Issue Date: January 9, 2012
Diels-Alder In Brick, Countering Veggie Bitterness
Give a group of kids a sidewalk to play on, and they might draw a hopscotch board. But what happens when a group of chemists are given a sidewalk? Well, if they’re chemists from the University of Kiel’s Otto Diels Institute of Organic Chemistry, in Germany, they’ll turn the sidewalk into a diagram of the Diels-Alder reaction.
Since 2005, the redbrick walkway that separates the Kiel institute’s main building from its spectroscopy and lecture hall annex has sported a depiction of the famed organic chemical reaction, which garnered alumni professor Otto Diels and his graduate student Kurt Alder the 1950 Nobel Prize in Chemistry. The diagram perfectly captures the entire reaction, in which a conjugated diene (four π electrons, in the s-cis conformation) and an alkene (two π electrons) combine to form a cyclohexene ring (C&EN, Nov. 21, 2011, page 34).
The brick artwork “demonstrates that Kiel has a long-standing excellent—although not known by everyone—tradition in chemistry,” says the institute’s director, professor Ulrich Lüning. Kiel has been home to a number of chemistry professors, including Ludwig Claisen, Theodor Curtius, Albert Ladenburg, and Carl D. Harries, who have worked intimately on important chemical reactions, Lüning says. “The most famous, however, is Otto Diels, and he was here the longest.”
Building upon this respect for Diels, at the dedication ceremony for the Diels-Alder walkway, Lüning and the rest of his institute officially renamed their school in honor of the former professor. They even invited one of Diels’s daughters to attend the event as a guest of honor. Since then, the brick walkway has been a focal point of the institute. For instance, Ph.D. students celebrate graduation by attending a party held on top of the chemical reaction.
As to what Diels himself would think of the walkway, Lüning exudes optimism. “I think he would be very pleased,” Lüning says. “His daughter was.”
Although Kiel’s walkway supplies passersby with one kind of reaction, the walkways of supermarkets often provoke a much different kind of reaction: namely, skepticism about the claims made by various food products. Shoppers incredulous about Hidden Valley ranch dressing’s boast that it “makes everything taste better,” however, can now rest easy, thanks to a recent study in the Journal of the American Dietetic Association (DOI: 10.1016/j.jada.2011.08.032).
Having observed the snack-time eating habits of preschoolers sensitive to the bitter taste of vegetables, a research team led by Jennifer O. Fisher of Temple University’s Center for Obesity Research & Education has discovered that serving 2.5 oz of Hidden Valley ranch dressing alongside broccoli greatly increases the likelihood that children will eat the much-maligned plant. In fact, bitter-sensitive children in Fisher’s study consumed 80% more broccoli when it was served with dip than when it wasn’t.
According to Fisher, serving vegetables with dip is an easy way to instill healthy eating habits in youth, something Newscripts thinks she could’ve learned simply by asking any mom of a preschooler. “Kids learn to like foods based on the positive experiences of eating them,” Fisher says. By masking the bitter taste of vegetables with dip, she reasons, kids become much more likely to try veggies again in the future.
What’s even more encouraging, says Fisher, is that her team found that broccoli served with low-fat ranch dressing was just as popular among preschoolers as broccoli served with regular dressing. On the basis of this observation, Fisher encourages parents to try serving other healthy masking agents—such as applesauce, hummus, and yogurt—with their kids’ veggies. It’s a simple trick that can go a long way toward helping children eat a more balanced diet.
- Chemical & Engineering News
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