Abstract:

Dietary fiber was prepared from sweet potato residue after starch extraction and was vacuum-packed with plastic bags for the 20 min ultra high pressure (UHP) treatment at 400, 500, and 600 MPa. The physical and chemical properties of UHP-treated and non-UHP-treated dietary fiber were measured. Little effect of UHP treatment was observed on the chemical structure of sweet potato dietary fiber, while the proportion of fiber type was changed: the content of water soluble fiber was reduced while that of insoluble fiber was changed reversely. Higher glucose absorption and sodium cholate binding capacities were found in UHP-treated fiber in comparison with non-UHP-treated fiber, especially in 500 MPa-treated fiber. Therefore, the conclusion was made that the glucose concentration in blood of animals or humans can be controlled at a relatively low level by the intake of UHP-treated sweet potato fiber which is able to inhibit the rapid rise in postprandial blood glucose level.

Key words: dietary fiber, ultra high pressure, sweet potato residue, glucose, sodium cholate