production of 2 hydroxy 4 methylthiobutyric acid ammonium salt from 2 hydroxy 4 methylthiobutyronitrile and to the use of the 2 hydroxy 4 methylthiobutyric acid ammonium salt produced by this process application_number US 54728004 A description suitable catalysts are titanium containing solids of which titanium compounds such as titanium nitride or titanium sulfide but especially titanium dioxides tio 2 are particularly suitable tio 2 is known in various crystal modifications of which anatase is the more catalytically active form the catalytic activity is further improved if some of the oxide functions are present as hydroxide anatase can be used in pure form but also in a mixture with rutile or other metal compounds such as oxides of manganese molybdenum niobium vanadium or tungsten or zeolites or mixtures of two or more of these compounds the catalyst can be used as a powder extrudate or in a pressed form together with a support material such as for example aluminium oxide or zir nium oxide the form of the catalyst of only minor significance for its effective s and is adapted to the requirements of the plant design it is known that mmp cyanohydrin is immiscible with water at ambient temperature however its solubility in water increases markedly with a rise in temperature thus a saturated aqueous solution at 57 u00b0 c already contains approx 25 mmp cyanohydrin the hydrolysis reaction in the presence of a suitable titanium containing catalyst is performed at a temperature of between 60 u00b0 c and 190 u00b0.