Solar dryers for food applications: Concepts, designs, and recent advances

摘要

Considering the growing energy crisis, the need for green-energy alternatives is inevitable. Food processing must consider the application of renewable energy for replacing conventional and energy-intensive unit operations; drying in particular. The utilization of solar energy for drying of foods remains to be attractive in terms of energy efficiency, cost-effectiveness, and rural applicability. However, a huge technological gap exists; developing low-cost and energy-efficient dryers for the production of high-quality foods is a challenge. Proper design and selection of components for a solar dryer are mandatory for the effective utilization of thermal energy. Considering these aspects, this review focuses on providing an exhaustive report on the available dryer designs and other critical considerations, along with a summary of diverse applications for different foods. Besides, various recent advancements, challenges, and limitations for implementing large-scale solar drying of foods are presented in terms of technology, energy considerations, and other socio-economic aspects. Thus, this review provides valuable insights into the state of the art of solar dryers, to assist the progress of this green and sustainable technology for food applications.