Ultraviolet induced stress response in fresh cut cantaloupe.

Changes in the composition of volatile compounds in cantaloupe melon (Cucumis melo L. var. reticulatus) as a result of UV induced stress were determined by gas chromatography-mass spectrometry (GC-MS). Several volatile ester compounds were present, of which twenty-seven were identified in fresh cut cantaloupe. Fruit exposure to UV light decreased the concentrations of most of the aliphatic esters by over 60% of the amounts present in the corresponding fresh cut fruit. Cyclic and acyclic terpenoids, including phytoalexin compounds beta-ionone, geranylacetone and terpinyl acetate, were also produced as a result of UV exposure for 15 and 60 min, respectively. beta-Ionone, when added to crushed cantaloupe (0.01% w/w) completely inhibited microbial growth in the fruit for 24 h at 20 degrees C. Geranylacetone and terpinyl acetate reduced the microbial population from 6.3x10(8) in the untreated control to 1.2x10(8) and 3.5x10(7) CFU/g respectively. The results indicate the potential use of UV induced stress for screening cantaloupe melon cultivars for disease resistance, and as a minimal processing method to extend the shelf life of fresh cut cantaloupe products.