Menthol is the most important flavoring chemical. Without menthol it would be difficult to get that cool clean feeling when we brush our teeth or chew gum. Cough syrups and drops wouldn’t cool the throat and open nasal passages.
In 2007, it was estimated that production of menthol was in excess of 19,000 metric tons. Because of it’s importance, there is a huge demand for this flavor chemical. It is a natural material and therefore subject to price fluctuations as a result of envrionmental conditions.
Naturally, peppermint oil (Mentha piperita) contains approximately 35-45% menthol and corn mint oil (Mentha arvensis) contains 65-75% menthol. Mentha arvensis is largely grown in India and used to produce menthol. Because menthol is a solid at room temperature, it is obtained by freezing the oil and crystallizing it out.
Synthetic menthol is also available. Typically, synthetic menthol is more expensive than natural. For example synthetic menthol could be $20 per pound while natural menthol from Mentha arvensis in India can be $9 per pound. This is significant, because gum and toothpaste flavors can contain 40-60% menthol. These flavors can be used at 1-2% in gum and toothpaste applications. Consumers love a cool and refreshing nasal stimulating feeling. Flavor chemists would use menthol at higher levels in flavors and applications if it wasn’t “self limitating”. Meaning, too much menthol tastes bitter and offensive.
To get a cool taste without bitter notes, we use artificial chemicals called “cooling agents” in conjunction with menthol, but these are expensive ($30-100 per pound). As a flavor chemist, it’s difficult to keep everyone happy: make it taste good, make it taste unique, keep it simple,keep the cost down and use materials that are not subject to market variations. Most of the time, the solution is the same as for life in general “just do your best”.
Flavor chemists appreciate help. BASF developed a method to produce synthetic menthol at a cost lower than previous synthetic production methods. It became available on the market last Fall. Our world just got cooler. Thanks BASF!