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J. C. BEAULIEU, Food Processing & Sensory Quality Unit, USDA-ARS-Southern Regional Research Center, 1100 Robert E. Lee Blvd., New Orleans, LA 70179 Reports indicate esters declined 53 to 60% after 24h in stored (4° C) thin-sliced fruits yet other literature corroborating this was not found. Contrarily, it has been found that Industry-style fresh-cut fruits maintain volatiles and sensory quality through ideal storage for about 7d. Previous control samples termed “fresh-cut” were thin laminar slices. Such tissue might rapidly lose water and volatiles and suffer postharvest deterioration as a result of wounding and large exposed surface area, relative to volume. The goal was subsequently to compare SPME-GC-MS volatile profiles and SEM of cantaloupe tissue under various cutting and sampling regimes. Thin-sliced (4x3x0.2cm) tissue was compared with industry standard cubes (2.5cm3), prepared from adjacent equatorial fruit mesocarp. The surface area of slices was 26.8 ± 1.0cm2 compared with cubes, 38.0 ± 1.5cm2. Surface area per unit volume of slices was 9.86 ± 0.60 versus 2.39 ± 0.05cm2 for cubes which, was 4.2 times greater than cubes, indicating greater water potential gradients in sheets. Cell diameter in thin-sliced controls was 160.5 ± 33.2µm. Cell diameter decreased 54% to 55.1 ± 25.8µm after 1-day storage at 5° C and sheets had dehydrated and/or folded cell walls and tissue tearing, indicative of physiological stress. Cell diameter in 1-day old fresh-cut cubes at 5° C was 122.2 ± 49.5µm, and 80.6 ± 29.8µm after 4 days, with preserved structure. In 1-day, sheets lost 96.7% of 11 low molecular weight esters and 65.7% of 6 high molecular weight esters. After 3 days, low and high molecular weight esters decreased by 96.5 and 90.9%, respectively. Contrarily, after 1 to 3 days, esters increased between 120.1 – 197.3% in cubes prepared from identical tissue. Data indicate that cutting method was responsible for substantial volatile and integrity losses, leading to possible misinterpretation of flavor attributes and quality in cut cantaloupe.
Session 96, Fruit & Vegetable Products: General II
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |