The Ultrasonic/Emerging Extraction Technologies, Structure and Properties for Xiangxin Polysaccharide

ABSTRACT Xiangxin polysaccharide has many biological activities, so it is a key problem to keep the biological activity of Xiangxin polysaccharide to the maximum while improving the extraction rate. Ultrasonic‐assisted extraction (UAE) of Xiangxin polysaccharide has a wide application prospect, which can not only significantly improve the extraction rate of Xiangxin polysaccharide and retain its biological activity to the greatest extent, but also shorten the extraction time, lower the extraction temperature, reduce the amount of chemical reagents and reduce the environmental pollution. However, there are still bottlenecks in UAE. The existing ultrasonic equipment is small in scale, the power intensity is limited by the number of ultrasonic probes, and the noise is high, which is limited to laboratory use and cannot meet the requirements of industrial mass production. Ultrasound is a kind of mechanical wave, and the energy will be attenuated in the process of transmission, and its effective range is also limited. The stability of ultrasonic equipment is not high, which also makes it difficult to accurately guide production practice. In addition, the non‐specificity of ultrasonic action also causes some difficulties in the subsequent separation and purification of polysaccharides. Although the activity of Xiangxin polysaccharide can be improved by molecular modification, the structure of Xiangxin polysaccharide has not been fully clarified, which makes it difficult to modify Xiangxin polysaccharide directionally. In addition, the structure of Xiangxin polysaccharide prepared by different extraction methods is also different, and the structure–activity relationship of Xiangxin polysaccharide and its mechanism of action in the human body have not been fully understood, which has a certain impact on the clinical application of Xiangxin polysaccharide. Therefore, improving the extraction method, retaining and improving the activity of Xiangxin polysaccharide, and accurately understanding the structure and mechanism of Xiangxin polysaccharide are the hot and difficult problems to be solved in the study of Xiangxin polysaccharide, and also the important direction of Xiangxin polysaccharide research.