Cereal Chem. 70:734-739   |  VIEW ARTICLE

Effects of McGill No. 2 Miller Settings on Surface Fat Concentration of Head Rice. K. E. Bennett, T. J. Siebenmorgen, and A. Mauromoustakos.

Cereal Chem. 70:734-739. The surface fat concentration of 384 head rice samples milled with a McGill No. 2 miller was measured with a Goldfisch lipid extractor (Labconco, Kansas City, MO). The data were used to evaluate the effects of moisture content, milling time, pressure applied to the rice, and initial rough rice weight on the degree of milling of two varieties of long-grain rice. Moisture contents ranged from 9 to 14% wet basis; milling time ranged from 15 to 60 sec in 15-sec intervals; and initial rough rice weights were 125 and 150 g. The pressure applied to the rice during milling was adjusted by the position of a 1.5-kg weight on the lever arm and ranged from 6 to 18 cm, in 6-cm increments. Moisture content and milling time were found to be the most significant variables affecting surface fat concentration. Sample size was the least significant variable. Surface fat concentration decreased as moisture content, pressure applied to the rice, and milling time increased. It increased as sample size increased. A varietal difference in surface fat concentration existed. An equation that predicts the surface fat concentration for the various experimental settings was developed. Head rice yield is directly related to surface fat concentration. Equations relating the two at different moisture contents were developed. Milling at lower moisture contents typically produced higher head rice yields, even when differences in surface fat concentration were taken into account.