Soybean residue (okara) fermentation with the yeast Kluyveromyces marxianus

The soybean residue (okara) with high moisture content has generally been discarded, which has led to economic loss and socio-environmental problems. The effects of solid state fermentation using Kluyveromyces marxianus on the nutritional components, beany odor and processing properties of soybean residue were studied. The results showed that K. marxianus fermented soybean residue (FSR) had an increase in crude fat (24.5%), soluble dietary fibers (158%) and polysaccharides (262%), while phytic acid (61.7%) and the activity of a trypsin inhibitor (92.7%) decreased. A significant reduction in the beany odor was also observed. FSR showed higher water absorption and better emulsifying properties. Overall, the study indicated that fermentation with K. marxianus resulted in improved nutritional values and processing characteristics of the soybean residue.