SULFUR VOLATILES IN CUCUMIS-MELO CV MAKDIMON (MUSKMELON) AROMA - SENSORY EVALUATION BY GAS-CHROMATOGRAPHY OLFACTOMETRY

Simultaneous distillation-extraction (SDE) of muskmelon (Cucumis melo cv. Makdimon) and subsequent gas chromatographic analysis using an atomic emission detector identified twenty sulfur volatiles, including S-methyl esters of ethanethioic, butanethioic and pentanethioic acids, and dimethyltrisulfide. From aroma extraction dilution analysis (AEDA) seven key compounds were identified, four of which contained sulfur; S-methyl thiobutanoate, 3-(methlythio)-propyl acetate, 3-(methylthio)propanal and possibly dimethyltetrasulfide. Of these seven key sensory responses only two are described as fruity/floral (ethyl 2-methylpropanoate and 3-(methylthio)propyl acetate), the other five components being responsible for the earthy, stale musk aroma of this melon. However, comparison of odor units suggests a higher weighting than the AEDA results for the common fruity ester notes from methyl and ethyl 2-methytbutanoate and 2-methylbutyl acetate. Preliminary tests indicate that blending the flesh of this melon prior to SDE activates lipoxygenase and hydrolase activity and alters the aroma profile appreciably.