MATURITY & QUALITY
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
- Freedom from defects including freezing injury, chilling injury, insect damage, and scars
- Flavor depends upon soluble solids/acid ratio and absence of off-flavors
TEMPERATURE & CONTROLLED ATMOSPHERE (CA)
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.
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