Moisture determination is one of the most important and most widely used measurements in the processing and testing of foods. It is an important factor in food quality preservation and resistance to deterioration.
The amount of moisture in food products is a measure of yield and quantity and as such is of economic importance.
Moisture content must be known for optimum processing of foods, for example, in the milling of cereals, mixing of dough to optimum consistency, and production of bread with the best grain.
Moisture removal or dehydration has long been used as a technique for improving food storage stability. Small increases in the moisture content of low and intermediate moisture foods can significantly reduce their shelf life.
Determination of moisture content is necessary to calculate the content of other food constituents on uniform basis. The dry matter that remains after moisture analysis is commonly referred to as total solids.
Of the oven methods, microwave drying, infrared drying and the moisture analyzer technique are fastest.
Some force draft oven procedures require less than 1 hour drying, but most forced draft oven and vacuum oven procedures a much longer time.
Hygroscopic foods with low moisture contents may require the use of more sophisticated techniques, such as the Karl-Fischer procedure.
Oven drying procedures are official methods for a variety of food products. Reflux distillation is an AOAC method for chocolate, dried vegetables, dried milk and oils and fats.
Analysis of moisture contents of food