Modelling acidic corrosion of aluminium foil in contact with foods

The possible interaction between non‐coated aluminium and foods was studied using the corrosion behaviour of an aluminium household foil under different conditions of acidity, dissolved oxygen and temperature of the contacting phase. The aluminium foil was kept in contact with acetic acid solutions of pH values varying from 2.5 to 3.5 and dissolved oxygen concentrations between 0 and 8 ppm, under different conditions of temperature (from 0.3 to 50 °C) and contact time between 24 and 120 h. Corrosion was always detected and it was shown that all three variables influence the rate, and consequently the extent, of the interaction but pH and temperature have a greater effect since their relationships with rate are of an exponential nature. The relationship between corrosion rate and dissolved oxygen, however, is linear and has a minor accelerating effect on the corrosion rate. By applying the Arrhehius equation it was possible to evaluate the thermal sensitivity of the phenomenon with respect to the different variables. The activation energies vary between 31–635 and 88–471 J mol−1, indicating a higher thermal sensitivity at the lowest pH values and highest dissolved oxygen amounts. Copyright © 1990 John Wiley & Sons, Ltd