Vegetables Produce Facts English
Onions, Dry
Recommendations for Maintaining Postharvest Quality
![]() Department of Plant Sciences, University of California, Davis
Maturity & Quality
Maturity Indices
Quality Indices
Temperature & Controlled Atmosphere
Optimum Temperature Curing Storage Curing Storage Whole Onions Diced Onions 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. Whole Onions Diced Onions Ethylene may encourage sprouting and growth of decay-causing fungi. No commercial benefit has been identified for varieties with long storage potential. Onions are damaged by <1% O2 and 10% CO2. There is some commercial use of CA (3% O2 and 5-7% CO2) for sweet onion varieties (short storage potential). Diced onions benefit from CA conditions of 1.5% O2 and 10% CO2.
Disorders
Physiological and Physical Disorders Freezing Injury. Soft water-soaked scales rapidly decay from subsequent microbial growth. Translucent Scales. Resembles freezing injury and is prevented by prompt cold storage following curing; 3-4 week delay in cold storage increases risk significantly. Greening. Exposure to light following curing causes green-coloration of outer scales. Ammonia Injury. Brown-black blotches result from ammonia gas leakage during storage.
Special Considerations Disorders Photos
Date
August 1996 |
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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.
http://ucanr.edu/sites/Postharvest_Technology_Center_/Commodity_Resources/Fact_Sheets/Datastores/Vegetables_English/?uid=19&ds=799 (Accessed January 18, 2014).