











Return to Produce Storage Recommendations
Recommendations for Maintaining Postharvest Quality
Mary Lu Arpaia1 and Adel A. Kader2
1Department of Botany and Plant Sciences, University of California, Riverside, CA 92521
2Department of Pomology, University of California, Davis, CA 95616
Maturity Indices
Color (yellow, orange, and/or red) on 75% of fruit surface and soluble solids/acid ratio of 6.5 or higher.
Quality Indices
Color intensity and uniformity; size; shape; firmness; freedom from decay; and freedom from defects including freezing injury, chilling injury, insect damage, and scars. Flavor depends upon soluble solids/acid ratio and absence of off-flavors.
Optimum Temperature
5-8°C (41-46°F) for 2 to 6 weeks, depending on cultivar, maturity-ripeness stage at harvest, and decay control treatments used.
Optimum Relative Humidity
90-95%
Rates of Respiration
Temperature | 5°C (41°F) | 10°C (50°F) | 15° (59°F) | 20° (68°F) |
ml CO2/ kg·hr | 2-4 | 3-5 | 6-10 | 10-15 |
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 20°C (68°F)
Responses to Ethylene
Mandarins and tangerines can be degreened by exposure to 1-10 ppm ethylene for 1-3 days at 20 to 25°C (68 to 77°F)
Removal of ethylene from transport vehicles and storage facilities for citrus fruits can help reduce decay incidence.
Responses to Controlled Atmospheres (CA)
A combination of 5-10% O2 and 0-5% CO2 can delay color changes from green to yellow and other symptoms of senescence, but it is not very effective in decay control. Mandarins do not tolerate exposure to fungistatic CO2 levels (10-15%). Commercial use of CA is very limited.
Physiological Disorders
Chilling injury. Symptoms include pitting and brown discoloration followed by increased susceptibility to decay. Severity increases with longer exposures to lower temperature below 5°C (41°F).
Oil spotting (Oleocellosis). Harvesting and handling turgid citrus fruits can result in breaking of oil cells and release of oil that damages surrounding tissues.
Aging. Symptoms include shriveling and peel injury around the stem end.
Pathological Disorders
Major Diseases:
Control Strategies:
Reduce the pathogen population in the environment
Maintain fruit resistance to infection
Postharvest Technology Research and Information Center
Department of Pomology
University of California
One Shields Ave., Davis, CA 95616-8683
Send comments and questions to Postharvest Technology Research and Information Center
Copyright ©1996-2000. All rights reserved
Produce/ProduceFacts/Fruit/mandarin.html updated July 3, 2000