Reviews on osmotic dehydration of fruits and vegetables

Abstract

Osmotic dehydration (OD) is an operation used for the partial removal of water from plant tissues by immersion in a hypertonic solution, sugar and/or salt solution, to reduce the moisture content of foods before actual drying process. Osmotic dehydration found wide application in the preservation of food-materials since it lowers the water activity of fruits and vegetables. In conventional drying process food material goes under phase change because of high temperature-time combinations. High temperature affects the flavor, colour and textural properties of final product. The osmotic dehydration step can be done before the conventional drying process to enhance the mass transfer rate or to shorten the duration of drying time. The quality of osmotically dehydrated products is better and shrinkage is considerably lower as compared to products from conventional drying processes. This technique helps to conserve the overall energy relative to other drying procedures.