By Catherine Qiu
Whipped cream and egg whites add height to a variety of delectable desserts. One dessert that utilizes both is chiffon cake.
Egg whites are packed with protein, while egg yolks are a combination of protein and fats (“Science of Beating Eggs”). When egg whites are vigorously whisked, air gets incorporated. However, the egg whites' proteins denatures (unravels) and its hydrophobic amino acids are exposed. The amino acids form a net around air bubbles (“Meringue”). In the oven, the bubbles may expand and proteins may stiffen up. This trapped air can give a cake its height when baking without baking soda or powder. (“Science of Beating Eggs”).
While the cake is in the oven, we can work on the whipped topping. Whipped cream has a similar chemical structure to meringue. Whipped cream contains a fat called triglyceride, made up of three fatty acids. In the United States, the FDA requires that heavy whipping cream must have a fat content of 36% or more. In addition, using solid phase fat is ideal, and this is why many recipes call for cooling the bowl and whisk beforehand. Phospholipid barriers protect the triglycerides from water, due to triglycerides’s hydrophobic nature. While whisking, the phospholipids dissolve and bonds break. The triglycerides stick together to avoid excessive surface area exposed to water (Lower). Triglycerides cling to air, forming air bubbles, to the point where a tower of air bubbles will form-- a 3D sculpture of tiny overlapping spheres (“Milkfat Structure”).
Gustaf de Laval was the first to invent the hand-cranked centrifugal milk-cream separator. In a span of a couple days, the cream and liquid in milk could be separated. The process is much faster currently. When the cream portion is whipped, the result is cloud-like whipped cream. When overdone, the whipped cream starts to deflate to form butter. Adding bacteria cultures could form butter and buttermilk byproduct too (Lower).
Who knew so much chemistry was involved in making a cake?
Works Cited
Christensen, Emma. “Food Science: How Whipped Cream Whips.” Kitchn, Apartment Therapy, LLC., 3 May 2019, www.thekitchn.com/food-science-how-whipped-cream-81751.
“Meringue: The Science Behind a Wonderfully Fluffy Dessert.” Let's Talk Science, 12 Oct. 2019, letstalkscience.ca/educational-resources/stem-in-context/meringue-science-behind-a-wonderfully-fluffy-dessert.
Lower, Claire. “Cream Science: On Whipping, Butter, and Beyond.” Serious Eats, www.seriouseats.com/the-science-of-whipped-cream-butter-creme-fraiche.
“Milkfat Structure - Fat Globules.” Milkfat Structure - Fat Globules | Food Science, www.uoguelph.ca/foodscience/node/1891/.
“The Science of Beating Eggs.” NPR, NPR, 20 Feb. 2008, www.npr.org/templates/story/story.php?storyId=19190607#:~:text=When you beat egg whites,and the air leaks away.
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