The effects of heat shock (HT), 1-methylcyclopropene (1-MCP), or their combination (HT + 1-MCP) on the quality of fresh jujube fruits during cold storage were studied. Among them, HT showed the best preservation effect on jujube fruits, which was more effective than others in inhibiting the increase of red index, decay incidence, and weight loss and delaying the decrease of firmness, soluble solids content (SSC), titratable acidity (TA), and ascorbic acid (AsA) content. Besides, it could delay the degradation rate of the cell wall to maintain the integrity of cell membrane, and keep the high activity of active oxygen scavenging enzymes. During cold storage, malondialdehyde (MDA) content and relative electrolyte leakage (REL) of the HT group were significantly lower than those of the control group, 1-MCP, and HT + 1-MCP group (p < .05), while superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activities were significantly higher than those of other groups (p < .05). It was concluded that the postharvest HT treatment could effectively delay the senescence and decay of jujube fruits.
Practical applicationsJujube fruits have high nutritional value used for food and medicine. However, they are not tolerant to storage after harvest, resulting in high economic losses. Therefore, it is of great significance to find a suitable method to maintain the quality of jujube fruits.Our results revealed the effect of HT, 1-MCP, and their combination on the quality maintenance of jujube fruits, and found that HT could effectively maintain the quality of them, which could be used as an effective method for keeping jujube fruits fresh. K E Y W O R D S cold storage, delay senescence, enzyme activity, fruit quality, heat shock treatment, Ziziphus jujuba Mill 1 | INTRODUC TI ON Jujube (Ziziphus jujuba Mill.) is originated in China, which belongs to the Rhamnaceae family, with a long cultivation history of over 7,000 years (Xiao et al., 2015). The tree is found throughout the world, mainly in tropical and subtropical areas of Asia, Russia, northern Africa, southern Europe, and India (Hernández et al., 2015). Jujube fruits are widely consumed and popular with people due to their crisp texture, delicious flesh, high nutritional value, and bioactive ingredients (Almansa et al., 2016; Karakaya et al., 2020).