Experimental cookery

of Size of Particles. Colloidal Symposium Monograph. Vol. III. p. 251. Chemical Catalog Co. (1925). Thomas, A. W. Emulsions, A Review of the Literature. Ind. Eng. Chem. 12: 177 (1920). EMULSIONS Experiment 52. To determine some of the factors that affect the formation and stability of emulsions. Mayonnaise: Egg yolk 1 18 grams Mustard }i teaspoon Vinegar 1 tablespoon 15 grams Paprika yi teaspoon Oil yi cup 108 grams Sugar }4 teaspoon Salt >2 teaspoon In studying emulsions, a microscope is a great aid. For very fine emulsions a small portion is placed on a slide and covered with a cover glass. With coarse and unstable emulsions it is better not to use a cover glass for the weight of the cover glass often breaks the emulsion. If the oil or fat is colored a dark red with Scarlet R, the type of emulsion formed can be determined with the microscope. An oil-in-water emulsion has a red oil dispersed in small spheres; a water-in-oil emulsion has a red field and light-colored spheres. To color the oil or fat, add the powdered Scarlet R and then stir. It should stand over night to dissolve the dye thoroughly. Store the emulsions in jelly glasses. Label, then cover the glasses to prevent evaporation. Put away in the refrigerator to determine the permanency of the emulsion. A. To determine the effect of varying the method of combining the in- gredients in making mayonnaise. 1. Put the egg yolk into a small bowl, add the seasonings and the vinegar, and beat with a rotary egg beater. It may be necessary to tilt the bowl or egg beater at first, in order that the egg beater blades may come in contact with the small amount of material. Add the oil in small quantities at first, about j^ teaspoon, then in larger quantities as the emulsion is formed. 2. Mix the egg yolk and seasoning. Follow directions under Al, for beating. Add about ^ teaspoon of oil. Beat, then add y^ teaspoon of vinegar. Beat. Continue adding oil and vinegar alternately. After all the vinegar is added, add the oil in larger quantities. 3. Beat the egg yolk. Follow directions under Al, for beating. Add the oil a few drops at a time. After the emulsion is forming add the oil in larger quantities. Add the vinegar slowly after the oil is added. Add the seasoning last. Text I Stiffness Ease of making Flavor Comments Results and conclusions. 290 EMULSIONS B. To determine the effect of the temperature of the ingredients in making mayonnaise. 1. Add the vinegar and seasoning to the egg yolk. Beat. Chill in the re- frigerator, then set mixing bowl in ice, and add chilled oil slowly. Follow directions under Al, for adding the oil. 2. Heat the oil and vinegar to 100°C. Combine as in Al. C. To see how much oil can be added for the first addition to 1 egg yolk and 15 cc, of vinegar and obtain an emulsion. 1. Repeat Al, but add 6 or 7 teaspoons of oil at first, then beat and emulsify before more oil is added. Add the same amount of oil for the second portion; then increase the amount for the following additions of oil. 2. If 7 teaspoons of oil can be added under CI, repeat with 8 teaspoons. Repeat CI, adding 9 or 10 teaspoons of oil. Increase the quantity of oil for the first addition as long as an emulsion is obtained.