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This study evaluated the effects of 1‐methylcyclopropene (1‐MCP), chitosan (CTS), and combined 1‐MCP and CTS (1‐MCP&CTS) on the postharvest quality, bioactive compounds, antioxidant enzymes, and antioxidant capacity in Hui jujube during cold storage (0 ± 1°C and 90% ± 5% relative humidity for 75 d). The 1‐MCP&CTS treatment inhibited respiration rate and ethylene production, delayed the degradation of total soluble solids and titratable acid, and alleviated the decreases in total polyphenols, total flavonoids, anthocyanins, and ascorbic acid during storage. Compared to the control fruit, 1‐MCP&CTS treatment resulted in higher activities of superoxide dismutase, catalase, and ascorbate peroxidase and higher antioxidant capacity. The antioxidant capacity was positively correlated with the contents of bioactive compounds and antioxidant enzymes and negatively correlated with respiration rate and ethylene production. The results suggest that 1‐MCP and CTS can be applied to maintain the antioxidant systems and delay the senescence of jujube fruit. Novelty impact statement: The effects of 1‐MCP, CTS, and 1‐MCP&CTS during jujube storage were evaluated.Among treatments, the combined treatment had the best preservation effect.1‐MCP&CTS maintained bioactive compounds, antioxidant capacity, and storage quality of Hui jujube. [ABSTRACT FROM AUTHOR]

In this study, headspace solid‐phase microextraction coupled with gas chromatography‐mass spectrometry (HS‐SPME‐GC/MS) was used to identify individual volatile compounds in five jujube varieties, and E‐nose was used to identify their flavor. The results showed that a total of 45 volatile compounds were detected by GC‐MS in the five varieties, and the proportion of acids was the highest (38.29%–54.95%), followed by that of aldehydes (22.94%–47.93%) and esters (6.33%–26.61%). Moreover, different varieties had obviously different volatile components. E‐nose analysis showed that the R7 and R9 sensors were more sensitive to the aroma of jujube than other sensors. The strong response of R7 sensor was attributed to terpenes (or structurally similar substances) in jujube fruit, such as 1‐penten‐3‐one, 2‐octenal, (E)‐2‐heptanaldehyde, and (E)‐2‐hexenal and that of R9 sensor was attributed to the cyclic volatile components such as benzaldehyde, benzoic acid, and methyl benzoate. The multivariate data analysis (PCA, OPLS‐DA, and HCA) of the results of GC/MS and E‐nose showed that the five varieties could be divided into three groups: (1) Ziziphus jujuba Mill. cv. Huizao (HZ) and Z. jujuba cv. Junzao (JZ). Acids were the main volatile components for this group (accounting for 47.44% and 54.95%, respectively); (2) Z. jujuba cv. Hamidazao (HMDZ). This group had the most abundant volatile components (41), and the concentrations were also the highest (1285.43 µg/kg); (3) Winter jujube 1 (Z. jujuba cv. Dongzao, WJ1) and Winter jujube 2 (Z. jujuba cv. Dongzao, WJ2). The proportion of acids (38.38% and 38.29%) and aldehydes (40.35% and 38.19%) were similar in the two varieties. Therefore, the combination of headspace solid‐phase microextraction coupled with gas chromatography‐mass spectrometry and E‐nose could quickly and accurately identify the volatile components in jujube varieties from macro‐ and microperspectives. This study can provide guidance for the evaluation and distinguishing of jujube varieties and jujube cultivation and processing. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effects of 1‐methylcyclopropene (1‐MCP) treatment on the storage quality and volatile compounds of Xiaobai apricot fruit stored at 4°C. Three groups of apricot fruit were set in a 1 m3 container and treated with 0.5, 1, 1.5 μl/L of 1‐MCP for 20 hr at 20°C, respectively. The physiological parameters and volatile compounds of 1‐MCP‐treated and untreated apricot fruit were examined. Twenty‐eight volatile compounds were isolated and identified, and the main aroma compounds were determined to be linalool, α‐terpenol, 6‐methyl‐5‐hepten‐2‐one, theaspirane, benzaldehyde, nonanal, linalyl formate, butyl acetate, and hexyl acetate. The result showed that 1 μl/L of 1‐MCP treatment had the most effective impact on delaying the ethylene production, respiration rates, soluble solids content, and maintaining firmness, titratable acidity, and ascorbic acid content, and 0.5 and 1 μl/L inhibited the production of most volatile compounds during storage. Novelty impact statement: 1‐MCP treatment can keep apricot fruit in good quality, but decreased the production of Volatile compounds.Linalyl formate and the aspirane were isolated and identified, and these were hardly found in apricot fruit in the previous report.A high concentration of 1‐MCP treatment may promote the production of volatile compounds. [ABSTRACT FROM AUTHOR]

Harvested winter jujube fruit undergo rapid senescence and oxidation, which seriously affects their commercialization. This study aimed to investigate the effects of exogenous salicylic acid (SA) treatment on postharvest quality, antioxidant systems, and differential expressed genes (DEGs) of winter jujube during cold storage. We found SA treatment delayed weight loss and decay, inhibited respiratory rate and ethylene production, and maintained higher activities of superoxide dismutase, catalase, ascorbic acid peroxidase, and glutathione reductase. It also increased contents of phenols, flavonoids, ascorbic acid, and reduced glutathione. Transcriptome analysis showed that the DEGs in comparison groups were mainly involved in metabolic pathways, secondary metabolic biosynthesis, and plant hormone signal transduction. SA treatment up-regulated the antioxidant-related genes (SOD1/3 , GRXC2 , APX1 , and CTV5), and also participated in the regulation of plant hormone signaling related genes (ABF4, SnRK2, PYL2, PP2C, MKK4, ERF, EBF2 and JAZ), senescence associated genes (PME15, CTL2, INVE, ADH2, SAG21, SRK2H and ATG4), and transcription factors (MYB, ERF, C2H2, MTB3, WRKY, and FAR1). Therefore, we concluded that exogenous SA could enhance the antioxidant systems and maintain storage quality by regulating related gene expressions and metabolic pathways. These results contribute to understand the mechanism of delaying ripening and senescence of winter jujube. • SA treatment was conducive to maintaining storage quality of winter jujube. • SA treatment increased antioxidant enzyme activities and bioactive substance contents. • Exogenous SA up-regulated the antioxidant-related differently expressed genes. • SA treatment inhibited plant hormone signal transduction and senescence process. [ABSTRACT FROM AUTHOR]

Winter jujube inevitably suffers from rapid oxidation after harvest, leading to quality deterioration. Temperature plays an important role in the ripening and senescence of fruit. This study aimed to investigate the effect of different temperatures on the quality parameters, antioxidant enzyme activities, and antioxidant enzyme-related gene expressions of winter jujube. Jujube fruit were stored at room temperature (RT: 25 °C) and low temperature (LT: 0 °C) for 35 days, respectively. Compared with RT, LT maintained higher firmness and lower respiratory rate, inhibited the increase of weight loss, decay rate, total soluble solids (TSS) and reddening rate, delayed the decrease of titratable acid (TA) and ascorbic acid (AsA) content. LT-stored jujube fruit also showed higher antioxidant enzyme activities and related gene expression (Mn-SOD, APX, and GR , except CAT). We observed a significant correlation between fruit quality parameters and antioxidant enzymes, suggesting that fruit senescence is closely related to antioxidant ability. In short, LT delayed the ripening rate by inducing a series of physiological and molecular reactions, thereby improving antioxidant levels and storage quality. • Jujube ripening and senescence were investigated at room temperature and 0 °C. • Low temperature storage reduced respiration, weight loss, and decay. • Low temperature induced higher antioxidant enzyme activities and gene expressions. • Fruit quality parameters and antioxidant enzymes correlated significantly. • Fruit senescence may be closely related to the plant's antioxidant ability. [ABSTRACT FROM AUTHOR]

• The effects of storage temperature on Diaogan apricot were investigated. • Ice-temperature storage helped retain fruit firmness and pectin/cellulose content. • Ice-temperature storage enhanced the activities of antioxidant enzymes. • Ice-temperature storage ameliorated weight loss and respiration. • Ice-temperature is effective for maintaining apricot quality during storage. Ice-temperature storage is a new refrigeration method with temperatures ranging from sub-zero to the freezing point of the product being stored. However, few reports have evaluated the effects of ice-temperature (IT) storage on the cell wall metabolism and reactive oxygen metabolism of Xinjiang-grown Diaogan apricots. In this study, to determine the effects of ice-temperature storage on cell wall metabolism and reactive oxygen metabolism in Diaogan apricots, apricots were stored at −1.5 °C to−2.0 °C (ice temperature, IT), 0 °C–1 °C (low temperature), and 10 °C (control) for 70 d with sampling and evaluation every 10 d. Compared to storage at low temperature and 10 °C, IT storage (1) better maintained the firmness, ascorbic acid content, pectin content, and cellulose content of the fruit; (2) suppressed the activities of polygalacturonase and cellulase; (3) inhibited the rate of weight loss, respiration rate, ethylene production, plasma membrane permeability, and malondialdehyde accumulation; and (4) improved the activities of peroxidase, catalase, superoxide dismutase, and ascorbate peroxidase, thereby inhibiting the accumulation of hydrogen peroxide and superoxide anion during storage. Overall, the results show that IT storage is an effective way to improve the storage quality and antioxidant capacity of Diaogan apricots. [ABSTRACT FROM AUTHOR]

• Three kinds of preservatives (1-MCP, chitosan, Nata) were applied to jujube storage. • Comparison of different storage temperatures reflects the advantages of low temperature. • Comparison of different treatments shows the advantages of composite membrane treatment. The purpose of this study was to explore the effects of coating treatment using a composite of 1-methylcyclopropene (1-MCP), chitosan and natamycin (NATA) on the quality and antioxidant capacity of Chinese jujube (Zizyphus jujuba cv. Junzao) stored at different temperatures (Room temperature and 0 ± 1 °C). Respiration, ethylene release, and decay rates; Malondialdehyde (MDA); total phenol, flavonoid, and Ascorbic Acid (AsA) contents; Peroxidase (POD), Polyphenol Oxidase (PPO), Superoxide Dismutase (SOD), and Ascorbate Peroxidase (APX) activities; and free-radical scavenging ability were considered. The results showed that the low-temperature composite coating treatment of Chinese jujube effectively inhibits its decay and MDA accumulation; delays its respiration and ethylene release peaks; increases the activities of the antioxidant enzymes POD, SOD, and APX; and inhibits its PPO activity. Furthermore, the jujube retains its high concentrations of total phenols, flavonoids, and AsA as well as its free-radical-scavenging rate into the later storage period. Thus, the low-temperature composite coating treatment is an effective method for improving the postharvest quality of Chinese jujube and extending its preservation period. [ABSTRACT FROM AUTHOR]