Introduction to Bacon & the Art of Living
The story of bacon is set in the late 1800s and early 1900s when most of the crucial developments in bacon took place. The plotline occurs in the 2000s, with each character referring to a natural person and actual events. The theme is a kind of “steampunk” where modern mannerisms, speech, clothes, and practices are superimposed on a historical setting. Characters interact with one another with all the historical and cultural bias that goes with this. The period of technology it covers is breathtaking. Beginning in pre-history, it traces the development of curing technology until the present, where bacon curing is possible without adding nitrites.
The Curing Molecule
I’m going to give away the ending right at the beginning. Or rather, one part of the answer. I will tell you right up front much of what I’ve learned over many years, across many continents, about curing. If you have the solution to the riddle in mind, right from the start, it will make the importance of every puzzle piece far more impactful. The part I am revealing up front is what curing is technically.
This chapter is designed to give you enough background to understand the fundamentals of curing and appreciate some of its complexities. This is not intended to be a science textbook, so I take the liberty to present matters simplified. I don’t, for example, always indicate when I am talking about an ionic compound when I write a simple notation for nitrite as NOO. I also added, “Want to know more?” sections for those with a chemical background or desire a deeper understanding. Let me walk you through these concepts; a breathtaking story awaits! Don’t try and remember all the new terminology or make all the connections in your mind. Simply read this from start to finish without stopping if it gets tough to follow. I assure you that you will remember far more than you can imagine!
What is Meat Curing?
The most crucial question in a work on the history of meat curing is to understand what meat curing is! Meat curing is changing meat into a form that lasts outside a refrigerator. We can say that it imparts longevity to meat. In the curing process, there are two changes that we can identify with our senses. A delicious taste develops, and the colour changes to a characteristic pinkish/ reddish colour. A slightly less obvious characteristic is that cured meat is safe from microorganisms that make us sick. These characteristics are observed through observation, but what happens in the chemical reactions?
The large molecule, the building block for muscle or meat, is called a protein. An important class of proteins in our body is called hemeproteins (also spelt haem protein or hemoprotein). These are proteins that have something attached to them that biochemists refer to as a heme prosthetic group. A prosthesis helps a person who lost a limb to accomplish a particular task like a handshake still. In the case of proteins, the prosthesis is a non-protein addition to the protein that performs specific tasks. The heme prosthetic group allows proteins to carry oxygen, facilitate electron transfer and participate in oxygen reduction, among other processes. Curing is the reaction between protein and the small gaseous molecule called nitric oxide (NO).
In curing, nitric oxide is bound onto this heme component. We observe this binding of nitric oxide to the protein as a pinkish/ reddish colour. Nitric oxide is responsible for crucial characteristics of cured meat. The colour, the longevity and the fact that the product is free from microorganisms will likely make us sick. Another feature of cured meat we observed with our senses is the cured taste. Exactly how the taste is altered through curing is something we have not worked out yet.
How is Nitric Oxide formed?
Let’s begin by looking at how nitric oxide is formed. For our discussion, what is essential to know is that it is created both inside the body or by the body itself and outside the body. Almost every cell in our bodies can produce it. There are also two basic types of reactions that produce it.
i. Meat proteins contain an amino acid called L-arginine. The body can access nitrogen and combine it with an oxygen atom to create nitric oxide. Beginning in the 1990s, scientists started to understand that certain bacteria also have the ability to convert L-arginine into L-citrulline and nitric oxide, which cures meat. The exact mechanism is still under investigation, but this remarkable discovery accomplishes what has become like the search for the holy grail: curing meat without nitrate or nitrite.
ii. The second significant way that nitric oxide is created is the conversion of nitrate to nitrite and the nitrite to nitric oxide. The source of nitrate can be salts such as sodium or potassium nitrate, or it occurs in large volumes in certain plants we regularly consume. Bacteria break the nitrate down to nitrite, which is changed into nitric oxide through chemical reactions. In conventional curing operations, nitrate or nitrite salts create nitric oxide, which cures meat.
This means that bacteria are involved in the reactions involving nitrate and L-arginine. Interestingly, this seems to be why this remarkable discovery remained unidentified for so many years. The conversion of L-arginine only takes place when no nitrate is present. If nitrate is present, the bacteria use nitrate’s nitrogen, not L-arginine. That L-arginine plays a role in salt-only, long-term curing processes has been suspected for many years. In the 1990s, it was identified that the reaction was mediated through bacteria. What seemed to have happened was that the scientific community continued to relegate this to long-term cured hams and bacon. In recent years, commercial quick-curing factories using bacterial fermentation have become a reality in high-throughput commercial curing plants with no nitrates or nitrites. These developments in meat fermentation have been so successful that meat curing is achieved in approximately the same time as with sodium nitrite.
That sets the first part of the stage for our discussion about meat curing. My own life is an excellent example of how only knowing the facts, as I presented above, about meat curing does not mean that you can use the techniques. The reality is that these methods can only be effectively applied within the framework of a complete curing system, and developing such a system is far more complex than one imagines. I have, for example, known that bacteria can use L-arginine to create nitric oxide for a full five years before I started to unravel the context and requirements of what it will take to use this to cure meat in a commercial curing operation. Colour stability and a safe microenvironment must be created. The formation of biofilm must be managed. The speed of the reaction must be increased. So I can go on and on, and the point is simply this: it is a wonderfully complex endeavour.
Let’s return to the consideration of the two curing paths that we just looked at. In the course of this chapter, I will make repeated references to these two reactions. The story of bacon is, in a nutshell, the story of ways to produce nitric oxide in the fastest possible time to cure meat.
Many curers and scientists have been obsessed with finding another way to cure meat. In other words, not to use the nitrate-nitrite-nitric oxide path to curing due to questions that emerged about the safety of nitrate and nitrite. The use of bacteria to cure the meat achieves this! However, right at the outset, I want to caution that nitrate, nitrite, and nitric oxide are like the Father, the Son and the Holy Spirit in that where you find one, you find them all due to the high reactivity of these nitrogen species (Reactive Nitrogen Species) as we refer to them. Creating nitric oxide with bacteria from L-arginine may seem like solving the problematic use of nitrate and nitrites in meat curing, but if the two cousins of nitric oxide (nitrate and nitrite) will, in any event, both appear in meat cured with bacteria only, is it addressing the problem?
A far more fundamental question exists: whether the hysteria against nitrate and nitrite is warranted! Is the use of nitrite or nitrate problematic? Are these entities of concern when we consider human health? In recent years, evidence emerged that the exact opposite is true, namely that if we do not ingest sufficient nitrate and nitrite, this has far more detrimental health effects on humans than having them in our food.
Want to know more?
A closer look at the nitrate-nitrite-nitric oxide sequence in our bodies:
The researcher, Weitzberg (2010) reportes that “several lines of research . . . indicate that the nitrate-nitrite-nitric oxide pathway is involved in regulation of blood flow, cell metabolism, and signaling, as well as in tissue protection during hypoxia (meaning, a lower-than-normal concentration of oxygen in arterial blood).” This is the exact curing reaction when we begin with slatpetre (NO3–) or with nitrite NO2– as is the predominant current system of curing in high throughput curing operations. When we use sodium nitrite to cure the meat, the process still results in the formation of nitric oxide (NO). The curing reaction is therefore a “natural reaction” which takes place in our bodies and is essential to life.
Can we remove nitrogen (nitrate or nitrite) from our diets?
We are all aware of the importance of oxygen to our everyday lives. Without it, life as we know it is not possible. A second element as necessary to life as oxygen is nitrogen. Where does nitrogen come from, and why is it essential to life? Let’s take a step back and consider nitrogen for a moment before returning to nitrate and nitrite in food and the curing chemistry.
The Importance of Nitrogen
I have written extensively about how reactive nitrogen species are formed from atmospheric nitrogen, and I will leave the subject to be discussed later.
It is sufficient to point out that nitrogen is one of the most essential plant foods and is taken up in the structure of plants. From the plants, they provide sustenance to animals when they eat the grass. The ability of animals to absorb nitrogen is a critical element of what makes food nutritious. From very early, it has been shown by various scientists that animals fed with no nitrogen get sick and even die, whereas animals fed with food high in nitrogen thrive. This is important since, in evaluating the use of nitrogen in meat curing (through nitric oxide), we must first realise that without nitrogen, there is no nutrition. We need nitrogen like we need water or oxygen to live.
Want to know more?
The role of nitrogen in plants:
Nitrogen is part of the green pigment of plants, responsible for photosynthesis, called chlorophyll. It further is responsible for a plant’s rapid growth, increasing seed and fruit production, and improving the quality of leaf and forage crops. (Plant Nutrients and Lilies) This is important as we will later see how nitrate, nitrite and nitric oxide not only cures meat and ensures the overall health of our bodies, but how the same reaction is key to the nutrition of plants. The curing reaction is by no ways something foreign. It is vitally important to all aspects of animal and plant life and humans form part of this group of animals.
Nitrogen as plant food:
Potassium (K) and nitrogen (N) together with phosphorous (P) are considered the primary nutrients of plants. These are normally lacking in the soil because plants use them for growth and thus deplete it. As we will see, nature replenishes nitrogen, but modern farming created the demand to add extra nitrogen to the soil. Potassium (K), nitrogen (N) and phosphorous (P) are all part of the macronutrients. The secondary nutrients are calcium (Ca), magnesium (MG), and sulphur (S). These nutrients are normally abundant in the soil. When lime is applied to acidic soil, large amounts of calcium and magnesium are added. Decomposing organic matter normally yields enough sulphur. Potassium (K) is absorbed in bigger volumes than any other mineral element except nitrogen and in some cases, calcium. It assists in the building of proteins, photosynthesis, and fruit quality and it reduces diseases. (Plant Nutrients and Lilies) The abundance of potassium in plants can be seen from where we first identified it namely from potash or plant ashes soaked in water in a pot. Potassium is derived from this practice predating the industrial revolution.
All proteins, the building blocks of muscles, contain nitrogen. Our bodies use nitric oxide to stay healthy in many different ways. To such an extent, life will not be possible without nitric oxide in our bodies. The question is whether the body produces enough nitric oxide on its own, and the answer is no. We need to supplement what the body can’t obtain through our diet. Some of the foods where we get nitrate or nitrite in our diets are:
By far, the most significant source of nitrates is leafy green vegetables. The way that the nitrates end up as nitric oxide in our bodies is the nitrate-nitrite-nitric oxide sequence. These vegetables also contain nitrites and turn into nitric oxide through the steps of nitrite-> various-chemical-reactions ->nitric oxide.
Borehole water often has nitrate and nitrite from animal and human waste and fertilisers in surrounding areas. The sequence of reactions that change the nitrates in water into nitric oxide is the same as above: nitrate -> nitrite-> nitric oxide.
-> Cured Meat
Nitrate salts are found naturally around the world. Potassium nitrate, for example, is known as saltpetre. Nitrite salts are manufactured salts containing sodium and nitrite. Saltpetre (potassium or sodium nitrate) is used in meat curing today. If we consume cured meat, we ingest nitrates or nitrites, and it changes into nitric oxide in our bodies through the reaction nitrate-nitrite-nitric oxide or nitrite-nitric oxide. Cured meat is, however, the most minor and most insignificant source of nitrates and nitrites.
The path from nitrate to nitric oxide is essential to focus on here. Let me illustrate it in greater detail using saltpetre as an example. Saltpetre can be represented as one nitrogen atom and three oxygen atoms, and to make it easy, I will write it as NOOO to focus on the number of oxygen atoms. The astute observer will see that I leave the metal part of the saltpetre out and represent only the nitrate part. Nitrate joins forces with metals like sodium, calcium, or potassium to form sodium nitrate, potassium nitrate (known as saltpetre) or calcium nitrate. In terms of curing meat, only sodium plays a further role, and we will look at that later, but for now, it’s helpful to ignore the first part of the pair and focus only on the nitrate part.
When nitrate connects to one of the metals, it forms a very stable salt, which does not easily lose an oxygen atom. We said we represent nitrate in this chapter as NOOO, but you remember that the actual representation is NO3–. The stable molecule now loses an oxygen atom through bacteria that use the extra oxygen atom in its metabolism. So, NOOO loses an oxygen atom through the action of bacteria and nitrite is formed, which we represent as NOO (actually, NO2-). In contrast to nitrate, nitrite is an unstable molecule and is easily changed to one of the other Reactive Nitrogen Species (RNS), such as nitric oxide. If NOO loses an oxygen atom, NO or nitric oxide is formed. This reaction happens chemically and not through bacteria, and it involves nitrate first changing into other forms before it ends up as nitric oxide.
Ancient curing methods start with nitrate, which is changed to nitrite and nitric oxide. This is how it was done before sodium nitrite became available worldwide after World War I, and many artisan curers still prefer to start with nitrate when they cure meat. The reason is that the bacteria also contribute to the development of flavours in the meat, which one loses if one starts directly with nitrite in sodium nitrite, which does not require bacteria to change into nitric oxide to cure the meat. It became the norm following World War II to skip the step of changing nitrate to nitrite. It is time-consuming and may result in inconsistent curing by beginning the reaction sequence using sodium nitrite rather than nitrate.
Whether you talk about the reaction nitrate-nitrite-nitric oxide or nitrite-nitric oxide, these scenario has the loss of one oxygen atom at their heart in every step. The opposite is also possible, mainly because oxygen atoms can be added. At times, nitric oxide can gain an atom to form NOO or nitrite and NOO to form NOOO or nitrate. Remember that we said that you are likely to find the others where you find one. So, where you have nitrate, nitrite or nitric oxide, you are likely to find the others.
Want to know more:
It is easy to see that the 3 following the O which represents oxygen indicates that one nitrogen atom binds to three oxygen atoms in the nitrate molecule, but what does the minus sign indicate? The nitrogen and three oxygen atoms form a unit or a package. The nett charge of this package is, however, negative, which is what the minus sign indicates. We call this not a molecule, but a very special molecule called an ion (where there is only one atom) or an ionic compound as in the case of nitrate with nitrogen and oxygen atoms in the molecule. A compound is supply two or more elements grouped together. An ion is what we call a unit like this (which can be an atom or a molecule) but it has a net electrical charge which is either + (positive) or – (negative). Ionic compounds are held together by these ionic bonds or electrostatic forces, as we refer to them. The ion by itself has a charge as either + or – but when it connects with another ion of opposite charge, the molecule is neutral overall. It has a component which is positively charged (called an anion – a positively charged ion) and a negatively charged component (called a cation – a negatively charged ion). An example of an ionic compound from everyday life is table salt with one positively charged sodium ion (Na+) and one negatively charged chloride ion (Cl−) called sodium chloride or table salt. We call it a salt because one component is alkali and the other is acidic.
The combination of nitrogen and oxygen yields several salts of importance for example saltpetre. Like table salt is the colloquial term for sodium chloride, so the colloquial term for potassium nitrate is saltpetre. The nitrate component or ion, NO3– reacts with metal ions such as sodium, magnesium, potassium, or calcium. The metal components occur in solution (mixed into water) as a strong acid in the form of (HNO3) with a strong base (KOH) which reacts to form a crystal [P+].[NO3–] or PNO3. Traditionally, saltpetre refers to potassium nitrate.
Another metal it often combines with is sodium to form sodium nitrate. Sodium or natrum (German) is represented by the letters “Na” for sodium and again, the nitrate component which is NO3– combines to give sodium nitrate written as [Na+].[NO3–] to form NaNO3.
The final example is the metal calcium, abbreviated Ca which represents calcium, but calcium combines with two sets of nitrates (NO3–) x 2 written as (NO3)2 and the complete name is therefore Ca(NO3)2. In our discussions here we ignore the metal part of the molecule being in our examples above potassium (K), sodium (Na) and Calcium (Ca). For easy of reference, when we talk about nitrate, we only refer to the NO3–component but often, there would be either K or Na or Ca attached to the nitrate but because it plays no role in the rest of the chemical reaction, we will conveniently ignore these metal components.
Summarise different metals that combine with nitrate:
NOOO (nitrate) + K (potassium) = KNO3 (Potassium Nitrate)
NOOO (nitrate) +Na (sodium) = NaNO3 (Sodium Nitrate)
NOOO (nitrate) + Ca (Calcium) = Ca(NO3) 2 (Calcium Nitrate)
You not only learned three different metals that can attach to nitrate. The same three can also lose an oxygen atom to form a nitrite salt.
NOO (nitrite) + K (potassium) = KNO2 (Potassium Nitrite)
NOO (nitrite) +Na (sodium) = NaNO2 (Sodium Nitrite)
NOO (nitrite) + Ca (Calcium) = Ca(NO2) 2 (Calcium Nitrite)
This is another equally likely reaction that involved gaining oxygen atoms and not losing them (reduction). An example of an oxidation reaction is the reaction with L-arginine, which we looked at briefly and the oxidation of ammonia (NO3)/ ammonium (NH4+), both of which create nitric oxide and are mediated through bacteria. We will tell the story of the formation of nitric oxide from ammonia in a subsequent chapter.
We summarise the two reactions as follows:
-> Reduction (losing oxygen atoms)
One way to create nitric oxide is by removing oxygen atoms. We remove one of the three oxygen atoms from nitrate (NOOO) and get nitrite (NOO). In the name, the “a” is replaced with an “i”, and nitrite has one less oxygen atom than nitrate. If we remove one more oxygen atom from nitrite (NOO) we get nitric oxide (NO), the primary curing molecule.
So, let’s review the simple but essential chemistry. Don’t worry about trying to remember these. We will refer to them so often that you will quickly recognise them when we are done.
NOOO or (NO3–) = Nitrate or Saltpetre
NOO or (NO2–) = Nitrite
NO = Nitric Oxide
When nitrate loses one oxygen atom, it changes to nitrite and nitrite that loses one oxygen atom changes to nitric oxide.
NOOO (nitrate) – O = NOO (nitrite)
NOO (Nitrite) – O = NO (nitric oxide)
We have seen that you lose two oxygen atoms to form nitric oxide from nitrate salts. Chemists say that the number of oxygen atoms is reduced. The word “reduced” will be vital as we will say that the nitrate or nitrite is reduced, meaning it lost an oxygen atom.
The more reactive nitrite forms the same salts that nitrate forms with metal.
NOO (nitrite) + K (potassium) = KNO2 (potassium nitrite)
NOO (nitrite) +Na (sodium) = NaNO2 (Sodium Nitrite)
NOO (nitrite) + Ca (Calcium) = Ca(NO2) 2 (Calcium Nitrite)
-> Oxidation (Gaining Oxygen Atoms)
Earlier, we have seen that our bodies create nitric oxide through specific cell processes. Instead of removing an oxygen atom, it made nitric oxide by starting with a nitrogen atom. Then, it added an oxygen atom to the nitrogen atom, forming nitric oxide. This process is called oxidation (adding an oxygen atom).
Ammonia is oxidized through bacteria, adding an oxygen atom to nitrogen and creating nitric oxide. More about this later when we drill down into sal ammoniac. Another way this happens is when ammonia is burned in the presence of oxygen. In this case, it is oxidised to nitrogen gas (N2) or nitric oxide (NO). It must be noted that the oxidation of ammonium salts usually produces nitrogen gas.
The Ever-Presence of Nitrogen
Let’s consider how gas, nitrogen, enters our world and becomes part of the nutrition of plants and animals. Otto et al. (2010) estimate that with 1.4 billion lightning flashes each year, an estimated 8.6 billion tonnes of chemicals of one form or other are generated from the general formulation of NOx. Don’t get scared with the introduction of the x. It tells us we have a variable from which the exact number differs. You are already familiar with three of the forms this can take. Look at Nitric Oxide (NO), nitrite (NO2-), and nitrate (NO3-) and see if you can spot the function of the x, which in this case is either an implied 1, an overtly stated 2 or 3. Can you tell me why the one is implied and for what form of nitrogen and oxide?
This estimate by Otto et al. (2010) is staggering. It dwarfs what the curing industry can produce. It comprehensively obliterates the notion that nitrogen or nitric oxide, or even nitrite for that matter, are evil chemical species which is made by humans and added to meat which will, so it is reported, do harm to the human body.
Otto et al. (010) and many others show conclusively that nitrate and nitric oxide are pervasive on planet Earth. Nitrite is far less prevalent than nitrate. Nitrite is highly reactive and does not stay in this state very long (similar to nitric oxide). It forms a salt such as sodium nitrate, which is more stable and is naturally found in some vegetables and meat, but nitrites often occur in vegetables. Humans make most current sodium nitrites in dietary sources. Nitric Oxide is also “fleeting”, a gas that quickly reacts to become another species.
Want to know more:
“Nitrogen is an essential element for all forms of life and is the structural component of amino acids from which animal and human tissues, enzymes, and many hormones are made. For plant growth, available (fixed) nitrogen is usually the limiting nutrient in natural systems. Nitrogen chemistry and overall cycling in the global environment are quite complex due to the number of oxidation states. Nitrogen itself has five valence electrons and can be found at oxidation states between −3 and +5. Thus, numerous species can form from chemical, biochemical, geochemical, and biogeochemical processes.” (Hanrahan, 2005) Below I list the oxidation state of different nitrogen species (and important chemical data).
Global nitrogen species and selected chemical data by: Hanrahan, 2005.
If you’re interested to learn more, google oxidation states. For those with a lively interest in this, I give the oxidation state of key nitrogen species.
The special Oxidation States of Nitrogen
|+5||NO3||Nitrate ion, oxidizing agent in acidic solution.|
|+4||NO2||Nitrogen dioxide is a brown gas usually produced by the reaction of concentrated nitric acid with many metals. It dimerizes to form N2O4.|
|+3||NO2||An oxidizing agent usually produces NO(g) or a reducing agent to form the nitrate ion.|
|+2||NO||NH2OH Hydroxylamine, a weak base, can act as either an oxidizing or a reducing agent.|
|+1||N2O||Dinitrogen oxide is also called nitrous oxide or laughing gas.|
|0||N2||In basic solutions and as NH4 agent in aqueous solutions. When ammonia is burned in oxygen, it is oxidized to N2 or NO. The oxidation of ammonium produces nitrogen gas. Salts usually.|
|-1||NH2OH||In basic solutions and as NH4 agent in aqueous solutions. When ammonia is burned in oxygen, it is oxidized to either N2 or NO. The oxidation of ammonium produces nitrogen gas. Salts usually.|
|-2||N2H4||Hydrazine, a colourless liquid, is a weak base. Used as rocket fuel. It is disproportionate to N2 and NH3.|
|-3||NH3||In basic solutions and as NH4 agent in aqueous solutions. When ammonia is burned in the presence of oxygen, it is oxidized to either N2 or NO. The oxidation of ammonium produces nitrogen gas. Salts usually.|
Demonstrating Oxidation and Reduction
Let’s illustrate this with a helpful diagram that illustrates both oxidation and reduction of nitrate found in beetroot.
Nitrate–nitrite–nitric oxide pathway. Adapted from Niayakiru et al., 2020 by Milton-Laskibar (2021).
In the illustration above, beetroot contains nitrate (NOOO). Nitrate loses an oxygen atom, and nitrite (NOO) is created. This is done through bacteria. It loses another oxygen atom, and nitric oxide (NO) is formed. These are examples of reduction reactions or losing-an-oxygen-atom reactions. In our current survey, nitric oxide (NO) can react with a heam protein to cure the meat.
Nitric oxide (NO) can gain an oxygen atom to create nitrite (NOO), and nitrite can gain an oxygen atom to create nitrate (NOOO). There is another mechanism whereby nitric oxide (NO) gains two oxygen atoms at once, and nitrate (NOOO) is formed directly, skipping the formation of nitrite (NOO) altogether. These are all examples of oxidation reactions or gaining-an-oxygen-atom reactions.
I add another graph to explain the various ways that oxidation and reduction take place of nitrate, nitrite and nitric oxide.
Meat curing is no longer the only industry to recognise the importance of nitric oxide. The molecule vilified for hundreds of years as purportedly bad for us possesses some remarkable qualities that recently became the intense subject of scientific investigation. Without it, life is not possible, and few people know about it because it has only been discovered as late as the 1980s and 1990s.
Want to know more:
Nitric oxide turns out to be an extremely important molecule.
The Biologically Essential Molecule, Nitric Oxide; Reactive Oxygen Species (ROS) and Reactive Nitrogen Species (RNS)
Years ago, before the importance of nitric oxide was appreciated, consumers looked upon the fact that nitrite (which is very reactive and much more poisonous than nitrate) is used in food with great scepticism. They failed to understand that in nature N (nitrogen) easily and often becomes NO (nitric oxide), NOO (nitrite) or NOOO (nitrate or saltpetre). Also, NOOO (nitrate or saltpetre) often and easily becomes NOO (nitrite) and NO (nitric oxide). Where you find NO, chances are that you will also find NOO and NOOO. Likewise, where you find NOO, you will find NO and NOOO. This is a normal part of the functioning of the human body.
The fact that nitrite is poisonous must be qualified by the statement that nitrite is poisonous under certain conditions. What exactly those conditions are will become a major focus of our study, but simply to say that because something is poisonous under specific conditions, that it is dangerous to include it in food is itself a false assertion.
During this work, I will introduce a very important comparison namely between Oxygen and Nitrogen. Oxygen is like nitrogen in that under certain conditions it is toxic and can lead to death. In fact, it can be stated that ANY cell with a nucleus, as a normal process of the metabolism of the cell, generates both reactive species of oxygen and nitrogen. (Griendling, 2016)
We understand that even oxygen has unintended negative consequences such as ageing us and causing the ultimate demise of the body despite the fact that we recognise it as foundational to life on earth. The same two-edged sword experience is what we encounter in the discipline of curing and it is extremely important to understand it and responsibly ensure that no negative environment exists that may cause the nitrogen species to be harmful to humans in any shape or form.
The facts so far are crystal clear. Nitric Oxide (NO), the curing molecule, as its cousins of nitrate or saltpetre (NOOO) and nitrite (NOO) are essential to human and animal life and the functioning of our bodies. Nitrogen is probably no more or less dangerous than oxygen.
It’s Present in our Bodies!
Green et al. (1982) gave us these interesting results of nitrate and nitrite found in our urine, saliva, plasma, gastric juices and milk, which points to the fact that these compounds are ever-present in the body. It is part and parcel of human physiology!
When discussing nitric oxide, which we have seen as an essential part of our biology, or whether we are talking about nitrate or even nitrite, the first thing to grasp is that these molecules are naturally part of the human body and, as you can see from the table above, they are found in our saliva and our gastric juices. There are other places they are also found on the human body, but we will get to that later. A blanket statement such as that nitrite is terrible for us we can unequivocally call incorrect information!
The curing molecule is Nitric Oxide. There are different ways to produce nitric oxide. One is to start with the more stable nitrogen salt, saltpetre or nitrate (NOOO). Bacteria use nitrate or saltpetre in respiration without air, creating nitrite (NOO). Nitrite comes into contact with chemical elements, facilitating the loss of another oxygen atom, and bringing nitric oxide, which reacts with the protein. This reaction presents itself to us as creating a pinkish/ reddish colour. Nitric Oxide, an essential and versatile molecule, is produced in the human body through a chemical reaction with the amino acid L-arginine. This same reaction is also mediated through bacteria added directly to the meat, and fermentation becomes a very productive method to cure meat without using sodium nitrate or nitrate. So, nitric oxide comes to us through that which our bodies produce naturally or through our diet when we ingest either nitric oxide, nitrates or nitrites.
The reactions we looked at are beautiful to many and essential to understand and appreciate this work. It is the story of bacon. Some call it the story of nitrogen, while others call it the nitric oxide story. In my view, it is all these and much more. It is the story of life and the art of living it!
(c) eben van tonder
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