PHYSIOLOGICAL EFFECTS OF OXYGEN ON CARROTS IN STORAGE
The gas storage experiments with carrots, reported in the literature, are mostly of the type where concentrations of CO2 and O2 have been altered simultaneously (21-storage). From experiments with different products we know that a reduction of the oxygen concentration to 10% usually has little effect. From the results published by van der Meer (1962), Tomkins (1966) and van den Berg & Lentz (1966) we concluded that carrots seem to react unfavourably to CO2-concentrations above 5%.
The effect of oxygen concentration in the storage atmosphere (CO2-concentration < 1%) has not been studied thoroughly. Platenius (1942) reported injury after 6 days in an atmosphere with 2.8% O2 at 20°C, but non in 4.8% O2. He concluded that the critical level of oxygen seems to be about 4% at 20°C. In a long time experiment he found that carrots stored well for 6 months in 1–2% O2 at 2°C, and he suggested that the critical level might be lower at lower temperatures. On the other hand results from Canadian experiments (van den Berg & Lentz 1966) with two varieties ('Chantenay' and 'Nantes') show that carrots were damaged after 5 months kept in 3% O2 at 0–1 and 2.8–3.8°C.