24-10

J. C. BEAULIEU, C. C. Grimm, and J. A. Miller, Jr. Food Processing and Sensory Quality, United States Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, 1100 Robert E. Lee Blvd., New Orleans, LA 70124

Fresh-cut salad sales have been exponential however, fresh-cut fruit sales have yet to boom. Fresh-cut processing increases respiration rates and causes tissue disruption as enzymes and substrates normally sequestered within the vacuoles become mixed with cytoplasmic and nucleic substrates and enzymes. Processing may provoke flavor loss, browning, decay, vitamin loss, softening, shrinkage, color loss and a shorter storage life. Fresh-cut melons are notorious for “wetting” and accumulation of standing juices likely creates undesirable flavor and aroma changes. We initiated a study to investigate flavor changes in stored fresh-cut cantaloupe, but first needed to determine what volatiles were important, recoverable and which method of extraction delivered authentic results. Anthesis tagged immature and mature fruit and freshly cut cubes and homogenized cantaloupe juice were monitored with solid phase microextraction (SPME) and purge & trap via GC-MS for volatile compounds released under various sampling regimes. Sample preparations were performed in ambient conditions or oxygen-free at refrigerated and non-refrigerated temperatures. The recovery of C9 compounds (nonanal, nonenal, 2,6-nonadienal, 2,4-nonadienal) in immature fruit indicate lipoxygenase activity, as previously reported in the literature. In mature fruit, the absence of most C9 compounds indicates little or no lipoxygenase activity. Other aldehydes (pentanal, hexanal, heptanal, octanal, decanal) were only recovered in immature fruit and this may indicate potential auto-oxidation (artifacts). Esters (i.e. ethyl acetate, ethyl butanoate, 2-methyl propyl acetate, 2-methyl butanoate, methyl 2-methyl butanoate, butyl acetate, ethyl hexanoate, hexyl acetate, benzyl acetate) were predominantly recovered in mature fruit, with few aldehydes (benzaldehyde, nonanal, 2,6-nonadienal). The formation of 2-methylbutyl, 2-methylpropyl and thioether esters indicates the abundance of free isoleucine, valine and methionine, respectively. Determination of critical flavor compounds and relative abundance of substrates and enzymes may help breeders deliver varieties best suited for processing.