Use of tryptec enzyme preparations in treatment of chrome shavings

Prior research at this laboratory demonstrated that trypsin was an effectiv e enzyme for the isolation of protein products during the treatment of chro me shavings. Cost is the major deterrent to using research grade trypsin pr oducts. Recently, we found a commercial trypsin preparation that proved to be not only efficient in solubilizing the shavings but also cost effective. Several bench scale experiments were run to determine optimal enzyme conce ntrations and temperatures. It was found that by running the reaction at a temperature where the enzymes' activity is almost minimal (70 degrees C), h igher quality gelatin products could be obtained if one uses an enzyme conc entration of 0.25% or less. If one first incubates the chrome shavings at 3 7 degrees C, and then heats with agitation at 70 degrees C, gelatins with v arying blooms could be isolated by careful control of the enzyme concentrat ions (0.01% or less based on wet weight of shavings). If one incubates usin g the higher enzyme concentrations (0.2% or more), high yields of low molec ular weight hydrolysates could be obtained. Whether one uses the incubation s or not, the type of chrome cake isolated can be chemically treated to giv e fat and TKN contents that are less than one percent on a moisture-free ba sis, conditions that are necessary if one wants to recycle the chromium.