Experimental cookery

Surface area. The larger the surface for a given weight of material the greater the area over which fat may be absorbed. Cracks caused by handling or expansion in cooking, rolling thin rather than thick, roughened surfaces, due to little mixing or other causes, stretching and pulling the material out of shape in handling, all increase the surface area and thus tend to increase the fat absorption. The composition and nature of the food. Some foods by their nature tend to absorb more or less fat than others. For example, fried eggs may absorb less fat than some foods. This is due to the smooth surface and to the coagulation of the egg proteins, which tends to prevent fat absorption. Large amounts of flour on the surface of chops may tend to increase the fat absorption, owing to the absorption of fat by the flour. Variations in composition of the food and variations in the proportion of ingredients used in foods cause wide variations in the amount of fat absorbed. A food like doughnuts, containing sugar, fat, liquid, eggs, flour, and baking powder, may show wide variations in the amount of fat absorbed, even when the length of time of cooking and the amount of surface area are kept as 556 FATS AND OILS standardized as possible. Variations in the extent of mixing foods like doughnuts produce variations in the amount of fat absorbed during cooking because the characteristics of the dough are altered by mechanical treat- ment. The Amount o£ Fat Absorbed by Doughnuts Reported by Different Investigators Fat absorption in doughnuts by McKee. McKee has determined the amount of fat absorbed in frying doughnuts. The doughnuts were made under standard conditions and fried for 5 minutes at 200°C. The standard recipe averaged 34.7 per cent fat absorbed. When the fat was doubled and quadrupled in the doughnut recipe the fat absorption was increased to 43.4 and 47.8 per cent, respectively; sugar doubled caused an increase to 44.3 per cent. But when the sugar was quadrupled the doughnut dis- integrated during cooking, absorbing large quantities of fat. Fat absorption in doughnuts. From various sources. Morgan and Cozens have determined the amount of fat absorbed in frying dough- nuts. Their dough contained less egg and more flour than the dough used by McKee. Their doughnuts were larger than McKee's, which gave a rela- tively larger surface for a given weight of dough for the McKee doughnut. They cooked their doughnuts for 3 minutes at 205° to 210°C., which resulted in an average fat absorption of 17.4 per cent. The time of cooking, the temperature of the cooking fat, and the proportion of ingredients in the recipes used by McKee and Morgan-Cozens were not the same ; hence the fat absorption differed.