Food Texture & Rheology

Creating, maintaining and improving food texture is a tall order, as it has a direct impact on its sensory and processing properties.

Traditionally, food structure and texture was improved using ingredients such as emulsifiers andthickeners, e.g. gelatine. However, gelatine is not widely accepted by consumers and the food industry is seeking technologies to replace it. One approach is the use of enzymes.

Certain enzymes are natural modifiers of food texture. These so-called "network-forming" or "cross-linking" enzymes bind the biopolymers in a food together. This reaction, which can occur between proteins, carbohydrates or between proteins and carbohydrates, can improve the texture and mouth-feel of foods. At the moment there is only a limited selection of such enzymes available on the market - microbial transglutaminase is the one most widely used for enhancing bread volume and improving the texture of yoghurt, ice cream, tofu and cheese.

We are looking for new enzymes to modify the structure and texture of cereal-based foods. Increased interest in the benefits of whole grain products and in the addition of high fibre ingredients to foods creates a need for more cereal-based products.

However, consumers, particularly in Ireland, find it difficult to eat whole grain products because of their flavour and texture. In addition, many cereal products are currently"baked-off" from frozen doughs or part-baked products, and these do not compare favourably to products baked from fresh doughs. Thus the development of new enzymatic technologies to improve the texture, quality and nutritional value of these cereal products is the main aim.

The isolation of new network-forming enzymes from selected bacteria and fungi and characterise their specific modes of action at a molecular level. We will compare the enzymes to other commercially available enzymes and assess their interactions with cereal proteins. The abilities of the enzymes to improve the texture, quality and nutritional value of high fibre-, frozen- and part-baked cereal products will be determined.

We believe that the enzyme activities may also be applicable to other food products, such as meat, dairy, seafood, soybean and tofu.