The effects of okara on rat growth, cecal fermentation, and serum lipids

Abstract

Okara, a soymilk residue, was characterized and used as a supplement to enrich dietary fiber in rats. Okara comprised 49% total dietary fiber, of which only 0.55% was soluble, protein (33.4%), fat (19.8%), and ash (3.5%). Okara as a diet supplement had no influence on food intake, but the growth rate and feeding efficiency were lower in the okara-fed group than in the control group. Okara increased fecal weight and moisture. In okara-fed rats, in vivo colonic fermentation of okara resulted in a lower pH, but a higher cecal weight and higher total short chain fatty acid production, compared to controls. There were no significant differences (P≥0.05) between groups in albumin, protein, uric acid, bilirubin, or glucose content in rat serum. The okara-supplemented diet produced a nonsignificant reduction in HDL-lipids and triglycerides. Okara, a rich source of low-cost dietary fiber and protein, might be effective as a dietary weight-loss supplement with potential prebiotic effect. © 2006 Springer-Verlag.