Evaporation and Drying

Abstract

Evaporation is a food preservation technique in which dilute liquid foods and solutions are concentrated by the evaporation of water, with the aim of increasing microbiological stability and shelf life. A second major reason for the concentration of liquids is the reduction in transport and storage costs which can be achieved by reducing the product bulk volume. In this way concentrated liquids can be transported at relatively low cost and water added later, closer to the point of sale. In addition, evaporation can be used to increase the concentration of solutions prior to the removal of the remaining water by drying, particularly by spray drying. This is an attractive option because high-efficiency evaporation is significantly less costly than drying and other methods of removing water as the data in Table 12.1 show.