From ice cream to lattes, vanilla is one of the most popular spices in the world. It is also one of the most labor intensive to produce, and shortcuts lead to a less flavorful product. Today, scientists report a profile of 20 key chemicals found in vanilla bean extracts, including several previously unknown, that together create the complex and pleasing flavor of vanilla. The work could help makers and farmers develop better-tasting vanilla and improve quick-drying methods.
The researchers will present their findings at the fall meeting of the American Chemical Society (ACS).
“Vanilla is the second most expensive spice in the world,” says Diana Paola Forero-Arcila, Ph.D., who presents this work at the meeting. “One of the reasons it’s so expensive is that its flavor develops during a drying process that takes up to nine months.”
Two shortcuts are currently used to bypass this long and tedious hardening process. One is to speed it up with quick drying methods that attempt to recreate the delicious natural vanilla flavor in a fraction of the time. Another is to make artificial vanilla, familiar to consumers as a cheaper alternative to the real thing.
But these types of products fall flat in terms of flavor because they both focus on vanillin, says Forero-Arcila. Quick drying attempts to maximize the amount of vanillin in the dried bean, while artificial vanilla contains only one flavoring agent – lab-made vanillin. Although vanillin is an important part of the flavor of a vanilla bean, alternative products lack many other flavor compounds that develop during the long traditional drying process and are essential to the distinctive taste of vanilla. “It’s very important that we understand the complexity of vanilla flavor and try to identify the compounds behind that complexity,” says Forero-Arcila.
To capture this complexity, Forero-Arcila, who is a post-doctoral fellow at Ohio State University, used an approach called “untargeted aromatization” to identify the chemicals in vanilla bean extracts that are most important for aroma and taste. The researchers first made extracts of 15 grains from different countries that were dried differently. They then constructed a chemical profile of each type of bean and identified the compounds present. To find out how people reacted to the extracts, the team asked over 100 people to taste the samples and rate whether they liked or disliked the flavors.
By connecting the dots between chemical profiles and taste notes, the researchers identified 20 compounds that are key factors in determining whether a person likes the flavor of a vanilla extract. Among these compounds, some, such as vanillin, were expected. “Some of the compounds we identified are well-known vanilla components; however, this is the first report that they impact consumer acceptability,” Forero-Arcila says. And several compounds important to flavor were completely unknown, says Devin Peterson, Ph.D., the project’s principal investigator. Researchers are still analyzing these new vanilla compounds to determine the final structures, but they have observed that the compounds have phenolic and aglycone parts. They also identified certain compounds in the extracts that make people dislike the flavor. An example is anisaldehyde, which has a floral aroma. Forero-Arcila discovered that anisaldehyde is produced during the curing process from a previously unknown precursor.
With this new profile of compounds, the researchers plan to share what they have learned with others in the food and agricultural industries. They believe the profile could help growers and farmers identify valuable, high-quality extracts and price those extracts based on their quality. “The more you understand how to make materials more valuable, the more that value needs to flow throughout the system,” says Peterson. In the future, vanilla breeding programs and curing methods could focus on selectively producing the optimal compound profile for good flavor in vanilla plants.
The researchers acknowledge support and funding from The Ohio State University Flavor Research and Education Center.