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

Abstract

Controlled atmospheres (CA) have been widely used in postharvest storage off ruits and vegetables. The gasc ompositions of common CA are consisted of O₂, CO₂ and N₂, postharvest storage condition with gas combination of O₂ and CO₂ was rarely studied. In this research, the effects of CA with  different CO₂/O₂ levels, i.e. 70%O₂+30%CO₂, 60%O₂+40%CO₂, 50%O₂+50%CO₂, 40%O₂+60%CO₂, 30%O₂+70%CO₂, and air (control) on the storage life andproperties 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%O₂+40%CO₂ at 0°C, 50%O₂+50%CO₂ at 10°C, and 40%O₂+60%CO₂ at 20°Cmaximum inhibited respiration rate and ethylene production, maintain chlorophyll and ascorbic acid content, reduced the accumulation of acetaldehyde and ethanol, and extended thestorage life of broccoli florets to 49,31, and 14d. compared to 21d at 0°C, 12dat 10°C and 4d at 20°C in air-treated broccoli. These results indicated that an appropriate CA with O₂/CO₂ might be a potential strategy for postharvest storage of broccoli heads, and the appropriate proportion of O₂ and CO₂ might vary with different temperature.