甘草药渣发酵工艺优化及成分分析、抗氧化活性的研究

Optimization of licorice residue fermentation and analysis of its compositions and antioxidant activity

目的 优化复合益生菌发酵甘草药渣工艺,并分析发酵前后物质成分含量的变化及体外抗氧化活性。方法 以酿酒酵母菌与植物乳杆菌为发酵菌株对甘草药渣进行协同发酵,以总黄酮含量为响应值,对接种比例、接种量、发酵温度、发酵时间进行中心组合Box-Behnken 试验设计,并进行响应面分析;采用NaNO_(2)-A1(NO_(3))比色法及高效液相色谱法分别对发酵前后总黄酮、甘草苷、甘草素、异甘草素、甘草酸的含量进行测定。同时还考察了甘草药渣发酵物对DPPH 自由基和羟自由基的清除作用。结果 最佳发酵条件为:酿酒酵母菌与植物乳杆菌接种比例1∶3、接种量8%、发酵时间48 h、温度34℃,在此条件下甘草总黄酮含量为(1.98±0.02)%。发酵后总黄酮、甘草素及异甘草素的含量升高,而甘草苷、甘草酸含量有所下降。甘草药渣发酵物对DPPH及羟自由基具有明显的清除能力且在相同浓度下强于未发酵组。结论 复合益生菌发酵甘草药渣发酵工艺合理可行,发酵产物具有良好的抗氧化活性,在资源再利用方面具有积极意义。

Objective To optimize the fermentation of licorice residue by compound probiotics and analyze the chemical compositions and in vitro antioxidant activity before and after the fermentation.Methods Saccharomyces cerevisiae and Lactobacillus plantarum were used as fermentation strains for the co-fermentation of licorice residue.With the total flavonoid content as the response value,the central combination Box-Benhnken experiment design was used for the inoculation ratio,inoculation amount,fermentation temperature and fermentation time.Response surface analysis was conducted.The content of total flavonoids,liquiritin,liquiritingenin,isoliquiritingenin,and glycyrrhizic acid were determined by NaNO_(2)-A1(NO_(3))colorimetric method and high performance liquid chromatography before and after the fermentation,respectively.The scavenging effect of fermented licorice residues on DPPH radicals and hydroxyl radicals was determined.Results The optimal fermentation conditions included inoculation ratio of Saccharomyces cerevisiae and Lactobacillus plantarum at 1∶3,inoculation amount at 8%,fermentation for 48 h,and fermentation temperature at 34℃.Under these conditions,the total flavonoid content was (1.98±0.02)%.After the fermentation,the content of total flavonoids,liquiritingenin,and isoliquiritingenin was increased,while the content of liquiritin,and glycyrrhizic acid was decreased.The fermented licorice residue had significant scavenging effect on DPPH and hydroxyl radicals,stronger than the unfermented group at the same concentration.Conclusion The fermentation of licorice residue by complex probiotics is reasonable and feasible,and the fermentation product has good antioxidant activity,which promotes reuse of resources.