| 摘要 |
PURPOSE:To uniformly heat a food without causing deterioration of quality such as nutrient, flavor and visual appearance by applying plural kinds of microwaves having mutually different frequencies to the food. CONSTITUTION:A food 8 to be heated is packed in a microwave-permeable package 9, tightly sealed with a cover 91 and put on a conveyor line (L). The gate valve (a) is then opened and the food is conveyed into the first pressure- control chamber 1. After closing the gate valve (a), the inside of the chamber l is controlled to a prescribed pressure by using a compressor 7 and a pressure control valve (1B). The gate valve (b) of a microwave radiation chamber 2 controlled to the same pressure as that in the chamber 1 by adjusting a valve (2B) in advance is then opened and the food 8 is conveyed into the chamber 2. The gate valve (b) is closed and the temperature in the chamber 2 is raised up to 110 to 130 deg.C. The food is then conveyed into the second microwave radiation chamber 3 and microwaves are applied to the food 8. The food 8 is subsequently conveyed into a dry-heating chamber 4 and then into a cooling chamber 5 so as to be cooled to the ordinary temperature. |
