Potravní kvasnicný doplnek je tvoren hydrolyzátem lupinové mouky hydrolyzované kyselou syrovátkou, který obsahuje alespon 1,5 % hmotn. kyseliny mlécné. Zpusob jeho výroby spocívá v tom, ze se provádí fermentace syrovátky, pri níz se pri teplote 20 az 40 .degree.C postupne dávkuje lupinová mouka ve forme vodné suspenze, pricemz pH reakcní smesi se udrzuje na hodnote 3 az 4 a tento proces se ukoncí pri dosazení obsahu kyseliny mlécné nejméne 1,5 % hmotn., potom se pridá dalsí lupinová mouka ve forme vodné suspenze a provede se hydrolýza pri teplote 130 az 150 .degree.C a tlaku 340 az 370 kPa, po provedení hydrolýzy se provede dekantace, pri které se usazený nezhydrolyzovaný podíl odstraní a horní vrstva hydrolyzátu, obsahující 5 az 10 % hmotn. susiny se odvede k dalsímu zpracování, pri kterém se ochutí ovocným sirupem k príprave nápoje nebo se zahustí a ususí.The yeast food supplement of the present invention consists of a lupine flour hydrolyzate hydrolyzed by sour whey and contains at least 1.5 percent by weight of lactic acid. A process for preparing such yeast food supplement is characterized by fermentation of whey, during which fermentation lupine flour in the form of a free suspension is successively proportioned at a temperature ranging from 20 to 40 degC, wherein pH of the reaction mixture is maintained on the value of 3 to 4. The fermentation process terminates at the moment at which the amount of at least 1.5 percent by weight of lactic acid is achieved. Subsequently, further lupine flour in the form of a free suspension is added and a hydrolysis is carried out at a temperature ranging from 130 to 150 degC and a pressure in the range of 340 to 370 kPa. After execution of the hydrolysis, decantation, serving for the removal of settled non-hydrolyzed fraction, is carried out wherein the upper layer of the hydrolyzate containing 5 to 10 percent by weight of the dry matter is taken away for other treatment, in the course of which it is flavored with fruit syrup
