International journal of food science and technology vol:29 issue:3 pages:227-241
An experimental procedure was developed to validate experimentally the theoretical optimal process temperatures giving the maximum quality at the surface of conduction heating products for specified levels of sterility. The method involved filling a can with a 10% bentonite solution, placing glass capillaries containing a food quality indicator at the surface, and processing it at different temperatures for the necessary time in order to attain a specified sterility value at the least-lethality point. The acid catalysed sucrose hydrolysis reaction was used as a chemical time-temperature-integrator for a quality index of heat sterilized products. At a pH of 3.8, the kinetic parameters D-121.15 degrees C and z values of this reaction, were 214 min and 31 degrees C, respectively. Final surface retentions of sucrose compared well with theoretically predicted values from simulation modelling. Optimal temperatures calculated using either numerical computer optimization or generalized regression equations were in the range of experimentally determined optimal conditions.