利用香菇菌丝体发酵藜麦及其发酵产物中粗多糖的抗氧化评价

The Antioxidant Evaluation of Crude Polysacharide from Fermented Quinoa by Lentinus Edodes

以藜麦为固体培养基,利用香菇菌丝体将其发酵,通过正交试验设计探讨碳源、氮源、碳氮源添加比例、时间等因素对发酵产物中粗多糖含量的影响,测定最适发酵条件下发酵产物中粗多糖抗氧化活性。最终得出以粗多糖为目标产物的最适发酵条件为:碳源为淀粉,氮源为牛肉膏,碳氮源添加比例5:1,发酵时间15 d;在此条件下,香菇与藜麦的发酵产物中粗多糖含量达(58.89±1.33)mg/g,较未发酵藜麦提升了31倍;且其对DPPH·自由基和ABTS·^+自由基均表现出较好的体外清除效果,当粗多糖浓度为20 mg/mL时,其对DPPH·自由基和ABTS·^+自由基的清除能力均达到最高,分别为76.57%与60.16%。利用香菇菌丝体发酵藜麦后,能够大大提升藜麦培养基中多糖的含量,且发酵后的粗多糖具有较好的抗氧化能力,为发酵产物作为功能性食品的可行性提供一定数据支持。

In this study,the quinoa was used as a raw material for fermentation by Lentinus edodes,through orthogonal experimental design,the carbon source,nitrogen source,the ratio of added carbon and nitrogen source and fermentation time were measured in this experiment.And the antioxidant activities of crude polysaccharide in fermentation products under optimal fermentation conditions were determined.Finally,the optimal fermentation conditions for polysaccharides were as follows:the carbon source was starch,the nitrogen source was beef extract,earbon and nitrogen source addition ratio of 5:1,fermentation time of 15 days.Under these conditions,the content of polysaccharides in the fermentation product was reached to(58.89±1.33)mg/g,which is 31 times higher than unfermented quinoa.The extracted crude polysaccharide had significantly scavenging activities in both DPPH·radicals and ABTS·^+ free radicals.The scavenging rate of DPPH·radical and ABTS·^+ radical were 76.57% and 60.16% respectively,when the concentration of crude polysaccharide is 20 mg/L.After fermentation,the content of polysaccharides could be greatly increased,and the extracted crude polysaccharide has significant antioxidant capacity,these could provide several data support for the development of fermentation product using as functional foods.