Chemistry Flash – Maltol and Ethyl Maltol

After a long hiatus Chemistry Flash series returns with two new fragrant molecules that are commonly used in perfumery and some other fields of life. Get ready for the lesson.

The subject for today are chemical compounds popularly known as maltol and ethyl maltol.

Maltol – C7H8O3 (full name: 3-Hydroxy-2-methyl-4H-pyran-4-one) is an organic compound based on pyran ring – that is the 6 atoms: 5 carbons and 1 oxygen cyclic structure with two double C=C bonds on each side of the oxygen axis. It naturally occurs in larch tree bark, pine needles and roasted malt (the same one that is used for beer production). When in pure state it forms white crystals or powder that has the ability to dissolve in polar solvents such as water, ethanol which makes it really easy to use.

Maltol is a compound that carries the aroma similar to cotton candy and toffee, that’s why it is often used to enhance flavor of food products such as bread or various cakes. In European Union maltol is registered not as a food additive but as a flavor component, thus it doesn’t have the E-something number assigned to it. The interesting fact is that maltol is gaining more popularity as a flavoring agent for e-cigarettes liquids to tone down the taste of tobacco refill.

Maltol was first discovered by Stenhouse in 1862 and it was the first molecule in the family of 1,2-dicarbonyl compounds used in perfumery. A few more were discovered in later years.

Ethyl maltol – C8H10O3 (full name: 2-Ethyl-3-hydroxy-4-pyranone) is a compound derived from maltol which can be obtained by simply replacing a methyl group with ethyl group. In pure state it also forms white crystals like maltol but its fragrance profile is a little bit different. Ethyl maltol smells more like burnt sugar, cooked or candied fruit and can also resemble the aroma of chocolate/cocoa. While maltol can be naturally found in cocoa, coffee or malt, ethyl maltol was artificially created in the laboratory in 1969 and is around 500x more intensive than maltol.

Before the era of discovering ethyl maltol in the lab it was the natural maltol which was added to food and fragrance compositions. As soon as the synthetic maltol derivative was synthesised it took over the perfumery market of gourmand scents introducing a vibrant and powerful aroma of toffee, caramel, fudge, sugar, candy cane and other delicious treats. The most symbolic use of ethyl maltol in perfumery was in 1992 when perfumer Olivier Cresp used the synthetic compound to create Thierry Mugler Angel. This perfume is still an icon in PerfumeLand.

The next time you’re at the local funfair or when your sweet tooth will demand a gorgeous looking praline – remember about maltol and ethyl maltol and how they can find their way in your favourite little indulgences. Some other perfumes that might (but don’t have to) contain these compounds are:

• Prada Candy, Prada Candy L’Eau
• Thierry Mugler A*Men
• Dior Miss Dior Cherie
• Bottega Profumiera Gourmand
• Guerlain Shalimar Parfum Initial
• L’Artisan Parfumeur Amour Nocturne