Cereal Chem 56:567 - 572. | VIEW
Regression Analysis of Thiamin and Color Changes in Enriched Cookies Using Factorial Design.
P. M. Keagy, M. A. Connor, and T. F. Schatzki. Copyright 1979 by the American Association of Cereal Chemists, Inc.
Thiamin losses (12-94%) in cookies baked from commercially enriched flour are predicted by a least squares regression equation using baking temperature (334-342 F), baking time 7.6-12.7 min), unneutralized soda (0.3-35 mmol/100g of flour), and thickness (5.0-10.5 mm) as the major independent variables. Rest time of the dough (12-65 min) and the proportion of leavening gas from ammonium bicarbonate (50-90%) had no measurable effect. Cookie color and pH are also predicted by soda, time, temperature, and thickness. At a constant soda level, cookie color may be used as a quality control guide to thiamin loss. An augmented 2(6-2) fractional factorial experimental design of the Box-Wilson type was used to determine the combination of variables. Standard vitamin extraction methods were modified slightly to allow microbiological assay of niacin and of thiamin on aliquots of one extract. Average losses in the control cookies (temperature: 385 F, time: 9.8 min; excess soda: 3.3 mmol; and thickness: 7.0 mm) were 30% thiamin and 4.5% niacin.