皱皮木瓜果实发育后期品质变化及其成熟阶段的划分初探

Change in Fruit Qualities during the Late Stage of Fruit Development in Chaenomeles speciosa and Its Identification of Fruit Ripening Process

以湖北长阳产皱皮木瓜为材料,测定果实发育后期果实鲜质量、果长、果径、果色、果实硬度以及果肉干物质量、可溶性糖含量、总酸含量和总黄酮含量等品质指标的动态变化,划分不同成熟阶段,为判断果实适宜采收期、实现优质生产提供理论参考。结果表明：（1）皱皮木瓜果实发育后期果实鲜质量、果长、果径、果肉干物质量和可溶性糖含量均呈现上升趋势;果色由绿色、黄绿色渐变为淡黄色到黄色;果实硬度、果肉总酸和总黄酮含量呈先上升后下降趋势。（2）各品质指标快速变化的时间区域存在差异,果实鲜质量在花后105-150d增加较快,果色在150d后逐渐变黄,果实硬度在花后135-165d快速下降,果肉总酸、总黄酮含量则在花后105-120d快速增加至峰值。（3）根据主成分分析结果和各品质指标的变化特点,可初步将皱皮木瓜果实发育后期划分为未成熟（花后105d之前）、早期成熟（花后120-150d）和成熟（花后165-180d）3个阶段。研究表明,随着果实成熟度的提高,皱皮木瓜果实鲜质量、果色、果肉干物质量、可溶性糖含量等指标不断升高,果实硬度逐渐下降,其食用加工品质不断提升,而在早期成熟阶段（花后120-150d）果实的药用品质则相对较高。

In order to reveal the features of quality changes and identify the fruit ripening process,we investigated fresh fruit weight, fruit length, diameter, color, flesh firmness, dry matter content of pulp, soluble sugar content of pulp,total acid content of pulp, and total flavonoids content of pulp of Chaenomeles speciosa produced in Changyang County of Hubei Province,aiming to illuminate a theoretical basis for determining its proper harvest time and realizing its high-quality production. The results indicated that.. （1） Fresh fruit weight, fruit length, diameter, dry matter content and soluble sugar content of pulp increased during the late stage of fruit development. Fruit color changed from green, yellow green to faint yellow, yellow gradually. Flesh firmness and total acid content and total flavonoids content of pulp increased first and then decreased. （2）There were differences among periods during which quality traits changed rapidly. Fresh fruit weight increased rapidly from 105 to 150 days after full bloom （DAFB）. Fruit color turned yellow 150 DAFB. Flesh firmness decreased rapidly from 135 to 165 DAFB. Total acid content and total flavonoids content of pulp increased to peak rapidly from 105 to 120 DAFB. （3）According to the results of principal component analysis（PCA） and the characteristics of qualities changes, the late stage of fruit devel- opment of Ch. speciosa could be identified three periods：unripe period（before 105 DAFB）, early ripe period （120--150 DAFB）,and ripe period（165- 180 DAFB）. With the fruit maturity of Ch. speciosa, fresh fruit weight, fruit color,dry matter content and soluble sugar content of pulp increased,while flesh firmness decreased, which resulted in that the edibility qualities improved continually. However, the medicinal qualities were relatively high during the early ripe period.