Analysis of amino acids and carbohydrates in green coffee

J Biochem Biophys Methods. 2006 Nov 30;69(1-2):25-32. doi: 10.1016/j.jbbm.2006.02.001. Epub 2006 Mar 9.

Abstract

The analysis of carbohydrates and amino acids in green coffee is of the utmost importance since these two classes of compounds act as precursors of the Maillard reaction during which the colour and aroma are formed. During the course of the Maillard reaction potentially harmful substances like acrylamide or 5-hydroxymethyl-furfural accrue as well. The carbohydrates were analysed by anion-exchange chromatography with pulsed amperometric detection and the amino acids by reversed phase chromatography after derivatization with 6-amino-quinolyl-N-hydroxysuccinimidyl carbamate and fluorescence detection. Both methods had to be optimized to obtain a sufficient resolution of the analytes for identification and quantification. Sucrose is the dominant carbohydrate in green coffee with a concentration of up to 90 mg/g (mean = 73 mg/g) in arabica beans and significantly lower amounts in robusta beans (mean=45 mg/g). Alanine is the amino acid with the highest concentration (mean = 1200 microg/g) followed by asparagine (mean = 680 microg/g) in robusta and 800 microg/g and 360 microg/g in arabica respectively. In general, the concentration of amino acids is higher in robusta than in arabica.

Publication types

  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Amino Acids / analysis*
  • Carbohydrates / analysis*
  • Chromatography, High Pressure Liquid
  • Chromatography, Ion Exchange
  • Coffee / chemistry*
  • Food Analysis / methods*
  • Maillard Reaction

Substances

  • Amino Acids
  • Carbohydrates
  • Coffee