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L. W. ROONEY¹, J. M. Awika, M. Mitre-Dieste, L. A. Gordon, E. L. Suhendro, and R. D. Waniska. (1) Soil & Crop Sciences, Texas A&M University, Cereal Quality Laboratory, College Station, TX 77843-2474

Special sorghum varieties with high levels of catechins and phenols may contain antioxidants useful in functional foods.

Composition, milling, functionality, nutritional value, and antioxidant capacity of white, black, and brown sorghums were evaluated. Dry milling concentrated the phenols, tannins, and fiber into the bran; it was evaluated in yeast breads. Sorghum samples were analyzed for catechin equivalents (tannins) and total phenols using the vanillin-HCl and Folin-Ciocalteu methods respectively. The grains were decorticated using an abrasive, dry mill to produce bran and endosperm fractions. Dietary fiber, protein, fat, ash, crude fiber, and other components were analyzed using standard AOAC procedures. Breads containing 10% brans were baked and loaf volume, color, texture, and other attributes were measured. The oxygen radical absorbance capacity (ORAC) was measured using the procedure of Prior et al.

The total phenols and catechin equivalents (C.E.) in white, black, and brown whole sorghums were 0.16, 0.52, 0.77 and 0.0, 0.13, 2.37 mg/100mg, respectively. The brown bran, the outer 10% of kernel weight, contained 18.3 mg/g of C.E. or 7.8 times more concentrated than the original whole grain. ORAC values for the bran (10% yields) of white, black, and brown sorghums were 20.8, 132.8 and 176.8Umol TE/g, respectively. The bran of brown and black sorghums gave bread with significantly increased fiber and phenols; with excellent color, flavor, slightly firmer texture; and slightly less volume than the bread without bran. Brown sorghums can be milled to produce fractions with catechin equivalents, total phenols and ORAC values equal to or greater than blueberries.

Special sorghums could be effective, practical sources of phenols, catechins, dietary fiber, and natural color for nutraceutical foods.