Agroindustrial project analysi

132 AGROINDUSTRIAL PROJECT ANALYSISTable 4-3. Approximate Composition of Selected Rice Products(percent)ProductBiological Brown Polished Parboiledprofile rice rice rice Bran PolishProtein 10.1 7.2-9.0 7.4 10.6-14.0 12.1-14.2Carbohydrate 86.6 90.8 81.3 n.a. 59.9Fat 2.4 0.34 0.3 11.7 12.7Fiber 0.9 0.1 0.2 11.1 n.a.Ash (minerals) 1.2 0.5 0.7 13.1 12.3n.a., Not applicable.Note: Percentages are calculated to a moisture-free basis.Source: A. M. Altschul and R. W. Planck, "Effects of Commercial Processingof Cereals on Nutrient Content: Rice and Rice Products," in Nutritional Evaluationof Food Processing, 1st ed., ed. R. S. Harris and H. von Boesecke (NewYork: John Wiley and Sons, 1960), p. 204.pericarp, most of the embryo, and the outer alenrone layers areremoved as a powder called "bran." The inner alenrone layers andthe remainder of the embryo are subsequently rubbed off bybrushes, forming a powder called "polish." Bran is not used forhuman consumption and polish has limited uses because it tendsto turn rancid quickly." 6 In the United States, for example, 8.5 percentof the whole grain weight of rice is removed as bran, and 1.8percent is removed as polish.The approximate composition of selected rice products is containedin table 4-3; vitamin content is shown in table 4-4. The percentagesgiven in the tables indicate that those parts of the ricegrain that are removed by milling-namely, the bran and thepolish-are richer in nutrients than the endosperm. (The same,incidentally, is true of wheat.) Although whole rice is a good sourceof vitamins and minerals, these micronutrients are largely removedduring milling. Although protein losses through milling are relativelysmall, protein fractions-which are rich in lysine, the firstlimiting amino acid in rice protein-are removed with the branand polish. Thus, proteins in polished rice contain approximately16. A. M. Altschul and R. W. Planck, "Effects of Commercial Processing ofCereal on Nutrient Content: Rice and Rice Products," in Nutritional Evaluationof Food Processing, 1st ed., ed. R. S. Harris and H. von Boesecke (NewYork: John Wiley and Sons, 1960), p. 204.