1-Methylcyclopropene delays degradation of peel greenness but induces internal physiological disorders in cold-stored fruit of interspecific pears

The green-skinned interspecific 'Greensis' pear cultivar is a promising pear cultivar due to its crispness, juiciness, and strong resistance to scab disease. Postharvest storability and metabolic activity can be maintained by treating cold-stored pears with 1 mu L L-1 of 1-methylcyclopropene (1-MCP) for 16 hr at 22 degrees C. After 1-MCP treatment, the 'Greensis' pears were stored at 0.5 degrees C for up to 6 months, after which they were transferred at 22 degrees C for 7 days of shelf life. 1-MCP treatment had no visible effects on physiological responses, such as fruit weight loss, firmness, titratable acidity, and soluble solids content. However, metabolic profile analyses indicated that the 1-MCP-treated fruit had lower levels of amino acids and soluble carbohydrates (except for sucrose) than the control fruit. The incidence of cortex browning and cavities was much higher in 1-MCP-treated fruit than in untreated fruit. Similarly, the chroma values of the peel and cortex tissues were higher in 1-MCP-treated fruit than in untreated fruit. Moreover, the total chlorophyll and chlorophyll a contents were more preserved in 1-MCP-treated fruit than in untreated pears. Overall, 1-MCP treatment increased sucrose, chlorophyll a, and total chlorophyll contents, thus delaying chlorophyll degradation during storage. These results suggested that 1-MCP treatment delayed the skin color degradation of interspecific 'Greensis' pears during storage and prevented changes in the profiles of major metabolites. Nevertheless, the incidence and severity of cortex browning and cavities were highly increased in 1-MCP-treated fruit during storage.

Automated summary

The 'Greensis' pear cultivar is highly regarded due to its crispness, juiciness, and strong resistance to scab disease. It was found that treating cold-stored pears with 1-MCP for 16 hr at 22 degrees C can maintain postharvest storability and metabolic activity. However, 1-MCP treatment resulted in higher incidence of cortex browning and cavities in the pears.