FIRMNESS AND CONCENTRATIONS OF ACETALDEHYDE, ETHYL-ACETATE AND ETHANOL IN STRAWBERRIES STORED IN CONTROLLED AND MODIFIED ATMOSPHERES

'Pajaro' strawberries (Fragaria x ananassa Duch.) were stored at 0 degrees C in a range of controlled atmosphere (CA) conditions with CO2 concentrations up to 24%, O-2 concentrations down to 1%, or a combination of 10% CO2 and 2% O-2 Elevated CO2 concentrations resulted in firmer fruit, while low O-2 did not affect texture. Off-flavours developed after 3 days of storage at 20% CO2, but decreased when fruit was subsequently held for 24 h at 20 degrees C. However, off-flavours were persistent after CA storage for 7 days or more. Off-flavours were related to increases in ethyl acetate and ethanol concentrations but not to acetaldehyde. Beneficial atmospheres of close to 10% CO2 and 2% O-2 resulted in a firmer texture and delayed ripening with no off-flavour development. However, fruit quality was poor when similar atmospheres were developed in modified atmosphere (MA)-producing polythene bags. Rapid imposition of CA resulted in better quality fruit than when MAs around the fruit were developed gradually.