Eggcellent emulsions

Why do we need eggs in baking?

Cake  (photo credit: ING IMAGE/ASAP)
(photo credit: ING IMAGE/ASAP)
Have you ever tried to make homemade vinaigrette dressing? Try this experiment. In a bowl, place ½ cup of cooking oil, ½ cup of vinegar, 1 clove of crushed garlic, 2 teaspoons of sugar and two teaspoons of salt. Stir vigorously. It will appear that the oil and vinegar seem to mix, but after a short while they separate, the oil settling above the vinegar. You have just proven the conventional wisdom – “Water and oil don’t mix.” Or do they? It is possible to combine two unmixable liquids such as oil and water and have them remain stably mixed together. To achieve this, you need a third substance called an emulsifier.
On a chemical level, an emulsifier is a molecule resembling a magnet with two poles – a water-loving (hydrophilic) end and an oil-loving (hydrophobic) end. When added to an water-oil mixture and stirred vigorously, the emulsifier molecules form an outer “skin” surrounding both the water and oil droplets – the hydrophilic end attached to the water and the hydrophobic end to the oil. The reduced surface tension prevents the droplets from coagulation and resulting separation. This mixture is called an emulsion.
Emulsions are very common in our daily diet. Milk is perhaps the most common emulsion, combining fat and water, with protein as the emulsifier. Actually, the word “emulsion” comes from the Latin word “to milk.” Other popular emulsions include mayonnaise and chocolate.
One of the most commonly used emulsifiers in food is lecithin. Lecithin is abundant in egg yolks, making eggs the universal emulsifier and an essential ingredient in any baked goods that combine water and fat, such as hallot, cakes, and cookies.
The effect on texture is very pronounced.
Flour-water mixtures such as bread are rubbery and glutinous. With the addition of egg in the mixture (as in halla), the texture becomes less rubbery, softer and more cakelike.
Due to the presence of various proteins in egg whites, they too have emulsifier properties, enabling you to beat egg whites into foam, which forms the basis for many items from meringues to chiffon cakes to mousse.
Conventional wisdom, based on earlier medical research, suggested that overconsumption of eggs was unhealthy due to their high level of cholesterol. Studies that are more recent, however, show that although eggs do contain cholesterol, it is of the healthy (HDL) type. Contrast this with the bad (LDL) type of cholesterol or triglycerides, which the body synthesizes itself from carbohydrates. Research shows that increased consumption of eggs actually increases the ratio of HDL to LDL cholesterol in the blood and is therefore preferable to increased consumption of carbohydrates.
The presence of lecithin in egg yolks further reduces cholesterol buildup in the arteries. Recent studies show that atherosclerosis and heart disease are more likely caused by overconsumption of carbohydrates than by overconsumption of natural cholesterol-containing foods such as eggs.
Carbohydrates, when consumed together with protein, are absorbed more slowly into the bloodstream over time.
This is why dietitians recommend eating carbohydrates with protein, such as breakfast cereals with milk, and flourbased products with egg. This reduces the sugar shock to the system and the risk of getting diabetes.
The biggest danger from eating eggs comes from harmful salmonella bacteria that may contaminate raw eggs. For this reason, it is not advisable to eat raw/uncooked eggs. Heating by cooking or baking to over 80º eliminates this problem.
I am wary of calling eggs a “super food,” but their myriad benefits, both in improving the quality of our foods and their health advantages, certainly indicate that we should be using and eating more of them.
By the way, the next time you make vinaigrette, try adding half a teaspoon of granulated lecithin (available at any healthfood store).
Using egg white foam as a base, this cake is light, airy and low in fat.
✔ Egg whites from 7 large eggs
✔ 1⁄3 cup granulated sugar (sugar No. 1)
✔ ½ tsp. vanilla extract
✔ 1⁄3 tsp. salt
✔ 1 cup granulated sugar (sugar No. 2)
✔ ¾ cup cake flour Mix flour, salt and sugar No. 2 in a bowl.
Beat egg whites in a mixer until foam begins to form. Slowly add sugar No. 1 and vanilla and beat until medium peaks form.
Fold the flour mixture into the egg foam.
Pour into round cake pan and bake at 155º for 35 minutes or until golden brown.
Remove from oven, invert pan and leave to cool upside down. Remove cake from the pan when completely cooled.
Master baker Les Saidel is CEO of the Saidel Artisan Baking Institute (, which specializes in training and education in the field of organic, healthy, artisan baking and the inventor of Rambam Bread. He also lectures and works as a consultant in the fields of cereal chemistry, health and nutrition.