How do egg whites help to keep fats inside a cake?
Recently I tried to bake a cake (Caprese) from:
- ground almonds
- butter
- dark chocolate
- sugar
- eggs
I melted chocolate and butter, mixed all of this with whipped sugar yolks, and then... totally screwed the whipped egg whites, and decided (for science!) to skip folding the egg whites as part of the recipe and just add almonds. As a result, when the cake has actually started to bake, most of the incorporated butter rose to the surface as one slimy puddle.
Why and how egg whites help keep fats inside of cake? I'm mostly interested in chemical or physical explanations of the effect.
Best Answer
Egg whites are mostly protein. Long chain polymers like proteins typically have regions that are both hydrophilic (binding to water) and hydrophobic (preferring to bind to fats), so are great at forming emulsions and stable gels. When cooked (or even beaten long enough) the long chains unwind and the proteins denature, making it easier for these emulsions to form.
In your cake, the role of the egg whites is to form a stable emulsion trapping fats from the butter and chocolate, as well as air. As you found, the egg whites are a structural essential.
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Do egg whites add fat to a cake?
Egg whites are very neutral in flavor so they really do not contribute to the flavor of your baked good like the yolks do. Because egg whites contain a great deal of water and no fat they tend to have a drying effect on baked goods.What does adding egg whites to cake batter do?
When separated from the yolks and whipped to a foam, egg whites can be used to leaven a cake. Whipping egg whites has the same effect as cooking whites- the proteins unfold, reattach and trap water. Since the whipped whites are already partially \u201ccooked\u201d they don't contribute as strongly to the structure of the cake.What does adding extra eggs do to a cake?
Add an Extra Egg: Boxed cake mixes tend to be lighter in consistency, but if you're craving that thicker, moister cake, then all you have to do is add an extra egg to your mix. Prepare to be shocked and amazed at the difference one egg will make when you bite into that rich cake.What is the egg function in cakes?
Cakes, meringues, cookies, pastry creams and custards use eggs as main components to thicken, emulsify, build volume, stabilize and provide unique colors and flavors. Egg whites are essential for the characteristic whipping ability and volume buildup in cakes where it acts as a leavening agent.THE FUNCTION OF EGGS IN BAKING | whole eggs, egg whites, egg yolks
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