Nutraceutical potential of ripe and unripe plantain peels: A comparative study

Abstract

This study investigated the nutraceutical potential of ripe and unripe plantain fruit peels which are commonly discarded as food wastes. Proximate and mineral analyses of the samples were performed as per the standard methods of the Association of Official Analytical Chemists. Preliminary phytochemical screening of aqueous, acetone and methanol extracts of the peels was also carried out in accordance to standard methods. From the results of the study, acetone extract of the unripe peel showed the presence of eight phytochemicals while its ripe peel showed the presence of four. Aqueous and ethanol extracts of both peels showed the presence of same phytochemicals i.e., terpenoids, cardiac glycosides, phenols, flavonoids, alkaloids, reducing sugars and saponins. Meanwhile, tannins was absent in all three solvent extracts of both peels. Fat, ash, crude fibre and carbohydrate contents of the unripe peel were higher than those of the ripe. However, moisture and protein contents of the ripe peel were significantly higher (P < 0.05) than those of the unripe. Of all the nine essential minerals assayed (K, Na, Mg, Ca, P, Fe, Zn, Mn, Cu), concentrations of all except calcium were significantly higher (P < 0.05) in the unripe peel than those of the ripe peel. Notably, none of the heavy metals (Co, Cr, Cd, Pb, Ni) assayed was detected in both samples. This study concludes that ripe and unripe plantain fruit peels could serve as promising sources of nutrients and bioactive compounds essential for the health of both livestock and humans.