A brief overview of sustainable food drying technologies: An approach to sustainable development goals

Food loss and wastage remain critical global challenges, particularly in developing and least-developed countries, where inadequate post-harvest processing leads to significant economic, environmental, and nutritional losses. Drying is one of the most widely used food preservation techniques; however, conventional drying systems are highly energy-intensive and dependent on fossil fuels, contributing to environmental degradation and high operational costs. This review presents a comprehensive overview of sustainable food drying technologies based on renewable energy sources, including solar, geothermal, biomass, heat pump, and hybrid drying systems integrated with thermal energy storage and phase change materials. The working principles, advantages, limitations, energy efficiency, product quality, and techno-economic feasibility of these technologies are discussed. Beyond technical advances, drying also supports sustainable agriculture, food security, circular economy practices, gender equality, and rural development. Evidence shows that solar and biomass-based systems enhance food availability in vulnerable regions, while advanced methods improve nutritional retention and energy savings. The review aligns with the Sustainable Development Goals (SDGs) and provides insights into future research directions for advancing sustainable food drying systems.