Piperonal (FEMA# 2911, CAS# 120-57-0), probably better known as heliotropine, is really only a bit player in nature but, in contrast, it is often cast in a leading role by the flavor industry. The character of this popular ingredient closely resembles heliotrope flowers. It is also somewhat reminiscent of hay and vanilla, with a distinct floral, powdery edge. Even though the odor of piperonal does not really resemble the odor of the members of the coumarin family particularly closely, the powdery aspect is a very important note that they both have in common. This single aspect of similarity has ensured that piperonal has played a significant role historically in the highly problematic replacement of coumarin.
Piperonal is especially helpful in the ubiquitous French-style vanilla flavors. It is normally only present at less than 1 ppm in genuine Bourbon vanilla beans and plays an equally insignificant role in genuine French Tahitian vanilla beans (where the distinct character is actually driven mainly by anisyl derivatives). Despite this relative analytical insignificance, most commercial French-style vanilla flavors on the market today are dominated by piperonal. Beyond its importance in French-style vanilla flavors, and the very closely related caramel flavors, this unique raw material can be used in a much wider and more diverse range of flavors.
The dose rates given here are the levels of piperonal to be used in flavors that are intended to be dosed at 0.05% in a ready-to-drink taster, beverage or bouillon.