不同产地库尔勒香梨生育期果实品质变化规律及综合评价

Variation law and comprehensive evaluation of fruit quality of Korla fragrant pear from different production areas during growth period

中文关键词:  库尔勒香梨  生育期  果实品质  主成分分析  综合评价

英文关键词:Korla fragrant pear  growth period  fruit quality  principal component analysis  comprehensive evaluation

中文摘要:

      目的 分析库尔勒香梨生育期果实外观与营养品质变化规律, 比较果实品质的区域差异, 对不同产地商品果的品质进行综合评价。方法 采集花后60~140 d内, 不同产区(新疆库尔勒、阿克苏及甘肃酒泉)的9个果园共计81份库尔勒香梨为样品, 测定单果重、纵径、横径等外观品质指标, 并通过直接滴定法测定还原糖和总酸含量, 采用高效液相色谱法分析果实中的柠檬酸、苹果酸、酒石酸、富马酸、丁二酸和山梨糖醇、果糖、葡萄糖、蔗糖含量, 采用方差分析比较生育期果实品质的产地差异, 通过主成分分析法综合评价不同产地来源果实的品质优劣。结果 随着果实的不断成熟, 果肉硬度由7.19下降至2.91 kg/cm2。还原糖的含量由1.1上升到7.3 g/100 g, 总酸由3.63下降到0.71 g/kg。花后60~140 d, 果糖:葡萄糖:山梨糖醇含量比值由1:1.5:7.5上升为1:0.9:0.6, 苹果酸:酒石酸:柠檬酸含量比值由1:0.37:0.03变化为1:0.27:0.13, 糖酸比由24上升到174。成熟期3个产地横径、果形指数、柠檬酸含量在新疆与甘肃产地之间存在显著差异(P<0.05)。主成分分析结果表明, 前4个主成分累计方差贡献率为89.144%, 果形指数、果糖、横径、山梨糖醇、葡萄糖、还原糖、苹果酸、总酸可作为库尔勒香梨品质评价的重要指标。结论 库尔勒香梨在花后60~140 d的生育期内, 果实中山梨糖醇的比例随着成熟度的增加逐渐降低, 果糖和葡萄糖比例显著增加, 有机酸以苹果酸和酒石酸为主, 呈显著下降趋势, 花后140 d糖酸比最大, 风味最好。在采样果园中, 库尔勒3个果园的品质最好, 酒泉3个果园次之, 阿克苏3个果园品质较差。

英文摘要:

      Objective To analyze the variation law of the appearance and nutritional quality of Korla fragrant pear fruit during its growth period, compare the regional differences of fruit quality, and comprehensively evaluate the quality of commercial fruits from different producing areas. Methods A total of 81 Korla fragrant pear samples were collected from 9 orchards in different producing areas (Aksu, Korla, Xingjiang and Jiuquan, Gansu) within 60?140 d after flowering. The appearance quality indexes such as single fruit weight, longitudinal diameter and transverse diameter were measured, the content of reducing sugar and total acid was determined by direct titration, the content of citric acid, malic acid, tartaric acid, fumaric acid, succinic acid and sorbitol, fructose, glucose, and sucrose in the fruit were analyzed by high performance liquid chromatography, variance analysis was used to compare the quality differences of producing areas in growth period, and principal component analysis was used to comprehensively evaluate the quality of fruits. Results With the continuous ripening of the fruit, the firmness of the pulp decreased from 7.19 to 2.91 kg/cm2. The content of reducing sugar increased from 1.1 to 7.3 g/100 g, and the total acid decreased from 3.63 to 0.71 g/kg. From 60 to 140 d after flowering, the ratio of fructose:glucose:sorbitol increased from 1:1.5:7.5 to 1:0.9:0.6, and the ratio of malic acid:tartaric acid:citric acid changed from 1:0.37:0.03 to 1:0.27:0.13, the sugar-to-acid ratio increased from 24 to 174. There were significant differences in transverse diameter, fruit shape index, and citric acid content between Xinjiang and Gansu origins at the maturity stage (P<0.05). The results of principal component analysis showed that the cumulative variance contribution rate of the first 4 principal components was 89.144%, the fruit shape index, fructose, transverse diameter, sorbitol, glucose, reducing sugar, malic acid and total acid could be used as important indicators for the quality evaluation of Korla pears. Conclusion During the growth period of Korla fragrant pear from 60 to 140 d after flowering, the proportion of sorbitol in the fruit has gradually decreased with the increase of maturity, while the proportion of fructose and glucose has increased significantly, the organic acids are mainly malic acid and tartaric acid, which show significant decrease. The largest sugar-acid ratio and the best flavor have been obtained at 140 d after flowering. Among the sampled orchards, the quality of 3 orchards in Korla are the best, followed by the 3 orchards in Jiuquan, and the quality of 3 orchards in Aksu are poor.