Assessment of nutritional quality of water hyacinth leaf protein concentrate

This study was embarked upon to convert water hyacinth, an environmental nuisance, to a natural resource for economic development. Water hyacinth leaf protein concentrate (WHLPC) was extracted in edible form and determination of its physicochemical characteristics, total alkaloids and phenolic compounds was done. Analysis of proximate composition and amino acid profile of the WHLPC was also done. The level of heavy metals (mg/kg) in WHLPC was found to be Cd (0.02 ± 0.001), Cr (0.13 ± 0.001), Pd (0.003 ± 0.001) and Hg (0.02 ± 0.001) while concentrations of Pb, Pt, Sn, Fe, Cu, Zn, Ni and Co were found to be 0.001 ± 0.00. Level of all heavy metals was found to be within safe limit. Proximate analysis revealed that protein in WHLPC accounted for 50% of its nutrients, carbohydrate accounted for 33% of its nutrients while fat, ash and fibre made up the remaining nutrients. Amino acid analysis showed that WHLPC contained 17 out of 20 common amino acids, particularly, Phe (3.67%), Leu (5.01%). Level of total alkaloids and phenolic compounds was 16.6 mg/kg and 6.0 mg/kg respectively. Evidence from this study suggests that WHLPC is a good source of leaf protein concentrate (LPC); it is nutritious and acutely non toxic.