The present application relates to food product carriers for microwave or radiofrequency sterilization or pasteurization of food products. In an embodiment, a method of processing a hermetically sealed packaged food product with microwave or radiofrequency energy to achieve sterilization or pasteurization is included. The method can include loading one or more hermetically sealed packaged food products into a carrier, the hermetically sealed packaged food products having a non-uniform thickness. The carrier can include a first press plate and a second press plate. The method can further include reducing a gap distance between the first press plate and the second press plate sufficiently to compress a portion of the hermetically sealed packaged food product and applying at least one of microwave or radiofrequency energy to the food product to result in sterilization or pasteurization. Other embodiments are also included herein.
