酿酸茶酿制过程中生化成分变化趋势分析

【目的】研究酿酸茶酿制过程中生化成分变化趋势,为优化酿酸茶酿制工艺提供参考依据。【方法】将粗老茶鲜叶洗净晾干,等量(300 g)放入8个泡菜坛中,加入2.5 L冷开水,再分别加入5、10、15、20、25、30、35和40 g蔗糖(编号1~8号),水密封坛盖后置于阴凉处避光酿制,以新鲜包菜为对照(9号);每隔7 d测定1次酿制品的亚硝酸盐、茶多酚、茶氨酸含量及酿制液pH,并对生化成分及影响因素进行相关性分析。【结果】整个酿制过程中,8个试验组及对照组酿制品的亚硝酸盐含量随酿制时间的延长总体上呈下降趋势;酿制液pH随蔗糖添加量的增加而降低,14 d后基本趋于稳定;除6号和8号外,其他试验组酿制品茶多酚含量均随酿制天数的增加呈下降趋势;试验组及对照组酿制品的茶氨酸含量随酿制时间的延长呈波动式降低趋势,但随蔗糖添加量的增加而增加。酿制至21 d时,以蔗糖添加量为30 g的6号酿制品亚硝酸盐含量及pH最低,茶多酚和茶氨酸含量最高,酿制效果最佳。酿制品亚硝酸盐含量与酿制时间、蔗糖添加量呈负相关;酿制品茶氨酸含量与酿制时间、蔗糖添加量均呈正相关;酿制液pH与酿制品茶多酚、茶氨酸含量间分别呈极显著(P0.01,下同)和显著(P0.05,下同)负相关;茶多酚与茶氨酸含量间呈显著正相关;蔗糖添加量与酿制液pH呈极显著负相关,与酿制品茶多酚含量呈极显著正相关。【结论】粗老茶叶以料液比1:8.3加冷开水、料糖比10:1添加蔗糖后经21 d酿制,制得的酿酸茶茶多酚和茶氨酸含量无明显减少,亚硝酸盐含量低,是一种营养价值较高、极具推广潜力的特色茶饮。

Dynamics of biochemical components in brewing process of brewed sour tea

Objective]Change trend of biochemical components in brewing process of brewed sour tea was investigated, in order to provide theoretical basis for optimizing brewing process of brewed sour tea. Method]Fresh coarse-old tea leaves were cleaned with water and dried in the air;300 g cleaned tea leaves and 2.5 L cooled boiled water was loaded into pick-le jar; 5,10,15,20,25,30,35 or 40 g sucrose(No.1-No.8) was added into every pickle jar,and the neck of pickle jar was covered with water; eight pickle jars were placed in the shade for fermentation,with fresh cabbage(No.9) as control. Contents of nitrite,tea polyphenol and theanine in brewed product and pH value of brewed liquid were determined every seven days. Result]Results showed that,the nitrite contents of all brewed products in eight treatment groups and control group decreased with extension of brewing time in the brewing process of brewed sour tea. Furthermore ,pH value of brew-ing liquid decreased with increasing of sucrose amount,and was basically stable after 14 d. Except No.6 and No.8,the tea polyphenol contents of all brewed products in other treatment group declined with extension of brewing time. In addition , tea polyphenol contents of all brewed products in treatment group and control group showed fluctuating decrease with ex-tension of brewing time,and increased with increasing of sucrose amount. Nitrite content and pH value of all brewed prod-ucts in No.6(adding 30 g sucrose) was the lowest among all treatments at 21 d after brewing, but tea polyphenol con-tent and theanine content were the highest,showing the best brewing effect. Nitrite content in brewed product were signifi-cantly negatively correlated with brewing time and sucrose amount,theanine content were significantly positively correlated with brewing time and sucrose amount. pH value of brewed liquid were significantly negatively correlated with tea polyphenol content(P<0.01,the same below),and significantly negatively correlated with theanine content(P<0.05,the same below). There was significantly positive correlation between tea polyphenol content and theanine content,and there was extremely significantly negative correlation between sucrose amount and pH value of brewed liquid ,but sucrose amount was extremely significantly positively correlated with tea polyphenol content in brewed product. Conclusion]The optimal brewing process of brewed sour tea is as follow:coarse-old tea leaves are added to cooled boiled water at 1∶8.3 of material-liquid ratio,and after adding sucrose at 10∶1 of material-sucrose ratio,coarse-old tea leaves are brewed for 21 days. Tea polyphenol and theanine content of obtained brewed sour tea do not obviously decrease,and nitrite content is low,there-fore,brewed sour tea is a kind of characteristic drink with high nutritional value and market potential.