Identification of bitter modulating maillard-catechin reaction products

The influence of thermally induced reaction products of a known dietary bitter compound, catechin, on bitterness perception was investigated. Catechin was reacted in low-moisture simple Maillard models (200 °C for 15 min) consisting of glycine and a reducing sugar (D-glucose, D-xylose, or D-galactose). Based on liquid chromatrography-mass spectrometry (LC-MS) isotopic labeling techniques, eight reaction products were identified and subsequently structurally elucidated by tandem LC-MS/MS and two-dimensional NMR analysis; six were report to be flavan-3-ol-spiro-C-glycosides reaction products. One of the spiro products was reported to significantly suppress the perceived bitterness intensity of a caffeine solution. Additionally, this specific spiro product was further identified in cocoa and reported to increase in concentration during bean roasting.