狗牯脑茶发酵茶的制备及功能特性

Preparation and Characteristics of Fermented Gougunao Tea

摘要:

为促进低品质狗牯脑绿茶的高值化利用，该研究以狗牯脑夏暑茶为原料，通过食用菌固态发酵工艺，研究制备新型狗牯脑发酵茶，并对其感官品质、理化成分和体外活性进行分析。基于食用菌发酵产酶及多糖量，筛选出发酵狗牯脑绿茶的最适菌种为灰树花，经固态发酵制备得到狗牯脑发酵茶。分析显示，相较于狗牯脑绿茶，狗牯脑发酵茶的水浸出物、游离氨基酸、可溶性总糖和茶黄素含量显著增加，蛋白质和总酚含量显著下降。其中可溶性总糖增幅最大，达到92.23%，其次是水浸出物，增幅达39.54%，茶黄素含量也由0.201%增加到0.242%，茶多酚则由108.64 mg·g-1减少到94.53 mg·g-1。感官审评及电子舌分析结果显示，狗牯脑发酵茶的涩味减弱鲜味增强，整体滋味更趋醇厚鲜爽。狗牯脑发酵茶体外抗氧化活性比狗牯脑绿茶虽略有下降，但抑制α-葡萄糖苷酶（IC50=0.236 mg·mL-1）和胰脂肪酶（IC50=0.524 mg·mL-1）作用显著增强，同时促进乳杆菌增殖的作用也有一定增强。该研究结果可为低值狗牯脑绿茶及其他低值茶叶的深加工和技术创新提供思路和参考。

Abstract:

In order to promote the high-value utilization of low-quality Gougunao green tea, this study was conducted to prepare a new type of Gougunao fermented tea using the solid-state fermentation process of edible fungi, with summer Gougunao green tea as the raw material. The sensory quality, physicochemical composition, and in vitro biological activity of the fermented tea were analyzed. Based on the enzyme production and polysaccharide production during the fermentation process, the most suitable strain for fermenting Gougunao green tea was selected as Grifola frondosa, and the fermented tea was produced using the solid-state fermentation method.The results showed that compared with the Gougunao green tea, the water leachate, free amino acids, total soluble sugars, and theaflavin content of the fermented tea significantly increased, while the protein and total phenol content decreased significantly. Among these, the total soluble sugars increased the most, reaching 92.23%, followed by water leachate, which increased by 39.54%, and the theaflavin content increased from 0.201% to 0.242%. Meanwhile, the total tea polyphenols decreased from 108.64 mg·g-1 to 94.53 mg·g-1.Sensory evaluation and electronic tongue analysis revealed that the astringency of the fermented tea was reduced, and the freshness was enhanced, resulting in a more mellow and refreshing overall taste. In terms of in vitro antioxidant activity, the fermented tea exhibited slightly lower antioxidant capacity compared to the green tea, but it showed significantly enhanced inhibition of α-glucosidase (IC50 = 0.236 mg·mL-1) and pancreatic lipase (IC50 = 0.524 mg·mL-1), as well as a moderate promotion of Lactobacillus growth.The findings of this study provide valuable insights and references for the deep processing and technological innovation of low-value Gougunao green tea and other low-value tea products.