烘焙工艺对铁观音茶叶内含物变化规律的影响

以铁观音毛茶为材料,采用均匀设计法设置试验方案,结合二次多项式和双重筛选逐步回归分析,研究烘焙工艺中温度、时间和摊叶厚度等因素对茶叶内含物的影响.结果表明,精制清香型铁观音在80℃、150 min、4.0 cm和99℃、120 min、5.5 cm的条件下处理,可使生化品质达到较高.对烘焙温度、烘焙时间和摊叶厚度3个自变量及茶叶生化品质、儿茶素品质指数和苦涩味指数、y-氨基丁酸和茶氨酸含量5个因变量进行双重筛选逐步回归分析的结果表明：烘焙温度为主要影响因素,温度每上升1℃,儿茶素品质指数提高0.7424,儿茶素苦涩味指数提高0.0126;烘焙温度和时间对生化品质、γ-氨基丁酸和茶氨酸含量的影响呈负相关,即低温长时间烘焙有利于功能性氨基酸的富集.经计算,其优化烘焙工艺组合为：85℃、300 min、1.0 cm,此时茶叶中的γ-氨基丁酸含量为1.027 mg·g-1,茶氨酸含量为7.102 mg·g-1.

The influence of baking process on the inclusion changes of Tieguanyin tea

The relationship between the baking conditions and the inclusion changes of Tieguanyin tea was studied by the means of uniform design and double-screening stepwise regression （DSSR）.The involved baking conditions were baking temperature,baking time and thickness of tea.The results showed that,Fen-flavor Tieguanyin tea with high biochemical quality can be baked at 80 ℃ for 150 min with 4.0 cm thickness or at 99 ℃ for 120 min with 5.5 cm thickness.The data was analyzed by DSSR,which have 3 independent variables and 5 dependent variables.The analysis showed that,the baking temperature was the main influence factor;when temperature rose 1 ℃,the catechin quality index increased 0.7424,bitter index increased 0.0126.But baking temperature and baking time had a negative impact on the tea biochemical quality,the content of γ-aminobutyric acid and L-Theanine.The best baking condition was 85 ℃ for 300 min with 1.0 cm thickness to enrich the functional amino acids.After verification,the tea contains 1.027 mg · g-1 γ-aminobutyric acid and 7.102 mg · g-1 L-Theanine.