绿陈茶发酵后主要品质及香气成分的变化

Variation of the primary quality ingredients and aroma components of old green tea after post-fermentation

以绿陈茶为原料通过潮水后固体发酵,分析茶叶中主要品质成分及香气成分的变化。结果表明,发酵后,绿陈茶中的茶多酚、儿茶素总量分别下降了52.87%和87.12%,简单儿茶素降低了80.88%,酯型儿茶素降低了90.66%,其中EGCG降幅达92.7%,但没食子酸含量增加了888.72%;绿陈茶中的游离氨基酸总量下降了53.67%,叶绿素下降了27.6%,但可溶性糖及水溶性果胶含量分别增加了53.4%和50.15%,茶黄素、茶红素和茶褐素含量分别增加了33.33%、15.26%和129.3%。发酵后,茶样中的香气物质总含量相较于绿陈茶增加了235.80%,并新增了香叶醇、苯并环庚三烯,但二甲基-2-异丙基苯和1-甲基萘不再检测出,芳樟醇及其氧化产物发生了剧烈的变化。植醇和3-甲基-2丁烯基苯是所有茶样中含量最多的两类香气成分。经感官评定发酵后的茶样具有典型的四川黑茶品质风格特征。

Post-fermentation was performed on the old green tea to investigate the variation of the quality ingredients and aroma components of tea. The results showed that the contents of polyphenols,catechins decreased by 52.87% and 87.12% respectively after post-fermentation,simple catechins decreased by 80.88% ,ester catechins decreased by 90.66% and among that EGCE decreased by 92.7% ,however the content of GA increased by 888,72%. The contents of free amino acids and chlorophyll decreased by 53.67% and 27.6% respectively after post-fermentation, but the contents of water soluble sugar ,water-soluble pectin, theaflavins,thearubigins and theabrown increased by 53.4%, 50.15%,33.33%, 15.26% and 129.3% respectively. In addition the contents of old green tea aroma components increased by 235.80% after post-fermentation. The content of Phytol and 3-methyl-2-butenyl was the highest of all the aroma components in the different tea. However after post-fermentation, 1 - methyl - Naphthalene and 1,3- dimethyl - 5- （ 1 - methylethyl ） - Benzene was not be discovered,but the new components e.g. geraniol and benzocycloheptatriene were discovered. LinalooI-L and their oxidation products had also taken profound changes during post-fermentation. Overail, after post-fermentation,the characteristic of Sichuan dark tea was formation.