蕨菜微波真空干燥特性和品质试验研究

Experiment and research on the techniques for microwave vacuum drying of Pteridium aquilinum

为了快速干燥蕨菜这种营养价值高但难于鲜藏的特色山野菜,利用微波真空干燥技术,对蕨菜进行正交干燥试验,研究蕨菜干燥特性;并与冷冻干燥、热风干燥方法相比较,分析不同干燥方法对蕨菜干品品质的影响。在蕨菜的微波真空干燥过程中,微波功率对干燥速度的影响要高于真空度,并且提出了蕨菜含水率与微波功率、干燥时间和真空度之间的回归模型;对3种方法干燥后的蕨菜在颜色、维生素C含量和复水性方面进行对比,结果表明:微波真空干燥的蕨菜的复水性优于热风干燥和冷冻干燥;微波真空干燥后的蕨菜品质与冷冻干燥几乎相同,明显高于传统的热风干燥品质。微波真空干燥技术是适合蕨菜脱水的有潜力的干燥技术。

Pteridium aquilinum is a wild vegetable with special favor, which is characterized of very short shelf life and high nutrition value. Microwave Vacuum Drying （MVD） method was used to dry the Pteridium aquilinum quickly based on an orthogonal experimental design to determine the drying properties. Contrasting the microwave vacuum drying method with freeze drying method and hot air drying method, the qualities of dried Pteridium aquilinum were analyzed. During the MVD process for the Pteridium aquilinum, the effect of the microwave power on the drying rate was greater than that of the vacuum degree. A regression model between the mois^re content of the Pteridium aquilinum and MVD parameters including microwave power, vacuum degree and drying duration was established. The Pteridium Aquilinum dried by microwave vacuum drying method showed perfect rehydration characteristics, which obviously excelled that dried by hot air and freeze drying method. The quality indexes such as color and vitamin C of the dried Pteridium Aquilinum with the MVD method were quite similar to those with freeze drying method, which had a remarkable advantage over those with hot air drying method. Therefore, MVD is a potential technology for drying Pteridium aquilinum.