Protein enrichment of yam peels by fermentation with Saccharomyces cerevisiae (BY4743)

Abstract

Conventional sources of protein are becoming inadequate for protein-based food supply. Non-conventional sources are of much concern, but literature is sparse on the protein quality of yam peel biomass. Solid state fermentation (with and without ammonium sulphate) of yam peels was carried out for 96 h, using Saccharomyces cerevisiae (BY4743). Samples from fermented biomass were collected at 24 h interval for 96 h, oven dried at 60 °C, cooled, milled and assayed for chemical and amino acid composition. The crude protein, true protein, fat and ash contents increased significantly from 6.60%, 4.38%, 1.12% and 4.45% to 15.54%, 13.37%, 2.09% and 8.02% respectively when fermentation reached 96 h in the presence of ammonium sulphate. High protein content with good amino acids profile (leucine, valine, lysine and threonine as essential amino acids) was recorded in ammonium sulphate supplemented peels fermented for 96 h. Remarkable increase in protein and amino acids suggested that ammonium sulphate supplement influenced the biomass protein yield and quality.