Wu Qin Yan, Ma Sheng Zhou, Zhang Wen Wen, Yao Ke Bing, Chen Lu, Zhao Fei, Zhuang Yi Qing
Zhenjiang Institute of Agricultural Sciences in Hill Area of Jiangsu Province, Jurong 212400, China.
Agricultural Committee of Zhenjiang City, Zhenjiang 212009, China.
Food Chem. 2018 Feb 1;240:1081-1086. doi: 10.1016/j.foodchem.2017.08.004. Epub 2017 Aug 2.
The roles of the γ-aminobutyric acid (GABA) shunt and polyamine (PA) degradation pathway on GABA accumulation were investigated in fresh tea leaves under anaerobic and aerobic sequential incubations. The GABA accumulation was mainly completed in the first anaerobic incubation through the interaction of the GABA shunt with the PA degradation pathway. When treated with aminoguanidine, the diamine oxidase and polyamine oxidase activities were almost completely inhibited, and the GABA contents decreased by 40.7%, 46.4%, 41.0% and 37.5% in the tea leaves of the four cultivars 'Fuyun No. 6', 'Fudingdabai', 'Longjing No. 43' and 'Pingyangtezao', respectively. The glutamate decarboxylase activity decreased significantly, and the accumulation of GABA may increase or decrease because of varietal differences, which occurred mainly relying on the PA degradation pathway during the second anaerobic incubation. Thus, approximately 37%-47% of the GABA formed in fresh tea leaves under hypoxia was supplied by the PA pathway.
在新鲜茶叶中，通过厌氧和好氧顺序培养，研究了γ-氨基丁酸（GABA）分流和多胺（PA）降解途径对GABA积累的作用。GABA积累主要在第一次厌氧培养期间通过GABA分流与PA降解途径的相互作用完成。用氨基胍处理时，二胺氧化酶和多胺氧化酶活性几乎完全被抑制，在‘福云六号’、‘福鼎大白’、‘龙井43号’和‘平阳特早’这四个品种的茶叶中，GABA含量分别下降了40.7%、46.4%、41.0%和37.5%。谷氨酸脱羧酶活性显著下降，GABA的积累可能因品种差异而增加或减少，这主要发生在第二次厌氧培养期间依赖PA降解途径。因此，在低氧条件下新鲜茶叶中形成的GABA约37%-47%由PA途径提供。
