Effects of gas concentrations on fruits
III. Effects of oxygen concentrations and the delayed storage on white peach“Okubo”fruits
1971 Volume 40 Issue 4 Pages 430-436
Details
1971 Volume 40 Issue 4 Pages 430-436
Previous report revealed that effects of oxygen levels on white peach“Okubo”fruits and the development of low temperature injuries were influenced by the fruit maturity. To clarify these effects in relation to the maturity, fruits were stored in nitrogen atmosphere with 0, 1, 3, 5, 10 and 21% oxygen at 20°C, and with 1, 3 and 21% at 4°C.
Before 4°C storage, some of the fruits were stored for 3 days in air at 4°C (immediate storage), and another were ripened for 3 days in air at 20°C, (delayed storage). After immediate storage, some of the sampled fruits were ripened at 20°C in air for 2 days. Carbon dioxide was excluded in all treatments. Material fruits required 2-3 days to ripen in air at 20°C.
1. At 20°C, softening was retarded only at 0% O2 and peeling index change at 0, 1, 3 and 5% O2. The critical oxygen levels for the CO2 evolution rates were 1, 3 and 5% O2. The flat flavor was developed at 10 and 21% O2. No distinct differences were found in the titratable acidity and soluble solids contents among O2 treatments.
The fermented flavor was developed at 0 and 1% O2 and in some of the sampled fruits, at 3 and 5% O2. High ethanol contents were found in the fruits with the fermented flavor. The brown pit was found at 0% O2.
The ripening was retarded below 5% O2, but the low oxygen injuries developed below 5% O2. After 4 days at 20°C, the best quality was found in the fruits at 3, 5% O2 without injuries.
2. During the storage at 4°C, softening and peeling index change were not retarded at every O2 level both in the immediate storage and in the delayed storage. The CO2 evolution rate was retarded at 1% O2 in both storage and the rate in the delayed storage was higher than in the immediate storage at every O2 level. Low temperature injuries were found after 15 days and 20 days in the immediate storage and the delayed storage, respectively. The incidence of low temperature injuries were not retarded at low oxygen levels.
During the 4°C storage, some of the fruits at 1% O2 developed the fermented flavor and the development was faster in the delayed storage than in the immediate storage.
3. During ripening treatment after removal from the 4°C storage, the residual retardation effects due to the low oxygen levels were not found in softening and peeling index change.
4. At 4°C storage, no distinct differences in storage quality were found between 3 and 21% O2, and below 1% O2, the fermented flavor developed. At 4°C storage, the merits of the low oxygen levels in CA storage were not found. In case of the more ripened materials, the delayed storage seemed not to retard the low temperature injuries. More experiments must be followed at the lower temperatures.
