从4个季节(每个季节两个等级)共8个安溪铁观音茶样中提取并分离出74种香气组分。通过主成分分析法鉴定出安溪铁观音中的主要特征香气成分，它们分别是：橙花叔醇、法呢烯、吲哚、苯乙醇、反-2-己烯醛、壬醛、苯乙醛、亚油酸甲酯、亚麻酸甲酯、棕榈酸甲酯、顺-己酸-3-己烯酯、苯甲酸-3-己烯-1-醇酯、辛酸-2-苯乙酯、5-正丁基-δ-戊内酯、顺式茉莉酮、法尼基丙酮、棕榈酸、香叶基芳樟醇异构体。利用主成分分析法，基于综合评价函数 F＝β1F1＋β2F2＋…＋βkFk构建了安溪铁观音香气质量的评价模型，以不同特征值的方差贡献率βi(i＝1,2,…,k)为加权系数，利用所建立的模型计算各样本得分，然后进行排序评价各个茶样的香气质量。通过感官评价法进一步对模型评价结果进行了检验，结果显示两种方法具有很好的一致性，表明所建立的方法是可行的。%A total of 74 volatile compounds were extracted and separated from 8 Anxi Tieguanyin tea samples (harvested at four different seasons;two degrees each season). The major aromatic compounds in Anxi Tieguanyin tea were nerolidol, farnesene, indole, phenylethyl alcohol, (E)-2-hexenal, nonanal, benzeneacetaldehyde, methyl linoleate, methyl linolenate, methyl palmitate, (Z)-3-hexenyl hexanoate, 3-hexen-1-ol benzoate, octanoic acid, 2-phenylethyl ester, delta-nonalactone, cis-jasmone, farnesylacetone, palmitic acid, and geranyl linalool isomer as demonstrated by principal component analysis (PCA). A PCA model for the aroma quality evaluation of Anxi Tieguanyin tea was constructed using the variance contribution rates of various eigenvaluesβi (i=1, 2,……, k) as weight coefficients based on the comprehensive evaluation function: F = β1F1 + β2F2 +…+ βkFk and used to calculate aroma quality score for each tea sample for aroma quality evaluation. The evaluation results were in good agreement with those obtained from sensory evaluations, indicating the developed method to be feasible.
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