FoodNet

Experimental cookery

1932

Page 341

Presented as published in 1932. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
Hydration capacity. By hydration capacity is meant the swelling of the gluten in water, whatever the mechanism by which it is brought about, whether by absorption or other means. Gortner and Doherty have reported that a strong gluten has a faster rate of hydration, or imbibition as they express it, and also a higher maximum hydration capacity than a weak gluten. Distribution of water in dough. Alsberg in "Starch and Flour Quality" states that in bread dough about 50 per cent of the water is bound moisture or water of hydration incapable of serving as a solvent for other substances. The starch holds approximately half of this bound water, the gluten the remainder. Starch at room temperature can absorb about 30 per cent of its weight of water, whereas gluten may absorb 200 per cent of its weight. But starch constitutes so great a percentage of the flour that as a result the quantity of water it binds is nearly as great as that bound by gluten. The remaining 50 per cent of the water in bread dough, which may serve as a solvent for other substances and form steam, cannot be separated readily from the dough by mechanical means. It is held in the interstices of the dough by surface and mechanical forces. The proportion of water added. The proportion of water added also affects the character of the dough and baked product. If too little water is added the maximum cohesiveness and elasticity of the gluten is not at- tained. Water-binding capacity of flour, dough, and bread. Kuhlmann and Golossowa found that the water-binding capacity of the flours they tested was in the following order : Soya, rye, corn maize, durum wheat, soft wheat, and potato. No complete parallelism existed between the protein content of the flours and their water-binding capacity. Rye starch had a water-binding capacity of 78 to 80 per cent, whereas that of wheat starch was 40 to 42 per cent. A direct relationship was found between the water-absorbing capacity of the flour and its water-binding capacity. The water-binding capacity of bread doughs was about the same as flour, but a sharp increase occurred in bound water during baking so that a dough with a water-binding capacity of 60 per cent changed to about 85 per cent in hot bread. Kuhlmann and Golossowa found that the factors which increased the water-binding capacity of the dough decreased moisture loss in baking and in drying out or aging of the bread after baking. Both the method of making the dough and materials used influenced the water-binding capacity. Doughs made by a straight-dough method bound more water than those made by the sponge method. When the flour for the sponge method was scalded, the 420 FLOUR AND BREAD water-binding capacity was markedly increased over dough or bread made by the sponge method without scalding and slightly higher than dough made by the straight-dough method. The addition of maltose and buttermilk increased the water-binding capacity of the doughs and bread.