不同干燥方式对莲藕淀粉品质特性的影响

以莲藕为试验对象,探讨热风干燥、微波干燥、真空微波干燥和红外干燥四种不同干燥方式对莲藕淀粉的干燥时间、亮度、微观结构、晶体类型、粘度、凝沉稳定性、冻融稳定性和透明度影响。结果表明:热风干燥、微波干燥、真空微波干燥和红外干燥四种不同干燥方式处理的莲藕淀粉X-射线衍射图谱一致,晶体类型均为B型结构。在热风干燥和红外的淀粉颗粒形状较不规则,表面粗糙,有明显凹坑,颗粒间团聚和裂缝严重,外观品质极差;微波干燥和真空微波干燥的淀粉,大颗粒整体结构为椭球型,小颗粒为球形,无团聚,真空微波干燥莲藕淀粉颗粒较完整,轮廓清晰,表面光滑。四种干燥方式处理莲藕淀粉,真空微波干燥淀粉的亮度、凝沉稳定性均为最好,透明度最低,而微波干燥的干燥时间最短,冻融稳定性最好。综合分析,真空微波干燥方式优于其他三种方式,可适用于莲藕淀粉及淀粉制品加工的工业生产中。

Effects of Different Drying Methods on Quality Properties of Lotus Root Starch

With lotus root as experimental object,the effects of the drying time,brightness,microstructure,crystal type,viscosity,coagulating stability,freezing and thawing stability and transparency were studied through four drying methods such as hot air drying,microwave drying,vacuum microwave drying and infrared drying. The results showed that the X-ray diffraction patterns of lotus root starch treated by hot air drying,microwave drying,vacuum microwave drying and infrared drying four drying methods were consistent,and the crystal types were all B type,and the starch particles in hot air drying and infrared drying were irregular in shape,rough in surface and obviously pits. The starch of microwave drying and vacuum microwave drying was ellipsoidal,small particles were spherical,no agglomeration,vacuum microwave drying of lotus root starch was relatively complete,the outline was clear and the surface was smooth. The brightness,condensation stability,freeze-thaw stability of vacuum microwave drying starch were the best,the transparency was the lowest,and the drying time of microwave drying was the shortest freezing and the thawing stability of microwave drying was the best.Comprehensive analysis showed that the vacuum microwave drying would be more suitable for industrial production of lotus root starch and starch products than other three ways.