Maltol or methyl maltol, chemical formula C6H6O3, with caramel and cotton candy sweet aroma, and along with a fruity note. Together with ethyl maltol, they’re the second commonly used synthetic flavoring agent in food after vanillin.

Although its flavor enhancement effect is not as strong as ethyl maltol, it is less volatile and can be used at high temperatures, such as in baked and high-temperature processed food. See the detail of its comparison with ethyl maltol.

Natural sources
Maltol occurs naturally in a lot of foods by converting from sugars through the baking or roasting process, such as in bread, beans, cocoa, coffee, malt, and peanuts (1). It is also naturally present in the bark of larch tree and pine needles. (2)

http://www.chinafooding.com/Maltol