ENZYMATIC MODIFICATION OF YEAST PROTEIN ISOLATES

Yeast protein isolate with 85% of pure protein and 1.2% of nucleic aci ds in dry matter was isolated from Saccharomyces cerevisiae by a proce dure of two pre-treatment steps, acidic extraction and isoelectric pre cipitation. The application of this yeast protein isolate was limited by its functionality resulting from the partially extreme isolating co nditions. An enzymatic partial hydrolysis with Thermitase to a degree of hydrolysis of 5% not only improved the solubility and foaming prope rties, but also the water binding capacity and the emulsifying propert ies. The hydrolysate was free of bitter taste and could be applied eit her in two fractions of different solubility after centrifugation or a s a whole product in food systems to improve the physiological and fun ctional quality. The yeast protein hydrolysate had the same or even be tter properties than conventional protein products.