Although this appears to be true of roasted coffee in general, the magnitude of the CGA disappearance in medium and dark roasted coffee brews did not correspond to a relative difference in various parameter measures of MRP browning (namely, E, 420 nm absorbance and >10 kDa MRP) in the same brews. One explanation for this might be the absence of specific differences in the amount of MRP fractions with MW >10 kDa in medium to dark coffee brews, despite parallel significant decreases in all CGA isomers. Since our coffee brews represented only water soluble MRP, we might have underestimated the complete transformation to HMW melanoidins by not fully recovering all HMW MRP.