Application of hydrostatic pressure up to 600 MPa on a solution consisting of N-x-acetylarginine, N-x-acetyllysine and ribose in equimolar ratios (pH 7.4, T=60 degrees C, t=2h) resulted in a pressure-dependent increase of the pentosidine content. This marker for the advanced Maillard reaction could also be found protein-bound in enhanced yields by increasing pressure on p-casein incubated with ribose in solution.