Mepiquat: A Process-Induced Byproduct in Roasted Cereal-Based Foodstuffs.

Mepiquat, a growth regulator widely used in agriculture, is also known as a process-induced byproduct formed in coffee from natural constituents during heat treatments such as roasting. This study examines mepiquat formation in cereal-based foodstuffs treated at sufficiently high temperature to trigger methyl transfer reactions that involve glycine betaine and choline naturally present in cereals. Color measurements of roasted barley grains revealed a correlation between thermal treatment and mepiquat content.

N,N-dimethylpiperidinium (mepiquat) Part 2. Formation in roasted coffee and barley during thermal processing.

Previous work in model systems has demonstrated that mepiquat can be formed under typical roasting conditions from the amino acid lysine via the Maillard reaction and trigonelline, the latter alkaloid serving as a methyl donor. This study shows for the first time that mepiquat is formed in low mg kg(-1) amounts during the coffee roasting process and consequently can be detected in roast and ground as well as soluble coffee up to levels of 1.4 mg kg(-1).