Pomegranate
Maturity Indices pomegranate
- External red color (depending on cultivar)
- Red color of juice (equal to or darker than Munsell color chart 5R-5/12)
- Acidity of juice below 1.85%
Quality Indices
- Freedom from growth cracks, cuts, bruises, and decay
- Skin color and smoothness
- Flavor depends on sugar/acid ratio which varies among cultivars. A soluble solids content above 17% is desirable
- Tannin content below 0.25% is desirable
Pomegranate Optimum Temperature
5°C (41°F) for up to 2 months; longer storage should be at 10°C(50°F) to avoid chilling injury.
Pomegranate Optimum Relative Humidity
90-95%; pomegranates are very susceptible to water loss resulting in shriveling of the skins. Storing fruit in plastic liners and waxing can reduce water loss, especially under conditions of lower relative humidity.
Rates of Respiration
Temperature | 5°C(41°F) | 10°C(50°F) | 20°C(68°F) |
ml CO2/kg·hr | 2-4 | 4-8 | 8-18 |
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
Less than 0.1 µl/kg·hr at 10°C (50°F) or lower
Less than 0.2 µl/kg·hr at 20°C (68°F)
Responses to Ethylene
Exposure to ethylene at 1 ppm or higher stimulates respiration and ethylene production rates, but it does not affect their quality attributes. Pomegranates do not ripen after harvest and must be picked fully ripe to ensure the best eating quality.
Responces to Controlled Atmospheres (CA)
Very few studies of the responses of pomegranates to CA have been conducted. Storage in 2% O2 reduces chilling injury if pomegranates are kept below 5°C (41°F). In one study, pomegranates were stored successfully at 6°C (43°F) in 3% O2 + 6% CO2 atmosphere for 6 months.