不同做形干燥方式对名优祁红香气成分的影响

Effect of different shaping drying condition on volatil aroma components in famous Keemum black tea

采用顶空固相微萃取与气相色谱质谱联用技术,分别测定不同做形干燥处理(以2种做形干燥方式,2种含水率和3种不同温度为自变量,对应采用2×2×3三因素随机分组实验设计,另加2个对照,共有14个处理组。其中,做形干燥方式:手工做形干燥、机制做形干燥,记为S、J;含水率:15%、20%,以A1、A2表示;做形干燥温度:110、130、150℃,以B1、B2、B3表示)名优祁红的香气成分。结果表明,14组红茶中共鉴定出105种香气组分,主要成分为醇、醛、酯、酮、碳氢、苯环和酸类等7类化合物,这些挥发性物质中以醇类化合物种类最多,其次为醛、酯和烃类化合物,以及少量的酮类和其他物质,其中,150℃做形干燥组(SA1B3)检出的香气成分种类最高,达70种,高出对照组(CK1)15种;最低是手工20%含水率130℃做形干燥组(SA2B2)和机制20%含水率110℃做形干燥组(JA2B1),为47种,低于对照组。对比手工做形干燥组和机制做形干燥组红茶香气成分相对含量,发现前者醛类、酮类、烃类均高于后者,分别高出10.76%、11.67%、3.09%;酯类低于后者,低出21.53%。因此,不同做形干燥处理下的名优祁红,其香气成分在种类和数量上存在一定差异,且最优做形干燥方式为手工做形干燥、含水率15%、做形干燥温度150℃。

Using headspace-solid-phase micro-extraction coupled with gas chromatog-raphy-mass spectrometry（ HS-SPMEGC-MS）,the aroma components in Keemum black tea after different drying treatments were detected,which included a 2 × 2× 3 factorial randomized grouping design plus 2 control groups,2 drying methods,2 water content and 3 temperatures as independent variables,14 treatments in total.Drying methods by hand and by machine,were noted as S and J. Initial moisture contents were 15% and 20%,noted as A1,A2 and A3.Drying temperatures were 110,130 and 150 ℃,noted as B1,B2 and B3.The results showed a total of 105 aroma components were identified in these 14 samples,mainly including 7 kinds of compounds such as alcohols,aldehyde,and esters etc. Among these,alcohols were the most in abundance,followed by aldehydes,esters and hydrocarbons. The most aroma components（ 70 types） were detected in the drying group SA1 B3,which contained 15 components more than the control.The fewest were group SA2 B2 and JA2 B1,only 47 components in each,which lower than control groups. Comparing average relative percentage of all kinds of aroma components between the two drying methods,the contents of aldehyde,ketone and hydrocarbons were higher in drying by hands by 10.76%,11.67% and 3.09%,the contents of esters were lower in drying by hand by 21.53%,respectively.Some aroma compositions were not founded in each drying methods.Therefore,differences of aroma components in kind and quantity of famous Keemum black tea were caused by different drying treatments.The optimal drying method was shaping and drying should be handworked,the shaping in which should be at the temperature of 150 ℃,and the moisture content for the tea leaves ought to be 15% before the process.