QUALITY CHARACTERISTICS OF LONG-GRAIN RICE MILLED IN 2 COMMERCIAL SYSTEMS

Long-grain rice variety Kaybonnet was milled to three degree of millin g (DOM) levels in two commercial milling systems (a single-break, fric tion milling system and a multibreak, abrasion and friction milling sy stem) and separated into five thickness fractions. For both milling sy stems, the surface lipid content (SLC) and protein content of the mill ed rice varied significantly across kernel thickness fractions. SLC wa s influenced by DOM level more than by thickness, while the protein co ntent was influenced by thickness more than by DOM level. Particularly at the low DOM levels, the thinnest kernel fraction (<1.49 mm) had hi gher SLC than the other kernel fractions. Protein content decreased wi th increasing kernel thickness to 1.69 mm, after which it remained con stant. In both milling systems, thinner kernels were milled at a great er bran removal rate as indicated by SLC differences between the low a nd high DOM levels. For rice milled to a given DOM level, the multibre ak system produced fewer brokens than did the single-break system.