The new insight into the influence of fermentation temperature on quality and bioactivities of black tea. (January 2020)

• Record Type: Journal Article
• Authors: Qu, Fengfeng; Zeng, Weichao; Tong, Xin; Feng, Wen; Chen, Yuqiong; Ni, Dejiang
• Is Part Of: Lebensmittel-Wissenschaft + Technologie =. Volume 117(2020)
• Publication Date: 2020-01
• Subjects: Fermentation temperature -- Black tea -- Quality -- Antioxidant activity -- Glucose uptake; Food industry and trade -- Periodicals; Food -- Composition -- Periodicals; Microbiology -- Periodicals; Nutrition -- Periodicals; 664.005
• DOI: 10.1016/j.lwt.2019.108646
• Languages: English
• ISSNs: 0023-6438

Abstract

Abstract: This study aimed to figure out the optimum fermentation temperature by analyzing the major chemical constituents of black tea and its antioxidant activities, inhibitory activities against α-amylase, α-glucosidase and glucose uptake. Sensory evaluation revealed 28°C-fermented black tea showed best sensory quality with highest scores for aroma (6.5) and taste (29.8). With increasing fermentation temperature, polyphenols, polysaccharides, (−)-epigallocatechin, (+)-catechin, theaflavins and thearubigins decreased significantly, while amino acids, soluble sugars and volatiles increased when temperature increased up to 31 °C. Furthermore, black tea fermented at 28 °C showed strongest DPPH radical scavenging ability, anti-lipid peroxidation and inhibitory effect on α-glucosidase activity with IC50 value of 17.72 μg/mL, 1.49 mg/mL and 21.69 μg/mL respectively. While 25°C-fermented black tea showed highest inhibition rate of glucose uptake in Caco-2 cells. The results demonstrate that appropriately lowering fermentation temperature could improve both sensory quality and bioactivity of black tea. Highlights: Fermentation temperature (FT) had marked effect on chemical compositions of black tea. Lowering FT of black tea enhanced its antioxidant ability. Lowering FT of black tea enhanced its inhibitory effect on α-amylase and α-glucosidase activity. Lowering FT of black tea enhanced its abilities of inhibiting intestinal glucose uptake.