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Fruit Produce Facts English
Cantaloupe
Recommendations for Maintaining Postharvest Quality
Trevor V. Suslow, Marita Cantwell and Jeffrey Mitchell Department of Plant Sciences, University of California, Davis
Maturity & Quality
IntroductionCantaloupe (Cucumis melo L. var. reticulatus Naud.) is often, incorrectly, referred to interchangeably as Muskmelon. This botanical group, however, includes honeydew, crenshaw, Persian, casaba and other 'mixed melons'. Maturity IndicesCantaloupes are harvested by maturity and not by size. Commercial maturity is ideally at the firm-ripe stage or "3/4 to full-slip" when a clear abscission (slip, separation) from the vine occurs with light pressure. Cantaloupes ripen after harvest but do not increase in sugar content (see below). Cultivars vary in their external color at this stage of maturity and may retain a greenish cast. This skin color typically transitions from gray to dull green when immature, deep uniform green at maturity, and light yellow at full ripeness. A raised and well-rounded netting on the fruit surface is another indicator of proper commercial maturity. Quality Indices
U.S. grades are Fancy, No. 1, Commercial and No. 2. Distinction among grades is based predominantly on external appearances and measured soluble solids. Federal Grade Standards specify a minimum of 11% soluble solids for U.S. Fancy ("Very good internal quality") and 9% soluble solids for U.S. 1 ("Good internal quality"). A calibrated refractometer, measuring °Brix, is accepted as the current standard for soluble solids measurements. Sizing is based on count per 18.2 kg (40 lb.) container, most typically 9, 12, 15 and occasionally 18 or 23 melons per carton. An 18 to 45 count crate may also be used. Maturity & Quality Photos
Title: "Slip" and Cantaloupe Ripeness Photo Credit: Marita Cantwell, University of California, Davis 
Title: Maturity Indices Photo Credit: Marita Cantwell, University of California, Davis
Temperature & Controlled Atmosphere
Optimum Temperature2.2°C-5°C (36°F-41°F) Storage life is up to 21 days at 2.2°C (36°F) but sensory quality may be reduced. Typically 12-15 days of shelf life are attainable within the optimum range. Short term storage or transit temperatures below this range are used by some in the trade but may result in chilling injury after several days [for example,7 days or longer at temperatures below 2.2°C (36°F)]. Optimum Relative Humidity90%-95%; High relative humidity is essential to maximize postharvest quality and prevent desiccation. Water loss through scuffed and damaged surface netting can be significant. Extended periods of higher humidity or condensation may encourage the growth of stem-scar and surface molds. Rates of Respiration
To calculate heat production multiply ml CO2/kg·hr by 440 to get Btu/ton/ day or by 122 to get kcal/metric ton/day. NR - not recommended for more than a few days due to chilling injury. Rates of Ethylene ProductionIntact fruit: 40 - 80 µl/kg·hr at 20°C (68°F) Production Fresh-cut: - 7-10 µl/kg·hr at 5°C (41°F) Responses to EthyleneCantaloupes are moderately sensitive to exogenous ethylene and over-ripening may be a problem during distribution and short-term storage. Responses to Controlled Atmospheres (CA)Controlled atmosphere storage or shipping offer only moderate benefits for cantaloupes under most conditions. With extended transit times (14-21 Atmospheres (CA) days), cantaloupes are reported to benefit from delayed ripening, reduced respiration and associated sugar loss, and inhibition of surface molds and decay. Consensus atmospheres of 3% O2 and 10% CO2 at 3°C (37.4°F) has been demonstrated. Elevated CO2 at 10-20% is tolerated but will cause effervescence in the fruit flesh. This carbonated flavor is lost on transfer to air. Low O2 (<1%) or high CO2 (> 20%) will cause impaired ripening, off-flavors and odors, and other condition defects.
Disorders
Physiological and Physical DisordersChilling injury. Typically occurs after storage at temperatures < 2°C Disorders (35.6°F) for several days. Sensitivity to chilling injury decreases as melon maturity and ripeness increases. Symptoms of chilling injury include pitting or sunken areas, failure to ripen, off-flavors and increased surface decay. Pathological DisordersDisease can be an important source of postharvest loss depending on season, region and handling practices. Commonly, decay or surface lesions result from the fungal pathogens Alternaria, Penicillium, Cladosporium, Geotrichum, Rhizopus, and to a lesser extent Mucor. Treatment with hot air or hot water immersion (55°C for 0.5-1.0 min.) has been effective in preventing surface mold but has not been used extensively for commercial treatments. CA can be effective in delaying fungal growth on the stem-end and fruit surface. Special ConsiderationsRapid precooling soon after harvest is essential for optimal postharvest keeping quality. The precooling endpoint is typically 10°C (50°F) but 4°C (39.2°F) is more desirable. Forced-air cooling is the most common practice but Hydrocooling is also utilized. [For more information, see our publication "Fruit Ripening and Ethylene Management", available for purchase using our Publication order.] Disorders Photos
Title: Rhizopus Rot Photo Credit: Don Edwards, UC Davis 
Title: Sour Rot (1) Photo Credit: Don Edwards, UC Davis 
Title: Sour Rot (2) Photo Credit: Don Edwards, UC Davis
Date
February 1997 |
Use of Materials
The UC Postharvest Technology Center grants users permission to download textual pages (including PDF files) from this World Wide Web site for personal use or to reproduce them for educational purposes, but credit lines and copyright notices within the pages must not be removed or modified.
Except for these specified uses, no part of the textual materials available on the UC Postharvest Technology Center Web site may be copied, downloaded, stored in a retrieval system, further transmitted or otherwise reproduced, stored, disseminated, transferred or used, in any form or by any means, except as permitted herein or with the University of California's prior written agreement. Request permission from UC Postharvest Technology Center. Distribution for commercial purposes is prohibited.
The information in this fact sheet represents our best understanding of the current state of knowledge at the time of the latest update, and does not represent an exhaustive review of all research results. Links to any of these UC Postharvest Technology Center pages are permitted, but no endorsement of the linking site or products mentioned in the linking page is intended or implied by such a link.
How to Cite
Author(s) names. Initial publication or update date (located at the top). Title. Link to the specific Produce Fact Sheet webpage (Accessed date)
Example: Cantwell, M. and T. Suslow. 2002. Lettuce, Crisphead: Recommendations for Maintaining Postharvest Quality.
http://ucanr.edu/sites/Postharvest_Technology_Center_/Commodity_Resources/Fact_Sheets/Datastores/Vegetables_English/?uid=19&ds=799 (Accessed January 18, 2014).
