School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, PR China.
School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, PR China; Jiangmen Nanyue Guava Tea Farmer Cooperatives, Jiangmen, Guangdong 529000, PR China.
Food Chem. 2018 Oct 30;264:189-198. doi: 10.1016/j.foodchem.2018.05.035. Epub 2018 May 8.
There are both soluble and insoluble-bound forms of phenolics in tea-leaf products. In order to increase total soluble phenolics contents, guava leaves tea (GLT) was first fermented with Monascus anka and Saccharomyces cerevisiae, and then hydrolyzed with complex enzymes. The changes in phenolics profiles, antioxidant activities and inhibitory effect on α-glucosidase in processed GLT were investigated. Compared with the un-fermented GLT, fermentation and complex enzymatic processing (FE) significantly increased the total phenolics, total flavonoids, quercetin and kaempferol contents by 2.1, 2.0, 13.0 and 6.8 times, respectively. After the FE, a major proportion of phenolics existed in the soluble form. Quercetin was released in the highest amount among different phenolics. In addition, soluble phenolic extracts from GLT following FE exhibited a highest antioxidant activity and inhibitory effect on α-glucosidase. The paper suggested an improved method for processing GLT into high-value products rich in phenolics and flavonoids aglycones with enhanced health benefits.
茶叶产品中的酚类物质既有可溶形式也有不可溶结合形式。为了增加总可溶性酚类物质的含量，先用红曲和酿酒酵母对番石榴叶茶（GLT）进行发酵，然后用复合酶进行水解。研究了加工后的 GLT 中酚类物质谱、抗氧化活性和对α-葡萄糖苷酶抑制作用的变化。与未经发酵的 GLT 相比，发酵和复合酶处理（FE）使总酚、总黄酮、槲皮素和山奈酚的含量分别显著增加了 2.1、2.0、13.0 和 6.8 倍。FE 后，大部分酚类物质以可溶形式存在。不同酚类物质中，槲皮素的释放量最高。此外，FE 后的 GLT 中的可溶性酚提取物表现出最高的抗氧化活性和对α-葡萄糖苷酶的抑制作用。本文提出了一种改进的方法，可将 GLT 加工成富含酚类和类黄酮苷元的高附加值产品，具有增强的健康益处。
