利用茉莉花茶香气指数鉴定其窨制品质及构建决策树模型

在检测分析32个茉莉花茶样挥发性成分的基础上,结合文献引证分析了茉莉花茶、茉莉花、茉莉花干和茶坯的茉莉花茶香气指数(Jasmine tea flavor index,JTF index)。结果表明,JTF值与茉莉鲜花的芳香物质整体挥发水平存在相关性;针对29种特征挥发物对32个茉莉花茶茶样进行主成分分析(Principal component analysis,PCA),得到不同窨制品质的显著聚类特征,推断JTF指数与29种特征挥发物的缺失可作为茉莉花茶窨制品质判定指标。进一步构建这32个茉莉花茶茶样窨制品质的决策树鉴定模型(判别准确率为93.8%),确定特征挥发物的缺失峰数(节点为4)和JTF值(节点为0.915)为判定节点,证实了JTF值与29种特征挥发物的缺失可应用于茉莉花茶窨制品质鉴定与掺假判别,并且建立决策树模型,能够快速、准确检测出不同窨制品质的茉莉花茶,尤其为掺假(如添加香精)等检测提供依据。

The Construction of Jasmine Tea Flavor Index and Decision Tree Model in Identificating Scenting Quality

The ‘jasmine tea flavor’ (JIF) index of well-scented, poor-scented and not-scented jasmine teas was determined by analysis of the volatile components of 32 samples combined with relative references. Results showed that the JTF index was highly correlated with the total volatiles. Principal component analysis (PCA) were performed on 29 volatile compounds in 32 jasmine tea samples. It can be found that the JTF index and 29 volatile compounds were very helpful for identification of fake jasmine teas. In addition, the Quality Determination Model for jasmine tea was constructed with two decision nodes (JTF index=0.915, less than 4 components were missed in the twenty-nine volatile compounds). It was confirmed that the criteria was feasible for the quality identification of jasmine tea. Moreover, the construction of a decision tree model will provide a promising method for quality control and technology development of jasmine tea, especially for the admixture (such as synthetic fragrance oil).