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Effects of 1−MCP on Storage Quality and Enzyme Activity of Petals of Edible Rose Cultivar ‘Dianhong’ at Low Temperatures

To explore the effect of 1-methylcyclopropene (1−MCP) on the storage quality of edible roses, flowers of the edible rose variety ‘Dianhong’ were used as materials to study the effect of post-harvest 1−MCP fumigation (concentration of 30 μL/L). The measures included respiration intensity, water loss rate, antioxidant-related substance content (soluble sugar, crude fibre, AsA, anthocyanin, total phenols and MDA), enzyme activity (SOD, CAT, APX, PAL and PPO) and petal appearance quality in different storage periods, which could provide a theoretical reference for research and development on storage and preservation technology for edible rose petals. The results showed that, compared with the control, 1−MCP treatment reduced the initial respiration intensity of petals by more than 80%, slowed the water loss rate, increased the crude fibre content and effectively maintained the contents of soluble sugars, AsA, anthocyanins and total phenols. For the petals in the treatment group at the end of storage, the rate of water loss was 3.73%, the content of soluble sugar was only 17% (62.27 μg/g)—lower than that of fresh petals—and the content of AsA (0.33 mg/g) was the same as that of pre-storage (0.34 mg/g). The contents of total phenols and anthocyanins were 30.60% and 11.63% higher than those of the control group, respectively. In addition, 1−MCP treatment increased the activity of SOD, CAT, APX and PAL and inhibited the activity of PPO. The MDA content at the end of storage was 14.36% lower than that of the control, which reduced the rate of membrane lipid peroxidation. Correlation analysis showed that sensory quality of petals in the 1−MCP treatment group was positively correlated with respiratory intensity and soluble sugar content and negatively correlated with water loss rate, MDA and crude fibre content (p < 0.05) among the four antioxidant enzymes. APX and PAL were positively correlated with anthocyanin content and total phenols content, respectively. These results confirmed that 1−MCP could effectively maintain the storage quality of edible rose petals by increasing the antioxidant capacity of petals and prolong the storage period of fresh petals to 49 days.