Cereal Chem. 70:727-733   |  VIEW ARTICLE

Milling Characteristics of Various Rough Rice Kernel Thickness Fractions.

H. Sun and T. J. Siebenmorgen. Copyright 1993 by the American Association of Cereal Chemists, Inc. 

Rough rice from three cultivars of long-grain rice was separated into six kernel-thickness fractions and milled in a McGill No. 2 mill. The degree of milling (DOM) was measured with a milling meter (Satake). Rough rice kernel thickness, milling time, and cultivar had significant effects on both head rice yield (HRY) and DOM. Results showed that DOM and HRY were linearly related in all thickness fractions, as well as in the bulk, unfractionated rice. HRY for each thickness fraction within each cultivar was calculated for set levels of DOM using these linear relationships. Compared to the HRY of unfractionated, bulk rice, the overall HRY was increased by milling the fractionated rice separately only in the Newbonnet cultivar, which has a large percentage of thin kernels. The Newbonnet weighted-average HRY was increased by as much as 3.8% over the HRY of unfractionated, bulk rice. When the thinnest thickness fraction of each cultivar was removed from consideration in the weighted-average procedure, the weighted-average HRY of the remaining thickness fractions was higher than that of the unfractionated control, not only for Newbonnet, but for Millie and Lemont cultivars as well.