Sterilizing process for foods by applying microwaves thereto

A sterilizing process for a food mixture by applying microwaves thereto, comprising the sequential steps of:

• placing a solid food material into a container which is capable of transmitting microwaves therethrough;
• then
• feeding a liquid material having an elevated temperature close to the temperature that said mixture is to be heated to and 80.degree. C. to 100.degree. C. higher than that of said solid food material into said container;
• whereby said container is completely filled with the mixture of said solid and liquid food materials;
• hermetically sealing said container before said mixture of said solid and liquid food materials reaches an equilibrium temperature thereof to thereby allow for some contraction on cooling before applying the next step;
• and
• applying microwaves under ambient pressure to said container before said mixture reaches an equilibrium temperature to raise the temperature of the mixture of said solid and said liquid materials in said sealed container to a sterilizing temperature of from 70.degree. to 105.degree. C., whereby said mixture becomes sterilized without damage to said container.