學生姓名:
蔡尚文
指導教授:
劉修銘
學期:
111上
摘 要:
Black tea is a fully fermented tea type. Fermentation is a critical stage in the manufacturing of black tea during which catechins are oxidized to theaflavins (TFs) and thearubigins (TRs) by the action of polyphenol oxidase and peroxidase. These tea compositions will control the
final quality of black tea fermentation. This talk aims to investigate the effect of different fermentation processing conditions on the compounds, bioactivities efficacy, and sensory quality of fermented black tea juices and enzymatic treated black tea. The content of catechin,
caffeine, free amino acids, TFs and TRs were analyzed by high performance liquid chromatography (HPLC) and spectrophotometry. The results showed that black tea juices fermented at 35°C and pH 5.1 for 75 min have the best sensory quality and the highest TFs content. Tri-leaves and quad-leaves were better fermentation materials than mono-leaf and di leaves. The amount of catechin and caffeine decreased with enzymatic treatment, while the TFs and TRs content increased. According to the results, enzymatic treatment increased black tea quality parameter including the TFs/TRs ratio, tea liquor color, and briskness index. The results of anti-oxidant capacity determined by TEAC method and DPPH free radical scavenging method revealed that the antioxidant capacity of black tea significantly increased with
enzymatic treatment. The enzymatic treated black tea demonstrated the greater inhibitory effect on α-amylase, α-glucosidase, and lipase activity. In conclusion, the adding of extra cellulase, PPO, and POD to the black tea during manufacturing process may enhance the tea quality and bioactivity of black tea. It is important to combine the data of sensory quality with compounds to obtain the best processing conditions and the optimal antioxidant activity and metabolic abilities in fermented black tea.
20221019專題討論題目、大綱、摘要-11032063蔡尚文.pdf