Classification of fruit solar dryers and the role of phase change materials in enhancing performance: A review

This review provides a detailed overview of fruit solar dryers. It focuses on their design, operation, and the incorporation of advanced technologies like phase change materials. Solar drying is advocated as an effective approach for fruit preservation, reducing post-harvest losses and maintaining nutritional quality. The categorization encompasses various solar dryer concepts classified by air flow (natural, forced, and combined systems), operational modes (direct, indirect, and mixed), and building structures (cabinet, tunnel, greenhouse, etc.). The role of PCMs in enhancing dryer efficiency is significant, as they regulate temperature, reduce energy fluctuations, and facilitate continuous operation during periods of low solar radiation. This review critically examines the key properties of PCMs. It focuses on their thermophysical characteristics, classifications, and strategic applications in solar dryers. Recent innovations demonstrate the significant potential of PCMs to improve efficiency, optimize energy consumption, and enhance product quality. The review identifies research gaps in previous studies. It highlights the potential for further investigation into the application of PCM in solar dryer systems. This study offers a thorough review that consolidates existing knowledge. It serves as a valuable resource for researchers and practitioners aiming to improve sustainable food preservation technology through advanced solar drying systems.