Study on Solid Fermentation and Antioxidant Function of Natto

[Objectives]To study the optimum conditions of solid fermentation of natto with antioxidant function as an index.[Methods]Single factor experiment and orthogonal experiment were designed to study the effects of temperature,time,initial pH and inoculum amount on the antioxidant activity of natto solid fermentation.The optimum conditions of natto solid fermentation were determined and the antioxidant ac-tivity of natto extract was compared.[Results]The optimal fermentation conditions were as follows:temperature 32℃,initial pH 7.0,inocu-lation amount 8%,fermentation time 32 h.The hydroxyl radical scavenging rate of natto solid fermentation crude extract was the highest,which was 82.7%.The optimized nato fermentation extract showed stronger scavenging ability for-OH and O,:,and showed obvious dose-effect relationship.ICso was 3.63 and 4.24 mg/mL,respectively,and the scavenging efficiency was 1.3 and 1.9 times higher than that of the unoptimized fermentation extract,respectively.[Conclusions]Natto is rich in nattokinase and other functional factors,and its antioxidant ac-tivity can be improved by optimizing fermentation technology,so that natto products can be widely used,including cosmetic raw materials,nat-to skin care soap,health food and medicine,etc.,and have a broader development prospect.

Extraction of Astragalus Polysaccharides and Ganoderma lucidum Mycelia Polysaccharides and Their in Vitro Antioxidative Effects

[Objectives]To explore the extraction and in vitro antioxidant effects of astragalus polysaccharides(APS)and Ganoderma lucidum mycelia polysaccharides(GLMPS).[Methods]By studying the polysaccharides of the herbal medicinal material Astragalus membranaceus and the fungal medicinal material Ganoderma lucidum mycelia,two polysaccharides were mixed according to different proportions and concentrations by using the principle of traditional Chinese medicine compound combination.The effect of polysaccharides on the scavenging ability of hydroxyl radical system was determined by salicylic acid method.[Results]When the compound ratios of GLMPS and APS were 1∶1,1∶4,1∶5,4∶1,and 5∶1,the scavenging effect of compound polysaccharides was better than that of single-component polysaccharides,and with the increase of concentration,the scavenging effect increased.When the ratio of GLMPS and APS was 5∶1,the hydroxyl radical scavenging rate of the compound polysaccharide reached 59.77%,which was 18.72%higher than that of single GLMPS and 28.58%higher than that of single APS.The scavenging effect of compound polysaccharide is closely related to the compound ratio and concentration.[Conclusions]APS and GLMPS can obtain better hydroxyl radical scavenging ability than single-component polysaccharides through compounding in appropriate proportions.In addition,within a suitable concentration range,as the concentration increases,the scavenging ability also increases.