1. Microwave Heating

2. Microwave ?
 A type of Electromagnetic wave
 Frequency 400MHz – 20000MHz
 Can be absorbed by water, fat or
sugar in foods
 Can convert into Heat

4. How Microwaves preserve foods?
 Foods contain water ,sugars and fats
 Microwaves can be absorbed into
them
 For Foods 915MHz – 2450 MHz

5. Contd..
After absorption …………
 Microwaves  oscillations of polar
molecules
Energy  Heat
 Heat can preserve foods

6. Microwave oven
 Creates radio waves at 2.45 GHz
 This waves propagate towards matter
inside the oven
 Waves vibrate polar molecules
 Heat generates within the matter
 Works until door is opened or timer
reaches zero

7. How make it real

8. Benefits
 Save time
 Easy to heat foods
 Retain Nutrients and vitamins
 Easy to clean
 Automated
 Prevent “Browning”

9. Disadvantages
 Loss some beneficial chemicals
 No crust formation
 Dense foods do not cook evenly
 Foods with lower water content
toughened
 Cause cancers