Effect of low oxygen storage conditions on volatile emissions and anaerobic metabolite concentrations in two plum fruit cultivars

By harvest time, small amounts of acetaldehyde were accumulated in the flesh of plums, such as 0.31 mg/L for the cv. Stanley and 1.03 mg/L for the cv. Valjevka. This relative difference in concentrations remained constant throughout the whole period of storage in a regular atmosphere. The long-term effects of higher concentrations of CO2 are the same as for very low oxygen concentrations; significant amounts of ethanol accumulate in the tissue. Out of a total number of 42 different odour compounds identified in the juice, 11 compounds were alcohols, 6 aldehydes, 17 esters, 2 terpenes, 3 organic acids, and 1 lactone. Very low oxygen atmospheres slow down the production of esters and aldehydes, but have little effect on the production of lactones and terpenes. It was shown that a very low oxygen concentration, without much CO2 (fluctuating anaerobiosis treatment), does not encourage the production of significant amounts of ethanol and acetaldehyde in the fruit flesh, but does significantly slow down the biosynthesis of aromatic volatiles.