贮藏温度对‘京沧1号’枣果实表皮蜡质的影响

Effect of Storage Temperatures on the Epidermal Wax of Ziziphus jujuba‘Jingcang 1’

为探究不同贮藏温度对枣果实表皮蜡质的影响,明确不同成熟度表皮蜡质的差异,为后续表皮蜡质与果实采后贮藏品质的研究提供理论依据。选取初红期、半红期的‘京沧1号’鲜枣为试材,分别于低温(0±1)℃、货架(10±1)℃和常温(25±1)℃条件下贮藏12 d,观察贮藏过程中果实表皮蜡质超微结构,并测定其蜡质含量及化学组成。结果表明:贮藏前初红期表皮蜡质存在大量裂缝,半红期果实表皮蜡质覆盖完整,且其表皮蜡质含量和组分种类高于初红期;贮藏结束时初红期果实表皮蜡质含量较高、种类更加丰富;果实表皮蜡质中主要化合物为脂肪酸、烷烃、烯烃、醇类、醛类和酯类物质,其中二十烷、二十一烷、棕榈酸、硬脂酸、油酸等含量较高;常温对果实表皮蜡质的影响最大,货架次之,低温影响最小。综上,低温能够延缓枣果实表皮蜡质的形成、保持蜡质的含量及种类不变。研究结果可为后续对表皮蜡质变化与枣果采后贮藏品质相关性的研究提供理论依据。

To investigate the effect of different storage temperatures on the epidermal wax of jujube fruits and clarify the difference in epidermal wax of different maturity to provide theoretical basis for the subsequent research on the epidermal wax and postharvest storage quality of fruits.Z.Jujube‘Jingcang 1’fresh fruits at the early-red and semi-red periods were selected as the test materials,and stored at low temperature(0±1)℃,shelf(10±1)℃and room temperature(25±1)℃for 12 d respectively,and the changes in the ultrastructure of the fruits epidermis were observed and the waxy content and chemical composition were determined during storage.The results showed that a large number of cracks existed in the epidermal waxes of the jujubes in the early-red period before storage,and the epidermal waxes coverage of the fruits in the semi-red period was intact,and the epidermal waxes content and component species were higher than those in the early-red stage.At the end of storage,the wax content of the earlyred jujube fruit epidermis was higher and the species were more abundant.The main compounds in the fruit epidermal waxes were fatty acids,alkanes,olefins,alcohols,aldehydes and esters.Among them,the contents of eicosanes,eicosanoids,palmitic acid,stearic acid and oleic acid were higher.Normal temperature had the greatest effect on fruit epidermal wax,followed by shelf life,and least by low temperature.In conclusion,low temperature can delay the formation of fruit wax and maintain the content and type of wax unchanged.The results can provide a theoretical basis for the further research of the correlation between changes in epidermal wax and postharvest storage quality of fresh jujube.