Ripening and ethylene biosynthesis in controlled atmosphere stored apricots

Ethylene synthesis and metabolism were studied in apricot fruits (Prunus ar meniaca L. cv. Bulida, under controlled atmosphere (CA) conditions (20% CO2 and 20% O-2; 20% CO2 and 1% O-2; 0.03% CO2 and 1% O-2) and at a temperatur e of 2 degrees C. In control apricots stored outdoors in air containing 20% O-2 and 0.03% CO2, the evolution of the physical and chemical parameters c haracteristic of ripening (loss of texture, decrease in acidity and increas e in soluble solids) was slow during the storage period. However, for apric ots stored in CAs containing 1% O-2 and 20% or 0.03% CO2, these parameters did not show significant changes during the storage period. Ethylene produc tion was completely inhibited in apricots stored in the three CAs, while co ntrol fruits showed a maximum ethylene level after 2 weeks of storage. This inhibition was accompanied by lower levels of 1-aminocyclopropane-1-carbox ylic acid, free and total, which were more pronounced in apricots stored in the CAs containing 20% CO2. In apricots stored in the CAs containing 1% O- 2, the ethanol content increased after 1 week of storage, and this caused a smell and taste that made the fruits unsuitable for consumption.