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Recommendations for Maintaining Postharvest Quality


Adel A. Kader
Department of Plant Sciences, University of California, Davis

Maturity & Quality

Maturity Indices

Pepino dulce (Solanum muricatum Ait.) should be harvested when ripe (yellow) to have the best flavor quality. Skin color changes with ripening from green to pale white to cream to yellow (with purple stripes). Pepinoes soften as they ripen.

Quality Indices

  • Fruit shape varies from round to elongate and length varies from 5 to 20cm, depending on cultivar and number of fruit/plant
  • Skin color (yellow to golden-yellow) and flesh color (light orange)
  • Freedom from defects (such as sunburn and bruising) and decay
  • Juiciness (more than 40% juice)
  • Sweetness (soluble solids range from 6-12%; minimum acceptability at 10% or higher)
  • Titratable acidity is low (0.04-0.10%); citric acid is predominant
  • Vitamin C content varies among cultivars from 30 to 70mg/100g fresh weight

Maturity & Quality Photos

Title: Quality

Photo Credit: Adel Kader, UC Davis 

Temperature & Controlled Atmosphere

Optimum Temperature

7.5-10°C (45-50°F); storage potential = 4-6 weeks, depending on cultivar and ripeness stage.

Optimum Relative Humidity


Rates of Respiration

8-12ml CO2/kg·hr at 20°C (68°F); non-climacteric respiratory pattern.
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.

Rates of Ethylene Production

Less than 0.1 ml/kg·hr at 20°C (68°F)

Responses to Ethylene

Exposure to 10-100ppm ethylene stimulates chlorophyll degradation (loss of green color) and respiration rate of mature-green pepino fruit, but has no effect fully ripe (yellow) fruit.

Responses to Controlled Atmospheres (CA)

No published information.


Physiological and Physical Disorders

Chilling injury. Storing pepinoes at temperatures below 7.5°C (45°F) for two weeks or longer, depending on temperature, will result in chilling injury. Symptoms develop upon transfer to higher temperatures and include pitting, skin browning, and flesh browning. Ripe pepinoes are less sensitive to chilling injury than partially-ripe or mature-green fruit.

Pathological Disorders

Alternaria Rot. Pepino fruit, especially when chilled, are susceptible to Alternaria Rot caused by Alternaria solani. Symptoms include dark-brown to black spots beginning at the stem end and expanding to the rest of the fruit. Control strategies include minimizing mechanical injuries during harvesting and handling and avoiding chilling injury and water stress by maintaining the optimum ranges of temperature and relative humidity throughout the handling system.


February 2000

Use of Materials

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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. (Accessed January 18, 2014).

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