膜分离技术在果汁浓缩中应用的研究进展

传统的多级真空蒸发浓缩技术的应用常因加热而导致果汁质量下降。最有前途的替代法是反渗透浓缩,但高渗透压使其很难以单级系统把果汁浓缩到超过25~30°Bx。近年来,新研发的膜和膜过程包括膜蒸馏、渗透蒸馏和集成膜技术可以弥补反渗透浓缩果汁技术的缺陷。本文综述了反渗透、直接渗透、膜蒸馏、渗透蒸馏以及集成膜分离技术在浓缩果汁加工中的应用研究进展,分析了各自的特点和存在的问题,并展望了膜浓缩果汁技术的应用前景。

RECENT ADVANCES ON MEMBRANE SEPARATION TECHNOLOGY FOR THE CONCENTRATING FRUIT JUICES

Traditionally,fruit juices have been concentrated by multi-stage vacuum evaporation,resulting in a loss of fresh juice flavors due to the thermal effects.The promising alternative is reverse osmosis concentration.However,it cannot reach concentrations larger than 25 to 30°Brix with a single-stage RO system due to higher osmotic pressure limitation.Technological advances related to the development of new membranes and improvements in process engineering have been proved to overcome this limitation.New membrane processes,including membrane distillation and osmotic distillation,and integrated membrane processes are still being identified and developed in concentrated fruit juice processing to improve product quality and reduce energy consumption.Recent advances and developments of membrane processes for concentrating fruit juices are reviewed,and research trends in membrane concentration techniques have also been discussed in this paper.