Heat pump dehydrator is an efficient drying system that utilizes the thermal energy of drying exhaust gas absorbed by evaporator as well as the electric energy from compressor. It can reduce the overall energy consumption by achieving high COP and SMER (Clements et al., 1993).
This technology enables the drying process to operate at lower temperatures than conventional methods which results in less shrinkage and damage to the product. It also allows for a more flexible operation, because of the possibility of combining different drying methods. This combination is beneficial because it may overcome some of the disadvantages associated with single MW drying such as higher product throughput and shorter drying times, and it can provide improved quality attributes such as colour, flavour compounds and rehydration of products.
However, heat pump drying requires more sophisticated engineering and control systems than conventional drying technologies. For this reason, it has not yet been widely implemented in the South African fruit and vegetable industry. It is therefore important to investigate the effectiveness of this technology in the context of food processing and preservation in sub-Saharan Africa.
Several studies have demonstrated that heat pump drying can provide a number of benefits in the dehydration of fruits and vegetables. These include improvements in microbial safety, colour, vitamin C retention, volatile compounds, aroma, sensory characteristics and rehydration efficiency. Moreover, heat pump drying can be adapted to the tropical climate conditions of Sub-Saharan Africa. Therefore, it is considered to be a promising technique for preserving and improving the quality of local fruit and vegetables. heat pump dehydrator