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.