Recommendations for Maintaining Postharvest Quality
Maturity & Quality
Eggplant fruit are harvested at a range of developmental stages. Depending on cultivar and temperature, the time from flowering to harvest may be 10 to 40 days. Generally fruit are harvested immature before seeds begin to significantly enlarge and harden. Firmness and external glossiness are also indicators of a pre-maturity condition. Eggplant fruit become pithy and bitter as they reach an overmature condition.
The diversity of eggplant types being marketed has increased greatly in recent years. Standard (American) eggplant quality is primarily based on uniform egg to globular shape, firmness and a dark purple skin color. Additional quality indices are size, freedom from growth or handling defects, freedom from decay, and a fresh green calyx. Other eggplant types include:
U.S. grades are Fancy, No. 1, and No. 2, and No. 3. Distinction among grades is based solely on size, external appearances, and firmness.
Maturity & Quality Photos
Temperature & Controlled Atmosphere
Optimum Relative Humidity
Rates of Respiration
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.
0.1-0.7 µl/kg·hr at 12.5°C (55°F)
Eggplant fruit have a moderate to high sensitivity to exogenous ethylene. Calyx abscission and increased deterioration, particularly browning, may be a problem if eggplants are exposed to >1ppm ethylene during distribution and short-term storage.
Controlled or modified atmosphere storage or shipping offer little benefit to eggplant quality maintenance. Low O2 levels (3-5%) delay deterioration and the onset of decay by a few days. Eggplant tolerates up to 10% CO2 but storage life is not extended beyond the benefit of reduced levels of O2.
Temperature & Controlled Atmosphere Photos
Physiological and Physical Disorders
Freezing Injury. Freezing injury will be initiated at -0.8°C (30.6°F), depending on the soluble solids content. Symptoms of freezing injury include a watersoaked pulp becoming brown and desiccated in appearance over time.
Use of Materials
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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.