The present invention relates to a process for the manufacture of a suspension of mustard bran particles comprising the following steps: a) providing an aqueous dispersion of mustard bran particles originating from the seeds of black mustard (Brassica nigra) and/or the seeds of brown Indian mustard (Brassica juncea), said mustard bran particles having a volume weighted mean diameter of more than 300 µm; b) producing a milled suspension of mustard bran particles by passing the dispersion one or more times through a high shear device selected from a high pressure homogenizer and an ultra-fine friction grinder, said high pressure homogenizer being operated at a pressure drop of at least 100 bar. Treatment of these types of mustard bran in a high shear device increases overall bioaccessability of the proteins contained in the bran. This is desirable in view of the high nutritional value of these proteins. The invention also provides a food product comprising an aqueous phase, said aqueous phase comprising 0.5 to 15 wt. % of mustard bran particles originating from the seeds of black mustard and/or the seeds of brown Indian mustard, said mustard bran particles having a volume weighted mean diameter of less than 600 µm.La présente invention concerne un procédé de fabrication d'une suspension de particules de son de moutarde comprenant les étapes suivantes : a) prévoir une dispersion aqueuse de particules de son de moutarde issu de graines de moutarde noire (Brassica nigra) et/ou de graines de moutarde brune (Brassica juncea), lesdites particules de son de moutarde présentant un diamètre moyen pondéré en volume supérieur à 300 µm ; b) produire une suspension broyée de particules de son de moutarde en faisant passer la dispersion une ou plusieurs fois à travers un dispositif à cisaillement élevé choisi parmi un homogénéisateur haute pression et un broyeur à frottement ultra-fin, ledit homogénéisateur haute pression fonctionnant à une chute de pression d'au moins 100 bars. Le