Effect of high hydrostatic pressure combined with pH and temperature on glucose/fructose-leucine/lysine/glutamate browning reactions

Effect of high hydrostatic pressure (100 MPa) combined with pH (6.0, 7.0 and 8.0) and temperatures (80°C and 90°C) on Maillard reaction was investigated via the sugar (glucose or fructose)-amino acid (leucine, lysine or glutamate) solution models. Overall intermediate and final browning products produced were spectrophotometrically measured, and 5-(hydroxymethyl)-2-furfural (HMF) content was gas-chromatographically detected. Increases of pH and temperature accelerated the production of intermediate and final products of all solutions, while high pressure treatment suppressed the reaction. HMF was the most abundant compound among the detected compounds on chromatograms. Its content was also increased with the increase in temperature, but decreased in high pressure treatment. Effect of pH on the productions of intermediate and final compounds in glucose-amino acid systems was greater than in fructose-amino acid systems. Among three amino acids used, lysine was the most reactive amino acid in the productions of intermediate and final browning products, including production of HMF.