Effect of humidity triggered controlled-release 1-methylcyclopropene (1-MCP) on postharvest quality and safety of papaya fruit

Authors: SHU, CHANG - Oak Ridge Institute For Science And Education (ORISE); Wall, Marisa; Follett, Peter; SUGIMOTO, NOBUKO - Verdant Technologies; Bai, Jinhe; Sun, Xiuxiu

Submitted to: Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/20/2023
Publication Date: 9/22/2023
Citation: Shu, C., Wall, M.M., Follett, P.A., Sugimoto, N., Bai, J., Sun, X.N. 2023. Effect of humidity triggered controlled-release 1-methylcyclopropene (1-MCP) on postharvest quality and safety of papaya fruit. Horticulturae. 9(10). Article 1062. https://doi.org/10.3390/horticulturae9101062.
DOI: https://doi.org/10.3390/horticulturae9101062

Interpretive Summary: 1-Methylcyclopropene (1-MCP), a synthetic plant growth regulator, is used commercially to slow down the ripening of fresh fruit by blocking ethylene action. 1-MCP is structurally related to the natural plant hormone ethylene, and it has been widely applied for postharvest fruit preservation. In the present study, we tested the effects of different concentrations of controlled-release 1-MCP on the post-harvest quality and safety of papayas harvested at ½ yellow. The objective of this research was to find the best concentration by testing commercially available humidity triggered controlled-release 1-MCP sheets to extend the post-harvest shelf life and quality of papayas. --jv

Technical Abstract: This study explored humidity-triggered controlled-release 1-MCP sheets on postharvest quality and safety of papaya. ‘Rainbow’ papaya underwent cold storage at 10 ± 0.5 °C, RH 85 ± 2% for 14 days, then transferred to 20 ± 0.5 °C, RH 85 ± 2% for 10 days to simulate shelf life. Controlled-release 1-MCP sheets were cut into different sizes and placed in the containers in advance to create corresponding concentrations at 0.5, 1.0, 2.0, and 4.0 ppm. Results showed that 1-MCP treatment inhibited softening, weight loss, peel color deterioration, and decay incidence, without any adverse sensory effects. The effect on fruit weight loss and firmness was dose-dependent, with the least weight loss and softening at 4.0 ppm, and no physiological disorders were observed at any concentration of 1-MCP. Papayas in all 1-MCP treatments received high likeness ratings from a sensory panel. The firmness results indicated that 0.5-1.0 ppm 1-MCP treatments extended shelf life by 1-2 folds, and 2.0-4.0 ppm treatments extended more than 5 folds. The humidity-triggered controlled-release 1-MCP sheets are effective and convenient and may serve as an important tool for regulating postharvest papaya ripening with economic benefits. --jv