TABLE OF CONTENTS Finally, in terms of conclusions on the process of pollution in a liquid food, the striking points can be noted:
Because of the convective transfer through the liquid, the concentration of any contaminant at any time is uniform. s
And thus, the contaminant transfer from the package into the liquid food can be considered as a one-dimensional transfer, taking place per unit area, the volumes being reduced to lengths, whatever the shape of the flask or bottle.
The process of transfer is controlled either by one-dimensional transient diffusion through the thickness of the polymer package or convective transfer at the polymerliquid interface.
The ratio of the volumes of liquid and package, a, on the transfer is negligible, when this number is larger than 20 40, depending on the desired accuracy. The value of a is equal to 166 for a litre bottle in cubic form with a thickness of 100 ?m.
The effect of the convective transf er is of great importance. The dimensionless number R defined by the ratio h L/D, where L is the total thickness of the polymer package in contact with the liquid food on one side, expresses the effect of the convective transfer. As the rate of convective transfer h plays such an important role in the contaminant transfer, it should be necessary for the food package problems which concern the public health, to follow the process which was defined for pharmaceutical applications. The pharmacists...
