Study on osmo-convective dehydration of papaya (Carica papaya L.) slices and evaluation of quality during storag

Abstract

Osmotic dehydration (OD) is one of most important complementary treatment and food preservation technique in the processing of dehydrated foods, since it presents some benefits such as reducing the damage of heat to the flavor, color, inhibiting the browning of enzymes and decrease the energy costs. Osmotic dehydration results in increased shelf-life, little bit loss of aroma in dried and semidried food stuffs, lessening the load offreezing and to freeze the food without causing unnecessary changes in texture. Drying is a technique of conservation that consists of the elimination of large amount of water present in a food by the application of heat under controlled conditions, with the objective to diminish the chemical, enzymatic and microbiological activities that are responsible for the deterioration of foods. Hot air drying often degrades the product quality, provides low energy efficiency and lengthy drying time during the falling rate period. It has been reported that hot-air drying of food materials, involving their prolonged exposure to elevated drying temperatures, results in substantial deterioration of such quality attributes as color, nutrient concentration, flavor and texture. Papaya (Carica papay L.) is an important fruit crop grown widely in tropical and subtropical low land regions. Excellent in vitamin C, pro-vitamin A, minerals as well as rich in dietary fiber, papaya is emerging as a popular fresh fruit which offers health benefiting properties. The desire to eliminate this problem, prevent significant quality loss and achieve fast and effective thermal processing, has resulted in the increasing use of microwaves for food drying.