Extraction Process Optimization and Physicochemical Properties of Polysaccharide from Wheat Germ Modified by Steam Explosion

In order to improve the extraction yield of wheat germ polysaccharide,the steam explosion technology was used to pre-treat wheat germ,and then the response surface method was used to optimize the extraction conditions of wheat germ polysaccharide. The optimized extraction conditions of steam explosion wheat germ polysaccharide were the following: extraction time 30 min;extraction temperature 70 ℃;solid-liquid ration 1∶5 (g/mL)and repetition of the extracting procedure 3 times. Under such conditions,polysaccharide yield was 18.72%. The average molecular weight of polysaccharides was mainly composed of 2.26×10⁵,5.91×10⁵ and 1.76×10⁶ Da,and the peak area ratio was 14.56%,17.73% and 67.71%,respectively. The polysaccharide surface structure was flaky with irregular broken,and had good oil holding ability. These results show some preliminary characteristics of the wheat germ polysaccharide,providing a theoretical basis for further understanding wheat germ polysaccharide properties.