1- 甲基环丙烯对李果实冷藏及货架期非挥发性风味物质的影响

使用多变量分析方法研究1-MCP对‘黑琥珀’李果实0℃贮藏和随后的20℃货架期间非挥发性的糖、有机酸和氨基酸的影响。单因素试验结果表明：低温贮藏期间，李果实蔗糖和苹果酸含量逐渐下降，D-果糖含量先降后升，其余组分均在贮藏67d时达到释放高峰；货架期间，96d后的货架期非挥发性组分含量均达到高峰。主成分分析结果表明：与出库时相比，冷藏67d后的货架9d时各组分含量均降低，而贮藏后期的货架9d时则升高；冷藏67d时及冷藏96d后的货架期，1-MCP处理均显著降低了糖、酸类物质的峰值，减缓了糖、酸物质的代谢速率，维持了冷藏期间的营养品质并延缓了货架期的品质劣变。偏最小二乘和通径分析结果表明：D-果糖与感官甜酸比呈显著正相关，是主要的直接与间接因子；苹果酸对感官酸度和可溶性固形物(SSC)均有显著正相关性，且对SSC主要通过D -葡萄糖的间接效应来实现；山梨糖醇与pH值呈极显著负相关。

Effect of 1-Methylcyclopropene on Non-Volatile Flavor Substances in Plum during Cold Storage and Subsequent Shelf Life

Post-harvest plum fruits(Prunus salicina cv.Black amber) were treated with 1-methylcyclopropene(1-MCP) and then stored at 0 ℃ for 28,67 or 96 d before shelf-life storage for 9 d at 20 ℃ to deal with the effect of 1-MCP on non-volatile components in plum during cold storage and subsequent shelf life was investigated using multivariate analysis.One-way analysis of variance(one way-ANOVA) showed that the levels of sucrose and malic acid decreased gradually,D-fructose level decreased at first and then increased in plum fruit during cold storage,whereas the peaks of other components productions were detected on day 67 of cold storage.In contrast,non-volatiles in plum fruit reached their peaks on at the end of the shelf life after 96 d of cold storage.Principal component analysis(PCA) showed that the contents of various components in plum fruits stored for 67 d at 0 ℃ decreased at the end of the shelf life compared with those at the beginning,while plum fruits after 96 d of storage at 0 ℃ showed an opposite change during the subsequent shelf-life storage.Because of 1-MCP treatment,the peaks of sugars and acids in plum fruits stored for 67 d and for 96 d significantly dropped during the shelf life,and the metabolic rates of these substances slowed down,the nutritional quality was maintained,and fruit deterioration was delayed.Partial least squares regression(PLSR) and path analysis showed that D-fructose was significantly and positively correlated with sensory sweetness/sourness ratio,and was a major direct or indirect factor.Malic acid correlated significantly and positively with sensory sourness or soluble solids content(SSC),while D-glucose had an indirect impact on SSC.Sorbitol was significantly and negatively correlated with pH value.