continuous chilling, to below 10 C within 24 h.” (Fung, 1981)
Another way to prevent cold shortening is to select bigger carcasses with more fat. The smaller and leaner carcasses are more susceptible to cold shortening due to the reduced fat cover, which results in the deep areas chilling faster. This results in tougher products. Apart from carcass selection, this can be overcome by introducing a conditioning step (semi-hot boning) of 4 hours more until rigor has occurred (in beef it can take 24 hours or even longer). To reduce the time for rigor to occur, electric stimulation is used immediately after slaughter. It must however be reminded that in pork, cold shortening is not such a big problem because postmortem metabolism in pork occurs faster.
Generally speaking, hot boning can even double microbiological shelf life due to the fact that surface bacteria have not had time to grow before antimicrobial salts are added. Even if the meat is slightly tougher, in comminuted meats this is not a problem because a higher ultimate pH is achieved (what we achieve with phosphates in South Africa). Because of the higher pH there is an increased water holding and emulsifying capacity, which will yield a product that is juicy and of superior quality. Pre-rigor meat also acts as an oxygen-scavenger. It removes residual oxygen from inside the package after closure, resulting in a long shelf-life.
This does not mean that micro should not remain a major concern in hot or semi-hot boning. There will be an increase in moisture on cutting surfaces and great care must be exercised to prevent this becoming a vector for microbial contamination and growth.
In hot boning, it is easier to remove fat from the warm cut. Care must be taken to maintain a juicy product with flavour, brought out by the fat. It will be important to reduce fat variability rather than cause it to increase. (Fung, 1981)
Summary of Benefits of Hot Boning Compared to Cold Boning
Ockerman and Basu from Ohio State University reported the following benefits of Hot Boning compared to cold boning.
- Higher meat yield (1.4%)
- Labour savings (20%, faster – 4 mins / carcass) (with the right equipment to hold carcass still and pull muscles downwards)
- Less weight loss during chilling (1.5% less)
- Less purge in a vacuum package (0.1 – 0.6%)
- More uniform products
- Darker colour
- Reduced refrigeration space (50 – 55%)
- Lower refrigeration cost (40 – 50%)
- Shorter processing time (40 – 50%)
- Lower transport cost (primals vs carcasses)
- Superior water holding capacity
- Higher emulsifying capacity
(Dikeman and Devine, 2014)
- Shape distortion of cuts because the bone is removed;
- Reduced flexibility in production;
- Stricter hygiene requirements;
- Increased temperature control;
- New cutting procedure;
- Retrofitting of traditional cold boning area;
- Retraining or hiring new cutting personnel;
- Possible reduced tenderness because of cold and rigor shortening;
- Alteration of colour;
- Accelerated micro growth.
(Dikeman and Devine, 2014)
In the USA, hot boning is used mostly by whole-pig fresh sausage processors who use hot boning and rapid salting.
Rigor Complex Formation of Actomyosin
With the onset of rigor mortis, ATP disappears from the muscle. In the absence of ATP, actin and myosin combine to form rigor complex of actomyosin (Kamejima, et al., 1982) Willi Wurm, Master of Meat Science and Processing put it in terms that I can understand. In private communication he said that “actomyosin has to be separated again during a sausage emulsion process, by adding phosphate. Only separated Actin and Myosin have the capability to make an emulsion with fat and water. With hot boning methods you can keep the Actin and Myosin separate, when you grind the deboned meat and add salt. After that you cool or freeze the meat or process. The Actin and Myosin remain separate, and you can process without phosphate. You can also vacuum pack whole muscle pieces before the postmortem process and wet-age it. It will be classified better than normal wet-aged beef meat. Be careful to store the warm packed meat for the first night outside the fridge on tables and then refrigerate the next morning for 4 weeks.
Oscar Mayer was the first to apply hot boning to a large commercial operation. They used it to process packer sow hams to be used in sausage manufacturing. (Dikeman and Devine, 2014) The weight of these sows, which is “owned by a packing plant”, therefore packer sows, is between 110 and 140kg.
After the initial publication of this article I received fascinating comments from around the world.
We also have developed and patented the technology with which to process beef without exposing the spinal cord. A huge advantage for BSE. NO BONE MEAL AS WELL. Labor savings as much as 30-50%. We will soon be taking a 3 day industry standard of kill floor to truck down to 1 day.” For those of you who are interested, Gary can be contacted at NSCbeef@yhaoo.com, 117 Land Grant Lane Baird, Tx 79504 325-665-0602 Cell 325-518-5038.
Another person (still awaiting permission to use his name) recalled that “all the American processors were using hot boned meat, also went to a company called Marjacks who were producing a lot of further processed products, not sure if they are still going but would be a good source of information as would Wayne Poultry as they had an incredible set up for hot deboning.”
Not everybody had such a positive experience with hot boning of beef. Someone (awaiting aproval to use his name) said, “I used to do a bit back in the 80s not great for presentation or yield. Hot Beef Boning, selling vac packed into wholesale. Very fast, but poor yields and doesn’t do much for cutting quality. We soon stopped it.”
I have never been exposed to hot boning. The South African Meat Safety Act of 2000 (ACT No. 40 OF 2000) stipulates that meat must be cooled to a core temperature of 7 deg C before dispatch. Paragraph 40 (1) reads as follows. “A chiller used for chilling warm carcasses, sides, quarters or portions must be capable of providing uninterrupted cooling to reduce the core temperature of the meat to 7 def C before dispatching.” According to this definition, it seems as if hot boning can be done as long as the bond meat reaches the required 7 deg C temperature before dispatch. I will take the matter up with a meat inspector.
In Germany, hot boning was widely used. Gero Lutge, the third-generation Master Butcher I was talking about in the introduction, sent me the following account of his dad’s use of hot boning. he writes, “in the earlier years my dad went to the local abattoir on Monday morning to slaughter the amount of pigs he pre-ordered. Then he loaded it onto his bakkie (pick up) in half pigs. Had a Schnapps and a beer at the tavern on the abattoir premises and went back to his butchery to immediately brake the pigs, debone them and prepare them for the week ahead. The meat trimmed for emulsion processing was immediately processed with a lot of ice so still not cooled down. The only additive he added was curing salt and spice. Even if he filled the emulsion a day later, the water intake and binding was tremendously higher than with phosphate when the pH level of the meat decreased overnight in the chiller.”
I am sufficiently intrigued to at least test pre-rigor meat for sausage production and legally there may be a way to do it even in South Africa. The motivation will be to simplify the process by removing the need of the 2-4% addition of extenders, stabilisers and emulsifiers. I am motivated by the comparison made by Ockerman and Basu from Ohio State University between cold and hot boning where they clearly and persuasively show the economic advantages of hot boning.
There is every reason to look into this very carefully!
Dikeman, M., Devine, C.. 2014. Encyclopedia of Meat Sciences. Second Edition. Academic Press.
The Des Moines Register Sun Mar 10, 1974 (Active link to article)
Fung D. C., Kastner C. L., Lee C-Y., Hunt M. C., Dikeman M. E., Kropf D. H.. 1981. Initial Chilling Rate Effects on Bacterial Growth on Hot-Boned Beef. Journal of Food Protection, Vol 44, July 1981.
Henrickson, R. L.. 1983. Status of Hot Processing of Meat in the United States. Oklahoma Agricultural Experiment Station, Animal Science Research Report.
Kamejima, S., Ishioroshi, M., Yasui, T.. (1982) Heat Induced Gelling Properties of Actomyosin: Effect of Tropomyosin and Troponin, Agricultural and Biological Chemistry, 46:2, 535-540, DOI: 10.1080/00021369.1982.10865074
Knipe, L. https://meatsci.osu.edu/node/127
Mellett, F. Private conversations.