Fuzzy logic for accurate control of heating temperature and duration in canned food sterilisation

Autoclave thermal process is an important sterilisation procedure in the food canning industry. The performance of sterilisation is determined by the heating temperature and duration and the pressure in the autoclave, as well as by product's properties. In this study, a fuzzy logic controller is developed to maintain a small steady-state temperature error (121 ± 0.5 °C) for an sterilising duration (F0) by adapting to process deviations in the autoclave. The precise temperature control associated with on-line F0 updation assures food stuff that can be heated at the specified temperature for an expected duration and could lead therefore to successful sterilisation. The controls are implemented on a PLC (programmable logic controller) for affordability, reliability, and robustness and the operations are supervised using a web-based SCADA (supervisory control and data acquisition) system for remotely supervisory monitoring and control.