Process for the conversion of starch and protein-containing cellulosic waste products into nutrients richer in proteins

A process for the recovery of high-protein materials from starch and protein-containing pieces and crumbs of broken baked goods from bakeries which process comprises

• dispersing said baked goods in comminuted form in water;
• subjecting said dispersion to an acid-, enzyme-, or microorganism-induced hydrolysis under suitable conditions sufficient to convert the starch in said dispersion to a fermentable sugar;
• thereafter separating and recovering protein containing solids from the hydrolyzed dispersion by means of ultrafiltration, and
• aerobically cultivating in the remaining sugar-containing liquid a yeast that is capable of fermenting the sugar-containing liquid and utilizing the sugar therein for growth, and
• finally recovering from the fermented liquid a high protein yeast formed by said fermentation whereby said protein containing solids and said high protein yeast are suitable for use in human and animal food products.