The objective of this work was to promote the autolysis and the fractionation of the yeast (Saccharomyces sp.) for the production of autolysate and extract, as well as phosphorylated protein concentrate, from ethanol distillery yeast. Comparative studies of centesimal composition, essential amino acid profiles and protein nutritive value were performed for the unprocessed integral cells, and for autolysate, extract and phosphorylated protein concentrate. Protein and carbohydrate (dietary fiber) were the main components for the integral cells and autolysate. For the extract and the protein concentrate the main components were protein and minerals (ashes). The autolysate and the integral cells presented the highest essential amino acid indexes, followed by the protein concentrate and the extract. Protein digestibility ranged from 68% (integral cells) to 91% (extract). Net protein ratio ranged from 2.1 (integral cells) to 4.3 (casein-reference). There was no statistical difference in Net protein ratio among autolysate, extract and protein concentrate (3.9 to 4.2). The protein concentrate promoted the highest growth in the period (21 days), followed by the extract and the autolysate. The integral cells showed the lowest capacity to promote rat growth.
Saccharomyces; integral cells; autolysate; extract; protein concentrate; Saccharomyces cerevisiae proteins; fermentation
