Effect of γ-aminobutyric acid on the antioxidant system and biochemical changes of mango fruit during storage

Postharvest management of mango, as a climacteric fruit with high perishability rate, is of particular economic importance. In this study, the effect of gamma-aminobutyric acid (GABA) (50, 100 and 200 mu mol L-1) were evaluated regarding efficacy of delaying in fruit softening and maintaining nutritional quality of mango fruit during storage at 15 +/- 1 degrees C and 85% RH. According to the results, the total soluble solids content and titratable acidity were not influenced by the gamma-aminobutyric acid significantly; while, at 200 mu mol L-1 it has maintained firmness, ascorbic acid, phenols and flavonoids content of mango significantly. Also, the higher antioxidant capacity was found in treated fruits. The treated fruits had more activity of the catalase and peroxidase enzymes than the control. The gamma-aminobutyric acid significantly controls the activity of polyphenol oxidase enzyme during storage. The GABA treated fruits showed the higher a* value and lower b* and L* during the storage. These findings suggested that gamma-aminobutyric acid treatment could be useful at a proper concentration in order to improve postharvest quality of mango.