15F-17 |
Addition of nopal (Opuntia sp.) to bread as a source of fiber |
B. J. RODRIGUEZ-TERRAZAS1, E. Medina-Flores1, V. Mendoza-Guzman1, M. Makita1, and M. O. Duarte-Gardea2. (1) Division de Estudios de Posgrado, Facultad de Ciencias Quimicas, Universidad Autonoma de Chihuahua, Ciudad Universitaria s/n, Chihuahua, Chihuahua, 31170, Mexico, (2) School of Allied Health, University of Texas at El Paso, 1101 N. Campbell, El, Paso, TX 79902 Dietary fibers are those vegetable substances which are not digested by human gastrointestinal enzymes, they act by changing the physical properties of the intestinal contents and modifying the absorption of certain substances. Since it is difficult to change dietary habits, the addition of fibers to the regularly consumed products has been used to achieve the same results. The tender pulpy cactus leaves of nopal (Opuntia sp.)are used in Mexico in human feeding; their composition is mainly water and fiber. Our objective was to add raw grinded leaves of nopal to a whole wheat bread mix to increase the fiber content and evaluate its sensorial properties. Four different levels of nopal (0, 2.5, 5 and 7.5%)were added to a whole wheat bread formulation. Gluten was also added at 2% level to all products to strenghten wheat proteins and uniform crumb. Physical (color, volume and texture), chemical (total dietetic fiber) and sensorial tests were performed. Sensorial tests used nine semi-trained judges for texture and flavor profiles; and 28 consumers for preference tests. The results of physical tests after ANOVA at 95% confidence interval showed that color was different between samples to all parameters (Luminosity-L, a*-green-red and b*yellow-blue); while volume was not different, but texture was different in all breads. Total dietetic fiber was different between samples, increasing as nopal increased. Texture profile tests described the products as hard to chew as nopal increased, but moist and fibrous as the 0% nopal bread; flavor profile tests described breads as bitter, herbal and nopal flavor increasing as nopal increased, Consumers preferred the 7.5% nopal bread as the best product. This study shows that cactus leaves of nopal may be added to bread products to increase fiber contents with minimal changes on sensorial properties.
Session 15F, Product Development
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