Mulberry leaves contain various types of phenolics, especially glycosides of the flavonoids quercetin and kaempferol. The aim of the present study was to investigate the production of quercetin and kaempferol as well as the biological activity of mulberry leaves with solid-state fermentation by edible fungi. Among the test fungi, the fermentation with Monascus anka was found to obviously increase the level of quercetin and kaempferol in the mulberry leaves. After fermentation, the amounts of quercetin and kaempferol were up to 5.30 ± 0.35 mg/g dw and 1.87 ± 0.10 mg/ dw, respectively. Meanwhile, the changes in enzymes activities and the contents of quercetin and kaempferol during fermentation were systematically studied. The morphology observation demonstrated that the mulberry leaves were severely damaged after fermentation. In addition, the biological activities including free radical scavenging activity, α-glucosidase inhibition activity, and antimicrobial activity significantly enhanced with fermentation. This study provided a scientific basis for the production of the high value flavonoid aglycones from plant materials.

桑叶含有各种类型的酚类物质，尤其是类黄酮槲皮素和山fer酚的糖苷。本研究的目的是研究槲皮素和山emp酚的生产以及食用菌固态发酵桑叶的生物学活性。在测试真菌中，用红曲霉发酵被发现明显增加了桑叶中槲皮素和山奈酚的含量。发酵后，槲皮素和山奈酚的含量分别高达5.30±0.35 mg / g dw和1.87±0.10 mg / dw。同时，系统地研究了发酵过程中酶活性的变化以及槲皮素和山emp酚的含量。形态观察表明，发酵后桑叶严重受损。另外，随着发酵，包括自由基清除活性，α-葡糖苷酶抑制活性和抗微生物活性在内的生物活性显着增强。该研究为从植物材料生产高价值的类黄酮苷元提供了科学依据。