IMF: To Enhance the Shelf-Life of Food

Abstract

Drying is the oldest method of food preservation. By reducing the moisture content and water activity the microbial stability of the food materials can be increased. The minimum water activity (aw) for microbial growth is approximately 0.6. But in case of dehydration the texture, palatability and some physical properties of the food materials can be decreased. Intermediate moisture food (IMF) are shelf-stable products having water activities of 0.6-0.84, and the range of the moisture content from 15%-40% and are edible without rehydration. Osmotic dehydration has many advantages include low processing temperatures, short drying times, and 20%-30% lower energy consumption than typical dehydration processes. Sugar is the most important agent used as the humectants for candied intermediate moisture fruits, and salt is used for intermediate moisture vegetables and fish. Most of the fresh fruits can be transformed into IMF or candied fruit (also known as crystallized fruit) without adding synthetic colors and flavors or gelling agent. In this review paper the how different IMF enhance the self-life of the food materials are discussed.