GC-MS结合化学计量学用于探究六大茶类香气形成的差异  

Analysis of the aroma formation in six categories of teas by GC-MS combined with chemometrics

作　　者：谢关华 陆安霞 欧阳珂 孟庆[1] 童华荣[1] XIE Guanhua;LU Anxia;OUYANG Ke;MENG Qing;TONG Huarong(College of Food Science,Southwest University,Chongqing 400715,China;Faculty of Agriculture,Forestry and Food Engineering,Yibin University,Yibin 644000,China)

机构地区：[1]西南大学食品科学学院,重庆400715 [2]宜宾学院农林与食品工程学部,四川宜宾644000

出　　处：《食品与发酵工业》2021年第20期260-270,共11页Food and Fermentation Industries

基　　金：重庆市现代山地特色高效农业茶叶产业技术体系(2020-7)。

摘　　要：该研究运用气相色谱质谱联用技术(gas chromatography-mass spectrometry,GC-MS)对梅占(Camellia sinensis var.Meizhan)品种茶树鲜叶加工而成的六大茶类中挥发性化合物进行了检测,通过统计分析筛选每种茶的特有成分及关键变量,通过计算化合物气味活性值(odor activity value,OAV)和香气特征影响值(aroma character impact value,ACI)评价各挥发性化合物对成茶香气的贡献度,以此来探究六大茶类香气形成的差异。结果表明,除每种茶类的特有成分外,共筛选出罗勒烯、(E)-橙花叔醇、β-石竹烯等10种化合物,其含量变化对茶类香气的差异化形成起重要作用。绿茶和白茶中呈现清花香属性的化合物在其香气构成中的比例较高,黄茶中青香、花香、果香化合物的比例较均衡,乌龙茶中呈现花香的化合物比例较高,红茶中花果香化合物占主要优势,黑茶中果香化合物的比例明显高于其他茶类。不同的加工方式通过影响挥发性化合物的组成和含量来调控六大茶类香气的形成,对茶叶香气有主要贡献的化合物多为六大茶类共有成分,各茶类香型差异的关键在于优势化合物的组成比例不同。GC-MS was employed to detect the volatile compounds in six categories of teas processed from fresh leaves of the single tea cultivar,Camellia sinensis var.Meizhan in this study.Moreover,to compare the differences among the six teas on the aroma formation,the characteristic components and key variables of teas were screened by statistical analysis,and the contribution of each volatile compound to the aroma was evaluated by calculating the odor activity value(OAV)and aroma character impact value(ACI).The results showed that in addition to the characteristic components of each tea,a total of 10 compounds,including ocimene,(E)-nerolidol,β-caryophyllene,etc.,were screened out,and the changes of their content play a major role in the formation of differential tea aroma.Moreover,green tea and white tea possessed high proportions of compounds with fragrant properties in their aroma composition.Yellow tea had a relatively balanced proportion of green,floral,and fruity aroma compounds.Oolong tea had a high proportion of floral aroma compounds.Further study revealed that floral and fruity aroma compounds were dominant in black tea,and the proportion of fruity aroma compounds in dark tea was significantly higher than in other teas.Besides,different processing methods could regulate the aroma formation of the six categories of teas by influencing the composition and content of volatile compounds.We have also confirmed the important contribution of the common components in the six teas to the aroma,and the composition ratios of dominant compounds could be deemed as the critical factor that influences the aroma type of each tea.

关 键 词：梅占 GC-MS 化学计量学 气味活性值 挥发性化合物 香气形成 

分 类 号：TS272.7[农业科学—茶叶生产加工] O657.63[轻工技术与工程—农产品加工及贮藏工程]