A method of enzymatically producing a protein hydrolysate from a protein substrate is described, wherein a proline-specific endoprotease or a composition containing a proline-specific endoprotease and optionally a subtilisin or a metallo endoprotease, and other enzymes such as carboxypeptidases, is used to produce a protein hydrolysate enriched in peptide fragments having a carboxy terminal proline residue. Such protein hydrolysates may be used as such or to reduce bitterness in foods nutritionally supplemented by protein hydrolysates, as well as to produce hydrolysate containing foodstuffs having low antigenicity.