Using the yield as the standard,the optimal extraction methods for polysaccharides from Boletus aereus was screened and optimized among three extraction methods(hot water extraction,ultrasound extraction,and ultrasound-assisted composite enzyme method).Subsequently,the in vitro antioxidant activity of B.aereus polysaccharides was investigated.A single-factor assay was used to select the method with the highest polysaccharide yield.The response surface methodology was employed to further optimizing.Polysac-charides were graded using a stepwise alcohol precipitation method.The in vitro antioxidant activity was evaluated by DPPH assay,ABTS assay,hydroxyl free radical scavenging assay,and reducing power assay.The polysaccharide yields of hot water extraction,ultrasound ex-traction,and ultrasound-assisted composite enzyme extraction were 5.64％,6.74％,and 18.47％,respectively.The optimized process for ultrasound-assisted composite enzyme extraction was as follows:enzyme ratio(cellulase:protease)of 2:1,enzymatic hydrolysis temperature of 42.7 ℃,enzymatic hydrolysis time of 67 min,enzyme addition of 1.92％,ultrasound time of 20 min,and an expected yield of 18.867％.The B.aereus polysaccharides obtained exhibited excellent antioxidant activity.Their antioxidant capacities were pos-itively correlated with polysaccharide concentration and alcohol precipitation concentration.The polysaccharides obtained by 80％etha-nol precipitation showed the best overall antioxidant activity in vitro.Ultrasound-assisted composite enzyme extraction significantly im-proves the polysaccharide yield of B.aereus.The obtained polysaccharides exhibit excellent in vitro antioxidant activity.
维普
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