Jerusalem artichoke ( Helianthus tuberosus L.) is valued for its high inulin content and adaptability to marginal lands. This study investigated the changes in inulin content, antioxidant capacity, polyphenol concentrations, and enzymatic activities of eight cultivars during 60 days of cold storage. Inulin levels ranged from 582.43 g/kg (LZJ006) to 809.70 g/kg (LZJ055), with LZJ047 maintaining the highest content throughout storage. The antioxidant potential, as measured by ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, declined across all cultivars, correlating with the reduction in inulin content. The polyphenol content varied significantly, with LZJ119 having 2.17 times more than LZJ010. POD activity increased, while catalase (CAT) and superoxide dismutase (SOD) activities fluctuated during the storage period. Hierarchical Cluster Analysis identified three distinct antioxidant clusters, revealing significant correlations between inulin content and key antioxidant parameters (CAT, FRAP, DPPH). These findings highlight the pivotal role of inulin in preserving the antioxidant system and bioactive properties of Jerusalem artichoke tubers during extended cold storage, providing valuable insights for post-harvest management and cultivar selection.
Edible coatings are an effective strategy for extending the postharvest shelf life of fruits and vegetables. In this study, we developed a chitosan (CS)-based composite coating (CS-AA-Cur) loaded with ascorbic acid (AA) and curcumin (Cur) to synergistically enhance the cold preservation of strawberries (4°C). The coating’s efficacy relied on a dual mechanism: a CS-based physical barrier minimized water loss and oxygen penetration, while synergistic antioxidants (AA and Cur) scavenged ROS, suppressing lipid peroxidation and significantly reducing MDA content. Results demonstrated that the CS-AA-Cur coating significantly improved the postharvest quality of strawberries compared to CS alone. It effectively maintained the physicochemical properties by significantly reducing (p < 0.05) weight loss, decay rate, and the accumulation of oxidative stress markers (MDA and H 2 O 2 ). Additionally, the coating delayed fruit softening by modulating the activity of cell wall-degrading enzymes. Notably, the coating containing 20 mg Cur (CS-AA-Cur 20) exhibited the most potent preservation effect on strawberries, extending their shelf life to 15 days. These findings confirm that by integrating a physical barrier with antioxidant synergistic mechanism, the CS-AA-Cur coating holds immense potential for the preservation of perishable produce.
Cold storage can effectively delay the ripening of ‘Nanguo’ pears ( Pyrus ussuriensis Maxim.). However, the aroma-related esters of ‘Nanguo’ pears decreased after cold storage. In this study, we aimed to investigate the effect of intermittent warming (IW) treatment on the formation of aroma-related esters and unsaturated fatty acid synthesis from cold stored pears. IW-treated pears were exposed to 20 ± 1 °C for 1 day every 20 days during storage at 0 ± 0.5 °C, every 21 days was a cycle and a total of 90 days. The pears in control group were stored at 0 ± 0.5 °C for 90 days. After this 90-day storage, both groups of pears (control and IW-treated) were transferred to a shelf life of 12 days at room temperature. The results showed that, compared with the pears in control group, the productions of aroma-related esters and the expression levels of PuLOX1 , PuADH3 , and PuAAT1 in IW-treated pears were significantly higher during the shelf life ( P < 0.05). At the same time, IW-treated pears maintained significantly higher contents of linoleic acid and linolenic acid ( P < 0.05), which were precursors of aroma compounds. We also found that the expression of PuFAD2 and PuFAD3 had significant positive correlation with the contents of unsaturated fatty acids ( P < 0.05). The significantly higher expression levels of PuFAD2 and PuFAD3 in IW-treated pears may have played an important role in the improvement of ester contents ( P < 0.05). It could be inferred that IW treatment had an impact on the aroma-related esters of cold-stored ‘Nanguo’ pears through regulation of unsaturated fatty acid synthesis.
危险品化学品经营许可证（带存储）