Adding value to secondary streams of corn wet milling industry

Abstract

Corn steep liquor (CSL) is spontaneously fermented, mainly by thermophilic Bacillus strains, producing lipopeptide biosurfactants. These biosurfactants can be extracted with ethyl acetate at the same time that an aqueous phase is generated (named CSL-plus). The results showed that the biosurfactant extraction produced a liquor with a reduced content of fats and minor changes in the micronutrients concentration. The decrease in the fatty acid content is due to the extraction of biosurfactants and free fatty acids contained in the biosurfactant extract, composed mainly of C16 and C18 fatty acids. Therefore, it can be concluded that the extraction of biosurfactants gives a nutritional supplement (CSL-plus) with lower content of fats, improving the nutritional properties of CSL and consequently added value is given to the water stream generated. Moreover, it was demonstrated that the biosurfactant extract from CSL could be used to improve the solubilization of chicken broth cubes.