Investigation of CO2 precursors in roasted coffee

Xiuju Wang; Loong-Tak Lim

doi:10.1016/j.foodchem.2016.09.095

Investigation of CO₂ precursors in roasted coffee

Food Chem. 2017 Mar 15:219:185-192. doi: 10.1016/j.foodchem.2016.09.095. Epub 2016 Sep 15.

Authors

Xiuju Wang¹, Loong-Tak Lim²

Affiliations

¹ Department of Food Science, University of Guelph, Guelph, ON N1G 2W1, Canada.
² Department of Food Science, University of Guelph, Guelph, ON N1G 2W1, Canada. Electronic address: llim@uoguelph.ca.

PMID: 27765215
DOI: 10.1016/j.foodchem.2016.09.095

Abstract

Two CO₂ formation pathways (chlorogenic acid (CGA) degradation and Maillard reaction) during coffee roasting were investigated. CGA is shown not a major contributor to CO₂ formation, as heating of this compound under typical roasting conditions did not release a large quantity of CO₂. However, heating of a CGA moiety, caffeic acid, resulted in high yield of CO₂ (>98%), suggesting that CGA hydrolysis could be the rate limiting step for CO₂ formation from CGA. A large amount of CO₂ was detected from glycine-sucrose model system under coffee roasting conditions, implying the importance of Maillard reactions in CO₂ formation. Further studies on the heating of various components isolated from green coffee beans showed that CO₂ was generated from various green coffee components, including water insoluble proteins and polysaccharides. Around 50% of CO₂ was formed from thermal reactions of lower molecular weight compounds that represent ∼25% by weight in green coffee.

Keywords: CO(2) precursor; Chlorogenic acid; Coffee roasting; Thermal degradation.

MeSH terms

Carbon Dioxide / chemistry*
Chlorogenic Acid / chemistry*
Coffea / chemistry*
Coffee / chemistry*
Cooking*
Hot Temperature
Maillard Reaction

Substances

Coffee
Carbon Dioxide
Chlorogenic Acid