The Quest for Nitrite Free Curing

18 January 2020

Introduction

I have been involved in the curing industry for almost 15 years now and during this time I fell in love with one of the most enigmatic salts from antiquity called nitrites. Over the years I have written extensively on the development of meat curing (Bacon Curing – a Historical Review). I tracked its development from millennia ago in Salt – 7000 years of meat-curing and Nitrate salt’s epic journey: From Turfan in China, through Nepal to North India. Ancient developments came together for me in the article And then the mummies spoke!.

Despite the fact that I am convinced that current processing methods of hams and bacon do not pose any health rish for consumers, the demand for nitrite free bacon is not going away. Bacon and ham have always been a product for the people and whatever our personal views on the matter, the clear and growing consumer demand must be catered for.

Over the years I have seen spice companies acting with great dishonesty. They develop curing mixes that they claim accomplish meat curing without nitrites. The way they did this was by using plant extracts which are naturally replete with nitrate. Through bacterial reduction, they achieved the conversion of nitrates to nitrites which was then sold as a “natural” curing agent due to the fact that no synthetic ntirite was added. They circumvented food labeling legislation by not adding synthetic nitrite. In reality they still add nitrites to curing brines.

I have friends from around the world who build their brands on the claim that it is nitrite free and having investigated those claims, I can confidently say that they definitely add nitrites to curing of meat. It is an embarrassment just waiting to be exposed!

The Spanish Case

A Spanish producer launched a new curing system in the early part of the 2010s. They claim great results and that only plant and fruit extracts are being used. Despite this being a step in the right direction, several aspects of the development did not sit well with me, in particular the fanatical secrecy surrounding the product.

We were preparing for sausage trails today and the interview with the CEO milled through my mind. I do not understand the secrecy! Certainly there is a place for protecting proprietary information, but when the way it is being done goes against the food legislation governing all of us, it does not sit well with me. If the entire commercial viability of the approach is based upon complete secrecy, how do they expect to win the hearts and minds of the very consumers they are trying to rich out to by its nitrite-free curing brine. How will “trust me, I’m a doctor” in terms of this product be different from “trust me when I say that nitrites is not really bad for you?”

In the absence of information, people speculate and since the company is creating an enviroemt where people will speculate, let me also “speculate”. I asked the question how I would have done it if I had to copy what they did. For starters, remember that my approach is predicated on science. I have extensively looked at the curing reaction in Reaction Sequence: From nitrite (NO2-) to nitric oxide (NO) and the cooked cured colour and the colour of fresh meat in Difference between Fresh Cured and Cooked Cured Colour of Meat. There is a fundamental reason why the world works the way it works and understanding nitrite curing is intimae associated with our most fundamental understanding of the universe. In Fathers of Meat Curing I review some of the key developments.

– What they get right.

The company claims that they address Listeria spp (broad spectrum), Listeria
monocytogenes, E Coli H157, and Clostridium spp (broad spectrum). The organism responsible for the existence of the meat curing industry is Clostridium Botulinum. (Clostridium Botulinum – the priority organism) and the fact they address it in their research is significant. The curing brine is effective against Clostridium Botulinum is very important. Personally I would like to know how effective it is against damaging the spore and preventing its viability. I am not sure if the study looked at that. If not, I would ask for that detail.

– Questions about antimicrobial efficacy

Challenge tests were performed where the brines efficacy was tested against sodium nitrite and compounds such as sodium nitrite plus sodium erythorbate, and a control with no antimicrobial. They claim to have demonstrated that their product performs equally well against listeria mono and Clostridium botulinum. Still, my reservations will stand.

In reviewing references to the brine, I found a claim that it its anti-microbial activity is especially effective if used with dehydrated lactic acid. Dehydrated lactic acid will itself be effective against amongst other, Listeria Monosytogenes. The one that worries me is still the efficacy against Clostridium. The claim is that its efficacy is due to traditionally processed Mediterranean fruit and spice extracts. What bothers me is that through the ages of meat processing, the producer claim that extracts were used which until now has been hidden from science. There is a lack of understanding of the experimental character of the meat curer who would, over thousands of years, if not millennia, certainly have stumbled upon these miracle substances and have incorporated it into his or her processing techniques long ago.

A further claim is made that these extracts are high in naturally occurring compounds with antimicrobial and antioxidative capacities. There are indeed a number of extracts who claim exactly this. However, what is the role of these antioxidative agents in meat curing. The context of the claims seems to point to pathogen eradication when in actual fact its role is in the prevention of fat rancidity and the development of off flavours.

– Questions about colour

The claim is made that it is these extracts are responsible for the meat flavor as well as its typical reddish color and pathogen protection, without the risk of nitrosamine formation. It is the claims about antimicrobial efficacy of the compound that is the most worrying and second to this, is the claim about the fact that it imparts a cured colour to the meat.

The most fundamental question will be this – is it causing the meat to change colour or is it imparting a colour to the meat. Is it an external colour which is imposed upon the meat or is the meat itself changing colour as it does in the case of nitrite curing?

Identifying which one it is is very simple. Let me walk you through it. For the meat to change colour, it is a reversible reaction. During curing, meat often turns brown due to oxidation, just to turn the regular pinkish/ redish colour of cured meat. It the meat is able to go from brown to pinkish/ redish, back to brown and again back to pinkish redish, you are dealing with the meat changing colour.

Secondly, look at the fat. If the fat inside the meat change colour (to pink for example), it is an external colourant applied to the meat and whether this is a plant extract or not, it must be approved as a meat colourant by the relative legislative body.

Look for an accumulation of brine. Especially in pork belly (streaky bacon) this will be noticeable where the injected brines are often trapped between the horizontal layers of fat and connective collagen. If an external colour is used, the brine pockets will display a brighter colour than in the meat surrounding it. It is one of the many reasons why it is not advisable to use a colourant in ham or bacon injection.

No plant extract without nitrogen will cause the meat itself to change colour. This is one of the laws of nature. There are colours imparted to long term cured meats which forms a purplish colour, but as far as my knowledge goes, the exact mechanism is not well understood and despite a considerable effort, scientists have not been able to replicate this effect in short cured hams and bacon.

The molecule responsible for the cured colour of meat is Nitric Oxide. Without Nitric Oxide being produced somehow by the magical concoction of spice extracts, the meat itself will not change colour and a colourant will be used. The fact that this may be a natural colourant is then a matter for consumers to decide whether they are satisfied with this, but that the meat is not “cured” in the traditional sense of the word is a fact. At best you can call it fresh and coloured meat.

– Questions about flavour

If the plant extracts impart flavour to the meat and it is not natural, does this mean that meat prepared in this way is “flavoured meat?”

How Would I have Done it?

I did not speak to anybody about the production of this product, but as an interesting question, while I was working today on sausages, I wondered how I would have done it. For background to this, read my article, Regulations of Nitrate and Nitrite post-1920’s: the problem of residual nitrite.

For starters it would have been very easy if one used nitrates. I see no mention of it in their literature. If I had to guess how the cure is made, I would say they possibly could be using reduced amount of nitrates but my guess would be that if this is used, residue nitrites are disposed of during the curing process. How to convert the nitrate quickly to nitrite would have been the challenge. I would have used techniques developed through the celery and beetroot juice developments where nitrates in plant extracts were converted to nitrite. In salami manufacturing, the use of starter cultures have become so commonplace that it will be easy to impregnate the brine with bacterial cultures who can achieve the conversion quickly. I would have elevated the levels of ascorbic acid, to ensure that nitrites are rapidly converted to nitric oxide which achieves the cure. I would add plant extracts to bolster the reduction to NO, to add flavour, to assist in the colour and to confuse the issue. Paprika, red chili’s, red pepper, etc are good colour enhancers especially for a darker, reddish colour. In terms of micro I would rely on nitrite, nitrate and the anti microbial action of the plant extracts which I would add. I would set out a tight schedule in terms of how long the product must be cured before the important test is done for nitrites.

From correspondence with the company, I learned that they say that the meat itself does not change colour which means that they are not using nitrate, but in the absence of full disclosure, how do we know? Who says that the statement is not purposefully vague? However, lets take them at their word. Lets assume that nitrates are not used. Like them, I would reply on plant extracts.

Supporting Correspondence

Remember that I have no knowledge if this is actually how the curing brine is being made. I discovered one bit of information that I can use to get some idea if I am on the right track or not.

I looked at mail communication that was made public related to the product under the access to information law. In this communication, regulators are asking questions which I echo.

The company has to make known the materials used (more detail than edible spice and fruit extracts) and if they claim that the meat colour is changed itself, show how by which mechanism this is achieved. Failing which, it is an external colourant and must comply with colouring legislation. Failing such disclosure is against the letter and spirit of our food laws. (Refer to my article Concerning Chemical Synthesis and Food Additives)

The question is asked as to “what kind of processes are being used e.g. physical, chemical or microbiological for the extracts? How many steps are there in the extraction process?”

Another good question that came up was for a “simple flowchart”. The company claimed, I assume, that “simple ethanol water extraction, using traditional methods of extraction and no selective physical or chemical extraction of constituents” are used. The legislature ask for “further detail, for example, is the extract a standardized product? How do you prevent variation?” These questions would be asked from us who use the product in processing and the company has to comply.

The all important question is then asked related to the “active component or components that are being used as a substitute for nitrite/nitrate preservatives to prevent the growth of harmful microorganisms and/or increase shelf-life? If this is considered commercially sensitive information can you describe how it kills or prevents the growth of microorganisms? These are the same questions I have raised above. Meat science is not an isolated discipline being pursued in dark corners any longer. It is done at almost every university and high profile meat institutes and if another product was available for curing meat apart from nitric oxide, television programs would have been made about the discovery and every scientist on earth would have known about it.

Related to the colour of the meat, it seems as if the company stated that the meat does not actually change colour. The legislator asks, “Does any component impart a colour change in the pork meat?” The statement is then made that the company has said that “no component used imparts a colour change in the pork meat.” This being the case, the follow up question is then “Does any component prevent colour change?”

In terms of flavour, using the plant extracts will certainly qualify the products as flavoured bacon? How does the plant extracts not impart their flavour to the meat and how is the flavouring natural?

A Better Way

I am of the opinion that the use of pant extracts is warranted. I am working on a completely new direction that may or may not include plant extracts. Even if I opt for plant extracts, I have an ongoing problem with current extraction processes and prefer the products to be used in the form in which it is found in nature. The discussion from the legislator with the Spanish company bears this preference up. Resent equipment developments make a better raw material possible. Another key lesson to learn from the Spanish example is the importance of taking the consumer and industry along in the process. A man walking too far ahead of the people he is trying to lead is a man out for a walk and not a leader. He will achieve nothing! Bacon and ham and health – they all belong to all of us!