TIME‐VARIABLE RETORT TEMPERATURE PROFILES FOR CYLINDRICAL CANS: BATCH PROCESS TIME, ENERGY CONSUMPTION, and QUALITY RETENTION MODEL¹

Abstract

The batch retort model developed uses a heat transfer equation for heat conduction in cylindrical cans, first order kinetics for microbial inactivation, first order kinetics for quality losses and a transient energy balance to estimate steam consumption. For a given retort, lethality process and quality retention, the transient energy balance equation in the model allowed the identification of feasible time‐temperature profiles reducing energy consumption, total process time or both. In the examples analyzed and depending upon product specifications, time‐variable retort temperatures reduced process time by 18–55 min. These examples suggested that a change from constant to time‐variable retort temperatures could increase canning capacity by 20–50%.