Department of Processing and Food Engineering, CTAE, Maharana Pratap University of Agriculture and   Technology, Udaipur, Rajasthan

To extend the shelf life of fruits and vegetables, drying is a viable option, but it has its own difficulties. It preserves the fruits and vegetable by reducing the moisture content. The heat pump drying in one of the methods of drying which retains the nutritional component in the dried product as compare to the conventional methods. The major component of heat pump dryer is compressor. The low energy consumption is the main advantage of heat pump dryer. It can be used for heat sensitive product as can dry the product at low temperature as compare to the other conventional method. It can be used in combination with other technologies as infrared assisted heat pump drying, ultrasound assisted heat pump drying, and solar assisted heat pump drying. The processing and drying of food, the heating of crude oil in oil fields, the printing and dyeing industry, the distillation process, the pulp and paper industry, etc. are only a few additional uses for the heat pump. Improvement in efficiency of drying, ability to accurately control drying conditions, wide range of drying conditions, better product quality, increased throughput, and low operational cost are the key merits of the heat pump dryer.