Sensory evaluation of ‘Galia’-type melons treated with 1-methylcyclopropene after prolonged storage

Abstract

SummaryExposure to 300 nl l–1 1-methylcyclopropene (1-MCP) suppresses internal and external ripening parameters in melons harvested at the green/yellow stage of maturity. We investigated the sensory attributes and volatiles of ‘Galia’-type melons treated with the ethylene activity inhibitor 1-MCP at the green/yellow stage of ripening, compared to untreated and commercially-treated fruit after prolonged storage. Organoleptic and volatile analyses were performed after 15 d storage at 5°C and a 3 d marketing simulation at 20°C. 1-MCP-treated fruit had a lower level of total volatiles (3,334 µg kg–1 FW) compared to untreated fruit, or to fruit washed and waxed according to commercial practice. Most of the volatiles were esters, while a few were aldehydes, or ethanol. Methyl acetate, as well as methyl 2-methylbutanoate, which are associated with the ‘fruity’ aroma note, were significantly higher in 1-MCP-treated fruit. The “green” note, due to hexanal, remained relatively high in 1-MCP-treated fruit after storage, while it was not detected in commercially-treated fruit. Ethanol, ethyl acetate, and ethyl hexanoate volatiles that are associated with “off-flavour” and over-ripening were significantly higher in commercially-treated fruit. A trained panel described the sensory properties of the three treatments. The overall aroma notes were significantly more intense in commercially-treated fruit, while in 1-MCP-treated fruit they were much less evident. 1-MCP-treated fruit had the strongest “green” note, while commercially-treated fruit had the weakest. A very strong ‘acetone’ note was detected after commercial treatment, and was associated with ‘unpleasant’ and ‘non-typical’ notes. Members of an untrained panel preferred 1-MCP-treated melon and disliked commercially-washed and waxed fruit.