Aaqil Muhammad, Peng Chunxiu, Kamal Ayesha, Nawaz Taufiq, Zhang Fei, Gong Jiashun
College of Food Science and Technology, Yunnan Agricultural University, Kunming 650201, China.
College of Horticulture and Landscape, Yunnan Agricultural University, Kunming 650201, China.
Foods. 2023 Dec 13;12(24):4467. doi: 10.3390/foods12244467.
Tea () has grown for over 300 years and is recognized worldwide as among other well-renowned crops. The quality of black tea depends on plucking (method, standard, season, and intervals), withering and rolling (time and temperature), fermentation (time, temperature, and RH), drying (temperature and method), and storage conditions, which have a high influence on the final quality of black tea. At the rolling stage, the oxidation process is initiated and ends at the early drying stage until the enzymes that transform tea polyphenols into thearubigins (TRs) and theaflavins (TFs) are denatured by heat. By increasing fermentation time, TRs increased, and TF decreased. Each is liable for black tea's brightness, taste, and color. The amino acids and essential oils also grant a distinctive taste and aroma to black tea. Throughout withering, rolling, and fermentation, increases were found in essential oil content, but during drying, a decrease was observed. However, the Maillard reaction, which occurs when amino acids react with sugar during drying, reimburses for this decrease and enhances the flavor and color of black tea. As compared to normal conditions, accelerated storage showed a slight decrease in the total color, TF, and TRs. It is concluded that including plucking, each processing step (adopted technique) and storage system has a remarkable impact on black tea's final quality. To maintain the quality, an advanced mechanism is needed to optimize such factors to produce high-quality black tea, and an objective setting technique should be devised to attain the desirable quality characteristics.
茶叶已经种植了300多年，作为其他著名作物之一，在全球范围内得到认可。红茶的品质取决于采摘（方法、标准、季节和间隔）、萎凋和揉捻（时间和温度）、发酵（时间、温度和相对湿度）、干燥（温度和方法）以及储存条件，这些因素对红茶的最终品质有很大影响。在揉捻阶段，氧化过程开始，并在早期干燥阶段结束，直到将茶多酚转化为茶红素（TRs）和茶黄素（TFs）的酶被热变性。通过增加发酵时间，茶红素增加，而茶黄素减少。它们各自决定了红茶的亮度、口感和颜色。氨基酸和精油也赋予红茶独特的味道和香气。在整个萎凋、揉捻和发酵过程中，精油含量增加，但在干燥过程中，精油含量下降。然而，干燥过程中氨基酸与糖发生的美拉德反应弥补了这种下降，并增强了红茶的风味和颜色。与正常条件相比，加速储存使总颜色、茶黄素和茶红素略有下降。可以得出结论，包括采摘在内，每个加工步骤（采用的技术）和储存系统对红茶的最终品质都有显著影响。为了保持品质，需要一种先进的机制来优化这些因素以生产高品质的红茶，并且应该设计一种目标设定技术来实现理想的品质特征。
