混菌固态发酵提高甘蔗叶酚类物质含量及抗氧化活性

Improvement the Content of Phenolic Compounds and Antioxidant Activity in Sugarcane Leaves by Mixed Fungi Solid-State Fermentation

利用米曲霉和黑曲霉进行混合菌种固态发酵甘蔗叶,通过单因素试验和正交试验优化发酵条件,对发酵过程中甘蔗叶黄酮、多酚质量分数及β-葡萄糖苷酶和纤维素酶活力进行测定,并探讨发酵前后甘蔗叶酚类物质抗氧化活性的变化。结果表明,混菌发酵可以显著提高甘蔗叶中黄酮、多酚的质量分数;在接种量为45%、米曲霉与黑曲霉接种比例1∶2、基质含水量40%的条件下发酵4 d,黄酮质量分数为8.35 mg/g,多酚质量分数为8.54 mg/g,比未发酵甘蔗叶中黄酮和多酚质量分数提高了50.72%和50.62%;发酵第3天菌体代谢产生的β-葡萄糖苷酶和纤维素酶活力达到最大,分别为136.68 U/g和585.88 U/g,酚类物质含量变化与酶活力变化呈显著正相关;并且固态发酵后甘蔗叶酚类物质的抗氧化活性得到提高。

Sugarcane leaves were fermented with Aspergillus oryzae and Aspergillus niger for extracting secondary metabolites,and the solid-state fermentation conditions were optimized by single factor experiment and orthogonal experiment.The content of phenolic compounds and the activity of β-glucosidase and cellulase were determined during the solid-state fermentation process.The antioxidant activity of sugarcane leaves extract was determined before and after fermentation.The results showed that the contents of flavonoids and polyphenols in sugarcane leaves were significantly increased after fermentation.The flavonoid content was 8.35 mg/g(dry mass)and the polyphenol content was 8.54 mg/g(dry mass)after inoculation for 4 days with 45% inoculum,ratio of A.oryzae to A.niger 1∶2.40% water content of culture medium,increasing by 50.72% and 50.62% than the unfermented samples,respectively.The activity ofβ-glucosidase and cellulase reached maximum at 136.68 U/g and 585.88 U/g on the third day of fermentation,and the positive correlations were found between the contents of phenolics and the activities of two enzymes;The antioxidant activity of phenolics in sugarcane leaves was improved after solid-state fermentation.