基于多元统计法的南丰蜜橘品质评价指标的选择

Evaluation of fruit quality of Nanfeng Tangerine based on multivariate statistics

为简化南丰蜜橘果实品质系统评价指标,采用主成分分析和系统聚类法,以20个不同产地杨小-26南丰蜜橘为试材,对其单果质量、果形指数、出汁率、囊瓣数、化渣度、可溶性糖、可滴定酸、维生素C、可溶性固形物(SSC)等9个主要果实品质指标进行了分析。结果表明,在果实品质评价的9个主成分中,前6个主成分的累积贡献率达95.20%。将前6个主成分特征向量进行系统聚类分析,简化后的果实品质评价指标是:果形指数(或出汁率)、化渣度(或囊瓣数)、可滴定酸、维生素C、单果质量(或可溶性糖或可溶性固形物)。选取果形指数(或出汁率)、化渣度、可滴定酸、维生素C、可溶性固形物5个简化指标对南丰蜜橘品质进行聚类分析,在欧氏距离为1.0时,可将供试的20个不同产地南丰蜜橘分为4类,这一结果与实际口感评价结果吻合。

The main fruit quality indices such as simple fruit weight,fruit shape index,juice percentage,soluble sugar,titratable acid,vitamin C and soluble solids content were studied in Nanfeng tangerine cv.Yangxiao-26 from twenty different cultivating regions by using multivariate statistics.The selection types of fruit quality factors were confirmed by means of principal component analysis and systematic cluster analysis.The results revealed that cumulative proportion of former 6 principal components reached 95.20% through principal component analysis with 9 main quality indices.By using systematic cluster analysis with eigenvectors of former 6 principal component,five evaluation factors have been selected to simplify the evaluation course,and these five selected factors were：（1） fruit shape index or juice percentage;（2） melting grade or segment number;（3） titratable acid content;（4） vitamin C content;（5） simple fruit weight or soluble sugar or soluble solids content.The cluster analysis of fruit quality in Nanfeng tangerine was carried out by selecting simplified indices of fruit shape index,melting grade,titratable acid content,vitamin C content and soluble solids content.The fruit quality of Nanfeng tangerine from twenty different production regions could be clustered into four groups according to their euclidean distance of 1.0 and the results were the same with that of their sensory evaluation.