A taste for understanding

As consumers become ever more label savvy, demand for foods with fewer ingredients is growing – but how to achieve this whilst keeping food cheap, convenient, and tasty? Aidan Craigwood thinks that to get back to ‘real’ foods we’ll need to use chemistry to coax more properties out of fewer ingredients… 

It seems nearly impossible to make the “right” choice about what to eat nowadays. Changing food trends, conflicting media reports, and ever-evolving official guidance make food decisions confusing at best, and overwhelming at worst.

In response to this complexity, consumers are increasingly demanding foods with “clean” labels, which generally means fewer, simpler, and more familiar ingredients. But we have grown accustomed to the benefits of E-numbers and processing: we still want food to be cheap, convenient, and tasty. How can manufacturers square this circle? Probably the most successful answer has been to make fewer ingredients do more things – to coax, say, whole wheat to deliver the functionality that once came from using a white flour with additives like the delightful-sounding sodium stearoyl lactylate. In some ways, this is about going back to food’s roots: yoghurt’s ingredient line of ‘milk cultures’ only works because those cultures transform milk protein into a thickener, metabolise lactose into an acidifier, and modify fat molecules into preservative compounds.

Whatever the system, food science is making it increasingly possible to produce clean label versions of foods that perform just as well as the original

But whereas traditional foods were discovered by accident, modern formulators can take a more targeted approach. This article will explore how formulators are combining careful processing, an understanding of the detailed chemical composition of foods and fundamental scientific insight to transform labels, with emphasis on innovations in starch, protein and fermented ingredients. Whatever the system, food science is making it increasingly possible to produce clean label versions of foods that perform just as well as the original.

Starch is one of the leading examples of how the marriage of basic materials science and detailed chemical understanding can create a cleaner label. Historically, starch has been given new functionalities via chemical modification, whether by oxidising it with hypochlorite, cross-linking it with phosphates, or tacking on new functional groups like octenyl succinate and hydroxypropyl ether. These treatments are safe, but they’re certainly not label-friendly. As a result, more recent starch innovation has focused on functionalising native starches through heat, moisture, or pH treatments that don’t need to be labelled.

Other tricks to improve the function of starch include using natural enzymes to make changes like debranching of tree-like amylopectin molecules, creating starches that gel quickly and firmly

For instance, steaming starch under controlled conditions can anneal the crystalline junctions that naturally exist between the linear backbones of starch molecules (amylose). A starch treated in this way will have many of the same properties as one that has been chemically cross-linked, absorbing less water when cooked and keeping its integrity when sheared or frozen. Other tricks to improve the function of starch include using natural enzymes to make changes like debranching of tree-like amylopectin molecules, creating starches that gel quickly and firmly. Heating native starch under dry conditions can make the starch granule more amorphous and able to set quickly when reheated in moist conditions, much like chlorinated cake flour¹.

Breeding has provided still more options for formulators, such as naturally high-amylose maize or potato starches with charged side-groups that make them swell quickly in water². Of course, sometimes it’s much cheaper to use modified starches, and there are some effects, like increasing the hydrophobicity of starch, that are very hard to achieve without synthetic modification. But in many cases, careful processing and deliberate selection of the right starch makes it possible to find a clean alternative.

If starch is a good example of how food manufacturers have already succeeded in producing cleaner labels, protein is likely to create many of the successes of the future. To date, innovation around protein has focused largely on increasing protein content, in response to consumer demand for high-protein foods, like Greek yogurt. But other opportunities are on the horizon, especially for plant proteins.

Seeds, legumes, and grains can yield a range of cheap, protein-rich ingredients after processing. Yet flavour and functionality issues have meant these streams are used mainly for animal feed, not as high-value replacements for animal proteins like caseinate or egg white. However, better scientific understanding of the link between proteins’ sequences and possible functions, together with improved ability to fractionate proteins at scale, have helped formulators create plant protein products that are nearly as effective as animal protein ingredients, at lower cost.

Potato protein, for example, consists of two major species – the acidic protein, patatin and a mixed basic fraction. These two groups show nearly opposite responses to salt, pH, and heat treatment³; blended together, they offer acceptable-but-not ideal performance as emulsifiers and thickeners. Yet when separated and used in the correct conditions, they can match more expensive proteins pound for pound. Not bad for an ingredient that was once either thrown away or used for animal feed.

At the same time, swapping out strongly flavoured soya with other proteins like pea isolate has helped to create meat substitutes that are almost unnoticeable in some applications

Better control of processing conditions has also been essential to the success of plant-based products. In particular, the development of extruders designed to operate under relatively low-temperature, high-moisture conditions has helped transform textured vegetable protein from a spongy, niche vegetarian ingredient to a food capable of delivering the soft, but fibrous, mouthfeel normally associated with chicken meat. At the same time, swapping out strongly flavoured soya with other proteins like pea isolate has helped to create meat substitutes that are almost unnoticeable in some applications. There’s a long way to go before these products can truly replace the Christmas turkey, but in many ways they are closer to this goal than so-called “test tube meats” or other high-tech formulations that have yet to be produced at scale.

So far, these examples of clean label innovation have largely focused on substitutions, replacing ingredients with cleaner alternatives one at a time, but in most cases achieving a clean label requires more dramatic changes. One of the most promising methods to eliminate multiple ingredients at once is the careful use of fermentation, or bioprocessing, to produce a range of useful metabolites in a single step that may be label-invisible. For example, fermenting bread dough with particular strains of lactic acid bacteria is usually thought of as a flavour step, to create the tangy taste of sourdough. But these cultures also produce potent antifungal compounds that would be unacceptable to most consumers as additives, from monohydroxylated free fatty acids to phenyllactic acid, various cyclic peptides, and large antimicrobials like nisin⁴.

Similarly, the commercial preservative Verdad uses food-safe bacteria to produce a cocktail of fungus-inhibiting organic acids from sugar solutions. Although fermentation is not a panacea for producing clean label ingredients – it is widely used to create chemical-sounding additives like citric acid or xanthan gum – in this case, the careful choice of bacterial strains and fermentation conditions eliminates the need for extensive purification, allowing the product to be labelled as just cultured sugar⁵. Evolva, a company based on yeast biotechnology, has used fermentation to produce some increasingly sophisticated compounds at low cost. These range from flavours like vanillin through to sugar substitutes like rebaudioside D, one of the naturally sweet molecules in stevia leaves⁶. In principle, there is little to stop innovators from creating cultured replacements for other additives in foods. Some obvious targets include humectants like glycerol and sorbitol, thickeners like gelatine, or even costly ingredients like anthocyanin food colours.

This careful tweaking of food for labelling purposes can seem legalistic, if not even disingenuous

The combination of modern biological screening technology, and the naturally fast generation times of most microbes, makes it possible to develop cultures with novel traits fairly easily, even without genetic modification, and certainly in less time than it takes to breed, prove, and plant out new crop cultivars. This careful tweaking of food for labelling purposes can seem legalistic, if not even disingenuous. But in general, consumers’ desire for cleaner labels has steered food manufacturers in the direction many consumers have asked for: towards less extreme processing conditions, better understanding of the raw materials used, and greater reliance on biology to create changes.

The sheer complexity of food means that scientific analysis and engineering optimisation will have to be part of this journey if we are to make it quickly. Trial and error has helped create many of our favourite foods, even processed ones, but going back to “real” foods will require in-depth understanding of what they really are.

Author: Dr Aidan Craigwood is an innovation consultant and project manager for Innovia Technology, with a specialism in soft matter physics and complex fluids.

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References 1. Thomasson, C.A., Miller, R.A. and Hoseney, R.C., 1995. Replacement of chlorine treatment for cake flour. Cereal chemistry, 72(6), pp.616-620. 2. Karim, A.A., Toon, L.C., Lee, V.P.L., Ong, W.Y., Fazilah, A. and Noda, T., 2007. Effects of phosphorus contents on the gelatinization and retrogradation of potato starch. Journal of food science, 72(2), pp.C132-C138. 3. Ralet, M.C. and Guéguen, J., 2000. Fractionation of potato proteins: solubility, thermal coagulation and emulsifying properties. LWT-Food science and Technology, 33(5), pp.380-387. 4. Leroy, F. and De Vuyst, L., 2004. Lactic acid bacteria as functional starter cultures for the food fermentation industry. Trends in Food Science & Technology, 15(2), pp.67-78. 5. http://www.fda.gov/downloads/Food/IngredientsPackagingLabeling/GRAS/NoticeInventory/ucm264098.pdf 6. US Patent Application No. 2013/0171328