A method of sterilizing a food product (4) retained within a container (2), whose container and food product form a retail package, wherein said method includes the stages of partially filling the container with the food product to be retained, in order to leave a space filled with gas (10) inside the container (2), sealing the container with a closure (14), placing the container on support means (32), applying heat and pressure in a controlled manner for the product of the container and the food, to provide a sterilization effect, and in accordance with the application of heat and pressure (24), the container can move through the displacement of the support means (32) with the container fixed therein in order to cause the gas-filled space to move and can pass through at least part of the food product in the container, characterized in that the container is formed by a plastic material, and wherein the closure (14) of the container is coupled with a portion (36) of the support means (32) in order to ensure that the neck surrounding the closure (14) remains in the form required during the thermal process, to prevent deformation and / or leakage.Un método de esterilización de un producto alimenticio (4) retenido dentro de un contenedor (2), cuyo contenedor y producto alimenticio forman un empaquetado de venta al por menor, en donde el mencionado método incluye las etapas de llenado del contenedor en forma parcial con el producto alimenticio a retener, con el fin de dejar une espacio llenado con gas (10) dentro del contenedor (2), sellando el contenedor con un cierre (14), colocando el contenedor en unos medios de soporte (32), aplicando calor y presión de una forma controlada para el producto del contenedor y el alimento, para proporcionar un efecto de esterilización, y conforme al aplicar el calor y la presión (24), el contenedor pueda moverse por el desplazamiento de los medios de soporte (32) con el contenedor fijado en los mismos con el fin de provocar que el espa
