Swallow This (24 page)

It might strike you that there could conceivably be an important qualitative difference between enzymes that occur naturally, such as those found in human saliva, or in our guts, and those that are made commercially in a factory. These man-made enzyme preparations are used out of their original contexts to drive chemical reactions. Indeed, the processes used to extract and isolate enzymes for commercial use increases their effect. The European Food Information Council explains the potency of these factory-made enzyme products: ‘Purified enzymes do not lose their properties, on the contrary, these ‘cell-free’ preparations work even more efficiently.’

The enzymes used in food processing are obtained in very particular ways. Many of them are now developed using genetic modification (GM) techniques. Genetic engineering is bringing new enzymes to market all the time, as the European Commission explains:

Due to new technologies, new enzymes not accessible before can be cloned into and produced from a well-known host organism. Thereby, enzymes from almost any source in nature become accessible, including enzymes exhibiting unusual properties, such as extreme thermostability [stability in heat].

Ultimately, the European Commission points out, new technologies such as GM ‘might lead to enzymes not present in nature so far’. Depending on your philosophical approach to food technology, this might, or might not, sound like the plot line of a sci-fi horror story. Already, some of the most common enzymes in our food are GM. Their uses include catalase (for mayonnaise), chymosin (for cheese-making), beta-glucanase (in brewing), xylanase (in baking) and lipase (in oils). More and more commercial enzymes are made by GM methods these days, because genetic engineering makes it easier to produce them on an industrial scale.

Yet there is widespread ignorance that GM enzymes are used at all. If a manufacturer were to include a GM ingredient in a food or drink, under European law it would have to be labelled as such. The reason only a handful of foods in the UK contain GM ingredients is because when people see GM on the ingredients listing, they don’t want to buy the product. But because GM enzymes don’t need to be declared, citizens are not given a similar opportunity to reject them.

GM or otherwise, the enzymes used to make food and drink are manufactured from microorganisms, animal organs, and material such as fungi. For instance lipase, an enzyme used to make cheese, bread, dried egg white and protein powders, can be made from animal pancreatic tissue, certain types of Aspergillus mould, or the stomach tissue of calves, kids or lambs. Asparaginase, used in the manufacture of potato chips, crisps, biscuits, crackers and breakfast cereal, is made from
Escherichia coli
, a bacterium better known for being found in the lower intestine of warm-blooded organisms. As Andrew Whitley, Britain’s foremost authority on artisan baking, puts it:

For the food enzyme industry, all of nature is a chemistry set. No organisms are too exotic or repulsive to be investigated for possible active agents.

The catholic collection of substances from which commercial enzymes may be harvested should clearly raise ethical issues. Observant Muslims, Jews and vegans would be horrified to learn, for instance, that the phospholipase used to make their bread was once derived from pig’s pancreas. They need never know, however, because neither the presence of enzymes, nor their source material, need be disclosed.

Once the raw materials are sourced, how are commercial enzymes made? The production involves large-scale fermentation in tanks with capacities of up to 150,000 litres. The contents are referred to in the enzyme business as a ‘broth’. But what is in the recipe? The European Commission observes: ‘Details of components used in industrial-scale fermentation broths for enzyme production are not readily obtained. Not surprisingly, as manufacturers do not wish to reveal information that may be of technical or commercial value to their competitors.’ As for ordinary people, if the regulators are struggling, we haven’t a hope in hell of discovering what went into the enzyme soup. Likely ingredients, however, are waste materials and by-products from the food and agricultural industries, materials as diverse as sugars, sulphite liquid from cellulose production plants, hydrolysed [chemically broken down] wood and starch, fruit juices, potatoes, phosphates, soya meal, dairy, meat and vegetable proteins, derivatives of ammonia, cotton seed, corn-steeping liquid and fish meal. Usually, the raw materials are dissolved or suspended in water, and heated. The enzymes are secreted into the fermented broth.

From the broth stage, the disrupted cells go through further purification steps. The European Commission describes these as follows in its usual all-embracing, comprehensive manner: ‘A variety of chemical, mechanical and thermal [heat] techniques (concentration, precipitation, extraction, centrifugation, filtration, chromatography).’ The resulting enzyme concentrate is then sold to food and drink companies in various forms – liquids, slurries, granules and powders – depending on what is required, preparations that contain additives to stabilise the enzyme activity and act as preservatives.

Need the soupy, hazy pedigree of the enzymes used to make our food and drink cause us any concern? The enzyme industry would argue that we should continue to enjoy the fruits of enzyme technology without a care in the world. But how much confidence should that give us? Bear in mind the cautionary tale of azodicarbonamide and potassium bromate. For decades, bakers were shovelling these chemical additives into their products, on the basis that they had been granted Generally Regarded As Safe (GRAS) status from regulators. Belatedly, European regulators got round to banning them when the scientific case against them became too glaring to ignore. The former was linked to respiratory problems, allergies and asthma; the latter is thought to be carcinogenic. Both of these have been replaced by – guess what? – supposedly safer enzymes. Safe for how long? As artisan baking expert Andrew Whitley wryly observes, ‘safety assurance has a short shelf life’.

Can we trust that factory-made enzymes are safe? The enzyme industry’s tight-lipped lack of transparency doesn’t exactly build confidence. When the European Commission asked the Austrian Federal Environment Agency to assemble a collection of information on enzymes, the research team made a point of noting tactfully in its final report the lack of co-operation it had received from enzyme companies:

The project team explicitly acknowledges the efforts made by some individual representatives of industry to provide information, however, also regrets not having received all data requested from industry.

The team notes how initially, ‘co-operation with industry was very promising’ but ultimately, even after giving the industry more time to supply data that would answer its questions, ‘these data were not provided by industry’. So the project team had to base its conclusions mainly on relatively limited data available from other sources. On key issues, such as whether genetic engineering has different impacts on the properties of enzymes, the team pointed out that available data sources were ‘very narrow’.

It is well known that enzymes can trigger health problems in people. Biological ‘bio’ washing powders, for example, can cause skin irritation. Itchy skin is relatively trivial, but as potential allergens, enzymes can have more dramatic effects if inhaled as a dust. Enzymes are a well-documented occupational hazard for those who work in industrial bakeries; workers in such environments are usually screened for allergies and respiratory problems, and having passed these checks, are required to wear protective clothing and impervious gauntlet gloves. Once an individual has developed an immune response to the enzyme, re-exposure produces increasingly severe responses that can be dangerous or even fatal. What begins as a runny nose, or soreness of the fingertips, can develop into breathing difficulties and, in rare cases, severe anaphylactic shock, which can prove fatal. This is why dry, dusty enzyme preparations are being replaced by liquid or granular ones where the enzymes are said to be ‘immobilised’. Even so, enzyme companies usually recommend to food and drink manufacturers that employees working with liquid enzymes use eye protection to avoid splashes.

What effects might enzymes have on people who eat and drink products made with them? Potential impacts on the health of consumers of such products, as well as the people who make them, cannot be ruled out. European Commission researchers point out that although there is at present no evidence of reactions to eating enzymes in food, in theory, such sensitisation could occur. What’s more, many enzymes have been specifically designed to remain highly stable during the heat and stress of food and drink production processes, which means that they ‘could more easily pass through the intestine without being fully degraded or denatured’. One such example is fungal alpha-amylase: a study has found that 20 per cent of its allergenicity can survive in the crusts of bread. Another example is transglutaminase, which is used in bread and pastries, such as croissants, to make the dough more elastic, and also to bond low-quality meat products. One group of researchers has found that it can generate the epitope [part of molecule] responsible for coeliac disease. Proteases, a class of enzymes that makes particularly effective detergent, are commonly used in industrial baking and for meat tenderising. These are the most likely to cause allergies and sensitivities because they have the easiest access to the bloodstream through soft tissues.

It is also theoretically possible that allergenic enzymes, even if not present in the final product, could contaminate the factories where they are used. The vast majority of product recalls that food manufacturers are forced to make concern conventional allergens, such as nuts and soya, which have lingered on in the wrong place at the wrong time. Even with the most scrupulous manufacturing precautions, allergens have a habit of turning up like the proverbial bad penny, because they are difficult to control in an industrial plant environment.

Allergies apart, no enzyme has yet been shown to be toxic, mutagenic or carcinogenic, but it is accepted that residual contaminants, derived from the enzyme source itself, or produced during processing, such as mycotoxins and aflatoxins, could be a health hazard. In the USA, enzymes must have Generally Regarded As Safe (GRAS) status, for what that’s worth. In the UK, enzymes used in food are classed as ‘substances that the available evidence suggests are acceptable for use in food’. Note that mealy-mouthed, damage-limiting, covering-my-back phrase ‘available evidence suggests’. As we know from the experience of the team tasked by the European Commission with collecting data on enzymes, not enough information is available to draw deeply informed conclusions. It is almost as if regulators have been unable to keep up with the speed at which enzymes are being developed, or form a full picture of their long-term implications.

For legislative purposes, commercial enzymes are treated as ‘natural’. Any testing that has taken place is narrow and restrictive, looking at each enzyme in isolation with an obstinate tunnel vision. No serious attention has been given to the fact that enzymes, most notably in baking, are often used in compound mixes of up to five at a time, along with other chemical additives, and coyly named as ‘improvers’. What might the cocktail effect of such enzyme and chemical mixes be? How might they multiply the allergen and toxin risk? No regulatory body appears to have given this any serious consideration.

But why should this cause us a minute’s concern? Speaking for enzyme companies, the European Food Information Council argues that ‘the concept of acceptable risk is intrinsic to the notion of pushing back the frontiers [of science]’. Of course, the issue for most people is, ‘Do I and my family really want to be part of a human experiment at the cutting edge of enzyme technology?’ Don’t spend too long thinking about that question. You aren’t being consulted on the question, and so, to all intents and purposes, your opinion doesn’t matter.

13

Old

The word ‘fresh’ can be relied upon to conjure up positive images. Used honestly and accurately, it is an epithet that fits the perky greenness of recently harvested vegetables, a handful of cut herbs from the garden, or fruit just picked in the orchard. It conveys the sense of food prepared and consumed the same day, without any refrigeration: newly fired pizza, a Sunday dinner cooked in the late afternoon and eaten in the early evening, a just-baked scone, a stir-fry hot from the wok. At a stretch, fresh can describe ingredients that have been lightly processed: a kipper still warm from the smokehouse, even a pat of newly churned butter. Yet the word ‘fresh’ is used by food retailers and manufacturers in an entirely different way: to refer to products that have undergone some treatment to prolong their edible life.

If you stop to think about it, this usage is a contradiction in terms. ‘Fresh’ is, or ought to be, time sensitive. By its very nature, freshness is a fleeting and finite state, a concept located at the top end of a timescale that inevitably leads downwards to decomposition and decay. For food manufacturers and retailers, however, the word ‘fresh’ has assumed an obligingly elastic meaning. They sell us chilled food and drink under the banner of fresh – ready meals, dips, salads, sandwiches, fried fish, soups, smoothies, cooked meats, spreads, cook-in sauces, pizza, desserts, chicken nuggets – and give it a use-by date that leads us to believe that they will stay like this for days at a time.

By rights, the confused notion of fresh food that lasts some considerable time should be oxymoronic, but in food manufacture, freshness has become synonymous with a more truthful, accurate term: ‘shelf-life extension’. A number of more and less sophisticated technologies have been developed with the sole purpose of making food last longer. As a consequence old, tired food masquerading as fresh has become a big part of our diet.

Over 80 additives that have a preservative effect are approved in Europe. Each has an E number, the tell-tale badge that indicates to consumers they are man-made. The chemical industry tries doggedly to convince us that any instinctive hostility to such preservatives merely reflects the scientific illiteracy of the general public. The Food Additives and Ingredients Association (FAIA,
http://www.faia.org.uk
), a body representing chemical companies that make these additives, attempts to relax us by telling us that many of them are just ‘synthetic copies of the natural [preservative] products that are present in nature’. If we only understood more about them, we wouldn’t be so reluctant to consume them, we’re told. So what are they?