Forskning

November 1, 2012

Investigating the chemical changes of chlorogenic acids during coffee brewing – conjugate addition of water to the olfenic moiety of chlorogenic acids and their quinides

M F Matei et al, 2012, Investigating the chemical changes of chlorogenic acids during coffee brewing – conjugate addition of water to the olfenic moiety of chlorogenic acids and their quinides,Journal of Agricultural and Food Chemistry, published online ahead of print.

ABSTRACT:
Coffee is one of the most popular and consumed beverage in the world and is associated with a series of benefits for human health. In this study we focus on the reactivity of chlorogenic acids, the most abundant secondary metabolites in coffee, during the coffee brewing process. We report on the hydroxylation of the chlorogenic acid cinnamoyl substituent by conjugate addition of water to form 3-hydroxy-dihydrocaffeic acid derivatives using a series of model compounds including monocaffeoyl and dicaffeoylquinic acids and quinic acid lactones. The regiochemistry of conjugate addition was established based on targeted tandem MS experiments. Following conjugate addition of water a reversible water elimination yielding cis-cinnamoyl derivatives accompanied by acyl migration products was observed in model systems. We also report the formation of all of these derivatives during the coffee brewing process.