Microwave Heating

Microwave ?

A type of Electromagnetic wave Frequency 400MHz – 20000MHz Can be absorbed by water, fat or sugar

in foods Can convert into Heat

How Microwaves preserve foods?

Foods contain water ,sugars and fats Microwaves can be absorbed into

them For Foods 915MHz – 2450 MHz

Contd..

After absorption …………

Microwaves oscillations of polar molecules

Energy Heat

Heat can preserve foods

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

How make it real

Benefits

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

Disadvantages

Loss some beneficial chemicals No crust formation Dense foods do not cook evenly Foods with lower water content

toughened Cause cancers