Tasty Greetings, Plant Distress Signals

In an age when people expect their personal electronic devices to be all things—music player, navigator, camera, phone—it’s not surprising that they also want more out of their GREETING CARDS. Gone are the days of a simple “Happy Birthday” or “Congrats” note inside. Nowadays, cards are expected to sing, make us laugh—and taste like a cupcake.

In collaboration with American Greetings, Pennsylvania-based firms First Flavor and David Michael & Co. have developed a new line of flavorful greeting cards called Tasties. Launched during the summer, the cards feature First Flavor’s Peel ‘n Taste strips, which have previously appeared on coupons and in magazine ads for products such as Welch’s grape juice (C&EN, Feb. 25, 2008, page 18). The flavor strips—similar to dissolvable breath strips—come in a sealed foil pouch and are made of a hydrocolloid film, a flavoring system that includes the sweetener sucralose, emulsifiers, a plasticizer, and artificial coloring, according to Jay B. Minkoff, president and chief executive officer of First Flavor.

The Peel ‘n Taste concept was inspired by the film “Willy Wonka and the Chocolate Factory,” Minkoff says. After watching the flick, First Flavor cofounder Adnan Aziz, a University of Pennsylvania student at the time, applied for a school grant to develop the product. Eventually, David Michael & Co. came on board to help create the custom-designed flavor for each strip. The development process is iterative, Minkoff tells Newscripts, requiring “adjustments to the flavoring system until an edible strip is created that meets with a client’s specifications.”

Currently, the Tasties cards are available in chocolate, glazed donut, cupcake, and margarita flavors and can be found in Walmart and Target stores, as well as other locations in the U.S. No word yet on whether a chicken-soup-flavored “Get Well” card is in the works.

People greet each other with cards and handshakes, but it seems that plants greet some insects with a specific bouquet of volatile chemicals. For instance, harmful herbivores such as caterpillars induce certain distressed plants to release a blend of compounds that calls in reinforcements: PREDATOR BUGS.

This was the finding of a study conducted on wild tobacco plants (Nicotiana attenuata) recently published in Science by Silke Allmann and Ian T. Baldwin of Max Planck Institute for Chemical Ecology, in Germany (2010, 329, 1075). The researchers found that when tobacco hornworm caterpillars (Manduca sexta) munched on the plants, the insects’ saliva triggered an immediate release of green leaf volatiles (GLVs)—an S.O.S. signal to predator bugs of the genus Geocoris.

Unlike other herbivore-induced plant volatiles, GLVs—which consist of six-carbon aldehydes, alcohols, and their esters—are emitted by wounded leaves immediately after attack. For a predator, this quick defense response is “analogous to reading today’s paper,” Baldwin says. The GLV release broadcasts breaking news about “the exact location of the feeding herbivore,” he says.

Using gas chromatography-ion trap mass spectrometry and GC×GC time-of-flight MS, Allmann and Baldwin compared the ratio of (Z)- and (E)-GLV isomers emitted by mechanically wounded tobacco leaves with those treated with hornworm saliva. The researchers found that the caterpillar-spit-treated leaves released an increased amount of (E)-GLVs, such as (E)-hex-2-enal, that attracted the predator Geocoris bugs.

Although the researchers haven’t yet been able to identify the exact cause of this saliva-triggered isomerization, “our best guess is that it’s a heat-labile enzyme,” Baldwin says. “Silke is busy collecting lots of M. sexta larva spit and attempting to characterize this putative isomerase.”