Physicochemical Properties, Antioxidant and Antimicrobial Activities of Unripe Green and Ripened Yellow Banana (Musa sp.) Peel and Pulp Oil Extracts

Abstract

Background: Banana peel (Musa Sp.) is more nutritional and rich in phytochemical compounds than its pulp. All parts of the banana plant have medicinal applications. Damage from free radicals at the cellular level causes cell inflammation, increasing the risk of damage from sunlight, radiation, and related development of skin cancer. Objective: The purpose of this study was to assess the physicochemical properties, antioxidant, and antimicrobial activities of unripe green and yellow ripened banana fruit peels and pulp oil extracts. Methods: The oil extraction was done in Soxhelt apparatus using petroleum ether as a solvent. Then, the oil extracts were assessed based on the determination of oil yield, acid value, percent free fatty acid, peroxide value, and free radical scavenging activity using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and hydrogen peroxide, and ascorbic acid. The antioxidant and antimicrobial activities were determined based on ascorbic acid content, DPPH and hydrogen peroxide scavenging activities. The antimicrobial experiment was arranged in completely randomized factorial design with three replications. Results: The result indicated that significantly the highest oil yield (2.60±0.21%), acid value (2.66±0.20%), and free fatty acids (1.34±0.10%) were recorded for green peel oil extract. Significantly, the highest DPPH radical scavenging activity was recorded for green peel (5.85%) followed by green pulp (4.80) and the least for yellow peel (4.50). Ascorbic acid and hydrogen peroxide scavenging activity were significantly higher for yellow peel and green pulp oil extract extracts than for green peel oil extract. The strongest antibacterial activity with the maximum zone of inhibition (15.5mm), minimum inhibitory concentration (0.125μg/ml), and corresponding minimum bactericidal concentration (0.25 μg/ml) was recorded for ripened peel oil extract against Staphylococcus aureus. The antifungal activity of the oil extract presented the highest zone of inhibition (15.67mm), minimum inhibitory concentration (0.125 μg/ml) and corresponding minimum fungicidal concentration (0.25 μg/ml) were recorded for unripe green banana fruit pulp oil extract against Aspergillus versicolor. Conclusion: The result indicated that the banana fruit peel oil extracts demonstrated differential antioxidant and antimicrobial potentials. Thus, the banana peel waste oil extracts proved to have potential sustainable applications in nutritional and drug development technologies.