关键词: 冻梨, 品质, 品种筛选, 相关性分析, 主成分分析, 模糊综合评判

Abstract: 【Objective】 In order to find out the key indicators and select suitable pear cultivars for freezing, different frozen pears were selected as the research objects to analyze their frozen quality. 【Method】 There were 13 quality indicators and sensory evaluation of fifty-nine frozen pear cultivars were evaluated, in which, the quality indicators included peel L^*, flesh L^*, a^*, b^*, h, soluble solid content (SSC), titratable acid (TA) content, the ratio of soluble solid content to titration acid content (SSC/TA), juice yield, pH, stone cell content, alcohol content and juice leakage. The correlations of 13 quality indicators and sensory evaluation were analyzed and the principal components analysis (PCA) was used to screen the key indicators. Then the fuzzy evaluation method was used to rank the pear cultivars based on their suitability for frozen.【Result】Correlation analysis showed that considerable variations were found in different frozen quality indicators and sensory evaluation among tested pears. Peel L^* showed a positive correlation with juice leakage rate (P＜0.05), flesh L^* was significantly correlated with flesh a^* andb^* (P＜0.01), and flesh h showed a negative relationship with flesh a^* (P＜0.01). In addition, the sensory evaluation was significantly correlated with the flesh L^*, TA content, SSC/TA, Stone cell content and juice leakage rate (P＜0.01). The PCA results showed that the eigenvalues were greater than 0.9 and the cumulative proportion was 74.257% of the first four principal components. The first principal component was named taste factor (TF), it contained 37.272% information of the total amount. TF was mainly determined by SSC content, the TA content and the pH. The second principal component was named browning factor (BF), it contained 19.687% information of the total amount. BF was mainly determined by flesh a^* and flesh h. The third principal component was named roughness factor (RF), it contained 10.074% information of the total amount. RF was mainly determined by stone cell content. The fourth principal component was named appearance factor (AF), it contained 7.224% information of the total amount. AF was mainly determined by peel L^*. Among the 13 quality indicators, SSC, TA content, pH, flesh a^* andh, stone cell content, peel L^*, together with juice leakage rate contributed the most, so these seven factors were selected as the key indicators for the evaluation of frozen pear qualities. Based on fuzzy evaluations, the cultivars of Jianbali, Shatangli, Ruan'erli, Balixiang, Okusankichi, Baiba Lixiang, Hongnanguo and Reli were selected as the suitable ones (Huangjin Duima was removed because of its high stone cell content). However, the Xianghuang, Hongmacha, Housui, Huanghua, Lshiiwase, Okusankichi, Sumuli, Waseaka and Xinli No.7 were not suitable cultivars to make frozen pears because of the lower SSC and TA contents. Sensory evaluation indicated that the suitable frozen pears had high SSC and TA content, light browning. This was basically consistent with the results of PCA and fuzzy evaluation. 【Conclusion】Based on the quality evaluation, price and market share of 59 pears cultivars, ussurian pear is selected as the most suitable ones to make frozen pear, except for some cultivars with higher stone cell content and lower TA content.

Key words: frozen pears, quality, varieties selection, correlation analysis, principal component analysis, fuzzy evaluation