FoodNet

Experimental cookery

1932

Page 231

Presented as published in 1932. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
on the cut surface. It separates more readily than mayonnaise with a lower percentage of oil. Ordinary mayonnaise containing from ^ to ^ cup of oil to- 1 egg yolk, and 15 cc. of vinegar averages from 65 to 75 per cent of oil. Hall and Halstrom, by introducing the oil beneath the surface of the forming emulsion, obtained mayonnaise with a concentration of 89 to 93 per cent of oil that remained stable for two years when stored at 8°C. Some Food Emulsions Salad dressing. The Food and Drug Administration has defined mayonnaise as being made with either egg yolk or whole egg. Hence, a product which may be similar to mayonnaise but stabilized with egg white, or part egg yolk and part starch paste, is called a salad dressing. Home- makers have used many emulsifying agents such as egg yolk, whole egg, egg white, cooked egg yolk, gelatin, starch paste, meat extract, and mashed potato. However, they are not equally efficient. The order for efficiency is as follows : egg yolk, whole egg, egg white, gelatin, and starch paste. Fats such as butter and lard may be melted and substituted in a mayon- naise formula, but the product is a salad dressing. Mineral oil may also be used in a mayonnaise formula. Boiled salad dressings are also emulsions. French dressings. French dressings are usually temporary emulsions, but some are quite stable. There, seems to be less separation of oil at the top and of water at the bottom, if the phase-volume rule is observed, and the oil composes about 74 per cent of the emulsion.. The seasonings, pow- dered paprika and mustard, are the emulsifiers. It is possible that traces of some substances in the vinegar may occasionally aid emulsification. Emulsions stabilized with flour. In gravies and sauces the amount of oil that can be permanently emulsified is much smaller than in maj'onnaise. Gravies and sauces in which the oil separates may be made smooth again by adding water and stirring while heating. The addition of water lessens the percentage of oil in the product. Emulsions stabilized with flour or starch need a higher percentage of water than mayonnaise. The starch absorbs a large portion of the liquid, which accounts for a large part of the water, but even if the maximum absorptive power of the starch is accounted for a large amount of water is still needed. This type of emul- sion belongs in the class of hydrated colloids referred to by Fischer and Hooker, in which they state that the water must not be reduced below a lower limit and must not exceed an upper limit. Cream puffs. Cream puffs are good examples of a batter in which the fat is emulsified. See Chapter XII, Experiment 80. In the recipe as given in the experiment, the fat constitutes about 17 per cent of the uncooked ingredients, if the fat content of the butter is used as 85, the eggs as 10.5, and the flour as 1.5 per cent. The cooking of the water, flour, and fat will increase this percentage, as will the baking, on account of evaporation of REFERENCES 287 water. The fat does not run or ooze out of the dough while the puffs are baking.