Cans are widely used to sterilize food products in retorts using conventional processing techniques. Their construction material and the design of the rippled body lead to changes in the internal volume during thermal processing. This change in internal volume is due to the effective pressure, which is the difference between the pressures inside and outside the package. Knowledge of this variation in volume with respect to the pressure is important for the correct calculations of the package filling, head space, and to determine an appropriate over pressure to guarantee integrity of the cans and efficiency of the heat exchange process. The goal of this work was to determine the profile of the internal volume changes as a function of the effective pressure for five types of cylindrical commercial cans with the following capacities: 200, 307, 430, 908 and 2700 mL. Polynomial functions were fitted to the experimental data with residual standard values below 10% and high values for the correlation coefficients, indicating that they could be applied to predict volume changes according to the effective pressure.
Canning; sterilization; package deformation; effective pressure; pressure control
