Study on Alkaline Extraction Process Optimization of Polysaccharides from Coelomic Fluid of Phasolosma esculenta and Its Antioxidant Activity in vitro

In order to improve the utilization rate of the coelomic fluid of Phascoloma esculenta, the optimal extraction technology and its antioxidant properties in vitro were explored. The polysaccharide of Phascoloma esculenta was extracted by alkali extraction method and optimized by orthogonal experiment. The total reducing power, DPPH scavenging rate and hydroxyl radical scavenging rate were used to determine its antioxidant properties. The composition of monosaccharides was determined by high performance liquid chromatography, and the polysaccharide composition was analyzed by infrared spectroscopy. The results showed that the optimal extraction process conditions for polysaccharides from the coelomic fluid of Phascoloma esculenta were extraction temperature of 50 ℃, alkaline extraction time of 3 h, and NaOH concentration of 1.5%. The yield of polysaccharides under this process was 0.92%. The half scavenging concentration (IC₅₀) of the total reducing power, DPPH scavenging rate and hydroxyl radical scavenging rate were 2.976, 0.567 and 0.605 mg/mL, respectively. The results of HPLC showed that the polysaccharide was mainly composed of glucose and infrared spectroscopy showed that the polysaccharide contained acetylamino and pyran rings and connected by α-glycosidic bonds. It could be seen that the polysaccharides from the coelomic fluid of Phascoloma esculenta have good antioxidant properties and application prospect.