Recent Developments of Heat Pump Dried Agriculture Produce: An Overview of Technical and Theoretical Application

Abstract

Foods are very fundamental needs for all living beings. Cereals are harvested to meet the food requirements but it is difficult to simultaneously consume all foods. India, especially lack of consciousness of post-harvest technology and management for fresh food, large economic losses. Drying is a decrease in moisture from the product and is the most important process for storing agricultural products. The drying process involves the transfer of mass and heat in order to rapidly evaporate water from the product. Food qualities such as color, flavor, and structural alterations are changed by drying, nutritional value, and physical appearance and morphology. A heat pump is a heat generating device that transmits energy from heat by absorbing a low temperature range and released to a higher temperature. The heat pump consists of an expansion valve, two heat exchangers (evaporators and condenser) and a compressor. Heat pump calibration creates a regulated drying atmosphere (temperature and humidity) to improve quality of food product with low energy consumption. The main advantages of heat pump dryers (HPD) are the ability of the heat pump to recover energy from the exhaust and the ability to independently control the temperature and humidity of the dry air. This comprehensive review was conducted to study the drying behavior of various food materials under HPD in order to obtain high quality products.