Reduction of Off-flavors in Commercial Soy Protein Isolate (SPI) by Fermentation

Abstract

Three kinds of microorganisms were used to improve flavor of commercial soy protein isolate (SPI): Saccharomyces cerevisiae, Torulopsis holmii and Aspergillus niger. The three microorganisms significantly decreased such typical beany flavors; hexanal, hexanol, and 1-octen-3-ol and increased the preferable fermented flavors; diacetyl and acetoin, which closely resemble those of fresh cheese. Protein hydrolysis occurred during ferme ntation when SPI was treated with T. holmii and A. niger. These results indicates that the fermented SPIs can be used without serious flavor problems as major protein sour ce for a wide variety of imitation dairy products.