Authors: Joanna Blythman
In so many ways, starch is a never-ending source of inspiration to food manufacturers. Classless starch finds a role in every echelon of food processing, everything from stiffening an up-market reduced fat crème fraiche, to putting a shine on a down-market gravy. Its facelessness allows it to go everywhere and anywhere. Using starch, food manufacturers can even concoct products that defy the fundamental principles of food preparation. The example of mayonnaise comes to mind. In its traditional incarnation, the recipe requires only two ingredients: oil and egg yolk. A touch of salt, vinegar or lemon juice can be added, but they are not essential; oil and egg yolk whisked into a natural emulsion is, in itself, a pleasurable thing to eat. Here, for comparison, are the ingredients of an Asda Extra Light Mayonnaise:
Water, Spirit Vinegar, Sugar, Modified Maize Starch, Vegetable Oil (5.5%), Pasteurised Salted Free Range Egg Yolk (4.5%) [Pasteurised Free Range Egg Yolk, Salt], Dijon Mustard [Water, Mustard Seeds, Spirit Vinegar, Salt, Preservative (Potassium Metabisulphite), Acidity Regulator (Citric Acid)], Salt, Maltodextrin, Acidity Regulator (Lactic Acid), Colour (Titanium Dioxide), Stabiliser (Guar Gum), Preservative (Potassium Sorbate), Antioxidant (Calcium Disodium Ethylene)]
Instead of two ingredients, you have twenty. Sugar, salt and vinegar cover in taste terms for the paucity of egg and the generous volume of water. A ‘light’, low-fat tag dangles the promise of improved health, while the choice of feel-good free-range egg strategically draws attention away from feel-bad, rough and redneck spirit vinegar, and a whole gang of additives. This and many other clever concoctions are only made possible by the uniting presence of starch. No wonder food manufacturers are glued to the stuff.
12
The use of chemicals in food processing doesn’t go down well with the general public. Manufacturers know this, hence the general food industry shift to ‘clean label’ products that appear to contain only natural, recognisable ingredients you would find in a domestic larder.
The odd bit of information that comes our way about less visible chemical techniques used behind the scenes of food processing – and it is the very odd bit because such information needn’t be disclosed on product labels – is often disturbing. Who wants to think that the oil they are cooking with was stripped from seeds using the toxic solvent, hexane, or degummed using caustic soda? Who licks their lips when they learn that the centre of their chocolate cherry stays liquid because the sugar was processed using corrosive hydrochloric acid? And what should we do with such knowledge? Stop eating processed food entirely?
Most of us crave a less radical solution. Can’t scientists come up with a more benign way to give us the range of processed foods that we have become accustomed to? A hi-tech magic bullet that would take factory food into a new, improved, more civilised era, sweeping away all the persistent health and environmental concerns that attach to old, unpopular chemical treatments?
If you believe certain not disinterested voices in the food industry, such a solution already exists. Enzymes, we are told, are one of the leading ‘green chemistry’ technologies, designed to reduce or eliminate generations of hazardous substances that have now fallen from grace. According to the European Food Information Council, a body ‘supported by companies of the European food and drinks industries’ to convey science-based information to the public’ – in other words, an industry lobby group – ‘enzymes make clean, green food’.
If your grasp of chemistry is shaky, the word enzyme might cause you to stumble. In simple terms, enzymes are proteins that occur naturally in the cells of plants, animals and microorganisms. They are essential to the metabolism of all living things. The human body, for example, uses enzymes to carry out many biochemical processes, such as digestion. The names of most, but not all, enzymes end in ‘ase’, as in amylase, protease.
In commercial terms, enzymes are best known for their industrial applications. They are used, for example, to make laundry and dishwashing detergents, for stone-washing jeans, in pulp and paper manufacture, for leather de-hairing and tanning, in de-sizing of textiles and de-inking paper, to make contact lens cleaner, and for the degreasing of cattle hides. But don’t let any of that put you off enzymes in your food and drink. Here, the Enzyme Technical Association, a trade association of companies that make and market enzyme products, explains the ‘enzyme advantage’:
The use of enzymes frequently results in many benefits that cannot be obtained with traditional chemical treatment. These often include higher product quality and lower manufacturing cost, less waste and reduced energy consumption. More traditional chemical treatments are generally nonspecific, not always easily controlled, and may create harsh conditions. Often they produce undesirable side effects and/or waste disposal problems.
What’s not to like? Food manufacturers are certainly convinced that enzymes are the way forward. They have embraced enzyme technology to such an extent that nowadays, nearly all commercially prepared foods contain at least one ingredient that has been made with them. Enzymes are already widely used in the production of sugar syrups, starches, artificial sweeteners, bakery products, soft and alcoholic drinks, instant breakfast cereals, cereal-based baby foods, cheese, dairy and egg products (such as dried egg powder), fruit juice, instant noodles, vegetable oil, confectionery, meat tenderising brines, flavourings and instant coffee. New trademarked enzyme products are coming onto the market all the time.
Food manufacturers use enzymes as catalysts, triggers to speed up chemical reactions that would otherwise proceed very slowly, or in some cases, not happen at all. There are millions of enzymes in nature, and they act quickly: some of them perform their task up to five million times a minute. So enzymes work all sorts of magic and make many products feasible that would otherwise never pass Go. Enzymes, in the words of companies active in the field, do ‘the work of a small factory’.
By using certain amylases during fermentation, for instance, brewers can make low calorie beers. Most of the controversial sweetener, high fructose corn syrup (HFCS), which finds its way into soft drinks, sweets, baking, jams and jellies and many other foods, is now produced using enzymes, such as alpha-amylase. To ensure that bakery goods, such as breakfast bars, and sweets maintain desirably soft, chewy centres for weeks at a time when otherwise they would harden, manufacturers use invertase. Amyloglucosidase will give industrial bread an evenly brown crust, while maltogenic amylase will delay the rate at which it stales. Industrial baking plants often use a mix of enzymes – typically three to five at a time – in most or all of their products, on a daily basis. A dash of pectin methylesterase will make your frozen raspberries and green beans firmer.
Many of the flavours we come across in familiar cheeses – Cheddar, mozzarella, Parmesan, Emmental, cream cheese – are not due to the intrinsic taste of local milk, or to patient maturation and flavour development, but to the action of man-made enzymes called lipases that are added during the ripening stage of production. In order to make a juice that is crystal clear rather than cloudy, manufacturers will process the juice with pectinase. This enzyme is also used to treat citrus fruits before they are made into marmalade, or candied, and to extract the very last little bit of juice from grapes by breaking down their cell walls before they are made into wine. Pectinase firms up fruits and vegetables so that they retain their shape better during processing. If, for instance, you have ever eaten one of those yogurts that has a layer of fruit at the bottom with whole, more intact strawberries rather than just a purée, those berries could have been treated with pectinase. To strengthen them before the processing onslaught, the strawberries, fresh or frozen, could have been incubated in a solution of calcium chloride, a salt more commonly used for ice and dust control on roads, to which the enzyme has been added. One company that makes such an enzyme product says that it increases the firmness of the fruit or vegetable, improves what manufacturers call ‘fruit integrity’ during processing, and extends the shelf life of soft fruit. Fresh peeled citrus fruit segments destined for ready-to-eat fruit salads are often processed with pectinase to give them a better texture and appearance.
If some of these uses of enzymes sound like more of a boon to the manufacturers than the consumer, rest assured that the same can be said for many enzyme products. For instance, one type of maltogenic amylase for bakery is marketed as VERON® xTender – ‘The Extra Tender Shelf-life Extender’, which sums up all you really need to know about its purpose. A protease enzyme, Maxipro HSP, won the coveted prize for the Savoury/Meat Innovation of the Year Award at the Food Ingredients Europe Excellence Awards, for its ability to extract protein from animal by-products, such as blood. DSM, the company that makes it, explains:
With Maxipro HSP, our radically new enzyme solution, the industry is able to capture the nutritional and commercial value of blood side streams by recovering all the available protein, enabling a more sustainable production of processed meat products. MaxiPro HSP has proven to be particularly efficient in removing the heme part from the blood protein hemoglobin. This heme group is responsible for the red-to-dark brown color and the iron taste, making hemoglobin difficult to apply in high end meat applications … The result is a more effective decolorisation process that preserves the valuable functionalities of the globin protein, while selectively removing the strong taste and dark odor of the heme.
You can see why this enzyme product is feted by manufacturers of low-grade meat products. The global meat industry is ever keen to maximise the potential of its by-products, and DSM says that Maxipro HSP has ‘excellent gelation and waterbinding properties’. But it’s a rare consumer who really relishes the thought of enzyme-treated blood in their bangers.
Subtilisin is another enzyme employed to reinvent red blood cells as a usable ingredient. It produces a purified product that ‘may be spray-dried and is used in cured meats, sausages and luncheon meats’.
Enzymes reach right down the food chain to the farm and the slaughterhouse. Many animal feedstuffs are treated with phytases, carbohydrases and proteases. One feed enzymes company commentator explains their purpose:
Animal feed is the largest cost item in livestock and poultry production, accounting for 60–70 per cent of total expenses. To save on costs, many producers supplement feed with enzyme additives, which enable them to produce more meat per animal or to produce the same amount of meat cheaper and faster.
The phrase ‘cheaper and faster’ is always music to the ears of producers of intensively reared meat.
Enzymes cut farmers’ costs because they can use less protein in the feed, and protein is expensive to buy. One enzyme company boasts that chickens fed a two per cent lower protein diet supplemented with a protease enzyme grew as large as birds that were fed a standard diet containing more protein. Enzymes also improve the profile of cheaper animal feeds, such as feather meal. A by-product of processing poultry, it is made by processing feathers, using heat and pressure, grinding them, and drying them. This type of feed is used in fish farming as a cheap, low-rent alternative to fish meal. But it does have an image problem, as BioResource International, a feed enzyme company explains:
It is widely known that feather meal – as an alternative to expensive fish meal – is one way for animal producers to diversify their feed protein sources. However, feather meal use is limited by the perception that it is poorly digested, not as balanced, and is of poor quality. True. True. And true. But that was then. Today, BRI’s Valkerase® can take your underperforming, poorly digested feather meal and turn it into a more optimised source of digestible proteins and peptides that rivals that of other protein sources.
Mmmm, anyone fancy a fillet of farmed salmon or rainbow trout?
At the abattoir, proteases do the job of recovering protein from the skeletons of animals and fish after butchering or filleting, as one company explains: ‘Material recovered using proteases can be produced from coarse and fine scrap-bone residues from the mechanical fleshing of beef, pig, turkey, or chicken bones.’ Using such enzymes, a further five per cent of the adhering flesh can be removed – sucked, scraped or otherwise mechanically extracted – from the bones or cartilage. The process for extracting every last little bit of protein isn’t one for faint hearts. The carcasses are mashed and incubated in hot water with the enzymes for several hours. ‘The meat slurry produced’, one authority explains, ‘is used in canned meats and soups’. Waste not, want not.
There are other more direct ways to use enzymes for meat. Older, lower value animals, such as unproductive dairy cows, whose less than prime flesh would otherwise be tough, can be injected with a type of papain enzyme directly into the jugular vein shortly before slaughter; this has the effect of tenderising their meat.
Over 150 enzymes are now used by the food and drink industry. News to you? And to most people. As the Enzyme Technical Association reflects, ‘the importance of enzymes in everyday life is one of today’s best-kept secrets’. But why don’t we know more about their extensive use? After all, some enzymes, notably those used in starch processing and high-fructose syrup manufacture, are now traded as commodity products on the world’s markets, so global financial markets are fully aware of them, even if most citizens are in the dark about their very existence.
The simple answer to this question is that because enzymes are so powerful and effective in their action, the amount needed to accomplish the desired effect is small, usually 0.1 per cent, or less, of a product’s overall composition. It is assumed that enzymes used in food and drink manufacture are generally deactivated or used up during processing, and therefore not present in the final food product. Enzyme companies successfully lobbied for a regulatory distinction between what food is produced
from
and what it is produced
with
, and regulators agreed to treat enzymes as processing aids: ‘they shall be present in the food in the form of a residue, if at all, and shall have no technological effect on the finished product’. Under European law, processing aids don’t need to be labelled. Fresh efforts by the European Commission to revisit the classification of enzymes are under way, but as one industry consultant points out: ‘The industry will kick and scream if that vast majority of enzymes are not in fact regulated as processing aids.’ For the time being, unless enzymes are used as additives – and hardly any are – you won’t see them on the product label.