Responses of Postharvest Broccoli (Brassica oleracea L. var. italica) florets to controlled atmospheres with varying CO2/O2 levels at different temperature

Controlled atmospheres (CA ) have been widely used in postharvest storage of f ruits and vegetables. The gas c ompositions of common CA are consisted of O 2 , CO 2 and N 2 , postharvest storage condition with gas combination of O 2 and CO 2 was rarely studied. In this research, the effects of CA with  different CO 2 /O 2 levels, i.e. 70% O 2 + 30% CO 2 , 60% O 2 + 40% CO 2 , 50% O 2 +50% CO 2 , 40% O 2 + 60% CO 2 , 30% O 2 + 70% CO 2 , and air (control) on the storage life and properties of broccoli during storage were investigated at different temperatures including 0, 10 and 20°C. Results showed that the storage period of air treatments at 0, 10 and 20°C was 21, 12, and 4d . Treatments with 60%O 2 +40%CO 2 at 0°C, 50%O 2 +50%CO 2 at 10°C, and 40%O 2 +60%CO 2 at 20°C maximum inhibited respiration rate and ethylene production, maintain chlorophyll and ascorbic acid content, reduced the accumulation of acetaldehyde and ethanol, and extended the storage life of broccoli florets to 49, 31, and 14d . compared to 21 d at 0 °C, 12 d at 10 °C and 4 d at 20 °C in air-treated broccoli. These results indicated that an appropriate CA with O 2 /CO 2 might be a potential strategy for postharvest storage of broccoli heads, and the appropriate proportion of O 2 and CO 2 might vary with different temperature.