Jiang Hao, Zhang Min, Mujumdar Arun S, Lim Rui-Xin
State Key Laboratory of Food Science and Technology, Jiangnan University, 214122, Wuxi, Jiangsu, China.
J Sci Food Agric. 2014 Jul;94(9):1827-34. doi: 10.1002/jsfa.6501. Epub 2014 Feb 13.
To overcome the flaws of high energy consumption of freeze drying (FD) and the non-uniform drying of microwave freeze drying (MFD), pulse-spouted microwave vacuum drying (PSMVD) was developed.
The results showed that the drying time can be dramatically shortened if microwave was used as the heating source. In this experiment, both MFD and PSMVD could shorten drying time by 50% as compared to the FD process. Depending on the heating method, MFD and PSMVD dried banana cubes showed trends of expansion while FD dried samples demonstrated trends of shrinkage. Shrinkage also brought intensive structure and highest fracturability of all three samples dried by different methods. The residual ascorbic acid content of PSMVD dried samples can be as high as in FD dried samples, which were superior to MFD dried samples.
The tests confirmed that PSMVD could bring about better drying uniformity than MFD. Besides, compared with traditional MFD, PSMVD can provide better extrinsic feature, and can bring about improved nutritional features because of the higher residual ascorbic acid content.
为克服冷冻干燥（FD）能耗高以及微波冷冻干燥（MFD）干燥不均匀的缺点，开发了脉冲喷射微波真空干燥（PSMVD）技术。
结果表明，若将微波用作加热源，干燥时间可大幅缩短。在本实验中，与FD工艺相比，MFD和PSMVD均可将干燥时间缩短50%。根据加热方式的不同，MFD和PSMVD干燥的香蕉块呈现出膨胀趋势，而FD干燥的样品则呈现出收缩趋势。收缩还导致了不同方法干燥的所有三个样品中结构致密且脆性最高。PSMVD干燥样品中抗坏血酸的残留量可与FD干燥样品中的含量一样高，优于MFD干燥样品。
测试证实，PSMVD能比MFD实现更好的干燥均匀性。此外，与传统MFD相比，PSMVD可提供更好的外在特性，且由于抗坏血酸残留量更高，能带来更好的营养特性。
