The invention relates to a method of sterilisation and/or pasteurisation of a food product (8) held within a container (12), said container of a type which, in conjunction with the food product, forms a retail pack which can be purchased and the food product removed therefrom for consumption. The containers (12) are moved during the controlled application of heat and pressure during the process to allow a gas space or bubble within the container to move through the food product during the process. This allows the sterilisation and/or pasteurisation to be efficiently achieved. The retail pack and support means (32) for the containers to move the same are also part of the invention.
