Quality Evaluation of Different Varieties of Freeze-dried Seedless Grape Crisp

In order to select the most suitable varieties for grape crisp processing,the quality evaluation of freeze-dried seedless grape crisp was carried out. In this study,18 quality indexes such as total sugar,vitamin C contents,total phenol contents and crispness of 10 varities of freeze-dried seedless grape crisp were determined. Based on the descriptive analysis and the principal component analysis,the core indexes for evaluating the quality were selected,while the comprehensive quality was evaluated according to the comprehensive score. The results showed that the output capacity and total sugar contents coefficient of variation were less than 10% in 18 indicators,while the larger coefficient of variation was found in other indicators. There were different degrees of correlation among the indicators. The principal component analysis showed that the cumulative variance contribution rate of the first five principal components was 89.57%,which could reflect the information of the original indicators better. According to these results,six indicators of crispness,total acid contents,anthocyanin contents,a^*,total phenol contents and the output capacity were selected as the core indicators for evaluating the quality of seedless grape crisp. According to the comprehensive scores and rankings of the 10 seedless grape crisp quality evaluation,the grape crisp variety was divided into four grades,‘Zijinzaosheng’,‘Jinxingwuhe’,and ‘Wuhezaohong’ were grade I,which were more suitable for grape crisp processing.