Evaluation of fruit quality of Nanfeng Tangerine based on multivariate statistics

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.