Fresh-cut Cantaloupe Research Articles

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 β-ionone, geranylacetone and terpinyl acetate, were also produced as a result of UV exposure for 15 and 60 min, respectively. β-Ionone, when added to crushed cantaloupe (0.01% w/w) completely inhibited microbial growth in the fruit for 24 h at 20 °C. Geranylacetone and terpinyl acetate reduced the microbial population from 6.3×10 8 in the untreated control to 1.2×10 8 and 3.5×10 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.

Cutting Blade Sharpness Affects Appearance and Other Quality Attributes of Fresh‐cut Cantaloupe Melon

ABSTRACT: Cantaloupe melon pieces (1.8 cm dia × 3.5 to 4.0 cm cylinders) were prepared using stainless steel borers with sharp or blunt blades, and stored for 12 d in air at 5 °C. Pieces prepared with the sharp borer maintained marketable visual quality for at least 6 d, while those prepared with the blunt borer were unacceptable by d 6 due to surface translucency and color changes. Borer sharpness did not affect changes in decay, firmness, sugar content, or aroma, but blunt‐cut pieces had increased ethanol concentrations, off‐odor scores, and electrolyte leakage compared to sharp‐cut pieces. Respiration rates at 5 °C were similar for both cutting treatments, but ethylene production rates were sometimes higher in pieces cut with the blunt blade.

Effects of Ascorbic Acid on Peroxidase and Polyphenoloxidase Activities in Fresh‐Cut Cantaloupe Melon

ABSTRACT: Peroxidase (POD) and polyphenol oxidase (PPO) in minimally processed cantaloupe melon (Cucumis melo L. var. reticulatus Naud) were assayed and the effect of ascorbic acid on their respective activities during storage at 4 °C was determined. POD activity decreased with storage and was inhibited by ascorbate treatment. Two native electrophoretic POD bands with estimated molecular weights 240 and 170 kDa respectively were obtained. Isoelectric focusing separated six acidic POD isozymes with isoelectric points between 5.1 and 6.0, possibly subunits of the POD isozymes. PPO activity in the cantaloupe melon extract was very weak and the fruit's content of oxidizable phenolic compounds was negligible.

Identification of volatile compounds in cantaloupe at various developmental stages using solid phase microextraction.

Using an automated rapid headspace solid phase microextraction (SPME) method for volatile extraction in cantaloupes, 86 compounds already reported for muskmelons were recovered and an additional 53 compounds not previously reported were identified or tentatively identified. The SPME method extracted a copious number of volatiles that can be analyzed to clearly differentiate between variety, growth stage, and stage of harvest ripeness. Most of the newly reported compounds in cantaloupe were esters and aldehydes that have already been demonstrated as flavor-related compounds in other products. All esters believed to have flavor impact increased progressively after pollination, and this trend continued with increasing harvest maturity. However, compound recovery often decreased when fruits were harvested over-ripe. Most aldehydes increased during early growth stages and then tapered off with increasing harvest maturity. The SPME method suitably recovered most compounds reported to impart characteristic flavor/aroma in muskmelons. SPME offers experimental flexibility and the ability to discover more compounds and address flavor quality changes in fresh-cut cantaloupe.

Cantaloupe melon peroxidase: characterization and effects of additives on activity.

Peroxidase in cantaloupe melon (Cucumis melo L. var. reticulatus Naud.), a fruit commonly fresh cut processed, was characterized to determine reaction pathway, optimal conditions for activity and effect of some additives on enzymatic action. Mn2+, CaCl2, NaNO2 and kinetin had partial inhibitory effects on enzyme activity. Activity was effectively inhibited by compounds capable of chelating peroxidase heme iron such as diethyldithiocarbamate and tiron, but unaffected by EDTA. Free radical scavenger, superoxide dismutase, also had no effect on reaction velocity. Enzymatic action was consistent with that of ascorbate peroxidase based on the relatively higher affinity for ascorbate over guaiacol. Optimum activity temperature was 50-55 degrees C. The enzyme was stable at temperatures below 40 degrees C and at 50 degrees C for up to 10 min. Over 90% of total activity was lost at 80 degrees C within 5 min. Broad pH optima, 5.5-7.5 at 50 degrees C and 6-7 at 30 degrees C, were obtained. Peroxidase activity in cantaloupe was higher than those in strawberry (Fragaria ananassa Duch.) and lettuce (Lactuca sativa L.), suggesting a relatively high oxidative stress in fresh cut cantaloupe. The potential use of ascorbate as an additive in fresh cut cantaloupe melon was demonstrated by its ability to preserve color in minimally processed fruits for 25 days at 4 degrees C, possibly as a result of an enhanced antioxidative action of the ascorbate-peroxidase complex and trace metal ion cofactors.

Comparison of calcium chloride and calcium lactate effectiveness in maintaining shelf stability and quality of fresh-cut cantaloupes

Fresh-cut cantaloupe cylinders were dipped for 1 min in 2.5% solutions of either calcium chloride (CaCl2 )a t 25°C or calcium lactate at 25 and 60°C. Firmness, microbiological (total plate count, yeast and mold, and microaerophilic bacteria) and sensory characteristics, respiration (CO2) and ethylene (C2H4) production were evaluated during 12 days storage at 5°C and 95% relative humidity air. Both calcium salts maintained melon firmness throughout cold storage. CaCl2, but not calcium lactate, imparted undesirable bitterness to the fruit pieces. No significant differences were observed in the physiological behavior of the treated fresh-cut compared to just-cut samples. © 2000 Elsevier Science B.V. All rights reserved.

Fresh-cut cantaloupe: effects of CaCl2 dips and heat treatments on firmness and metabolic activity

Abstract Calcium chloride (1–5%) dips were applied to melon cylinders taken from commercially ripe (3/4 to full slip) cantaloupe melons for 1–5 min. A wound response was observed after cutting, and CO2 production was higher in untreated samples than in calcium treated and intact fruit. Dip time did not significantly effect respiration rate. Application of calcium dips at any temperature resulted in unchanged ethylene production throughout storage, and inhibited respiration. Calcium chloride dips improved firmness of fresh-cut cantaloupe during storage at 5°C, with 1 min dips showing the same effect as 5 min dips. When dipped for 1 min in 2.5% calcium chloride solutions at 20, 40 or 60°C, firmness was maintained or improved, especially at higher dip temperatures while total calcium concentration in the melon tissue was increased on average by 300%.

438 Optimization of a SPME Method for Flavor Characterization in Fresh-cut Cantaloupe

Fresh-cut melons in many consumer-ready packages are notorious for “wetting” and accumulation of standing juices. These conditions likely create undesirable flavor and aroma changes. We initiated a study to investigate flavor changes in stored fresh-cut cantaloupe. One objective was to optimize solid phase microextraction (SPME) to evaluate organoleptic compounds. Static head-space SPME analyses were performed on fresh-cut cantaloupe cubes (≈2.5 mm, 5 mm, or 2.5 cm), expressed juice, and homogenized slurries. SPME fiber (100 μm PDMS vs. 75 μm Carboxen/PDMS) exposure time (5, 7.5, 10, 12.5, 15, 17.5, 20 min) was evaluated at 40 °C with various head-space: product ratios, plus or minus NaCl to produce typical chromatograms. Fibers were desorbed in an HP5890 GC with a DB-624 or DB-5 column for 45-min runs and an HP6890 GC (DB-5) equipped with a 5973 MS detector for 35-min runs. Albeit qualitative, the best chromatograms were obtained with 7-ml slurries, stirred with NaCl, exposed to a 10 0μm PDMS SPME fiber for 12.5 min. The 100 μm PDMS fiber produced better chromatograms considering the fact that many important flavor volatiles are low-molecular-weight polar esters and alcohols. These conditions were subsequently used to analyze numerous fresh-cut cantaloupe samples stored various times (0 to 9 days). Over 100 peaks were identified, many of which changed through storage and some are suspected as probable agents responsible for undesirable flavor changes. Our analyses are progressing in an attempt to authenticate compounds associated with flavor-related changes in numerous fresh-cut cantaloupe varieties from various growing regions.

412 Quality of Packaged Fresh-cut Cantaloupe

Cantaloupe at commercial stage of maturity were sliced, i.e., prepared as minimally proceed, rinsed with or without sodium hypochloride solution (50 ppm), and drained. They were stored in perforated polyethylene package (PE) at 1 °C in air and controlled atmosphere (2 % O2 and 5 % CO2) for 5 and 10 days. Fresh-cut cantaloupe slices were analyzed initially and after 5 and 10 days of storage for weight loss, lycopene content, fungus infection, flavor and taste, TSS, pH, ethanol, firmness, and electrolyte leakage. Fruit stored in CA exhibited lower weight loss, higher lycopene content, less fungus infection, better flavor and taste, more firmness, higher TSS content, and lower electrolyte leakage than store in air. When compared to fruit treated with sodium hypochloride, lower lycopene content, higher fungus infection, inferior flavor and taste, more softness, and higher electrolyte leakage were detected in fruit that were not rinsed with sodium hypochloride solution. Extended storage time resulted in higher weight loss, increased fungus infection, bad taste, off-flavor, more softness, lower TSS content, and higher leakage value. This study indicates that it is possible to extend the shelf-life of fresh-cut cantaloupe slices from 5 to 10 days if kept at 1 °C in 2% O2 and 5% CO2 in PE package.

361 Quality Changes During Storage of Intact and Fresh-cut Cantaloupe Melon

Although minimal processing increases the perishability of products, largely due to microbial decay, quality changes may be similar between tissues from intact produce and fresh-cut pieces. This study compared pulp quality changes of intact cantaloupe melons and of sanitized fresh-cut pieces (1.8 x 3-cm cylinders) during storage in air at 2.5 (cv. Corona) and 5 °C (cv. Corona and Durango) for 15 days. Quality evaluations included subjective (visual quality, decay, translucency, aroma, off-odor) and objective (color, firmness, SSC) measurements. At 5 °C, visual quality of the pieces was below the limit of salability by day 15 due to decay, whereas pulp from stored melons was excellent. Pulp from intact melons did not suffer from development of translucency as did the fresh-cut pieces. At 5 °C, pulp from intact fruit had higher aroma scores than pieces, but there were no differences in off-odor scores. At 2.5 °C there were no differences in the subjective quality measurements of pulp from intact or fresh-cut pieces. Pulp from intact fruit had higher chroma (at 2.5 and 5 °C) and L* (only at 5 °C) than the pieces after 6 or 15 days, depending on the variety. There were no differences in hue between intact and fresh-cut pulp. Pulp from intact and fresh-cut pieces had similar firmness changes and SSC during storage at 2.5 and 5 °C. We conclude that pulp of intact fruit and fresh-cut pieces had similar quality up to 15 days at 2.5°C; but at 5 °C, the fresh-cut pieces lost intrinsic quality (visual quality, aroma, and color) before the pulp of intact fruit did.