Dried fruits and vegetables are important food products that can improve quality, extend shelf life, and maintain health. The drying process, however, is a high energy consuming process, which is associated with higher production costs and environmental degradation (Strumillo and Adamiec 1996). This has led to research efforts in improving energy efficiency in the drying process. One approach is to use a heat pump dryer which can recover latent and sensible heat from the air during the drying process.
A heat pump dehydrator is a drying machine that uses an evaporator and a condenser to reduce the moisture content of the dried product without changing the original shape of the material. The heat pump dryer has many advantages over conventional drying machines. For example, it can operate at temperatures below room temperature and is able to extract the water from the product at a much lower rate than the boiling point of water. In addition, the heat pump dryer can reuse the water that is produced during condensation for drying purposes, which helps to minimize the amount of waste water.
A number of studies have been conducted to investigate the potential of using a heat pump dehydrator in the drying of fruit and vegetable produce. The results of these studies show that the quality of the dried produce can be maintained with the use of a heat pump dryer. In addition, the cost of the drying process can be reduced with the use of a heat pump dehydrator.