The food technologist who wishes to produce a gelled product is faced
with two basic options for achieving the desired effect; whether to use
a protein or a polysaccharide. Although a gel can be formed by either a
protein or a polysaccharide, the resultant gels have different
characteristics: - Polysaccharide gels are characterised by their fine
texture and transparency which is achieved at a low polymer
concentration. They can be formed by heating and cooling, pH adjustment
or specific ion addition . - Protein gels are characterised by a higher
polymer concentration (5-10%) and are formed almost exclusively by heat
denaturation. Before reaching a final decision, the technologist must
take a number of factors into consideration. The purpose of this book is
to help the technologist in his choice by providing fundamental
practical information, in one book, on the properties of gels (and
factors which influence them) for both types of biopolymer. To help the
reader, each chapter is (wherever possible) organised in the same way so
that, for example, information on structure will always be available in
section 2. The examples in the Applications section of each chapter are
not meant to be exhaustive, but to illustrate the various ways in which
the particular polymer can be used to form a gelled product.