摘要
为了提高古树茶香气质量评价的客观性和科学性,利用顶空固相微萃取(Solid Phase Micro-Extraction,SPME)结合气相色谱-质谱法(Gas Chromatography-Mass Spectrometry,GC-MS),从云南的13个古树普洱生茶样品中分离鉴定出94种挥发性香气组分,通过主成分分析鉴定出主要的特征香气成分,分别是:芳樟醇及其氧化物、橙花叔醇、香叶醇、β-紫罗酮、香叶基丙酮、(Z)-2-癸烯醛、β-环柠檬醛、壬醛、己酸-反-2-己烯酯和水杨酸甲酯。另外,利用主成分分析法,基于综合评价函数F=β_1F_1+β_2F_2+…+β_kF_k构建了古树普洱生茶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,用所建立的模型计算各样本得分并排序来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,表明所建立的质量评价模型是可行的。
This study aimed to enhance the objectivity and scientificity of the aroma quality evaluation of Pu-erb raw tea made from ancient trees of Yunnan.A total of 94 volatile compounds were separated and identified from 13 tea samples by SPME and GC-MS.In addition, major characteristic aromatic components were identified by principal component analysis(PCA), which were Linalool and its oxides, Nerolidol, Geranio1,β- Ionone, Geranyl Acetone, ( Z ) - 2 - Decenal, beta- Cyclocitral, Nonanal, (E)-2-hexenyl ester Hexanoic acid,and Menthyl Salicylate.In addition, a PCA model for the aroma quality evaluation of Pu- erh raw tea made from ancient trees was constructed based on the comprehensive evaluation function: F =,β1F1 +β2F2 +…+βk Fk, which used the variance contribution rates of various eigenvaluesβi ( i = 1,2,…, k) as weight coefficients.The model was used to calculate and rank aroma quality score of each tea sample for aroma quality evaluation.The evaluation results were in good agreement with those obtained from sensory evaluation, which indicated that it was feasible to use this model to evaluate the aroma quality of pu-erh raw tea made from ancient trees.
出处
《食品工业科技》
CAS
CSCD
北大核心
2017年第15期264-269,279,共7页
Science and Technology of Food Industry
关键词
古树
普洱生茶
香气
质量评价模型
主成分分析
ancient trees
Pu- erh raw tea
aroma
model of quality evaluation
principal component analysis (PCA)