不同成熟采收期对清水白桃果实达到完熟时品质的影响(英文)

以软溶质水蜜桃清水白桃为试材,分别在树上完熟的前6、4和2d采样,贮藏于25℃,相对湿度90%的环境条件下至完熟,与树上完熟果实相比较,调查了果实的生理变化、色泽和果汁品质性状,并对完熟果实进行了风味评定。结果表明,贮藏期间的果实乙烯释放量以完熟前2d采收的果实增加最快并在果实完熟时达到最大,树上完熟的果实乙烯释放量最少。树上完熟前6d采收的果实,果皮亮度、果汁的蔗糖含量、“果香型”内酯类物质含量均低于后3次采收的果实,其中以树上完熟前2d采收的果实为最高。相反滴定酸、柠檬酸、天冬酰胺和“清香型”香气物质含量以树上完熟前6d采收的果实最高。完熟果实的风味评定也显示了树上完熟前2d采收的果实综合评价最高,早期采收的果实即使贮藏后达到完熟果肉硬度,甜度和香味少、酸味重。另外,树上完熟的果实肉质粗,酸度低,有怪香味,综合评价不高。

Effect of maturity stage at harvest on quality of ripe Shimizu Hakuto peach (Prunus persica)

Fruit of Shimizu Hakuto peach (Prunus persica Batsch.), a melting white flesh cultivar, were harvested at immature(IM), hard-mature(HM), firm-mature(FM), and tree-ripe(TR) stages, corresponding to 6, 4, 2 and 0 days before the TR stage. All fruit except the TR ones were stored at 25 ℃ until full ripeness before comparison of fruit quality. The rate of ethylene production from the intact fruit increased during storage, the highest being from the FM fruit. Skin L* and C* values and juice sucrose and aromatic lactone contents were significantly higher in HM and FM fruit than in IM and TR fruit after storage. Titratable acidity, citric acid, asparagine, and off-flavor volatile contents were the highest in the IM fruit after storage. The analytical data corresponded well with the sensory evaluation scores, suggesting that the FM fruit was most acceptable. The IM fruit was rated as unsavory because of its finn and less fine texture, low sweetness and aromas and high sourness. From these results, we concluded that Shimizu Hakuto peach should be harvested at the FM stage to supply consumers with fruit of the highest quality. The effective parameters for judging the optimum maturity stage for harvest were discussed.