IN-VITRO BINDING OF BILE-ACIDS BY EXTRUDED POTATO PEELS

Potato peelings have nutritional value as a source of dietary fiber. Peels were extrusion-cooked at 104 or 143 degrees C with feed moistures of 31, 33.5, or 36%. An in vitro digestion procedure was developed to measure binding of bile acids to peels and other materials. Peels bound more deoxycholic than cholic acid, and extruded peels bound more of each acid than did nonextruded peels. Extrusion resulted in greater glycocholic acid binding, but there was no difference in taurocholic acid binding by extruded or nonextruded peels. Bile acid binding by cholesterol, pectin, and cellulose was similar to levels reported using radioassays. Deoxycholic acid binding was correlated with total and insoluble dietary fiber and with iron content.