Quality of 'Oso Grande' strawberries is affected by O-2, CO2 and N2O concentrations during controlled atmosphere storage

Abstract

Consumers around the world appreciate strawberries for their taste. They have low calories and high concentrations of soluble fibers, vitamin C and flavonoids. This paper verified the combined effect of O-2, CO2, and N2O levels on 'Oso Grande' strawberries stored at 10 degrees C, under controlled atmosphere (CA). Five different gas mixtures were used: 0.03 kPa CO2 + 20 kPa O-2, 80 kPa N2O + 20 kPa O-2, 90 kPa O-2 + 10 kPa N-2, 60 kPa O-2 + 40 kPa CO2, and 20 kPa O-2 +20 kPa CO2 + 60 kPa N2O. The lowest incidence of postharvest decay was observed with treatment 20 kPa O-2 + 20 kPa CO2 + 60 kPa N2O, followed by 80 kPa N2O + 20 kPa O-2 and 90 kPa O-2 + 10 kPa N-2. The treatment 60 kPa O-2 + 40 kPa CO2 induced an increase in the production of acetaldehyde and ethanol, and these levels were considered inadequate for human consumption. The first factor, named senescence, displayed a positive correlation with soluble solids, luminosity, hue angle, firmness and incidence of decay. The second factor, named CA-induced injury, showed that total acidity correlated negatively with ethanol and acetaldehyde levels. Hierarchical cluster analysis indicated that strawberries stored under 80 kPa N2O +20 kPa O-2 for 14 days more closely resembled the quality of fresh fruit at the moment of harvest. 'Oso Grande' strawberries stored at 10 degrees C under 80 kPa N2O + 20 kPa O-2 and 90 kPa O-2 + 10 kPa N-2 were in better conditions, with no metabolic alterations, showing that these are the ideal storage conditions.