ABSTRACT
Changes in volatile aroma constituents of fresh-cut cantaloupe melon with storage were determined by headspace solid-phase microextraction gas chromatography-mass spectrometry. The compounds isolated from the fruit immediately after cutting were predominantly aliphatic and aromatic esters. Storage of fruit at 4 degrees C caused a considerable decrease in concentration of esters and synthesis of the terpenoid compounds beta-ionone and geranylacetone over a period of 24 h. This change in the volatile profile with storage is consistent with that of a stress-induced defense response in the cut fruit as an adaptation process to tissue exposure and cell disruption. The same effect occurred in fruit stored at 22 degrees C and in those treated with sodium azide and ascorbic acid prior to storage. Fruit treated with ascorbic acid and sodium azide had higher concentrations of beta-ionone and geranylacetone and retained these compounds better with storage time. The reduction of esters appears to be an important early reaction step in the loss of freshness during storage of fresh-cut cantaloupe.
Subject(s)
Cucumis/chemistry , Food Preservation , Fruit/chemistry , Norisoprenoids , Odorants , Ascorbic Acid/pharmacology , Cold Temperature , Esters/analysis , Food Handling , Gas Chromatography-Mass Spectrometry/methods , Sodium Azide/pharmacology , Terpenes/analysis , VolatilizationABSTRACT
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.
