安吉白茶品质综合评价研究

Study on the comprehensive evaluation of the quality of Anjibaicha

目的探明安吉白茶品质状况并构建安吉白茶品质评价体系。方法以16份不同茶样为实验材料,测定分析安吉白茶水分、游离氨基酸、没食子酸、生物碱和儿茶素类等16项指标,通过相关性分析和主成分分析等方法评价不同茶样质量。结果安吉白茶水分含量3.87%~6.78%,游离氨基酸含量3.25%~6.62%,没食子酸含量1.22~3.84mg/g,生物碱含量38.32~45.78mg/g,其中咖啡碱含量33.54~38.73mg/g,可可碱含量3.58~11.01mg/g,茶碱含量0.02~0.46mg/g;总儿茶素含量133.76~166.13mg/g,其中儿茶素没食子酸酯含量0.05~0.21mg/g。16个品质指标变异系数为4.17%~97.87%,其中游离氨基酸和茶碱等指标变异性较大,变异系数在95%以上;而咖啡碱、总儿茶素、表没食子儿茶素没食子酸酯和生物碱等指标变异性较小,变异系数在10%以下。相关性分析表明,安吉白茶品质指标间存在正相关或者负相关,其中有39对指标间呈极显著相关(P<0.01),18对指标间呈显著相关(P<0.05)。主成分分析结果表明,前5个主成分累计贡献率为85.176%。安吉白茶品质评价模型为F=0.391F_(1)+0.221F_(2)+0.156F_(3)+0.147F_(4)+0.085F_(5),其中综合排名前5位的茶样编号为10、9、11、13和4,后5位的茶样编号为5、2、7、1和3。结论基于本研究建立了安吉白茶品质评价模型,采用主成分分析法可以评价安吉白茶品质,该研究结果为安吉白茶的品质改善和质量评价体系的建立提供了理论依据。

Objective To explore the quality and construct the evaluation system of Anjibaicha.Methods The 16 indicators such as water content,free amino acids,gallic acid,alkaloid,and catechins of 16 distinct Anjibaicha samples were determined and then comprehensively evaluated by correlation and principal component analysis.Results Anjibaicha had a water content of 3.87%‒6.78%,a free amino acid content of 3.25%‒6.62%,a gallic acid content of 1.22‒3.84 mg/g,an alkaloid content of 38.32‒45.78 mg/g,including 33.54‒38.73 mg/g of caffeine,3.58‒11.01 mg/g of theobromine,and 0.02‒0.46 mg/g of theophylline.The total amount of catechins were 133.76‒166.13 mg/g,with catechin gallate accounting for 0.05‒0.21 mg/g.The coefficient of variation for the 16 quality indices ranged from 4.17%to 97.87%.The indacators including free amino acids and theophylline had a coefficient of variation of over 95%,while the indicators such as caffeine,total catechins,epigallocatechin gallate,and alkaloids had a coefficient of variation below 10%.The correlation analysis revealed that the indicators of Anjibaicha were either positively or negatively correlated,with 39 pairs of indicators being very significantly correlated(P<0.01)and 18 pairs being significantly correlated(P<0.05).The principal component analysis revealed that the first 5 principal components of cumulative contributed rate was 85.176%.The mathematical model of comprehensive score was established for Anjibaicha samples by principal component analysis:F=0.391F_(1)+0.221F_(2)+0.156F_(3)+0.147F_(4)+0.085F_(5),and the tea samples with the highest numbers were 10,9,11,13,and 4,while the samples with the lowest numbers were 5,2,7,1 and 3.Conclusion Based on this study,it has established the quality evaluation model of Anjibaicha,and the principal component analysis method can be used to evaluate the quality of Anjibaicha.The study’s findings provide a theoretical foundation for future Anjibaicha tea quality improvement and the establishment of a quality evaluation system.