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2.3.3.3.3 Food Structure- ‘Mouth Feel’

Reducing fat, salt, and sugar in processed foods has become a driver in recent years. In some cases the amount of flavour enhancers could be decreased by using nanotechnology, e.g. researchers at Leatherhead Food International are developing nanoparticulate sodium chloride which as a result of its larger surface area, gives the same salt taste, but at a fraction the amount . However, replacement of taste enhancers does not always only affect taste, but also the texture (or 'mouth feel') of food. This is particularly true of low-fat foodstuffs, where the fat is generally replaced by a natural or synthetic polymer, e.g. guar gum or cellulose, to provide a similar mouth feel. However, these do not completely replace the sensation to the consumer and so there is a drive by many different companies to identify better alternatives. Mouth feel is a complex interaction between chemicals within the food, the physical structure of the food and the mouth. Engineering alternatives to the natural textures of food, is therefore a challenging task. Nanostructured components made from natural and synthetic polymers, could be one means by which the missing ingredients are more effectively replaced.

Whey proteins offer one alternative. Much research has gone into exploring ways in which these can be manipulated to form different structures based on solution chemistry and processing conditions . For example, hydrolysates of whey proteins can self-assemble to form nanostructured systems, which can be incorporated in processed food. In addition to altering the structure of food, these can be used to encapsulate nutrients, as described above.

Other alternatives which are being explored include the use of nano-emulsion technologies for the reduction of fat content in foods. Various institutions including Wageningen University, the Food Research Institute (Norwich) and Leatherhead Foods International are researching water-in-oil-in-water nano-emulsions, which produce the same mouth feel as fat droplets within mayonnaise, but have a much lower fat content^54,56.