褪黑素处理对蜂糖李果实的保鲜效应

通过测定蜂糖李贮藏期间果实呼吸强度、失重率、硬度、可溶性固形物、可滴定酸、维生素C(V_C)含量、过氧化物酶(POD)活性、多酚氧化酶(PPO)活性、丙二醛(MDA)含量以及感官品质的变化,研究不同浓度褪黑素(0、50、150、250、350和450 μmol/L)处理对蜂糖李果实采后常温(23±2)℃贮藏过程中保鲜效应影响。结果表明:适宜浓度(150~350 μmol/L)褪黑素处理能够有效地降低蜂糖李果实的呼吸强度和失重率,延迟果实软化、保持果实较高的可溶性固形物和可滴定酸,减少V_C的降解,维持果实较好的感官品质和风味;提高POD活性,抑制PPO活性的上升,降低丙二醛的积累,减轻膜脂过氧化程度,延缓果实的成熟与衰老。实验结果表明,250 μmol/L的褪黑素溶液处理保鲜效果最好。

Effects of Melatonin Treatments on Preservation of Fengtang Plum Fruits

In this study,the effects of melatonin at different concentrations(0,50,150,250,350 and 450 μmol/L)on Fengtang plum(Prunus salicina)were determined by measuring respiration rate,weight loss,firmness,soluble solide content(SSC),titratable acid(TA),vitamin C(V_C),the activity of peroxidase(POD)and polyphenol oxidase(PPO),the content of malondialdehyde(MDA)and organoleptic evaluation of quality of the fruit during storage at room temperature of (23±2)℃. The results showed that appropriate concentration of melatonin(150~350 μmol/L)effectively reduced the respiration rate and weight loss rate of the fruit;delayed the fruit softening,kept higher SSC and TA,inhibited the degradation of V_C,maintained good organoleptic evaluation quality and flavor;at the same time,melatonin treatment improved the activity of POD,reduced the activity of PPO and the accumulation of MDA,thus inhibited the degree of membrane lipid peroxidation,and delayed the maturation and senescence of Fengtang plum. Among the above melatonin treatments,the fruits treated with 250 μmol/L melatonin showed the best effects.