FoodNet

Foods, their selection and preparation

1935

Page 259

Presented as published in 1935. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
1 Definitions and Standards for Food. Food and Drug Administration. Federal Security Agency, No. 2, July, 1944. Flour Strength. "Strength” is the term used to describe the breadmaking power of the flour. Strong flours are desirable for yeast breads made in loaves and for popovers. For tender breads, cakes, and cookies less strong flours are more satisfactory. While many factors in the flour contribute to its strength, the most important is the amount and the kind of proteins present. When flour is mixed with water to form a dough and kneaded, gluten is developed from the gliadin and glutenin present. This makes the flour form a dough and gives that dough elasticity. The starch can be washed out from a small portion of such a dough, leaving the gluten. If this ball of gluten is baked while still moist, steam is formed and the ball expands to many times its original size. As the baking continues, the gluten co¬ agulates, or hardens, so that it retains its shape when cold. The amount and quality of the gluten formed are important to flour strength. Flour strength is determined by standard baking tests, and measurements of the shape and volume of the resulting loaves. These tests show that other factors in the flour in¬ fluence the quality and behavior of the gluten and so are important in flour strength. The shape of the loaf depends upon the amount and especially the quality of the gluten. Gluten quality, that is, its cohesive¬ ness, elasticity, and water-holding capacity, depends upon amounts and kinds of acids and minerals present in the flour, rather than upon any inherent differences in the gluten-forming constituents themselves. The volume of the loaf is dependent upon gas formation and gas retention. Gas for¬ mation requires a sufficient supply of soluble carbohydrates and starch-splitting and sugar¬ splitting enzymes. These are generally present in all flours.- The retention of the gas, which is apparently the more important factor in loaf volume, depends upon the [285] elasticity of the gluten. The softer glutens allow the gas to escape, and the volume of the loaf is correspondingly smaller. Water Absorption. The water absorption of a flour varies with both the amount and the quality of the gluten. It is of interest to the baker, as an indication of the probable breadmaking quality and the amount of bread that will be obtained from a given weight of flour. Aging, up to a point, in¬ creases the water absorption of flour. Varia¬ tions in water absorption account for the dif¬ ferences in the amounts, of liquid to flour required to obtain mixtures of standard consistencies in home baking. Slight adjust¬ ments in amounts of liquid to flour may be required when changing from one flour to another of a different source, class, or grade, or when using flour from new wheat. In changing recipes from hard-wheat to soft-wheat flour, one must remember that hard-wheat flour absorbs a larger proportion of liquid than soft-wheat flour. The basis for substitution cannot be given definitely, since the amounts will vary with the amounts of gluten present. A general rule is that 1 cup of hard-wheat flour minus 2 table¬ spoons is equivalent to a full cup of soft- wheat flour.