Effect of low-oxygen atmosphere on quality changes, acetaldehyde and ethanol accumulation in early and late harvest of "Hayward" kiwi fruit

Early and late harvested "Hayward" kiwifruit (soluble solids content 6.6 and 10.3% respectively) were stored under ULO conditions. Quality changes of fruit were evaluated during and after storage for up to 270 days (first harvest) and 250 days (second harvest) in 0.5% O-2, 1% O-2, 1% O-2 + 1% CO2 and air at 0 degrees C. Flesh firmness, soluble solids content, flesh color, acetaldehyde content, ethanol content and flavor index were measured. Flesh firmness of kiwifruit decreased with storage duration Fruits stored in 1% O-2 + 1% CO2 retained a satisfactory level of firmness (0.8 kg early harvest and 1.5 kg late harvest) and were firmer than fruit of other treatments Soluble solids content of fruit increased in all treatments. Flesh color changes of fruit stored in 1% O-2 + 1% CO2 were less pronounced than other treatments. Acetaldehyde and ethanol content of fruit stored in 0.5% O-2 was higher than other treatments and increased with storage duration. Late harvested fruit had higher acetaldehyde and ethanol content than early harvested ones. The flavor index of fruit of both harvest dates stored in 0.5% O-2 was lower than that of fruit stored in other atmosphere composition.