Luo Qiuyu, Li Qinmei, Li Jiayu, Xu Wei, Lin Ling
College of Horticulture, Sichuan Agricultural University, Chengdu 611130, China.
Foods. 2024 Jul 20;13(14):2287. doi: 10.3390/foods13142287.
Pickled tea is an anaerobically fermented tea common in Thailand, Myanmar and Yunnan minority areas. γ-aminobutyric acid (GABA) is non-protein amino acid with multiple bioactives, which can be easily produced under anaerobic conditions. During the processing of pickled tea, controlling the process parameters is effective for the production of GABA-rich products; however, the precise parameters remain to be clarified. In the present study, the fresh leaves of (L.) Kuntze () 'FudingDabai', 'MabianLv No. 1', 'Wuniuzao' and 'Fuxuan No. 9' were used as raw materials to process GABA-rich pickled tea. Single-factor and orthogonal experiments were conducted to determine the best tea cultivars and optimize the best processing parameters via comparing the content of GABA, tea polyphenols (TPs) and other biochemical components of GABA-rich pickled tea. The results of the signal-factor experiment showed that the fresh leaves of 'MabianLv No. 1' had the highest GABA content of 2.61 mg·g after treatment with vacuum for 6 h; therefore, 'MabianLv No. 1' was selected as the raw material for the subsequent experiments. Orthogonal experiments showed that the highest GABA content of 2.53 mg·g was found in the pickled tea with 8 h of vacuum treatment, 20 min of rolling after microwave fixing, 20 min of spreading and 20 d of anaerobic fermentation at room temperature. Further, the sensory evaluation showed that it possesses a strong sour taste with a slight sweetness and a light yellow color and better comprehensive quality. This indicates that these parameters are optimal for the processing of GABA-rich pickled tea. This study will provide scientific basis for the subsequent production of high GABA tea.
腌茶是一种在泰国、缅甸和云南少数民族地区常见的厌氧发酵茶。γ-氨基丁酸（GABA）是一种具有多种生物活性的非蛋白质氨基酸，在厌氧条件下很容易产生。在腌茶加工过程中，控制工艺参数对生产富含GABA的产品有效；然而，精确的参数仍有待明确。在本研究中，以福鼎大白茶、麻叶绿1号、乌牛早和福选9号的鲜叶为原料加工富含GABA的腌茶。通过比较富含GABA的腌茶中GABA、茶多酚（TPs）和其他生化成分的含量，进行单因素和正交试验，以确定最佳茶树品种并优化最佳加工参数。单因素试验结果表明，经6 h真空处理后，麻叶绿1号鲜叶的GABA含量最高，为2.61 mg·g；因此，选择麻叶绿1号作为后续实验的原料。正交试验表明，在经8 h真空处理、微波杀青后揉捻20 min、摊晾20 min和室温厌氧发酵20 d的腌茶中，GABA含量最高，为2.53 mg·g。此外，感官评价表明，其酸味浓郁，略带甜味，色泽淡黄，综合品质较好。这表明这些参数是加工富含GABA腌茶的最佳参数。本研究将为后续高GABA茶的生产提供科学依据。
