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Persimmon
Recommendations for Maintaining Postharvest Quality
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Carlos H. Crisosto, Elizabeth J. Mitcham, and Adel A. Kader
Department of Pomology, University of California, Davis, CA 95616
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
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Yellow to orange color
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Medium to large size
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Firm (penetration force, using an 8-mm tip, is above 5 lb-force for 'Fuyu'
and similar cultivars)
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Freedom from growth cracks, mechanical injuries, and decay
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Soluble solids of 21-23% in 'Hachiya' and 18-20% in 'Fuyu' and similar
non-astringent cultivars
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No astringency (tannin content)
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Nutritive value: good source of carotenoids, vitamin A, vitamin C, and
dietary fiber
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
90-95%
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.
Responces to Controlled Atmospheres(CA)
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Low oxygen (3- 5%) delays ripening.
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Carbon dioxide at 5- 8% helps retain firmness and can reduce chilling injury
symptoms on 'Fuyu' and similar cultivars.
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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.
Physiological Disorders
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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.
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Exposure to carbon dioxide levels above 10% during storage for longer than
one month can cause brown discoloration of the flesh and off- flavors.
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Produce/ProduceFacts/Fruit/persimmon.html updated July 5, 2000
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