为提高茶提取物的风味品质，本文基于酶制剂现代生物技术的应用，利用外源酶或酶助剂有针对性地改善茶叶中特定成分的构成与含量，从而使茶的加工过程真正变得可调可控，实现对其风味品质的改善或重构塑造。以蒸青绿茶为原料，通过多种酶制剂及辅助手段的联用、采用有效裂解选择与定向控制综合浸提处理手段后，依次经去渣、离心、浓缩、调配、杀菌、灌装工艺过程，最终制备成独具风味的绿茶浓缩液。结果表明酶处理产品具有清香高、浓而持久、入口鲜爽、醇厚无苦涩的滋味品质特征，且茶叶有效利用率由30%增至46%，提高幅度达53.33%。在处理过程中观察到叶片组织结构被分解破坏，茶汤中肉眼可见絮状物增多，可溶性固形物含量不断增加，特别是与风味高度相关的指标还原糖和游离氨基酸总量的增长率明显高于对照组。在呈味物质方面，浓缩液中呈鲜味的氨基酸含量成倍增加，24种游离氨基酸增加了3.5倍，同时不良风味物质茶多酚及咖啡碱比例下降，而儿茶素的组成、酚氨比更趋合理，使得整体风味更加醇和、滋味饱满与协调。在香气总量和组成方面，经由酶处理后茶汤的挥发性成分总量提高了33.6%，其中芳樟醇的含量提高了75.3%。醇系化合物以及醛系化合物是浓缩汁中体现清新花香型的主要呈香物质，通过关键风味物质的有效生物降解释放与浸出调控调节，实现对茶提取物的风味品质改善与重构调控研究。%In order to improve the sensory quality of green tea extracts comprehensively, steamed green tea, the raw materials in this paper, was extracted by a series of enzymes and then experienced deslagging, centrifuge, concentration, blending and finally was sterilized and filled into green tea concentration with unique flavor. Our study shows that the tea infusion of enzyme-treated group had high and lasting fragrance and also owned the characteristic of umami, less bitter taste compared with untreated. What’s more, the total yield was found raised from 30% to 46%, Increased by 53.33%. In the process of enzymolysis, tea leaf tissue was broken constantly and floccules increased accordingly. Meanwhile, soluble solid content of tea infusion increased significantly, especially in the total reducing sugar and the total free amino acid. By measure of the flavor components, the growth of tasty amino acid and the decrease percent of tea polyphenol and catechins were observed in enzyme-treated group, which lead to more coordinating mouthfeel than control. The aroma analytical data suggested that the total volatile components and linalool increased by 33.6% and 75.3% respectively under enzymes treatment. Alcohols and aldehydes which present fresh flowery scent were the main kinds of volatiles in the green tea concentration. We achieve to improve and reshape the quality, flavor and aroma of tea extract through effective adjustment, biodegradable release and regulation of key flavor compounds.
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