A systematic literature review of the drying of cocoa in 2003-2023

Abstract

Post-harvest losses in cocoa plantations often occur in developing countries and can be significantly reduced by using various drying technology designs. This comprehensive review presents the development of drying cocoa beans, such as sun drying, convective solar drying, oven drying, freeze drying, heat pump drying, and hybrid solar drying, as well as an analysis of the quality of the cocoa drying. Based on the review that has been explained, hybrid solar drying is a perspective that needs to be developed for the future. Hybrid solar can be assisted with various drying models or can be known as mixed mode hybrid solar drying, the addition of heat can also be assisted with heat pump-biomass drying, assisted again with photovoltaic hybrid and auxiliary heater. Most likely in the future hybrid solar drying will be added to the drying place (chamber) to the collector or also to the drying system with a water vapor absorber (desiccant). The application of mirrors, the development of solar collectors to overcome the volume of hot air transfer, and the application of selective coatings on absorber sheets to increase solar energy collection can improve dryer performance. Air-based solar collectors are not the only method available. Water can be a heat exchanger that can be applied in solar collectors to replace air. In this technique, hot air for drying food products needs to flow through the water to the air heat exchanger, and a hot water tank is used as storage material.