Fat Tuesday: Why Chocolate Tastes So Good
So cute you could eat him. Image courtesy flickr user Kolin Toney.
Today Periodic Tabloid welcomes guest blogger and former chemistry prof Rebecca Guenard.
There is no denying chocolate’s power over us. Laboratory experiments show that its mere scent initiates rapid fire of our pleasure-anticipation and food reward neurons. But obviously the real delight comes from putting chocolate in our mouth.
The human mouth is a highly selective chemical sensor. Some of us may have learned in elementary school that there are receptors in the mouth that can distinguish sweet, sour, salty, and bitter tastes. [Though as discussed on a recent episode of Distillations, the tongue map is a myth!—Ed.] Scientists are now certain of a fifth receptor tuned to detecting the amino acid glutamate. And, most currently, researchers are trying to determine whether humans can taste fat through the selective binding of these macromolecules to chemical sensors in the mouth.
Fat taste buds may still be up for debate, but one thing is certain: we are keenly able to detect fat through texture. In a 2004 article in the Journal of Neuroscience Dr. Edmund Rolls writes, “Texture in the mouth is an important indicator of whether fat is present in a food, which is important not only as a high value energy source, but also as a potential source of essential fatty acids.” Dr. Rolls, a prolific neuroscientist and psychologist formerly at the University of Oxford, identified the specific neuron in primate brains—and later, the area of the human brain—which responds to the texture of fat.
In my case, texture is definitely what makes chocolate so pleasurable. “That’s the cocoa butter,” Dr. John Hayes, Assistant Professor of Food Science and Director of the Sensory Evaluation Center at Penn State University, tells me. Chocolate is solid and brittle, but transforms in our mouths: “Cocoa butter has a melting point just below body temperature,” Dr. Hayes explains. “When we put it in our mouth it goes from hard to smooth, creamy, chocolaty goodness. It is that dynamic change that makes chocolate so compelling.”
Yes it is! I can’t wait to fire up neurons and activate potential taste receptors when I bite the ears off my chocolate bunny this weekend.
Rebecca Guenard is formerly a chemistry professor and currently a science writer. She maintains the humorous science blog Atomic-o-licious, aimed at simultaneously entertaining and educating nonscientists.
Chocolate Chemistry [Periodic Tabloid]
Episode 129: Taste [Distillations]