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During storage, winter jujube often experiences physiological disorders that can result in postharvest quality deterioration. To address this concern, a combination of 1% chitosan (CTS) and varying concentrations (0.02, 0.2, and 2 mg mL-1) of ε-polylysine (ε-PL) was applied. The findings indicated that the treatment involving the combination of 1% CTS with 0.2 mg mL-1ε-PL exhibited superior efficacy in preserving the hardness and titratable acid content of winter jujube. Additionally, the jujube fruits of this treatment exhibited a deceleration in the rise of decay incidence, red index, and weight loss rate. Simultaneously, the application of CTS combined with ε-PL treatment improved the levels of antioxidant enzyme activities (SOD, CAT, POD, and APX) and enhanced contents of antioxidant compounds (AsA and GSH). Moreover, the generation of reactive oxygen species (H2O2 and O2-.) was suppressed. Consequently, CTS combined with ε-PL treatment effectively enhanced postharvest quality and regulated antioxidant status of winter jujube. [ABSTRACT FROM AUTHOR]

Abstract: The effect of ultraviolet irradiation combined with chitosan coating on fresh jujube under ambient temperature was investigated. In the first period, the jujubes were irradiated for 4, 6, 8, 10 min at 253.7 nm ultraviolet, or coated with 1%, 1.5%, 2% and 2.5% of chitosan, respectively. In the second period, the jujubes were firstly irradiated 6 min, and then coated with 1.5% of chitosan. The result showed that combined treatment could reduce decay incidence of jujubes and restrain increase of respiration rate, weight loss, malonaldehyde content and electrolyte leakage of jujubes. Furthermore, the activities of superoxide dismutase, peroxidase, and catalase were maintained at higher level, and the decrease of ascorbic acid and chlorophyll was restricted. The present data indicated that treating post-harvest jujubes with ultraviolet irradiation combined with chitosan coating was an effective method, and might be considered in commercial application for preservation of postharvest fruit. [Copyright &y& Elsevier]

Abstract: The effect of 1% chitosan film with 0.04% nano-silicon dioxide on the qualitative properties of harvested jujube under ambient temperature was investigated. After 32d, the red index, decay incidence, weight loss, and respiration rate of the coated jujubes were lower compared with those of the control. The lower phenylalnine ammonialyase activity and higher activities of scavenger antioxidant enzymes (i.e., superoxide dismutase, peroxidase, and catalase) of the coated jujubes can be attributed to the compound coating. Increased malonaldehyde in the coated jujubes was restrained. Composite coating had shown to be superior in preserving total flavonoid than chitosan coating alone. But no differences were observed in terms of vitamin C loss and total polyphenol content between composite coating and control. Coating jujubes with chitosan+nano-silicon dioxide will be a promising alternative if nano-silicon dioxide is allowed for food use. [Copyright &y& Elsevier]

The effect of chitosan (0.1 mol/L) combined with sodium silicate (100 mmol/L) treatment on Alternaria rot caused by Alternaria alternata in postharvest jujube fruit (Ziziphus jujuba Mill. cv. Dongzao) was studied. The results showed that chitosan combined with sodium silicate treatment significantly reduced the lesion diameter, decay incidence, red index and weight loss of jujube fruit compared with control samples. Combining treatment increased the ascorbic acid, flavonoids, total phenolic compounds and lignin content. The level of superoxide anion (O2·-) and hydrogen peroxide of treated samples was also increased compared with the control samples. Meanwhile, the activities of phenylalanine ammonia lyase, polyphenol oxidase, superoxide dismutase, peroxidase, chitinase and β‐1,3‐glucanase were also accumulated in treated jujube samples, while the activity of catalase markedly decreased. These results indicated that chitosan combined with sodium silicate treatment could induce the disease resistance of postharvest jujube. Therefore, coating postharvest jujube using chitosan combined with sodium silicate could promise as a novel method for preventing the disease infection of postharvest jujube. [ABSTRACT FROM AUTHOR]