Abstract: In order to study the optimal extraction process and preliminary structure of the polysaccharide from the Xiuzhen mushroom, the fresh mushroom fruiting body was used as the raw material, the polysaccharide content and iron reducing power were used as the indicators on the basis of the single factor experiment, and the extraction of the polysaccharide was optimized by response surface methodology. The structure was preliminarily analyzed by infrared spectroscopy and scanning electron microscope, and the thermal stability was analyzed. The results showed that the optimal water extraction process conditions for the polysaccharides of Xiuzhen mushroom were as follows: the extraction time was 3.2 h, the extraction times were twice, the extraction temperature was 90 ℃, and the ratio of liquid to material was 20 mL/g. The predicted value was 53.02 mg/g, the measured value was 53.98 mg/g, and the iron reducing power was 0.634. The measured results were in good agreement with the predicted values. The structure showed that the polysaccharide of Xiuzhen mushroom is a polysaccharide of pyranose configuration, with loose three-dimensional structure, smooth surface and hard texture. In this study, the extraction process of Xiuzhen mushroom polysaccharide was optimized, and the preliminary analysis confirmed that it was a polysaccharide substance, which provides a theoretical basis for the subsequent development and research of Xiuzhen mushroom polysaccharide functional substances.

Key words: Xiuzhen mushroom, polysaccharide, extraction process, response surface analysis, preliminary structure