FoodNet

Experimental cookery

1932

Page 344

Presented as published in 1932. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
The protein particles in the flour may be compared to chewing gum, for many of the properties are similar. Anyone who has chewed gum is familiar with its manipulation, so that it makes an excellent illustration. The size of the piece of gum is very much larger than that of the protein particle. The stick of chewing gum w^hen first placed in the mouth may be brittle and crumbly. As it becomes moist it sticks together and develops tenacity, adhesiveness, and cohesiveness. If two sticks of gum that have been chewed are brought in contact with each other they adhere or stick together; if pulled, they stretch. In the literature on dough, this change in shape through hydration, surface contact, and particles adhering to each other is called attenuation. The more the pieces of gum are pulled the more attenuated they become, but if the elastic strands touch each other in large areas they adhere, and when worked more and more, they become matted together in one piece. When the protein particles in the dough become moist they sw^ell and form gluten. The behavior of the protein particles when moistened is similar to that of the gum. When first moistened they are crumbly and do not adhere together. After the particles become hydrated they become sticky and tenacious. When the dough is stirred the surfaces of the particles come in contact and adhere to each other. The stirring of the dough stretches and pulls the surface contacts so that the gluten becomes attenuated and filaments formed. Attentuation of the gluten is often referred to as develop- ing the gluten or dough. Gluten forms a continuous phase in dough. The protein in the dough forms a continuous network or mesh structure throughout the dough. In this meshwork are the starch granules, the sugar, salts, and water. The protein particles compose only a portion of the flour content, although after they are hydrated the relative volume that they occupy in the dough is greater than their volume in the flour. If to the chewing gum we add some small round particles that do not change their shape and are about the size of small tapioca a better picture of dough structure STARCH 423 is obtained. The small round particles will prevent the chewing gum from forming one solid mass and will tend to keep the pieces of gum apart, so that manipulation and sliding over the round particles is required to bring different surfaces of the gum in contact with each other. In the dough the whole starch granules do not swell appreciably until a temperature of 60° to 65 °C. is reached. Thus in a dough mixed at ordinary temperatures they do not change their volume or shape. A good quality of gluten adheres strongly to other particles of gluten and forms many strands of network around the starch granules. A good quality of gluten must be elastic enough to stretch around the starch granules, and in addition stretch and retain gas bubbles formed in the dough that make the structure porous. No dough will retain all the gas formed within it, but a gluten of good quality will retain a very large portion of the gas bubbles. A poor quality of gluten will not stretch when the gas is formed but will break in places, and too large a proportion of the gas formed is lost.