Carbon dioxide sorption by stored canola under different storage conditions

Sorption of carbon dioxide (CO2) by canola seeds with 8, 10, 12 and 14% moisture contents (wet basis) was measured for different durations up to 72 h. The canola seeds were exposed to 15%, 40% and 100% initial CO2 concentration at 10, 20, and 30 °C and under normal atmospheric pressure. Equilibrium sorption was determined, and it was found sorption equilibrium was established in less than 20 h except at 8% moisture content canola at 10 °C. At 30 °C and higher than 10% moisture content, equilibrium was established in less than 1.5 h. The maximum equilibrium sorption was 3.0 g/kg of dry mass of canola under 10 °C with 100% initial CO2 concentration. Sorption significantly increased by high intergranular CO2 concentrations and low temperatures. Moisture content of the canola seeds did not significantly influence the equilibrium sorption even though wet canola seeds had a faster sorption of CO2 than dry canola seeds before equilibrium was reached. Spoiled (visible mould) or non-spoiled canola seeds had similar equilibrium sorption, and sorption by spoiled canola could be established in less than 6.5 h under any tested condition.