Mechanism for prolonging cold storage life of Li jujube (Zizyphus jujuba Mill. cv. Lizao) fruit by heat air treatment

To understand the mechanism for prolonging cold storage life of Li jujube fruit by heat air treatment, the effect of treatment with 42℃ heat air for 1 h on Li jujube fruit was studied through analyzing the changes of physiology and biochemistry as well as ultrastructure of postharvest Li jujube fruit during cold storage under(5±1)℃. The results indicate that, during the early storage period under short time treatment with heat air, the activities of amylase and polygalactouronase are effectively decreased; starch content reduction is inhibited; the degradation speed of pectin and the decrease speed of flesh hardness are slowed down, and the release rate of ethylene in fruit is decreased. During the later storage period, the decomposition rate of middle lamella and primary wall of the Li jujube fruit treated with heat air for a short time is delayed, exosmosis of cell contents is inhibited, and the cell structure is protected, so the storage time of Li jujube fruit is prolonged. But the effect of heat treatment on respiratory intensity of jujube fruit is not obvious.