Effective HPLC method for the determination of aromatic Amadori compounds

An effective HPLC method was developed to separate and determine the phenylalanine, tryptophan, and tyrosine Amadori compounds in Maillard reaction mixtures. Using ammonium hydroxide as a major eluent component, the Maillard reaction mixtures of aromatic amino acid and glucose were separated in high resolution on an anion exchange column CarboPac PA-1. Aromatic amino acids and their Amadori compounds were determined by a UV detector at 260 nm. Glucose can be determined by a pulsed amperometric detector with the potentials and durations of E(1) = 0.05 V (t = 360 ms) and E(2) = 0.60 V (t = 120 ms). The effective gradient program was to increase the content of 0.5 mol/L sodium acetate from 0 to 100% in the 0.1 mol/L ammonium hydroxide solution. The separation was based on the acidity differences between the amino acid residues of amino acid and its Amadori compound. The method was simple and sensitive and was demonstrated to be applicable for the kinetic study of the Maillard reactions in aromatic amino acid and carbohydrate systems.