Experimental cookery

Fat. When the fat in the recipe is increased the fat absorbed during cooking is increased. When the fat in the recipe is increased, the extent of mixing does not affect the fat absorption so much, i.e., fat absorption does not decrease so rapidly with longer mixing as in the regular recipe. There is also the possibility of variation of amount of fat absorbed, when dif- ferent kinds of fats, such as butter, Crisco, or lard, are used in the dough. When flour is increased, which the homemaker tends to do because in- creased fat gives a softer dough, the fat absorption is not always increased by doubling the fat in the recipe. Egffs. When the number of eggs in the recipe given in the outline is increased from 2 to 3, with no other change, the dough is softer and more sticky, because of the moisture content of the egg. This tends to cause increased fat absorption. The coagulation of the increased egg in the crust tends to decrease the fat absorption. The final result is the sum 562 FATS AND OILS of these antagonistic effects. Sometimes one factor and sometimes the other predominates. In making doughnuts the tendency would be to add more flour to roll the dough more readily, and this would decrease the fat absorption. Other factors in addition to the two mentioned above will also affect the amount of fat absorbed. These include surface area and the extent of mixing. The volume of the doughnuts w^ith increased egg may be larger than the volume of those in the regular recipe, giving a greater surface area for absorption of fat. Doughnuts made with increased egg may contain tunnels, and there is a tendency for them to be tough. The Shortening Power of Fats and Oils Shortening power has been defined and tested in various ways. The ordinary household way is to test the product by feel either by breaking or by crushing. Davis has defined shortening as follows: "That material has the greatest shortening power, which when baked in a dough under stand- ard conditions gives to the product a minimum crushing or a minimum breaking strength." Shortening power or the ability of fats and oils to make a product more tender so that it breaks or crushes more readily is due to several factors. These factors for discussion may be classified as follows: (1) differences in structure of the dough, (2) differences in adsorption of different fats and oils at interfaces and orientation, and (3) the surface area covered by the fat or oil. The author is aware that this classification is somewhat superficial, for plasticity, the melting point of the fats used, and other factors might be listed. But differences in plasticity of the fats used will influence the structure of the dough and thus may be considered under the classification given.