State Key Laboratory of Tea Plant Biology and Utilization, Key Laboratory of Tea Biology and Tea Processing of Ministry of Agriculture and Rural Affairs, International Joint Research Laboratory of Tea Chemistry and Health Effects of Ministry of Education, Anhui Provincial Laboratory, Hefei, Anhui 230036, People's Republic of China; School of Tea and Food Science and Technology, Anhui Agricultural University, 130 Changjiang West Road, Hefei 230036, China.
The National Key Engineering Lab of Crop Stress Resistance Breeding, the School of Life Sciences, Anhui Agricultural University, Hefei 230036, China.
Food Chem. 2023 Dec 1;428:136785. doi: 10.1016/j.foodchem.2023.136785. Epub 2023 Jul 1.
In this study, an optimized yellowing process for yellow tea (YT) was developed by response surface methodology. The results showed that increasing the yellowing temperature from 20 °C to 34 °C, increasing the relative humidity from 55% to 67%, and reducing the yellowing time from 48 h to 16 h, caused a 40.5% and 43.2% increase in the yellowness and sweetness of YT, respectively, and improved the consumer acceptability by 36.8%. Moreover, metabolomics was used to explore the involved mechanisms that resulted in the improved YT quality. The optimized yellowing promoted the hydrolysis of 5 gallated catechins, 6 flavonoid glycosides, theogallin and digalloylglucose, resulting in the accumulation of 5 soluble sugars and gallic acid. Meanwhile, it promoted the oxidative polymerization of catechins (e.g., theaflagallin, δ-type dehydrodicatechin and theasinensin A), but decelerated the degradation of chlorophylls. Overall, this optimized yellowing process could serve as a guide to a shorter yellowing cycle.
在这项研究中，通过响应面法开发了一种优化的黄茶（YT）变黄工艺。结果表明，将变黄温度从 20°C 升高到 34°C、相对湿度从 55%升高到 67%、变黄时间从 48 小时缩短到 16 小时，分别使 YT 的黄度和甜度提高了 40.5%和 43.2%，并使消费者接受度提高了 36.8%。此外，还利用代谢组学来探讨导致 YT 品质提高的相关机制。优化的变黄过程促进了 5 个没食子酰儿茶素、6 个黄酮糖苷、茶红素有和二没食子酰葡萄糖的水解，导致 5 种可溶性糖和没食子酸的积累。同时，它促进了儿茶素（如茶黄素、δ-型脱氢儿茶素和茶黄素 A）的氧化聚合，但减缓了叶绿素的降解。总的来说，这种优化的变黄过程可以作为缩短变黄周期的指导。
