33F-24 |
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J. M. AWIKA and L. W. Rooney. Dept. of Soil & Crop Sciences, Texas A&M Univ., 434 Heep Ctr., 2474 TAMU, College Station, TX 77843-2474 Cereals are widely consumed and are a valuable means to deliver beneficial natural antioxidants to humans. However, most mainstream cereals contain low levels of these compounds relative to fruits and vegetables. The focus is thus changing towards specialty cereals with above average phenol contents. Our objective was to compare the antioxidant properties of specialty cereals and their products to determine the ones with the best potential as a source of cereal antioxidants. Specialty grains were analyzed for phenol content (Folin-Ciocalteu), tannins (vanillin-HCl), and antioxidant capacity (ABTS, DPPH, and ORAC). Brans from selected grains were used as ingredients in bread and cookies (at 6-30% baker’s levels). These products were analyzed for antioxidant activity and sensory attributes. The cereals were compared to fruits and vegetables (DM basis). Phenol levels correlated strongly with antioxidant activity by all methods (R2 > 0.97). Brown and black sorghums had antioxidant activities that were 5-15 times higher than other cereals. The ABTS values (µmol TE/g) were: brown sorghums, 145-240, black sorghums, 72-112; purple and red corn, 8-13; black rice, 18; barley, 3-10; red wheat, 3. These sorghums had ORAC (µmol TE/g) values (220–870) comparable to blueberries (87-870 ). Only the brown sorghums had tannins (3.0–5.6 mg CE/g). Antioxidant levels in sorghum brans were 3-5 times higher than in their grains. Among baked products, the cookies retained more antioxidants (72-78%) than bread (57-60%). Sorghum bran products were rated similar or higher than wheat bran products for acceptability at equivalent bran substitutions. The sorghum products scored higher on appearance – they had darker naturally appealing color. Specialty sorghums are a rich source of high antioxidant phenols compared to other cereals or fruits. Their bran fractions produce good quality baked products with significant antioxidant retention. These sorghums have a potential to improve nutraceutical quality of foods.
Session 33F, Nutraceuticals & Functional Foods: Antioxidants and phytochemical analysis
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