Controlled atmosphere (CA) storage and modified atmosphere packaging (MAP)
are beneficial tools for extending the postharvest life of fresh fruits and vegetables, but
specific tolerance levels to gas composition must be determined in order to apply these
techniques. Perforation-mediated modified atmosphere packaging (PM-MAP) for
sweetcorn utilizing impermeable containers with a diffusion window was designed to
establish 15, 20 or 25% CO2 atmospheres at 1 and 10 °C. The desired CO2 concentrations
were obtained at 1 °C, but were about 3-5% lower than expected at 10 °C. It took about 5
d to reach the equilibrium atmospheres at 1 °C, and about 2 d at 10 °C. Sweetcorn cobs in
CA tolerated 2% O2 and up to 25% CO2 alone for 2 weeks at 5 °C, but elevated
respiration suggested that they may be damaged by the two gas levels in combination,
although no significant ethanol or acetaldehyde production was detected in any CA or
PM-MAP treatment.