Vegetables Produce Facts English
Bean, Snap
Recommendations for Maintaining Postharvest Quality
![]() Department of Plant Sciences, University of California, Davis Beans, Snap PDF
Maturity & Quality
Maturity Indices Snap beans (yellow, green and purple types) are harvested when they are rapidly growing and developing. Harvest occurs about 8-10 days after flowering for typical mature snap beans. Beans should be harvested when the fruit is bright green, the pod is fleshy and seeds are small and green. After that period, seed development reduces quality and the pod becomes pithy and tough and looses green color. Quality Indices Beans should be well formed and straight, bright in color with a fresh appearance, and tender but firm. They should snap easily when bent. Leaves, stems, broken beans, blossom remains, insect damage should not be present. Decreased quality during postharvest handling is most often associated with water loss, chilling injury, and decay
Temperature & Controlled Atmosphere
Optimum Temperature 5-7.5°C (41-45°F) Very good quality can be maintained for a few days at temperatures below 5°C but chilling injury will be induced (see Physiological Disorders). Some chilling may occur even at the recommended storage temperature of 5°C after 7-8 days. At 5-7.5°C (41-45°F) a shelf-life of 8-12 days is expected. Relative Humidity 95-100%
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 Responses to Ethylene Exposure to ethylene at usual storage temperatures causes loss of green pigment and increased browning. Concentrations above 0.1 ppm reduce green bean shelf-life by 30-50% at 5°C. At recommended storage temperature, O2 concentrations of 2-5% reduce respiration rates. Snap beans tolerate and are benefited by CO2 concentrations between 3-10%. The main benefit is retention of color and reduced discoloration on damaged beans. Higher CO2 (20-30%) concentrations can be used for short periods, but can cause off-flavors. Temperature & Controlled Atmosphere Photos
Disorders
Physiological and Physical Disorders Rough handling at harvest or damage from shipping containers can result in translucent areas that are susceptible to decay. Pathological Disorders Special Considerations Disorders Photos
Date
May 1998 |
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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.
http://ucanr.edu/sites/Postharvest_Technology_Center_/Commodity_Resources/Fact_Sheets/Datastores/Vegetables_English/?uid=19&ds=799 (Accessed January 18, 2014).