Temperature & Controlled Atmosphere
Optimum Temperature
0°C (32°F)
Storage life at 0°C is typically:
Bunched: 10-14 days
Immature roots: 4-6 weeks
Mature roots: 7-9 months
Fresh-cut (Lightly processed): 3-4 weeks
Common storage conditions rarely achieve the optimum temperature for long- term storage to prevent decay, sprouting, and wilting. At storage temperatures of 3-5°C, mature carrots can be stored with minimal decay for 3-5 months.
Common ‘Cello-pack' carrots are typically immature and may be stored successfully for 2-3 weeks at 3-5°C. Bunched carrots are highly perishable due to the presence of the shoots (tops). Good quality is generally maintained only for 8-12 days, even with contact ice.
Lighlty processed (fresh-cut, cut and peel) carrots typically maintain quality of 2-3 weeks at 3-5°C.
Optimum Relative Humidity
98-100%
High relative humidity is essential to prevent dessication and loss of crispness. Free moisture from the washing process or unevaporated condensation, common with plastic bin-liners (and due to fluctuating temperatures) will promote decay.
Rates of Respiration
Temperature ml CO2/kg·hr
°C (°F) Topped Bunched
0 (32) 5-10 9-18
5 (41) 7-13 13-25
10 (50) 10-21 16-31
15 (59) 13-27 28-53
20 (68) 23-48 44-60
25 (77) NA NA
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.
NA= Not applicable.
Rates of Ethylene Production
>0.1 µl/kg·hr at 20°C (68°F)
Responses to Ethylene
Exposure to ethylene will induce the development of bitter flavor due to isocoumarin formation. Exposure to as little as 0.5ppm exogenous ethylene will result in perceptible bitter flavor, within 2 weeks, at normal storage conditions. Thus, carrots should not be mixed with ethylene-producing commodities.
Responses to Controlled Atmospheres (CA)
Controlled atmosphere is of limited use for carrots and does not extend postharvest life of carrots beyond that in air. CO2 concentrations above 5% have been shown to increase spoilage. Low oxygen concentrations, below 3%, are not well tolerated and generally results in increased bacterial rot.