Abstract
Controlled atmosphere (CA) storage is a beneficial tool for extending the postharvest life of fresh fruits and vegetables, but specific tolerance levels to gas composition must be determined in order to apply this technique. Sweetcorn was stored for 14 days in air or 2% O2 plus 0, 15, or 25% CO2 at 5°C to determine the best atmosphere composition for maintaining quality. Sweetcorn was more sensitive to reduced O2 plus elevated CO2 than to either alone. Storage in 2% O2 + 25% CO2 significantly increased the respiration rate compared to air storage, indicating induction of fermentative metabolism ,while there was no significant effect of 2% O2 + 0% CO2 or 2% O2 + 15% CO2 on respiration, and storage in either 15 or 25% CO2 in air (17.7 or 15.6% O2, respectively) significantly reduced respiration. CA storage maintained higher levels of sugars, which is the main quality parameter for sweetcorn. Elevated CO2 significantly reduced loss of greenness in the husks. CA also improved the silk and kernel appearance, but it had no effect on kernel denting. The impact of CA on dimethyl sulfide (DMS), the main characteristic aroma component in sweetcorn, was also beneficial since CA maintained significantly higher DMS content compared with the air control. CA with 2%O2 + 15% CO2 gave the best results in terms of quality maintenance for 14 days storage since it preserved the highest sugar level and reduced deterioration in sweetcorn visual quality. Sweetcorn tolerated 2% O2 or 25% CO2 alone for 2 weeks, but may be damaged by the two gas levels in combination
