食品微波冻干技术及装备研究进展

Research progress on technology and equipment for freeze-drying food by microwave

冻干技术能够最大限度地保留食品的营养成分,在我国食品干燥行业得到了一定的应用。由于冻干技术存在干燥周期长、能耗大、成本高等缺点,目前我国冻干食品以出口为主。微波具有内热源特性,采用微波高效加热技术与传统冻干技术相结合而发展的微波冻干技术从上世纪中期已受到国外学者与企业界广泛关注。但是,微波冻干存在非常明显的不均匀与低压气体放电现象,这一关键技术问题一直以来制约其商业化应用。近些年来,由于科学技术的迅猛发展和学科领域的交叉、相互渗透,为微波冻干关键技术的研究、装备开发及商业化应用提供了技术及经济支撑,微波冻干技术、理论得到不断完善。综述了国内外微波干燥技术在高效、节能、均匀及装备方面的研究进展。

Freeze- drying technology used in food drying can maximize the retention of nutrients in food.The foods dried by freeze- drying are mainly exported at present since long drying period,large energy consumption and high cost. Microwave has the characteristics of inner heat source. Microwave freeze-drying technology is developed by the combination of microwave heating technology and traditional freeze- drying technology,which has been widely concerned by foreign scholars and business community since the middle of the last century. But the key technical problem has been restricting its commercial application because of the phenomenon of very obvious uneven and low- pressure gas discharge. In recent years,microwave freeze drying technology and the theory has been continuously improved due to the rapid development of science and technology and the interdisciplinary intersection and mutual penetration,which provide technical and economic support for research of the key technologies,equipment development and commercial application. The research progress of microwave drying technology at home and abroad in high efficiency,energy saving,uniform and equipment is summarized.