Experimental cookery

The ingredients and their concentration. When the proportion of water in the product is rather high, as in griddle cakes, waffles, and muflfins, or in the so-called "pour" batters, the consistency of the batter permits the fat to form spheres easily because the batter is not stiff enough to deform the spheres entirely. Melted fat or oil is generally used in the *'pour" batters. In addition the lecithio-protein of the egg yolk used in these prod- ucts has strong emulsifying properties and increases the tendency to disperse the melted fat or oil as an oil-in-water emulsion. Observations have shown that the major portion of the fat, unless the fat solidifies and with the exception of fat adsorbed by the sugar crystals, is distributed as an oil-in- water emulsion in thin batters. In biscuits and pastry, in which the proportion of water is relatively smaller, and because the method of adding the fat to the flour is different from that in the "pour" batters, the major portion of the fat is adsorbed by or coats the flour particles. In cake a plastic fat like butter, when creamed with the sugar, always produces a more tender product than when the butter is melted. And, in general, all plastic fats produce more tender cakes than oils or melted fats. Consistency of fat and degree of saturation. Both these factors have been SUMMARY OF EXPERIMENTAL WORK 567 considered. Obviously unsaturated glycerides have an opportunity to cover a greater surface area of the flour particles in biscuits and pastry because there are no emulsifying agents such as egg to tend to prevent their spreading. Concentration of fat. Other things being standardized, the surface area covered is greater as the concentration of the fat or oil is increased. Shortening power of a fat or oil varies in different products. Because of differences in methods of combining, in the concentration and kinds of ingredients, in concentration of the fat, in temperature of the fat, and in manipulative factors the shortening power of the same fat may vary in relation to that of other fats in different products. For example, butter generally produces tougher pastry than any of the plastic fats or the oils commonly used in food preparation, but butter generally produces more tender cakes than oils. The more tests one makes to determine the shorten- ing power of fats and oils, the more one hesitates to make dogmatic state- ments about the comparative shortening powers of various fats. However, in considering the comparative shortening power of fats and oils, the results published in the literature are usually based on the performance of the fat in pastry only. Summary of Experimental Work by Different Investigators on Shortening Power of Fats and Oils A machine to test the shortening power of cooked foods needs to be very sensitive. Davis has devised such a machine, called a shortometer. From tests upon cookies he reports lard to be the best shortening agent. He gives no explanation of the results obtained.