Chen Yiyong, Zeng Lanting, Liao Yinyin, Li Jianlong, Zhou Bo, Yang Ziyin, Tang Jinchi
Tea Research Institute, Guangdong Academy of Agricultural Sciences & Guangdong Provincial Key Laboratory of Tea Plant Resources Innovation and Utilization, Dafeng Road 6, Tianhe District, Guangzhou 510640, China.
Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Tianhe District, Guangzhou 510650, China.
Foods. 2020 Jan 8;9(1):66. doi: 10.3390/foods9010066.
Amino acids contribute to the nutritional value and quality of black tea. Fermentation is the most important stage of the black tea manufacturing process. In this study, we investigated protein degradation and proteinaceous amino acid metabolism associated with enzymatic reactions during fermentation in the black tea manufacturing process. The results showed that the concentrations of both protein and free amino acids decreased during fermentation. We also confirmed that proteins were broken down into free amino acids by artificially synthesized dipeptide benzyloxycarbonyl glutamyl-tyrosine (Z-Glu-Tyr). Metabolites of the amino acid metabolic pathway increased significantly during fermentation. Furthermore, we confirmed that free amino acids were degraded to volatile compounds in a tracer experiment with the isotope precursor. These results provide information that will help black tea manufacturers improve the quality of black tea.
氨基酸对红茶的营养价值和品质有贡献。发酵是红茶制造过程中最重要的阶段。在本研究中，我们调查了红茶制造过程中发酵期间与酶促反应相关的蛋白质降解和蛋白质氨基酸代谢。结果表明，发酵期间蛋白质和游离氨基酸的浓度均降低。我们还证实，通过人工合成的二肽苄氧羰基谷氨酰 - 酪氨酸（Z-Glu-Tyr）可将蛋白质分解为游离氨基酸。发酵期间氨基酸代谢途径的代谢产物显著增加。此外，在使用同位素前体的示踪实验中，我们证实游离氨基酸可降解为挥发性化合物。这些结果提供了有助于红茶制造商提高红茶品质的信息。
