Effects of degree of ripeness on phenolic content and radical scavenging activity of banana flesh and peel
Abstract
The effects of degree of ripeness on total phenolic content and radical scavenging activity of imported Cavendish banana flesh and peel were investigated and compared to values reported in the literature of locally cultivated bananas. Three stages of ripeness were assessed: unripe (green), ripe (yellow), and overripe (brown). The average total phenolic content of the flesh and peels ranged from 13.89 ± 4.3 to 120.5 ± 51.6 mg gallic acid equivalent (GAE)/100 g dry weight. The average flavonoid content of the flesh and peels ranged from 5.33 ± 0.3 to 178 ± 0.01 mg catechin/100 g dry weight. The average radical scavenging activity of the peels and flesh ranged from 667.1 ± 67.2 to 1989.7 ± 14.6 mg BHT (butylated hydroxytoluene) equivalent/100 g dry weight. These values were quite low in comparison to the values reported in the literature on the Cavendish cultivar of the banana. Variations in extract preparation or storage conditions during importation of the bananas may be responsible for the lower values. The total phenolic content, flavonoid content, and radical scavenging activity were greater in the peels than the flesh at all stages of ripeness. In general, antioxidant properties were greater in the ripe and overripe flesh and peels than the unripe flesh and peel. The antioxidants present in the banana flesh and peel could be beneficial for prevention or treatment of diseases linked to oxidative stress.