33A-13 |
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A. J. PEREZ-GONZALEZ, G. Cedillo, R. D. Waniska, and L. W. Rooney. Dept. of Soil & Crop Sciences, Texas A&M Univ., 370 Olsen Blvd., Heep Ctr., 2474 TAMU, College Station, TX 77843-2474 Numerous additives have been studied to improve shelf-stability of corn tortillas. Soy flour is added to corn tortillas for nutritional purposes. Soy flour improves tortilla texture (pliability and rollability), an effect that has been attributed to the high water holding capacity of soy protein. Okara is the residue of soymilk production, and is usually underutilized. The acceptance of soy ingredients such as ²novel² concentrates and cell wall products has increased in recent years. The objective was to evaluate the impact of alternative soy ingredients on the quality and shelf stability of corn tortillas. Tortillas were produced from nixtamalized corn flour (NCF) and soy ingredients (partially defatted soy flour, concentrate, ²novel² concentrate, cell wall product, and okara) included to add 3 or 6% protein. Masa was subjectively evaluated for machinability and stickiness. Tortilla texture was analyzed at 7 d of storage by subjective tests (pliability and rollability with a five-point scale), and an objective extensibility test (Texture Analyzer). Masa machinability and stickiness were not affected by soy addition. Soy-containing tortillas were more pliable than the control tortillas (p<0.05) during storage (7 d, 4oC). Best values (p<0.05) were for okara and the cell wall product. Tortillas containing okara had the best pliability and rollability among treatments. Soy-containing tortillas had lower modulus of deformation (p<0.05) after 7 days of storage when compared to the control. Significantly lowest values (p<0.05) were for tortillas containing the cell wall product and okara (3558.7 and 2785.6 N/m, respectively). Tortillas containing soy flour had a modulus of deformation of 3947.7 N/m. Alternative soy ingredients, such as cell wall products and okara, could be used to improve the shelf stability of corn tortillas. Protein content alone cannot entirely explain the texture change in corn tortillas containing soy ingredients.
Session 33A, Carbohydrate: General
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