New methods for non-destructive sterility testing of aseptically packed food products

A new method for non-destructive sterility testing of liquid foods in TBA (Tetra Brik Aseptic) packages is presented. It is based on monitoring the heat production and the volume change of the food container, when there is a bacterial growth in the contained food. For evaluation purposes a prototype has been built, that allows simultaneous monitoring of the temperature and the volume differences between two 1L TBA packages-a tested one and a reference one. An evaluation of the industrial applicability of the presented method is made in comparison with another newly introduced nondestructive sterility-testing method, based on indirect conductivity measurements of liquids in flexible food containers.