Effect of Milling Procedure on the Measurement of Dietary Fiber by a Gravimetric Method
Abstract Samples of white potato, sweet potato, hard red spring wheat, soft white winter wheat, and soft wheat bran were ground in a Wiley mill or a Cyclotec mill. A significantly (p < 0.0001) larger proportion of coarse material (>75μ) resulted from the Wiley mill, and a significantly (p < 0.0001) larger proportion of fine material (<45μ) was produced by the Cyclotec mill. The effect of particle size on the determination of soluble, insoluble, and total dietary fiber was less well defined. In 4 of 5 commodities tested, samples from the Cyclotec mill showed a greater amount of soluble fiber, while the reverse was true for insoluble and total fiber. The difference in total dietary fiber, with respect to the mill used in sample preparation, varied from 0.24% on a total 9.10% for potatoes to 1.00% on a total of 14.05% for hard red spring wheat.