Correcting head rice yield for surface lipid content (degree of milling) variation

• Published in: Cereal chemistry Vol. 84; no. 1; pp. 88 - 91
• Main Authors: Cooper, N.T.W, Siebenmorgen, T.J
• Format: Journal Article
• Language: English
• Published: St. Paul, MN The American Association of Cereal Chemists, Inc 2007; American Association of Cereal Chemists
• Subjects: Biological and medical sciences; calibration; Cereal and baking product industries; cultivars; food composition; Food industries; Fundamental and applied biological sciences. Psychology; lipid composition; lipid content; mathematical models; milling quality; Oryza sativa; rice; surfaces; yields; Variations; Cereal; Lipids; Yield; Grain milling; Rice; Surface
• ISSN: 0009-0352; 1943-3638
• DOI: 10.1094/CCHEM-84-1-0088

Head rice yield (HRY) is the primary parameter used to quantify rice milling quality. However, HRY is affected by the degree of milling (DOM) and thus HRY may not be comparable between different lots if the DOM is different. The objective of this study was to develop a method by which HRY values can be adjusted for varying DOM values when measured by surface lipid content (SLC). Seventeen rough rice lots including long-grain and medium-grain cultivars and hybrids were harvested from two 2003 and five 2004 locations. Duplicate subsamples of each lot were milled in a McGill No. 2 laboratory mill for 10, 15, 20, or 40 sec after zero, one, two, three, and six months of storage. HRY and SLC were measured. The average HRY versus SLC slope across all milling duration data sets was 9.4. As such, it is suggested that, when milling with a McGill No. 2 laboratory mill, the HRY of a rice lot can be adjusted by a factor of 9.4 percentage points for every percentage point difference between the rice lot SLC and a specified SLC.