甘草对银耳菌发酵代谢及发酵液抗氧化活性的影响

Effects of Radix glycyrrhizae on liquid fermentation metabolites of Tremella fuciformis and its antioxidant activity

中文关键词:  银耳菌  甘草  液态发酵  抗氧化活性  胞外多糖  色素

英文关键词:Tremella fuciformis  Radix glycyrrhizae  liquid fermentation  antioxidant activity  extracellular polysaccharide  pigment

中文摘要:

      目的 探究甘草对银耳菌液态发酵代谢及发酵液抗氧化活性的影响。方法 通过液态发酵制备不同甘草添加量的银耳发酵液, 对发酵液的pH、色素含量、生物量、银耳胞外多糖(Tremella fuciformis polysaccharide, TFPs)含量及结构变化、抗氧化活性变化进行分析。结果 添加甘草可抑制银耳菌色素的分泌, 并影响发酵液的pH; 当甘草添加量为10%时, 发酵120 h后, 生物量由(4.47±0.01) g/L显著增加至(13.04±1.86) g/L (P<0.05); 甘草添加量为2%时, 发酵24 h, TFPs产量达到最大值(28.00±1.31) g/L。添加甘草还可显著增加发酵上清液的抗氧化活性(P<0.05), 甘草添加量为6%, 发酵72 h, 发酵上清液对DPPH·清除率最高可到(98.23±0.10)%、发酵96 h, ABTS+·清除率最高可达到(99.11±0.15)%, 比未添加甘草的对照组分别增加了7.30%和5.18%。红外光谱确证, 添加甘草没有改变银耳菌发酵产生的胞外多糖的结构。结论 添加甘草能抑制银耳色素的分泌, 同时能增加发酵上清液中的TFPs含量及发酵上清液的抗氧化活性, 为促进银耳菌双向发酵体系的研究及健康产品的开发提供参考。

英文摘要:

      Objective To study the effects of Radix glycyrrhizae on the liquid fermentation of Tremella fuciformis and antioxidant activity of fermentation supernatant. Methods Tremella fuciformis fermentation broths with varying amounts of Radix glycyrrhizae addition were prepared by liquid fermentation. Subsequently, the pH, pigment content, biomass, Tremella fuciformis polysaccharides (TFPs) content and structural changes, as well as changes in antioxidant activity of the fermentation broths were analyzed. Results The addition of Radix glycyrrhizae inhibited the secretion of pigments in Tremella fuciformis and affected the pH of the fermentation broth. When the Radix glycyrrhizae content was added at 10%, the biomass increased significantly from (4.47±0.01) g/L to (13.04±1.86) g/L after 120 h of fermentation (P<0.05). When the Radix glycyrrhizae was 2%, the TFPs production reached its maximum value of (28.00±1.31) g/L after 24 h of fermentation. The addition of Radix glycyrrhizae also significantly increased the antioxidant activity of the fermentation supernatant (P<0.05). Specifically, When the Radix glycyrrhizae was 6%, the fermentation supernatant showed a maximum DPPH· scavenging rate of (98.23±0.10)% at 72 h of fermentation, and a maximum ABTS+· scavenging rate of (99.11±0.15)% at 96 h of fermentation, which were 7.30% and 5.18% higher than that of the control without Radix glycyrrhizae, respectively. Infrared spectroscopy confirmed that the addition of Radix glycyrrhizae did not alter the structure of extracellular polysaccharides produced by Tremella fungus. Conclusion The addition of Radix glycyrrhizae can inhibit the secretion of pigments by Tremella fungus, while increasing the content of TFPs in the fermentation supernatant and enhancing its antioxidant activity, which provides valuable insights for the research of the bidirectional fermentation system of Tremella fuciformis and the development of healthy products.