A Study of Cooking and Varietal Effects on Potato in Vitro Bile Acid Binding Capacity

Potatoes have received negative press about being unhealthy due to having high starch content, but these vegetables contain many healthful components. Many compounds in food, such as soluble dietary fiber, help reduce serum cholesterol levels by binding to bile acids in the digestive tract and causing the body to draw from serum cholesterol to create new bile acids. Potatoes were prepared three different ways (raw, steamed, steamed then cooled) and different varieties of potatoes were used, each with different chemical compositions (King Harry, Elba, Yukon Gold and All-Blue). The potatoes were subjected to an in vitro digestion to simulate the human body’s natural digestion. After digestion a bile acid binding procedure was applied to the potatoes and the absorbance of each sample was read with a spectrophotometer. Results were expressed as amount of bile acids bound and percent bound relative to cholestyramine for each potato sample. It was observed that cooling potatoes after steaming significantly increased bile acid binding ability of the potato. The amount bound for All-Blue and Elba potatoes was significantly higher than Yukon Gold and King Harry potatoes. These findings can help UMaine secure additional research funding and aid the Maine potato industry in promoting potatoes as a healthful food.