Handbook of Food Science and Technology 2

Food is a complex and heterogeneous system. It often consists of a
protein and/or polysaccharide matrix surrounding, sustaining a typically
aqueous continuous phase containing soluble hydrophilic compounds
(carbohydrates, salts, vitamins, etc.) and some dispersed elements (cells, fat
globules, gas bubbles, crystals, etc.) (Figure I.1). Such a system is
thermodynamically, biologically and chemically very unstable.