桃果实品质评价因子的选择

为了给桃品质评价指标的确定提供理论依据，该文研究测定了北京市郊栽培的水蜜桃、蟠桃、油桃3个品系的19个品种桃的可溶性固形物、可滴定酸、固酸比等主要品质指标，并采用“主成份分析”和“聚类分析”法对各品质指标进行分析。结果表明，在桃多个品质指标变量之间存在着相对独立性和密切相关性，经主成份分析后将许多相关的随机变量压缩成几个综合指标，通过系统聚类分析把多个品质指标分成了5类，最终将品质指标简化为单果重、硬度、水分含量、固酸比和风味5个具代表性的指标；又通过“合理—满意度”和多维价值理论的合并规则进行综合评价，评价结果为，水蜜桃品系中晚蜜、绿化9号和北京38号的表现性较好；蟠桃品系中以瑞蟠1号和碧霞蟠桃品质较优；油桃品系中品质最佳的为瑞光19号。这一结果与感官评价所得结果有高度正相关性。

Selection of factors for evaluating peach(Prunus persica) fruit quality

To support theoretic basis for the selection of indicators for evaluating the quality of peach. Quality parameters of 10 varieties in honey peach family, 6 varieties in flat peach family, and 3 varieties in smooth-skinned family grown in Beijing rural areas, including fruit weight, fruit shape index, skin color, flesh firmness, contents of total soluble solids (TSS), titratable acid (TA), flavor, etc, were measured. The data were analyzed by principal component analysis and systematic cluster analysis. Results show that there is either relative independence or close correspondence among the characteristics indicators of fruit quality. Based on the above results, 5 indicators stood for a comprehensive system for evaluating peach quality were obtained, which were fruit weight, moisture content, flesh firmness, flavor, and the ratio of TSS to TA. The data of these 5 indicators of all tested fruits were analyzed with rationalization-satisfaction index and the consolidating rule of multidimensional value theory. According to the results, Wanmi, Lvhua 9, and Beijing 38 in honey peach family, Ruipan 1 and Bixia in flat peach family, Ruiguang 19 in smooth-skinned family were of good quality, which was closely relative to the results of organic evaluation.