响应面法优化发酵对桑叶生物碱、黄酮和多糖含量的影响

Effects of optimized fermentation on the content of alkaloids,flavonoids and polysaccharides in mulberry leaves by response surface methodology

目的优化发酵条件,提高桑叶生物碱、黄酮和多糖3大活性成分含量。方法首先筛选菌种,然后以发酵温度、发酵时间、接种量为单因素,考察它们对桑叶重要活性物质生物碱、黄酮、多糖含量的影响,在此基础上采用响应面法优化其发酵条件。结果植物乳杆菌为最适发酵菌种,发酵菌液的浓度为3.0×10^(8) CFU/mL,在植物乳杆菌单菌发酵结果中,与对照组相比,黄酮、多糖含量差异不显著(P>0.05),生物碱含量提高了69.35%;经优化后以生物碱和黄酮含量为响应值,确定最佳发酵条件为:发酵温度37℃、发酵时间12 h和接种量15%,在此条件下含量分别为1.24和29.85 mg/g;发酵对桑叶多糖的影响不显著(P>0.05),桑叶生物碱和桑叶黄酮含量分别增加了26.53%和29.56%。结论植物乳杆菌发酵可明显提高桑叶生物碱和桑叶黄酮含量,对多糖含量影响不显著。

Objective To optimize fermentation conditions,and improve the content of alkaloids,flavonoids and polysaccharides in mulberry leaves.Methods After screening the strains,the effects of fermentation temperature,fermentation time and inoculation amount on the content of alkaloids,flavonoids and polysaccharides in mulberry leaves were investigated.On this basis,the fermentation conditions were optimized by response surface methodology.First,the strains were screened,and then the effects of fermentation temperature,fermentation time,and inoculation amount on the content of alkaloids,flavonoids,and polysaccharides,important active substances in mulberry leaves,were investigated using the single factor method,on this basis,the fermentation conditions were optimized by using response surface methodology.Results Lactobacillus plantarum was the most suitable strain for fermentation,and the concentration of fermentation broth was 3.0×10^(8) CFU/mL,in the single strain fermentation results of Lactobacillus plantarum,compared with the control group,there was no significant difference in the content of flavonoids and polysaccharides(P>0.05),and the alkaloid content was increased by 69.35%;after optimization,with the content of alkaloids and flavonoids as response values,the optimal fermentation condition was confirmed as follows:Fermentation temperature 37℃,fermentation time 12 h and inoculation amount 15%,under this condition,the content of alkaloids and flavonoids was 1.24 and 29.85 mg/g,respectively;the fermentation had no significant effect on the polysaccharide of mulberry leaves(P>0.05),and the alkaloid and flavonoid content in folium mulberry leaves by 26.53%and 29.56%,respectively.Conclusion Lactobacillus plantarum fermentation can significantly increase the content of alkaloids and flavonoids in mulberry leaves,but has no significant effect on polysaccharide content.