Protein concentrates were obtained after alkaline extraction of yeast from Saccharomyces uvarum (byproduct of beer production). In the yeast protein concentrates obtained after enzymatic hydrolysis with neutrase and protamex were determinated amino acids content, in vitro digestibility as well as nutritional value indexes. Both yeast protein hydrolysates were characterised by enzymatic digestibility and egzogenous amino acids content. Nutritional value studied protein preparations determined by chemical indicators were quite high and comparable with the respective indicators for majority plant proteins.