Comparative Evaluation of the Proximate Composition and Antibacterial Activity of Ground Musa paradisiaca (Plantain) Peels and Leaves

Abstract

The study was conducted between May and August, 2015. It determined and compared the proximate composition (measured in percentage, %) of the ground Musa paradisiaca peels and leaves, and the antibacterial activity (measured in millimeter, mm) of the aqueous and ethanol extracts (at concentration of 100 mg/ml) of the respective sample, using standard protocols. The peels percentage yield (91.59±1.26%) was higher (p<0.05) than that of the leaves (84.29±1.54%). Apart from the protein content (18.09±0.09%), the other proximate parameters viz: fat (9.60±0.16), crude fibre (39.17±0.83) and ash (22.24±0.23) in the ground leaves were higher (p<0.05) than the corresponding value in the peels. Higher carbohydrate (32.47±0.48) and moisture (12.78±0.58) were recorded in the peels than in the leaves. The anti-bacterial activity (mm) of the aqueous and ethanol extracts of the leaves against Staphylococcus aureus was 9.33±0.58 and 12.33±1.15, respectively while against Escherichia coli was 14.00±1.73 and 18.67±1.15, respectively. The ethanol extracts of the peels had higher (p<0.05) antibacterial activity against Staphylococcus aureus and Escherichia coli (14.33±1.53, 15.00±2.00) respectively than the respective value obtained for aqueous extracts. However, unlike the activity against S. aureus, there was no difference in activity against E. coli based neither on the extracting solvents nor on the study samples. Thus, Musa paradisiaca peels and leaves could serve as nutrient and antibacterial sources. However, the peels compared to the leaves may serve as better source for carbohydrate but with poor storability while the leaves may serve as better source for the other determined nutrients and as antibacterial against the studied pathogens. The study further revealed that the activity of the samples against E. coli was unaffected by the solvent type and that ethanol could be preferred to water as the extracting solvent for activity against S. aureus. Further studies are required, hence recommended to harness the present findings and ultimately to reduce their solid waste contribution.