Studies on keeping quality of imported 'Carabao' mango [Mangifera indica] fruit from the Philippines

The effects of packaging 'Carabao' mangoes, imported from the Philippines in polyethylene (PE) bags, with and without perforations, and kept at 20 degree C, were investigated. Their appearance, using a 6-point numerical peel color index (PCI), sugar and organic acid contents, and their tendency to shrivel were assessed. 1. Portions of the peel still remained greenish after day 7 in PE20 bag although fruit maturities, which were ranked as PCI-2 and PCI-3 initially, advanced to PCI-4 and PCI-5, respectively. The Hunter, a value which increased in both the peel and flesh with time, was smaller in the fruit packaged in PE20 bag than it was in unpackaged fruits (control) of those packaged in the perforated PE bag. 2. Starch content in PCI-2 fruit was higher level than that in PC13 but it rapidly decreased in the first day of storage. Sucrose was a predominant sugar in 'Carabao' mangoes. The total sugar, sucrose, and fructose contents increased during storage. The tendency for sugar to increase was slower in the fruit in PE20 bag than in the others. Sugar content in PCI-2 fruit in perforated or PE20 bags were lower than that in PCI-3 fruits. Glucose content decreased in the control or perforated PE bag faster than it did in fruits in the PE20 bag. 3. Citric acid which is the predominant organic acid in 'Carabao' mangoes was initially higher in fruits at stage PCI-2 than in those of PCI-3; it decreased during storage. The tendency for citric acid to decrease in fruit in the PE20 bag was slower, but its level was similar to fruits of the control and perforated PE20 bags. Malic and succinic acids were also found in 'Carabao' mangoes but remained at a low level during storage. 4. Shriveling, which occurred in the peel of PCI-2 and -3 fruits, began on day 5 in control fruits and on day 7 in perforated PE bags, at which time the water loss was about 7 %. Shriveling did not occur in fruits in PE20 bags at both stages PCI-2 or -3. 5. Packaging PCI-3 fruits in perforated PE bags did not prevent increases in sugars, decreases in organic acids, nor advancement in flesh and peel color or water loss as compared with those of PCI-2. Thus, we recommend that imported 'Carabao' mango fruits at PCI-3 be packages in perforated PE bags because they were most effective in maintaining quality