Abstract: This study investigated the effects and mechanisms of SO2 capsule patches used individually or in combination with two types of preservatives (ethylene absorbent (EA) and 1-methylcyclopropene (1-MCP)) on preserving the postharvest quality and alleviating browning of green-skinned​ figs. Three treatment groups were established, including SO2, SO2 + EA, and SO2 + 1-MCP. Decay incidence, mass loss rate, color parameters, browning-related factors, and the activities of antioxidant enzymes were measured during the storage period. The results showed that all three treatment groups effectively delayed the occurrence of the respiratory rate peak and slowed down the senescence process. On the 12th day of storage, the control group exhibited decay incidence of 45%, mass loss rate of 2.4%, and a significant decrease in L* value, losing commercial value. The above indicators approached those of the SO2 group on the 18th day, indicating that treatment with SO2 capsule patches alone could delay browning, but this effect was limited. The storage period of figs was extended to 24 days in both combined treatment groups. On the 24th day of storage, both groups showed decay incidence of less than 15% and mass loss rate below 5%. SO2 + EA had a more pronounced inhibitory effect on fruit browning than SO2 + 1-MCP. At the end of storage, the soluble quinone content, phenylalanine ammonia-lyase (PAL) activity, and polyphenol oxidase (PPO) activity in the SO2 + EA group were 11.45%, 9.5%, and 62.5% lower than those of the SO2 + 1-MCP group, respectively. Additionally, the SO2 + EA treatment notably enhanced the activities of superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) by 5.36%, 31.58%, and 14.1%, respectively, compared with the SO2 + 1-MCP treatment. In conclusion, the SO2 + EA treatment can more effectively inhibit the quality deterioration and browning of postharvest green-skinned figs by inhibiting browning-related factors and enhancing the activities of antioxidant enzymes, providing an efficient technical solution for postharvest fig preservation.

Key words: green-skinned figs; SO2 capsule patches; 1-methylcyclopropene; ethylene absorbent; browning