RESIDUAL EFFECTS OF SHORT-TERM TREATMENTS WITH HIGH CO2 ON THE RIPENING OF CHERIMOYA (ANNONA-CHERIMOLA MILL) FRUIT

Cherimoya fruit were stored in air, or in a combination of 10% O-2 and 10, 15 or 20% CO2, at 8 degrees C and 98% relative humidity. After 3, 6, and 9 d, fruit were ripened at 20 degrees C to study the residual effects of treatments. Air storage progressively increased the ethylene production and reduced the days to ripen with respect to control fruit directly held at 20 degrees C. As compared with air, the treatments with CO2 reduced both the increase in ethylene production and rate of softening (especially of the skin) at 20 degrees C, and delayed fruit ripening. No marked effect of either treatment was found in the respiration rate and sugar accumulation during ripening, with maxima similar to those of control fruit. While some decrease in acidity with longer storage was found in ripe cherimoyas, only those treated with 20% CO2 for 9 d showed unacceptable quality, due to bitterness. The treatment with 20% CO2 can prolong the shelf-life of cherimoyas up to 1.5 d.