KUALA LUMPUR (THE STAR / ANN) - Some biochemists might joke that it is a crying shame that most people are not aware of E1105 (lysozyme) – for this enzyme additive is found in human tears and other body fluids, such as saliva, amniotic fluid, etc.
Lysozyme has an interesting history, being originally identified by Alexander Fleming in 1922 as the reason why egg whites are generally antibacterial. It is also the first enzyme to be detected which contains all 20 of the common amino acids; the study of lysozyme led to the eventual understanding of how enzymes work in the body. In food, E1105’s primary function is to act as an antimicrobial preservative, particularly against early bacterial biofilms in cheeses. If you are interested in how and why biofilms develop, refer to tinyurl.com/star2-biofilm.
If you like gooey confections, oozing with liquid caramel or syrups, then you have to thank E1103 (invertase). This is an enzyme which inverts sugar (or sucrose) into a syrupy blend of glucose and fructose, which oddly actually tastes significantly sweeter than sugar itself – and with a pleasantly dense, moist texture. The inverted sugar is then mixed with flavourings and used for your mucilaginous candy bars.
And if foods have too many calories, there are additives to moderate that too, such as E1200 (polydextrose), a synthetic low-calorie polymer of glucose used to replace sugar, starch and fats in cakes, confections, desserts, cereals, beverages, salad dressings, etc. It is classed as a soluble fibre and used mostly in diet foods or meals for diabetics. E1200 is derived from the interaction of glucose with two other natural additives, E330 (citric acid) and E420 (sorbitol) – and adding E1200 to food automatically “converts” low fibre content food into high fibre food. However, one commonly-observed and problematic side effect is excessive bowel laxation, so much so that the FDA requires a warning on the food label if any portion of food contains more than 15g of polydextrose. Possibly, actor Jack Nicholson had consumed too much E1200 when he was famously quoted as saying that one can never trust a fart.
Both E1201 (polyvinylpyrrolidone) and E1202 (polyvinylpolypyrrolidone) sound more like rocket fuels than food additives, but these synthetic compounds are used quite commonly in food processing. E1201 is used as a stabiliser and water-soluble dispersant for other additives, such as flavourings. E1202 is a cross-linked version of E1201, and is not water soluble but is capable of absorbing water and swelling very rapidly – this makes it a good disintegrant (dispersal agent) for medication pills. E1202 is also used for fining (filtering) beers and wines, as it binds well with polyphenols and tannins, precipitating these impurities and thus clarifying the alcoholic liquids.
Despite its chemical name, E1203 (polyvinyl alcohol) is more likely to be encountered in your breakfast bowl than at your local rave club. It is one of the compounds used to glaze the outside of dried fruits in muesli and other breakfast cereals to prevent dehydration. Other films and glazing agents reside in the range between E1204 (pullulan) and E1209 (polyvinyl alcohol-polyethylene glycol-graft-co-polymer).
The next range between E1404 (oxidised starch) and E1452 (starch aluminium octenyl succinate) are all wheat or corn starch-based additives – they are mainly used as bulking agents, thickeners, stabilisers and anti-caking agents. The last mentioned additive, E1452, is also subject to European Union regulations for contamination by heavy metals.
The final pair of additives to be discussed are E1520 (propan-1,2-diol or propylene glycol) and E1521 (polyethylene glycol). Although both are used in anti-freeze solutions, the similarities end there. E1520 is a major component of the liquids used in e-cigarettes, used to promote the smoothness of ice creams and various dairy foods, and is also a solvent for medications which are insoluble in water.
On the other hand, E1521 is more used as a surfactant (anti-foaming agent) in foods – it is also used as a laxative and in suppositories. Another common use of E1521 is in cosmetics, where it is a flexible thickener, humectant, solvent and moisturiser – it is often labelled as “PEG” followed by a number, which indicates the molecular weight. One cautionary note is that E1521 should not be left to oxidise, as it can react with air to form radicals like peroxides and other unstable compounds. Also there is some tangible risk of contamination by highly carcinogenic impurities such as dioxane or ethylene oxide during the production of E1521 – hence if you really do need to use beauty creams, please get them from responsible cosmetic companies, and keep them well-sealed after use.
Once again, please note that over-ingestion of many additives may lead to possible health hazards and side-effects – and it is simply not possible to cover all potential reactions due to the numbers and combinations of additives. Most food additives are regulated in their use, and therefore should not cause problems when processed foods are consumed in reasonable amounts by healthy humans.
So we have come to the end of the reviews about a few interesting E-number additives – the ones mentioned are just those that caught my eye and there are many more probably just as noteworthy but we just do not have the space to review them all. One thing to note is that although additives are required in the EU to be shown as part of the ingredients list, some additives are still never listed. This is usually because the quantities fall below the thresholds which require listing or they are listed under some generic group name such as “liquid smoke”, even though liquid smoke can contain hundreds of different polycyclic aromatic hydrocarbons. And as mentioned, not all additives have E-numbers – often these are then presented as just their common names or chemical names.
Sometimes there is also some duplicity in the listing of ingredients – quite often sugars are reported separately as various different compounds such as sucrose, glucose, fructose, dextrose, corn syrup, HFCS, et cetera. This is possibly a somewhat vain attempt to hide the unhealthy over-sugary nature of the food item.
What could be in your daily loaf
It is quite interesting what a closer examination of something as mundane as a sandwich loaf can reveal – especially about a range of additives which legally need not be mentioned.
Almost all commercial white bread is made from artificially bleached white flour – in the past, bleaching agents used were chlorine gas and chlorine dioxide, but the use of these chemicals is no longer permitted in the EU – although they are still commonly used in other countries, including in the United States. As the residual chlorine is so small, it would not normally be listed as an ingredient – even though the EU still considers it a potential carcinogenic risk.
What is also not listed are the industrially-produced enzymes used in baking commercial breads. A selection of enzymes used include amylase, maltogenic alpha-amylases, glucose oxidase, lipase, lipoxygenase, xylanase, protease and asparginase – the range of enzymes used can vary considerably between different baking factories and is usually a closely-guarded secret. Amylase is used to promote fermentation, maltogenic alpha-amylases help to extend the shelf life of bread, asparginase limits the browning of bread – and most of the other enzymes are used to strengthen the gluten in flours, so that bread loaves rise better and more consistently in the oven.
The hidden ingredients
The reason enzymes are not listed as ingredients is because they are considered “processing aids” which are broken down during food processing, and therefore should not be present in the final food product. As such, additives which need to be listed are only those items which are still detectable in the final processed food products – and as enzymes are destroyed by heat, there is no requirement to list them as part of the ingredients.
However, there are concerns that not all enzymes are always destroyed during food processing and there have been calls for enzymes to be included on the ingredients list – because residual unprocessed enzymes can set off allergic reactions. Another reason for concern is that the food industry is creating increasingly complex enzymes and not all of them are tested for potential toxicity issues – and as they do not need to be listed, food regulators may not know what consumers are potentially ingesting. It appears that the only guideline is that enzymes need to be “safe” for human consumption (as they should be destroyed during food processing).
Many industrial enzymes are produced using secretive, specialised, genetically modified (GM) micro-organisms – and they are widely used in many types of foods. For example, cheese is often curdled using enzymes derived from GM organisms – though this is not permitted with organic cheeses, as no artificial enzymes are allowed with produce labelled as organic.
The production of gelatin is often helped by enzymes dissolving proteins on the bones and fruit juices are pressed from softened fruits, their structure weakened by enzymes – then other enzymes are used to clarify the juices before heat treatment is applied to destroy the enzymes.
An interesting use of enzymes is as a food adhesive – for example, transglutaminase is used to cross-link proteins between different types of source proteins, creating smooth homogeneous blends of different animal and plant proteins. This is how those seemingly perfect meat rolls, chicken rolls, low-fat meat proteins, etc can be produced – if you check the ingredients, you will find that many of the low-cost “meat products” have soy and other animal proteins included, and they would not bind together without enzymes like transglutaminase.
GM enzymes are also used to produce the infamous High Fructose Corn Syrup (HFCS), a very cheap sugary substance derived from corn (or maize) and alleged to be one of the root causes of the current worldwide obesity epidemic – this is due to the use of HFCS in so many processed foods and drinks. Cadbury-Schweppes was advertising HFCS as an “all natural” ingredient until legal action in 2006 established that HFCS is an artificial ingredient which does not exist in the natural world. There will be more on this a little later – meanwhile, just as an aside, most of the industrially-produced HFCS is derived from GM corn from the US.
A rather weird use of enzymes is in the peeling of fruits, such as those found in the plastic snack cartons of ready-to-eat fruits you see in supermarkets or on airline food trays. As an example of what happens, the thick skin of oranges are scored and the fruits immersed in a pressurised bath of an enzyme called pectinase – after a couple of hours, the enzyme softens the orange skins so much that they can be peeled off easily and the segments can be separated without damage.
As additives, there appears to be only two enzymes which need to be disclosed, presumably because they are not wholly destroyed during food processing: E1103 (invertase) and E1105 (lysozyme) – both have been discussed earlier.
HFCS Revisited (Again)
Some of you may have heard that the immoderate consumption of HFCS can lead to obesity in humans – a common explanation is that a diet high in fructose has been seemingly linked to leptin resistance, and the end effect is that this causes people to eat more, as the hormone leptin is used as a primary signal to the brain to terminate eating.
The available research findings are actually rather more ambiguous, and somewhat complicated. For one, leptin resistance due to fructose was originally observed in laboratory rodents fed with high doses of HFCS and these rodents ate more, and gained more weight compared to control animals – and developed leptin resistance.
Further studies in humans consuming more reasonable amounts of HFCS produced rather less startling results – and the oft-mentioned notorious link between HFCS and obesity appears to be mainly derived from epidemiological studies which found a strong correlation between the widespread use of HFCS and obesity trends, particularly in the US. But as I often caution, correlation is not always proof of causation – and it may well be that the trend of including huge amounts of all types of sugars and modified starches in modern foods is just as plausible as an explanation.
Regarding leptin resistance, studies have shown that glucose is the sugar that induces the production of leptin – fructose does not induce leptin secretion. Additionally, the hormone ghrelin acts as an appetite stimulant and fructose also appears not to suppress ghrelin as much as glucose either. This can mean that a diet high in fructose can possibly mess around with the normal food signaling mechanisms and induce people to eat more – simply because the hunger hormone (ghrelin) is not turned off and the satiety hormone (leptin) is not turned on.
It may sound odd but HFCS is seldom labelled correctly on the ingredients list – for there are several grades of HFCS. In fact, the term High-Fructose Corn Syrup itself can be sometimes a misnomer as some grades of HFCS actually have less fructose than sugar – normal sugar is called sucrose, which is made up of 50% glucose and 50% fructose. HFCS is normally 24% water and the grades of HFCS are expressed as the percentage of fructose observed after the removal of water – the remainder sugar in HFCS is glucose. So HFCS 42 is 42% fructose and HFCS 90 is 90% fructose after the removal of the water content – the most common grades used are HFCS 42 (food, cereals, baked goods, et cetera) HFCS 55 (soft drinks) and HFCS 65 (other soft drinks). As fructose is about 1.73 times sweeter than sugar (and very much cheaper), food producers tend to load processed foods and drinks with HFCS, both to improve taste, and to mask the taste of other additives.
The next – and final – part discusses some “free” additives that you very probably do not want, an interesting flexible ingredient found in many foods – plus finally, a simple guide to reading the nutrition labels on packaged foods.