5-hydroxymethylfurfural is a member of the class of furans that is furan which is substituted at positions 2 and 5 by formyl and hydroxymethyl substituents, respectively. Virtually absent from fresh foods, it is naturally generated in sugar-containing foods during storage, and especially by drying or cooking. It is the causative component in honey that affects the presystemic metabolism and pharmacokinetics of GZ in-vivo. It has a role as an indicator and a Maillard reaction product. It is a member of furans, an arenecarbaldehyde and a primary alcohol.