Protein concentrates from yeast cultured in wood hydrolysates

Candida utilis NRRL Y-900 cells were cultured in glucose solutions generated by enzymatic hydrolysis of pretreated Eucalyptus globulus wood. Yeast biomass was subjected to chemical treatments with NH4OH solutions in order to obtain protein concentrates with high nutritive value having low contents of nucleic acids and high digestibility. Under selected conditions, 95% of the initial nucleic acids were removed from yeast cells. The protein recovery after the chemical treatments accounted for 88% of the amount contained in untreated biomass. The protein concentrates showed high in-vitro digestibility, and their amino acid profiles were not significantly altered in relation to those of untreated cells.