Fortification of Dry-milled Sorghum with Oilseed Proteins

Screen analysis Table 1-Screen analyses of sorghum and soy grits, reground products and cottonseed flour 1969) from yellow sorghum with less than 2% of kernels having brown subcoats. Brown-seeded sorghums were minimized because they have lower protein nutritional value and digestibility (Axtell et al., 1975) and contain pigments which can darken the fmal product as shown by Rooney et al. (1970). In addition, the pericarp layer of brown sorghums contains high concentrations of tannins which have astringent flavors according to Wall and Blessin (1969). Defatted, toasted soy grits (USDA, 1975) were obtained commercially. The liquid cyclone process (LCP) cottonseed flour (Ridlehuber and Gardner, 1974) was prepared at the Southern Regional Research Center, New Orleans. In the LCP process, glanded cottonseed is defatted and the pigment glands containing gossypol are removed. The screen analyses of the various sorghum, defatted, toasted soy and LCP cottonseed materials used in this study are shown in Table 1. Sorghum meal was prepared by passing the grits through corrugated rolls, screening through U.S. No. 35 and 80 Standard Screens and regrinding the coarse material. The sorghum and soy flours were prepared by passing the grits through an Alpine pin mill (18,000 rpm) followed by screening through 8xxsilk with subsequent regrinding of the coarse material. No regrinding was necessary for the LCP cottonseed flour. Other ingredients used in this study complied with commercial standards of identity.