Abstract
An inverse procedure has been proposed for on-line determination of thermal parameters in conduction heating foods to achieve appropriate sterilization. The proposed method made use of data collected at the early stages of the heating phase to predict the parameters responsible for the transfer of heat in the conduction heating food. Inherent with the proposed method are some limitations and instabilities, which are manifested especially when there happened to be noise or disturbances during data acquisition. To eliminate these limitations and instabilities a new robust procedure for on-line control to achieve appropriate sterilization in conduction heating foods is proposed in this paper. This method makes use of the well known fact that after a sufficiently large amount of time has elapsed, a semi-logarithmic plot of temperature against time yields a straight line: of which, from the slope and intercept, the thermal parameters responsible for heat transfer are determined. The inflection point in the time/temperature curve is used as an index to detect the time from which the straight line commences. The use of estimated parameters was validated by experiments to be helpful to achieve a targeted lethality.
