FoodNet

Experimental cookery

1932

Page 229

Presented as published in 1932. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
Fig. 28. — Mayonnaise. Same as Fig. 27, but after adding one-fourth cup of oil. Magnification approximately x 200. THE INGREDIENTS USED 283 ^y^^lLr-^. <'/^iQ|jp|r 3i^£JpVj^ Fig. 29. — Mayonnaise. Same as Fig. 28, but after adding three-eighths cup of oil. As the oil spheres become smaller with the addition of more oil the mayon- naise becomes stiffer. Magnification approximately x 200. Fig. 30. — Mayonnaise. Same as Fig. 29, but after the addition of one-half cup of oil. Magnification approximately x 200. 284 EMULSIONS they tend to form water-in-oil emulsions, are detrimental to mayonnaise. Hence it is recommended that the salt used should contain less than 0.1 per cent of foreign calcium salts. Kilgore's results indicate it is preferable to add the mustard to at least part of the vinegar to make a paste. This is then added to the egg yolk. Egg yolks. Johnson and Mark have reported that cold-storage eggs are inferior to fresh eggs for making mayonnaise. However, frozen yolks, either salted or sugared, are more extensively used at the present time than fresh yolks. Kilgore states the fresh yolk is usually too light in body to produce a good emulsion at the start. This is true in spite of the fact that fresh yolk is the best possible emulsifier and that less can be used than is required for frozen yolk. The freezing changes the physical consistency of the yolk. Upon defrosting the frozen yolks are very thick and paste like, owing to the binding of the water during freezing. The addition of a small amount of einulsified mayonnaise. Mayonnaise is very easily made if from ^ to 1/3 cup of previously made mayonnaise is added to the egg yolk and vinegar. This gives a larger quantity of mate- rial to work wnth, but if an emulsion is already started the emulsification of additional oil is accomplished more readily. After an emulsion is once formed, subsequent additions of oil are very easily emulsified. This is analogous to seeding in crystal formation and the addition of an old gel to gelatin to hasten jelly formation. Egg yolk is itself an emulsion con- taining about 30 per cent of fat. Kilgore states, ''another solution to the problem of producing high con- sistency mayonnaise having medium or low yolk content, is to start the emulsion by means of some finished mayonnaise added to the yolk and spices. This trick of starting an emulsion, or 'seeding' it, by means of one previously made is common in pharmaceuticals. It is the fundamental prin- ciple of a process for continuous emulsification." Temperature. Clayton states that, in general, the effect of rise In tem- perature Is to make emulsification easier. The reason for this is that viscosity Is reduced with a rise in temperature, but more important, a rise In temperature Is accompanied by a decrease in the interfacial tension of non-miscible liquids. Branch states that In commercial production of may- onnaise the temperature of the mixing room is kept at 65° to 75 °F. Breaking Mayonnaise Water may separate at the bottom of a mayonnaise after long standing. Robinson states that this seldom occurs if the amount of water in the mayon- naise does not exceed 15 per cent. With the percentage of water higher than 15 the separation occurs more frequently. Oil may separate at the top of the mayonnaise. Anything that destroys the film-forming properties of the emulsifying agent and lets the dispersed