Abstract:Granular agricultural products are constituted as a staple food source for over 70% of the global population, are recognized as a core component within the food processing chain, and are accorded significant economic importance in international trade. It has been extensively documented that inadequate desiccation during harvest seasons is associated with the facilitation of mould proliferation, the induction of germination processes, and the acceleration of product deterioration. These outcomes are manifested through compromised food security and incurred economic losses. Nevertheless, the porous structural characteristics inherent to granular crops, combined with the stress fission challenges encountered during dehydration processes, render alternative methods such as solarisation and hot air drying frequently inadequate for meeting crop-specific drying requirements. In this study, the implementation and relative merits of microwave and infrared drying technologies for granular crops are systematically examined. Subsequently, the enhanced drying efficiency and quality parameters achieved through microwave-hot air, infrared-hot air, and infrared-microwave hybrid drying systems are quantitatively demonstrated in comparison with conventional single-mode drying approaches. A comprehensive synthesis is presented regarding experimental findings and research priorities associated with microwave-vacuum, far-infrared vacuum, and fluidised bed drying applications.The developmental potential of emerging desiccation technologies – including radio frequency, ohmic, and heat pump-based systems – is critically evaluated through comparative analysis of dehydration kinetics, energy efficiency metrics, and product quality indices. A theoretical framework is established for the optimization of novel drying equipment and operational parameters. This systematic investigation contributes substantively to the realization of energy-efficient, low-carbon, and quality-preserving drying objectives, thereby providing crucial technical support for global food security initiatives and sustainable agricultural practices.
