Establishing comprehensive evalution system of American No.8 fresh apples based on principal component analysis

Five levels apples were classified by the comprehensive evalution indices of American No.8 fresh apples based on principal component analysis method.In this experiment,thirteen kinds of quality indices of 120 American No.8 fresh apples were determined by using conventional method,and the achieved indices were analyzed by using SPSS 19.0 software which aimed to select principal component factors. The results demonstrated that the former seven principal component factors could reflect the most information of original samples,whose cumulative contribution of variance accounted to 91.490%. The integrated scores were obtained through the former seven principal component values based on the important calculation of the principal component contribution proportion.Then fresh apples were classified into several levels by k- means clustering analysis based on each principal component factor scores and comprehensive scores of fresh apples,and the proportion of each level was 15.00%,28.33%,33.33%,19.17%,4.17%.The comprehensive evaluation and classification model which was established can provide scientific basis for comprehensive quality evaluation and classifying of American No.8 fresh apples.