In Vitro Binding of Bile Salts by Different Insoluble Dietary Fiber Extracted from Brewers' Spent Grain

Brewers’ spent grain (BSG), one of the major by-products of the brewing industry, has been mainly used as fertilizer or animal feed. Nevertheless, BSG was shown to contain a number of potentially high-value components such as insoluble dietary fiber (IDF). Recently, most studies on health benefits associated with IDF have been demonstrated. In the present study, the water holding capacity (WHC), swelling capacity (SC), oil holding capacity (OHC) and bile salts binding of the different insoluble dietary fiber extracted from BSG were tested in vitro. The results showed WHC, SC and OHC of the different IDF increased greatly. The WHC, SC and OHC of IDF extracted by alkaline hydrolysis were 2.63±0.11, 1.31±0.06 and 2.33±0.09 fold of BSG, respectively. The WHC, SC and OHC of IDF extracted by enzymatic hydrolysis were 2.94±0.14, 1.96±0.09 and 2.87±0.13 fold of BSG, respectively. We also investigated the in vitro binding of bile salts by BSG and IDF. IDF extracted by enzymatic hydrolysis showed a greater bile salts binding capacity than IDF extracted by alkaline hydrolysis. Bile salts binding by IDF may influence cholesterol lowering and lipid metabolism in body. It can be concluded that IDF extracted from BSG may have potential application as a food additive in functional foods.