真空充氮及沸水脱咖啡碱工艺对绿茶品质的影响

研究探讨了真空充氮和沸水脱咖啡碱工艺对绿茶品质的影响。结果表明：真空充氮和沸水脱咖啡碱工艺都能够显著改变绿茶挥发性风味成分的组成,使其色、香、味以及功能成分发生了一系列变化。单纯真空充氮处理后,茶样风味接受性下降,挥发性成分相对含量总量减少了39%,检出挥发性成分种类减少27种;酸类、呋喃类和其它杂类挥发性成分组成百分比增加,醇类减少。富集γ-氨基丁酸且脱咖啡碱茶样与只经过富集处理茶样相比,有55种挥发性成分相对含量减少了,有28种挥发性成分相对含量增加了,挥发性成分相对含量总量减少了56%。酸类、呋喃类在脱咖啡碱且富集处理茶样中所占百分比要较未脱咖啡碱富集处理茶样低,风味可接受性提高,说明脱咖啡碱加工工艺能改善高γ-氨基丁酸绿茶产品功能组成和风味可接受性。

Effects of the Treatment of Filling Nitrogen in Vacuum and Decaffeinating with Boiling Water on Quality of Green Tea

This article studied the effects of the treatment of filling nitrogen in vacuum and decaffeinating with boiling water on quality of green tea. Results showed that the two processing technologies could change the constitution of the volatile components significantly, causing a series of change on tea color, aroma, flavor, and constitution of functional components. After filling nitrogen in vacuum singly, the flavor acceptance of tea sample decreased, the comparative content of volatile compound decreased 39%, 27 kinds of detectable volatile compounds and alcohols decreased; the percentage of acid, furan and other volatile compound increased. Compared tea samples after filling nitrogen in vacuum and decaffeinating with boiling water to tea samples after filling nitrogen in vacuum singly, the comparative content of 55 kinds of volatile compounds were decreased, the comparative content of 28 kinds of volatile compounds increased, the total content of volatile compound decreased 56%. The percentage of acid, furan in the tea samples with filling nitrogen in vacuum and decaffeinating with boiling water are lower than those with filling nitrogen in vacuum singly, the flavor acceptance are also improved .These indicated that the process of decaffeinating with boiling water can improve the functional constitution and flavor acceptance of the GABA tea products.