2008 Volume 55 Issue 12 Pages 597-601
As okara ingestion suppresses the increase in plasma cholesterol level in rats, we attempted to effectively use okara as a functional food. Soymilk containing okara (okara/soymilk) fermented by lactic acid bacteria showed higher in vitro bile acid-adsorptive capacity than unfermented okara/soymilk. Lactic fermentation increased the alkali-stable polysaccharide content of okara/soymilk. Fecal bile acids and cecum content of rats fed fermented okara/soymilk were also increased. Moreover, lactic fermentation increased the propionic and butyric acid contents in the cecum. Alkali-stable polysaccharides generated by lactic fermentation were assumed to increase short-chain fatty acids in rat intestines and fecal bile acids. Alkaline treatment could extract bile acid-adsorptive compounds from fermented okara/soymilk, but decreased the adsorptive capacity of the extract. Protein was the main bile acid-adsorptive compound separated from fermented okara/soymilk, but no increase in bile acid-adsorptive capacity in the separated proteins was observed after lactic fermentation. Therefore, the increase in bile acid-adsorptive capacity appears to depend on alkali-stable insoluble polysaccharides generated by the lactic fermentation process.
