The proposed strategy permits the on-line control of processes with arbitrary fluctuations of the heating-medium temperature from its nominal value without using an additional sausage-centre temperature probe. This approach using a finite-difference algorithm for integrating the generalized heat conduction equation can be also applied to thermal processing of solid foodstuffs with an irregular shape. Computed functions of sensitivity related to three kinds of cooked sausages are given. An illustrative example indicates the effect of the proposed strategy.