| A physical dough testing instrument, the alveograph, was used in combination with other physical and chemical testing methods to study wheat flour components and how they govern the physical, physicochemical, and rheological properties of flour doughs.;A new parameter (DM) based on the first derivative of the alveograph curve was developed, and in combination with alveograph indices P, L, and W, and other analytical data, used to assess the baking qualities of hard wheat flours from the Midwestern and Pacific Northwestern regions of the United States. Stepwise regression analysis produced a model in which DM, P, and water absorption explained over 90% of the variability in loaf volume potential of the flours.;Protein content, water absorption and mixing properties, and alveograph indices were also used to evaluate the suitability of North American hard and soft wheat flours in the production of Chinese steamed bread (CSB), and regular pan bread (RPB). Results indicated that different factors govern the production of the two types of bread. High flour strength as determined by the alveograph was desirable in RPB production, and detrimental in production of CSB, whereas low to medium-low protein flours were suitable in production of CSB.;The effects of lipids on alveograph rheological dough properties were examined to relate dough handling properties to quality of baked products. Results from defatting and reconstituting studies established the fact that rheological changes brought about by defatting were mainly due to removal of free flour lipids. Effects of lipids on dough handling properties were shown to differ from their effects on baking properties.;Finally, lipid binding and fatty acid distribution were determined in pan bread crumb and crust and steamed bread from hard red winter and soft white winter wheat flours. Dough mixing, baking and steaming of the original flours reduced extractability of free flour lipids. Protein content did not appear to be the only factor in the degree of lipid binding. Flour lipids were bound in preference to shortening lipids. |
