Science and Engineering Faculty, Queensland University of Technology, Brisbane, Australia.
School of Food Engineering, Ludong University, Yantai, Shandong, China.
Crit Rev Food Sci Nutr. 2022;62(25):6872-6886. doi: 10.1080/10408398.2021.1907529. Epub 2021 Apr 27.
Waste in the food supply chain is estimated to be about 30-40% of the total food production, which aggravates the world hunger and increases waste management burden and environmental impact. Despite the dire food scarcity, majority of this food waste takes place in developing countries because of the lack of appropriate and affordable preservation techniques. Traditional open sun drying is the most popular food-reservation technique to the local farmers due to near-zero capital cost and cheap labor cost. However, this method is highly energy intensive, unhygienic, and time demanding. The high energy consumption resulting from uncontrolled simultaneous heat, mass, and momentum transfer processes in traditional drying systems highlights the necessity of pursuing sustainability in drying process targeting reduced energy consumption, environmental and social impacts. This paper presents a comprehensive review on the sustainable food drying technologies based on renewable energy sources, with emphasis on the developing countries. It was observed that the integration of thermal energy storage with heat pump makes the integrated drying system more efficient, and dries food with better quality. Likewise, advanced integrated drying systems, such as, solar with microwave, and heat pump with microwave make the drying process more cost and quality competent. Finally, impact of resource distribution and governmental incentives for renewable energy use in sustainable drying is discussed.
据估计，食品供应链中的浪费约占粮食总产量的 30%-40%，这加剧了世界饥饿问题，并增加了废物管理负担和环境影响。尽管面临严重的粮食短缺，但由于缺乏适当和负担得起的保鲜技术，大部分粮食浪费发生在发展中国家。由于零资本成本和廉价劳动力成本，传统的露天晒干是当地农民最受欢迎的食品保鲜技术。然而，这种方法能源密集度高、不卫生且耗时。传统干燥系统中不受控制的同时传热、传质和动量传递过程导致的高能耗突出了在干燥过程中追求可持续性以减少能源消耗、环境和社会影响的必要性。本文基于可再生能源，对可持续食品干燥技术进行了全面综述，重点关注发展中国家。研究发现，将热能储存与热泵相结合，使集成干燥系统更高效，能够更好地保持食品质量。同样，先进的集成干燥系统，如太阳能与微波、热泵与微波，使干燥过程更具成本效益和质量竞争力。最后，讨论了资源分布和政府对可再生能源在可持续干燥中的使用的激励措施的影响。
