不同品种白桃(Prunus persica L.Batsch)果汁的品质评价

Quality evaluation of white-flesh peach juices from different cultivars

测定了23个不同白桃品种的12项果汁品质指标和出汁率,借助主成分分析法和聚类分析法筛选核心指标,用层次分析法计算核心指标的权重,利用"合理-满意度"和多维价值理论对不同白桃品种的制汁特性进行综合评价,并根据得分将其分为3个等级,最后用判别分析法建立各等级白桃果汁的品质判别函数。结果表明白:桃果汁的制汁特性可用固酸比、出汁率、褐变度、L*值和总酚含量5个核心指标进行评价,罐桃14号、京玉和庆丰等为适宜制汁的白桃品种,利用19个品种建立各等级的桃汁品质判别函数,建模样本和检验样本的正确判别率均达到100%。

Twelve indicators of peach juices and the juice yield were determined among 23 different cultivars. The core indicators were identified by Principal Component Analysis （PCA） and Cluster Analysis. The weights of core indicators were estimated by Analytic Hierarchy Process （AHP）. ＂Reasonableness and Satisfaction Index＂ and Multi- value Theory were applied to establish the quality evaluation model. The 23 cultivars were graded into three levels ac- cording to the method of Cluster Analysis based on their scores. The discrimination functions were established for peach juice quality by Discriminant Analysis. According to the results, the ratio of SSC/TA, juice yield, brown de- gree, L＂ value and total phenolics were the core indicators which were used to evaluate the juice quality. ＂Guantaol4＂ and ＂Jingyu＂ were the most proper euhivars for juice processing and the ＂Dajiubao＂ was the least one among the 23 cultivars. Three discrimination functions were established for peach juice quality, which had satisfactory recognition accuracy up to 100% （modeling samples and test samples）. The discrimination method are very effective in evaluating the peach juice quality.