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Recommendations for Maintaining Postharvest Quality


Carlos H. Crisosto, Elizabeth J. Mitcham, and Adel A. Kader
Department of Plant Sciences, University of California, Davis

Maturity & Quality

Maturity Indices

Minimum maturity is based on skin color change from green to orange or reddish-orange (Hachiya) or to yellowish-green or yellow (Fuyu, California Fuyu, Jiro).

Quality Indices

  • Yellow to orange color
  • Medium to large size
  • Firm (penetration force, using an 8-mm tip, is above 5 lb-force for 'Fuyu' and similar cultivars)
  • Freedom from growth cracks, mechanical injuries, and decay
  • Soluble solids of 21-23% in 'Hachiya' and 18-20% in 'Fuyu' and similar non-astringent cultivars
  • No astringency (tannin content)
  • Nutritive value: good source of carotenoids, vitamin A, vitamin C, and dietary fiber

Maturity & Quality Photos

Title: Color Chart

Photo Credit: Adel Kader, UC Davis 

Title: Firm and Soft Fuyu Quality

Photo Credit: Don Edwards, UC Davis

Title: Firm and Soft Hachiya Quality

Photo Credit: Don Edwards, UC Davis

Temperature & Controlled Atmosphere

Optimum Temperature

0 ± 1°C (32 ± 2°F)

Freezing point. -2°C (28°F); may vary depending on soluble solids content.

Chilling injury. 'Fuyu' and similar non-astringent cultivars are chilling- sensitive at temperatures between 5°C and 15°C (41°F and 59°F) and will exhibit flesh browning and softening. Exposure to ethylene aggravates chilling injury at these temperatures.

Optimum Relative Humidity


Rates of Respiration

2-4 ml CO2/kg·hr at 0°C (32°F)
10-12 ml CO2/kg·hr at 20°C (68°F)
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

>0.1 µl/kg·hr at 0°C (32°F) 0.1-0.5 µl/kg·hr at 20°C (68°F)

Responses to Ethylene

Persimmons are very sensitive to ethylene action. Exposure to 1 ppm and 10 ppm ethylene at 20°C (68°F) accelerates softening to less than 4 lb - force (limit of marketability) after 6 and 2 days, respectively. Thus, ethylene removal and/or exclusion from transport and storage facilities is highly recommended.

Removal of Astringency from 'Hachiya' Persimmons

Ethylene (10 ppm) at 20°C (68°F) can be used to remove astringency but the excessive softening that results would make it very difficult to market the persimmons. Exposure to air enriched with 80% CO2 for 24 hours at 20°C (68°F) is effective in removing astringency while maintaining firmness.

Responses to Controlled Atmospheres (CA)

  • Low oxygen (3-5%) delays ripening
  • Carbon dioxide at 5-8% helps retain firmness and can reduce chilling injury symptoms on 'Fuyu' and similar cultivars
  • Postharvest life under optimum temperature and relative humidity in ethylene-free air can be up to 3 months vs. 5 months in optimum, ethylene-free CA (3-5% O2 + 5-8% CO2) conditions

Temperature & Controlled Atmosphere Photos

Title: Ethylene Effects

Photo Credit: Don Edwards, UC Davis


Physiological and Physical Disorders

  • Exposure to oxygen levels below 3% during storage for longer than one month can result in failure of persimmons to ripen and in off-flavors
  • Exposure to carbon dioxide levels above 10% during storage for longer than one month can cause brown discoloration of the flesh and off-flavors

Disorders Photos

Title: Bruise Browning

Photo Credit: Don Edwards, UC Davis

Title: Bruising

Photo Credit: Don Edwards, UC Davis

Title: Chilling Injury

Photo Credit: Don Edwards, UC Davis

Title: Impact Damage

Photo Credit: Don Edwards, UC Davis

Title: Leaf Rub Damage

Photo Credit: Don Edwards, UC Davis

Title: Physical Damage

Photo Credit: Don Edwards, UC Davis

Title: Sunburn Damage

Photo Credit: Don Edwards, UC Davis


November 1995

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. (Accessed January 18, 2014).

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