Ntezimana Bernard, Li Yuchuan, He Chang, Yu Xinlei, Zhou Jingtao, Chen Yuqiong, Yu Zhi, Ni Dejiang
Key Laboratory of Horticulture Plant Biology, Ministry of Education, College of Horticulture & Forestry Sciences, Huazhong Agricultural University, Wuhan 430070, China.
Key Laboratory of Urban Agriculture in Central China, Ministry of Agriculture, Wuhan 430070, China.
Foods. 2021 Oct 29;10(11):2627. doi: 10.3390/foods10112627.
The present study emphasizes the effect of withering time set at 4 ± 0.5 h (WT4), 6 ± 0.5 h (WT6), 8 ± 0.5 h (WT8), 10 ± 0.5 h (WT10), and 12 ± 0.5 h (WT12) on the sensory qualities, chemical components, and nutritional characteristics of black tea. The sensory evaluation revealed high total quality scores at WT8 and WT10. Polysaccharides, amino acids, and soluble sugars significantly increased with an increase in withering time, and an apparent peak value was obtained at WT10. However, polyphenols, flavonoids, glycosides, organic acids, catechins, alkanoids, and theaflavins decreased with an increase in withering time. With an increase in withering time, the content of aromatic substances showed a trend of increasing first and then decreasing. The peaks of alcohols, aldehydes, and acids appeared at 10 ± 0.5 h, 10 ± 0.5 h, and 8 ± 0.5 h, respectively. The content of esters, ketones, and hydrocarbons showed a downward trend with an increase in withering time. Aroma analysis revealed that withering time could not exceed 10 ± 0.5 h. Black tea withered up to WT10 showed enhanced inhibition of α-glucosidase and α-amylase activity with good sensorial attributes. Glucose uptake inhibition capacity increased up 6 ± 0.5 h and then decreased, while antioxidant capacity decreased with an increase in withering time. The overall results show that the 8 ± 0.5 h to 10 ± 0.5 h withering time could improve black tea quality and nutritional characteristics.
本研究着重探讨了设定为4±0.5小时（WT4）、6±0.5小时（WT6）、8±0.5小时（WT8）、10±0.5小时（WT10）和12±0.5小时（WT12）的萎凋时间对红茶感官品质、化学成分和营养特性的影响。感官评价显示，WT8和WT10时的总体品质得分较高。随着萎凋时间的增加，多糖、氨基酸和可溶性糖显著增加，在WT10时达到明显的峰值。然而，多酚、黄酮类化合物、糖苷、有机酸、儿茶素、生物碱和茶黄素则随着萎凋时间的增加而减少。随着萎凋时间的增加，芳香物质的含量呈现出先增加后减少的趋势。醇类、醛类和酸类的峰值分别出现在10±0.5小时、10±0.5小时和8±0.5小时。酯类、酮类和烃类的含量随着萎凋时间的增加呈下降趋势。香气分析表明，萎凋时间不能超过10±0.5小时。萎凋至WT10的红茶对α-葡萄糖苷酶和α-淀粉酶活性的抑制作用增强，感官特性良好。葡萄糖摄取抑制能力在6±0.5小时之前增加，之后下降，而抗氧化能力则随着萎凋时间的增加而降低。总体结果表明，8±0.5小时至10±0.5小时的萎凋时间可以改善红茶的品质和营养特性。
