Responses to Controlled Atmospheres (CA)
Controlled atmosphere storage or shipping offer a moderate level of benefit. Low O2 levels (3-5%) delay ripening and the development of surface and stem-scar molds without severely impacting sensory quality for most consumers. Storage times of up to 7 weeks have been reported for tomatoes using a combination of 4% O2, 2% CO2, and 5% CO2. More typically, 3% O2 and 0-3% CO2 are used to maintain acceptable quality for up to 6 weeks prior to ripening. Elevated CO2 above 3-5 % is not tolerated by most cultivars and will cause injury. Low O2 (1%) will cause off-flavors, objectionable odors, and other condition defects, such as internal browning.