44C-9 |
Characterization of starch of two species of jicama roots (Pachyrhizus erosus and P. ahipa). |
E. MERCADO-SILVA1, R. Galván-Mendoza1, E. Vázquez-Barrios1, and F. Martínez-Bustos2. (1) Departamento de Investigación y Posgrado en Alimentos, Universidad Autónoma de Querétaro, Centro Universitario, Cerro de las Campanas s/n, Querétaro, Qro., 76010, Mexico, (2) Centro de Investigación y Estudios Avanzados, Instituto Politécnico Nacional, Juriquilla, Qro., Querétaro, Qro., Mexico Jicama roots are consumed as vegetable because of their crispy texture and sweet flavor and it is used as substitute of the water chest nut in the Chinese cuisine. However, there are a big proportion of this product that does not be utilized in this market because of its poor visual quality and broken of the root. The processing of these roots to obtain byproducts could be help to increase the commercial value and its use. The objective was to characterize physical, chemical and reologically the starches obtained from two jicama species and to compare them with commercial potato and corn starches. Starch was obtained milling the root tissue with water or buffer at pH 4.0 at 1:5 ratio, the sediment was washed with water and drying at 45°C. Starch was analyzed for bromatological composition (AOAC), starch content, granule size and form , water absorption capacity by gravimetric method, Rheological behavior was studied under a heating program from 50 to 92°C (5.6°C/min) through a Rapid Viscoanalyzer and cristalinity by X-ray diffraction The dry mater was 89% and the starch content was 83 and 85% for P. erosus and P. ahipa respectively, the size granule was 5 to 35 mm with similar form to corn starch; damage starch was higher for samples obtained by water extraction (15%) and the viscosity was higher for starches extracted with buffer and similar to potato starch with high retro gradation in comparison with starches extracted with water. Water absorption capacity was high for two species (10 to 14 g water / g starch) and the X-ray diffraction pattern showed a crystal type A similar to corn starch The jicama starch showed potential characteristics and could be used as substitutes of commercial starches.
Session 44C, Fruit & Vegetable Products: Chemistry
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