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methional

n. (context organic compound English) The mercaptanaldehyde CH3-S-CH2-CH2-CHO that is a primary aroma constituent of several vegetables

Wikipedia
Methional

Methional is an organic compound with the formula CHSCHCHCHO. It is a colorless liquid that is a degradation product of methionine. It is a notable flavor in potato-based snacks, namely potato chips, one of the most popular foods containing methional. Traces of the compound can also be found in black tea and green tea based products. Methional contains both aldehyde and thioether functional groups. It is readily soluble in alcohol solvents, including propylene glycol and dipropylene glycol.