2-Ethyl-3-methylpyrazine (CAS 15707-23-0): The Nutty Aroma of Roasted Foods and Maillard Magic

3-Ethyl-2-methylpyrazine

2-Methyl-3-ethylpyrazine

2-Ethyl-3-methyl-1,4-diazine

FEMA 3155

2-Ethyl-3-methylpyrazine,

2-Ethyl-3-methylpyrazine, identified by the CAS number 15707-23-0 and FEMA number 3155, is a prominent alkylpyrazine that plays an essential role in the characteristic aroma and flavor profile of numerous roasted and cooked foods . With the molecular formula C₇H₁₀N₂ and a molecular weight of 122.17 g/mol, this heterocyclic compound belongs to the pyrazine family, which is renowned for contributing nutty, roasted, and earthy notes to food products . It typically appears as a colorless to slightly yellow liquid with a powerful, characteristic odor reminiscent of raw potatoes, peanuts, and chocolate .

This compound is a product of the Maillard reaction, a complex chemical reaction between amino acids and reducing sugars that occurs during the heating or roasting of foods . Specifically, 2-Ethyl-3-methylpyrazine is formed through the condensation of compounds like 2,3-pentanedione with ethylenediamine, and it has been identified as a volatile flavor component in a wide array of food items . These include roasted cocoa beans, coffee, peanuts, filberts, potato chips, roasted sesame seeds, roasted parsley, and various cooked meats such as beef, pork, and chicken . It is also found in bakery products, beer, rum, tea, and even seafood like shrimp and crayfish . This widespread occurrence makes 2-Ethyl-3-methylpyrazine a significant biomarker for the consumption of these processed and roasted foods .

In the flavor industry, 2-Ethyl-3-methylpyrazine is highly valued for its potent organoleptic properties. At low concentrations, typically with a detection threshold around 2 ppm in water and as low as 130 ppb, it imparts intense nutty, peanut, musty corn-like, and raw potato nuances . Its taste profile at 10 ppm is described as nutty and peanut-like with earthy and oily undertones . This makes it an indispensable ingredient for flavorists aiming to recreate authentic roasted and savory notes. It is primarily used to formulate flavors for peanut, chocolate, nut, and various potato-based products, adding depth and realism that is difficult to achieve with other ingredients .

The physical properties of 2-Ethyl-3-methylpyrazine are well-documented. It has a density of 0.987 g/mL at 25°C and a boiling point of 57°C at 10 mm Hg . It is sparingly soluble in water but miscible with organic solvents and ethanol . The compound is classified as a flammable liquid (UN 1993, Class 3, Packing Group III) with a flash point of 138°F (approximately 59°C) . 

As a food additive, 2-Ethyl-3-methylpyrazine (FEMA 3155) is recognized as safe for use as a flavoring agent by major regulatory bodies. It is listed by the FDA, approved by the Council of Europe (Number 548), and included in the EU Flavour Information System (FL No. 14.006) . It holds JECFA number 768, confirming its safety evaluation by the Joint FAO/WHO Expert Committee on Food Additives . When sourcing this compound, it is crucial to obtain it from reputable suppliers who provide certificates of analysis to ensure high purity (typically ≥98%) and compliance with food-grade standards for sensory applications .

In summary, 2-Ethyl-3-methylpyrazine (CAS 15707-23-0) is a cornerstone molecule in flavor chemistry. Its ability to convey the comforting, complex aromas of roasted nuts, chocolate, and cooked potatoes ensures its enduring value in creating delicious and authentic food experiences.