EXPERIMENTAL VALIDATION OF MODELS FOR PREDICTING OPTIMAL SURFACE QUALITY STERILIZATION TEMPERATURES

An experimental procedure was developed to validate experimentally the theoretical optimal process temperatures giving the maximum quality a t the surface of conduction heating products for specified levels of s terility. The method involved filling a can with a 10% bentonite solut ion, placing glass capillaries containing a food quality indicator at the surface, and processing it at different temperatures for the neces sary time in order to attain a specified sterility value at the least- lethality point. The acid catalysed sucrose hydrolysis reaction was us ed as a chemical time-temperature-integrator for a quality index of he at sterilized products. At a pH of 3.8, the kinetic parameters D-121.1 5 degrees C and z values of this reaction, were 214 min and 31 degrees C, respectively. Final surface retentions of sucrose compared well wi th theoretically predicted values from simulation modelling. Optimal t emperatures calculated using either numerical computer optimization or generalized regression equations were in the range of experimentally determined optimal conditions.