1-Methylcyclopropene treatment efficacy in preventing ethylene perception and ripening in intact and fresh-cut 'Galia' melon and 'Sunrise Solo' papaya fruits.

摘要

The objectives of this study were to determine the physiological responses of intact and fresh-cut melon (Cucumis melo L. var. reticulatus L. Naud. cv. Galia) and papaya (Carica papaya , L. var. Sunrise Solo) fruits in which ethylene perception was blocked through application of 1-methylcyclopropene (1-MCP). The whole fruits were treated with 1-MCP (melon, 1 or 1.5 μL L−1; papaya, 2.5 or 9 μL L−1) for 24 h at 20°C and stored at 20°C or processed and stored at 5°C.; Inhibition of ethylene perception via application of 1-MCP delayed the onset of the respiratory and ethylene climacterics and reduced maximum respiration and ethylene production rates of ‘Galia’ fruit ripened at 20°C. Softening of intact and fresh-cut ‘Galia’ melon was significantly reduced by 1-MCP, regardless of application time (ripening stage). Yellowing of the fruit surface during ripening was strongly and somewhat irreversibly delayed in 1-MCP-treated ‘Galia’.; Papaya fruit (‘Sunrise Solo’) treated with 1-MCP exhibited delayed initiation of the respiratory and ethylene climacterics and suppressed ethylene production during ripening. Softening was significantly delayed in fresh-cut and intact fruit. Papaya treated with 1-MCP retained higher levels of titratable acidity compared with non-1-MCP-treated fruit throughout ripening. The color change of the fruit surface from green to yellow was significantly but temporarily inhibited in 1-MCP-treated fruit.; Cell wall modification was studied in intact and fresh-cut ripe papaya fruit stored for 10 days at 5°C. Water-soluble polyuronides represented the major pectic fraction followed by the CDTA (1,2 cyclohexylenedinitrilotetraacetic acid)- and Na₂CO₃-soluble fractions irrespective of 1-MCP. Both hemicellulosic and pectic polysaccharides in intact and fresh-cut fruit showed some changes but this trend was slightly or not affected by 1-MCP. Neutral sugars from pectins and hemicelluloses including galactose, glucose and xylose decreased in both intact and fresh-cut fruit regardless of 1-MCP. Generally, either intact fruit or fresh-cut fruit pre-treated with 1-MCP exhibited little or no significant changes compared with fruit not treated with 1-MCP.; The studies presented herein have shown that 1-MCP has potential for extending the useful storage life of intact and fresh-cut melon and papaya fruits by delaying ethylene inducible ripening process.