Water is the most abundant component of most foods and has a predominating
influence on many quality characteristics, especially those
relating to texture. Heat processing and irradiation apart, available methods
of food preservation also largely depend on modification of the conditions
obtaining in the aqueous part of a food. Indeed, adjustment in the amount of,
and thereby of the state of, water in foods was the first technique to be exploited
by man for preventing natural wastage. In spite of this, it has only been in quite
recent times that a sound scientific basis has been laid for our understanding
of the condition and properties of this most ubiquitous of food constituents.