热处理对龙眼果实采后生理和贮藏品质的影响

Effects of Heat Treatment on Postharvest Physiology and Storage Quality of Longan Fruits

探讨了热处理对龙眼果实采后生理和品质的影响。用50℃热水处理龙眼果实10 min,晾干,用聚乙烯薄膜袋密封包装,置于(15±1)℃下贮藏。贮藏期间定期测定果实呼吸强度、失重率、果皮细胞膜相对渗透率、果皮丙二醛(MDA)、叶绿素、类胡萝卜素、花色素苷、类黄酮和总酚含量、果肉可溶性固形物(TSS)、可滴定酸(TA)、可溶性糖、还原糖和维生素C含量、果皮褐变指数和果肉自溶指数等指标。结果表明:与对照果实相比,50℃热水处理10 min,可有效降低采后龙眼果实呼吸强度,减少果实失重率,延缓果皮MDA含量和细胞膜相对渗透率的升高,保持较高的果皮叶绿素、类胡萝卜素、花色素苷、类黄酮和总酚含量和果肉TSS、TA、可溶性糖、还原糖和维生素C等营养成分含量,降低果皮褐变指数和果肉自溶指数。该处理可有效延缓采后龙眼果实衰老,提高龙眼果实贮藏品质。

Effects of hot water treatment on postharvest physiology and storage quality of longan （Dimocarpus longanLour.） fruits were investigated. The longan fruits were treated with hot water at 50 ℃ for 10 minutes. The fruits were dried prior to packaging and stored at （15＋1）℃. During fruit storage, fruit respiration rate, cell membrane relative leakage rate in pericarp, contents of malondialdehyde（MDA）, chlorophyll, carotenoid, anthocyanin, flavonoid and total phenolics in pericarp, contents of total soluble solids（TSS）, titratable acid（TA）, soluble sugar, reducing sugar and vitamin C in pulp, pericarp browning index and aril breakdown index of harvested longan fruits were determined. The results showed that compared with the control fruits, the treatments with hot-water could effectively reduce fruit respiration rate, decrease fruit weight loss, delay the increase of MDA content and cell membrane relative leakage rate in pericarp, keep higher contents of chlorophyll, carotenoid, anthocyanin, flavonoid and total phenolics in pericarp, and higher contents of pulp nutritional ingredients such as TSS, TA, soluble sugar, reducing sugar and vitamin C, decrease pericarp browning index and aril breakdown index. From the results it can be concluded that hot water treatment at 50 ℃ for 10 minutes can effectively delay fruit senescence, increase fruit quality of harvested longan fruits.