"The disparity between the pleasant and sickening feelings which banana flavoring can invoke lies in the intricacy of banana flavor chemistry. The fruit itself contains a mixture of volatile compounds that are responsible for its characteristic flavor. Up to 42 molecules have been identified to contribute to the aromatic profile of bananas . Each of these molecules, when isolated, has been reported to give off their own unique scent [2,3]. Most of the scents are described as floral, sweet, and generally fruity, which are expected when analyzing aroma compounds derived from bananas. However, there are a few volatile compounds that emit odors not usually associated with bananas. For instance, eugenol, one of the significantly abundant aromatic compounds found in bananas, smells spicy, like cinnamon [2,3].
Of all the volatile compounds detected in bananas and analyzed, one stands out as the banana flavor molecule: isoamyl acetate. With a scent often described as “over-ripe bananas”, pure solutions of isoamyl acetate are sold as “banana oil”. Isoamyl acetate is widely used as a flavorant to confer that over-ripe banana flavor in foods. Yet, as many can attest, pure “banana flavor” tastes awful, nothing like the actual fruit. Despite its presence in the banana itself, how does the banana-flavor molecule miss the mark so badly in candy?
Chemical complexity is one explanation, as there are 30-40 other aroma compounds that contribute to natural banana flavor. Additionally, in a ripe banana, although isoamyl acetate is one of the key molecules in banana aromatics, it is found in small amounts compared to the other volatile compounds [2,3]. Yet, even though isoamyl acetate is not the most abundant compound in the aromatic profile of bananas, it is a heady flavor on its own: this molecule can be tasted in concentrations as low as 2 parts per million .
So, maybe a banana-flavored Laffy Taffy contains a higher concentration of isoamyl acetate than an actual banana. Until scientists and flavor chemists figure out how to make banana-flavored foods actually taste like bananas, at least the yellow Laffy Taffy has its small but dedicated fan base