Cereal Chem 67:417-421   |  VIEW ARTICLE

Evaluation of Lime Heat Treatment on Some Physicochemical Properties of Amaranth Flour by Response Surface Methodology.

J. M. Vargas-Lopez, O. Paredes-Lopez, and E. Espitia. Copyright 1990 by the American Association of Cereal Chemists, Inc. 

This study was conducted to evaluate the effect of temperature, calcium hydroxide concentration, and cooking time on physiocochemical properties of amaranth flour to be made into tortillas. Response surface methodology was utilized for the evaluation. Changes in pH, water absorption index, color, and flow properties were assessed after selected levels of temperature, calcium hydroxide concentration, and cooking time were set at 80 and 90 C, 0.8 and 1.0 g of Ca(OH)2/100 g of amaranth, and 10 and 20 min, respectively. Regression models obtained for each physicochemical property accounted for 81.02-94.40% of the total variation. The effect of temperature and cooking time was significant for all measured parameters of experimental flours, whereas that of calcium hydroxide concentration in the tested range was only significant on masa flow properties. Values of pH, water absorption index, and color increased with increasing temperature and cooking time. In relation to flow properties, the power law model was found to correlate accurately the effects of shear stress and shear rate on fluid consistency and flow behavior indices. Lime-cooked amaranth flour may be used for preparation of tortillas and similar products.