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Bell
Pepper
Recommendations for Maintaining Postharvest Quality
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Marita Cantwell
Department of Vegetable Crops, University of California, Davis,
CA 95616
Maturity Indices
Green Peppers: fruit size, firmness, color
Colored Peppers: minimum 50% coloration
Quality Indices
- Uniform shape, size and color typical of variety
- Firmness
- Freedom from defects such as cracks, decay, sunburn
Optimum Temperature
Peppers should be cooled as soon as possible to reduce water loss. Peppers
stored above 7.5°C (45°F) suffer more water loss and shrivel. Storage
at 7.5°C (45°F) is best for maximum shelf-life (3-5 weeks); peppers
can be stored at 5°C (41°F) for 2 weeks, and although this reduces
water loss, chilling injury will begin to appear after that period. Symptoms
of chilling injury include pitting, decay, discoloration of the seed cavity,
softening without water loss. Ripe or colored peppers are less chilling
sensitive than green peppers.
Optimum Relative
> 95%; firmness of peppers is directly related to water loss
Rates of Respiration
| Temperature |
5°C(41°F) |
10°C(50°F) |
20°C(68°F) |
| ml CO2/kg·hr |
3-4 |
5-8 |
18-20 |
To calcualte 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
Bell peppers are nonclimacteric in behaviour and produce very low levels
of ethylene: 0.1-0.2 µl/kg·hr at 10°-20°C (50°-68°F).
Responses to Ethylene
Bell Peppers respond very little to ethylene; to accelerate ripening
or color change, holding partially colored peppers at warm temperatures
of 20-25°C (68-77°F) with high humidity (>95%) is most effective.
Responses to Controlled Atmospheres (CA)
Peppers generally do not respond well to CA. Low O2 atmospheres
(2-5% O2) alone have little effect on quality and high CO2 atmospheres (>5%) can damage peppers (pitting, discoloration, softening)
especially if they are stored below 10°C (50°F). Atmospheres of
3% O2+ 5% CO2were more beneficial for red than green
peppers stored at 5°C (41°F) to 10°C (50°F) for 3-4 weeks.
Physiological Disorders
Blossom end rot. this disorder occurs as a slight discoloration
or a severe dark sunken lesion at the blossom end; it is caused by temporary
insufficiencies of water and calcium and may occur under high temperature
conditions when the peppers are rapidly growing.
Pepper speck. this disorder appears as spot-like lesions that
penetrate the fruit wall; cause is unknown; some varieties are more susceptible
than others.
Chilling injury. symptoms of chilling injury include surface
pitting, water-soaked areas, decay (especially Alternaria), and discoloration
of the seed cavity.
Pathological Disorders
On California-grown bell peppers, the most common decay organisms are
Botrytis, Alternaria, and soft rots of fungal and bacterial origin.
Botrytis or Grey mold decay. this is a common decay-causing organism
on peppers; field sanitation and prevention of wounds on the fruit help
reduce its incidence. Botrytis will grow well at the recommended storage
temperatures. High CO2levels (>10%) which can control Botrytis
damage peppers. Hot water dips of peppers can effectively control botrytis
rot ( 55°C [130°F] water for 4 minutes) without causing fruit injury.
Alternaria rot. the presence of black Altenaria rot, especially
on the stem end of the pepper is a symptom of chilling injury; best control
measure is to store at 7.2°C (45°F)
Bacterial Soft Rot. soft rotting areas can be caused by several
bacteria which attack damaged tissue; soft rots can also common on washed
or hydrocooled peppers where water sanitation was deficient
Other Commonn Postharvest Defects
Mechanical damage (crushing, stem punctures, cracks, etc.) is very
common on peppers; physical injury not only detracts from the visual quality
of the peppers but also causes increased weight loss and decay.
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Produce/ProduceFacts/Veg/pepper.html updated July 7, 2000
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