Both may be guilty pleasures, but hamburgers and chocolate owe their status as mouth-watering treats thanks to chemistry. For hamburgers, it is that delicious brown, crusty surface that is left behind when the raw meat is exposed to high heat, something called the Maillard reaction. With chocolate, the substance falls in the literal sweet spot of deliciousness thanks to it’s tendency to go from solid to liquid at about the same temperature that one finds in the human mouth—75-85° F. At this temperature, chocolate spreads across our taste buds, releasing all sorts of complex flavors that can easily be acquired and transmitted straight to our brains. Yum.
As we enter weeks five and six of the weekly, online, video series “Chemistry Now,” the chemistry of food remains the hook for some exciting, accessible, downright tasty chemistry. As we’ve written before, please view the video, try the lessons, and let us know what you think.
Photo: Gerwin Sturm
Through the Chemistry Now series, NSTA and NBC Learn have teamed up with the National Science Foundation (NSF) to create lessons related to common, physical objects in our world and the changes they undergo every day. The series also looks at the lives and work of scientists on the frontiers of 21st century chemistry.
Video: “The Chemistry of Burgers” (part of a 6-part Cheeseburger Chemistry series) outlines myoglobin protein structures and their chemical changes when exposed to heat — part of what turns a patty of red, raw ground beef into a tasty brown burger.
Video: “The Chemistry of Chocolate” uses chocolate-making to illustrate and explain chemical reactions related to heat, melting point, and formation of crystal structures.
Middle school lesson: The Role of Energy in Cooking helps students make the connection between kinetic energy and heat and the use of heat to initiate a chemical reaction, such as in cooking.
High school lesson: Calorimetry—Measuring Heat Energy Transfer demonstrates the measurement of heat transfer from one substance to another.
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