Microwave heating is used in a variety of fields because of its characteristics, and it was put into practice in the food industry earlier than any other field. This was presumably because microwave heating is most suited for heating food, whose moisture content is usually high.
■ Advantages in heating food
Microwave food heating has more advantages compared to other conventional heating methods, including the following:
- Being able to apply heat to the inside of objects
- Clean heating without environmental pollution
- Being able to heat food through containers and packages
- Consistent drying performance
- The heating temperature can easily be controlled
- Sterilizing and dust-prevention effects
- Sanitary and clean equipment
■ Application to the food industry
Microwave heating's applications are classified into the following categories according to their functions:
Microwave ovens are the most common home and industrial cooking equipment. Our industrial cooking equipment is designed to reheat a large number of lunch boxes cooked for exhibitions and other events, using tunnel-type conveyor belts.
Food frozen at -20 to -30°C from a fresh condition can be partially thawed at -2 to -5°C using our tempering equipment. Our industrial thawing equipment is more often used to defrost meat, including beef, chicken, and pork, than cooked food, or end products.
Since conventional drying methods apply heat to the outside of food to evaporate the water contained in it, only its surface will be dried, and it will take a long time to dry the food completely. On the other hand, the microwave drying method is able to economically dry areas of objects with a low moisture content at a high rate. The method can be implemented in combination with hot air or under reduced pressure.
(4) Sterilization and prevention of fungi
The method has sterilizing and antifungal effects depending on the heating temperature: effective for general viable bacteria and fungi at 60 to 90°C; and sterilizing effects equivalent to those of retort sterilization at 120 to 130°C under pressure.