Ethyl maltol is an analogue of maltol (or methyl maltol), which is obtained by replacing the methyl group in maltol molecule with an ethyl group. They’re both flavors with the similar taste of caramelized sugar and are the basic components of some complex flavors and fragrances, and commonly used for the preparation of many fruit flavors, such as the flavors of citrus orange, pear, pineapple, cherry, grape, mango, apple, coconut and etc.
Ethyl maltol is a synthetic ingredient and is used more widely than maltol, which occurs naturally.
The biggest difference is that the flavor or aroma intensity of the former is about 3 to 4 times stronger than that of the latter and more volatile due to the slight difference in the molecular structure. And thus to reach the same flavor enhancement effect, the dosage of ethyl maltol is only one-third to one-fourth of maltol.
Maltol also has an odor of a burnt caramel, but with little fruity taste. Ethyl maltol has a stronger sweet fruity taste, while less caramel smell. This leads to their different uses. Maltol is especially suitable chocolate and caramel-flavored products, while ethyl maltol is commonly used as a fruity sweet flavor although it is not a real sweetener.
How is Ethyl Maltol Made?
Ethyl maltol can be commercially produced by chemical synthesis, generally with the manufacturing process of Grignard reagent preparation, grignard reaction, hydrolysis, chlorination and rearrangement reaction.
Firstly to obtain Grignard reagent (CH3CH2MgBr) by the reaction of magnesium with CH3CH2Br in the presence of anhydrous ether or tetrahydrofuran solvent.
Then react the Grignard reagent with furfural, and then hydrolyzed to obtain furfuryl alcohol intermediate. Chlorinate the furfuryl alcohol intermediate at low temperature, and then heated to hydrolyze and rearrange to obtain crude maltol in acidic medium, and finally purified by sublimation and recrystallized in ethanol. (https://patents.google.com/patent/CN101129184A/en " title="" aria-describedby="qtip-0" style="margin:0px;padding:0px;border:0px;font:inherit;vertical-align:baseline;text-decoration-line:none;color:#DD3333;transition:background-color 0s ease 0s, color 0.2s linear 0s;">1)
Here is the general flow chart:
Sparingly soluble in water; soluble in ethanol and in propylene glycol (can be diluted to 10%).