PHYSICS OF FOODSTUFFS

The aim of this article is to demonstrate that foodstuffs can be usefully and excitingly studied within the framework of physics. Many of the same issues that exercise the mind of researchers in traditional areas of soft condensed matter can be found within these homely materials, issues such as percolation, the nature of the glass transition and mechanisms of phase separation. By applying the conventional tools of the physicist new insights can be obtained into the structures and responses of foodstuffs. In turn these insights may lead to improvements in the overall quality of the food to be consumed-by the knowledge contributing to improvements in processing, texture or storage for instance. The article begins with a brief introduction to the different classes of molecules usually found in food: carbohydrates, lipids and proteins. This is followed by a description of some of the methods frequently used to characterize foods which may lie beyond the physicist's remit. The next sections discuss in detail some of the generic characteristics of gels, foams, emulsions and powders using case histories to expand on the general principles of these states of matter. Finally there is a brief description of some common processing methodologies.