OPTIMIZATION OF SURFACE QUALITY RETENTION DURING THE THERMAL-PROCESSING OF CONDUCTION HEATED FOODS USING VARIABLE-TEMPERATURE RETORT PROFILES

Optimal variable retort temperature profiles (VRT) for the sterilization of conduction heated foods were calculated using a quasi-Newton multivariable optimization algorithm considering both the maximization of surface quality and the minimization of total process time. When the maximization of surface quality was the objective, an increase up to 20% in quality retention was predicted for optimal VRT profiles as compared to optimal constant retort temperature profiles (CRT). When considering the minimization of total process time, the use of VRT profiles allowed reduction in the total process time of up to 45% while still providing the same surface quality as optimal CRT. Since the results could not be generalized, it was concluded that optimal VRT profiles should be calculated on a case-by-case basis.