1. Mini Review: Microwave Cooking –An Issue of Food Safety
Presented By:
Upasana
Research Scholar
Department of Home Science
Banaras Hindu University
Varanasi

2. Introduction
Microwaves are high frequency electromagnetic waves that alternate in both positive and negative direction.
The frequency range of microwaves is 300 to 300,000MHz.
They are reflected, transmitted or absorbed by materials in their path in a similar manner to light.
Metallic materials totally reflect microwaves while non- metallic materials such as glass and some plastics are mostly transparent to microwaves .

3. Microwaves are attracted to foods that are high in:
sugar
fat
water

4. Microwave Cooking :The Heating Process
Microwave energy is absorbed by the food and would lead to excitation, rotation/collision of polar molecules and ions inside the food.
The molecular friction would generate heat and subsequently lead to temperature rise.
motion
heating
friction

5. Continue… The microwave can heat the food in two different ways:
Dipole Interaction
Ionic interaction

6. Effect of microwave on different food
Microwaves altered food both chemically and molecularly, lost its nutrients and created harmful compounds in foods. Under being inacceptable conditions, the following effects have been observed when foods are subjected to microwave:
Milk, Meat and Pulses:
Major source of protein
Microwave destabilized the active-protein and bimolecular compounds
Protein degradation rate depends on the heating time and temperature

7. Continue… Cereals, Sugars and Oils:
Cancer causing agent i.e. protein-hydrolysate compounds are created in cereal grains
Unnaturally altered molecular composition of natural sugar and oils
Vegetables and Fruits:
Brief exposures of microwave to raw, cooked or frozen vegetables and fruits enhance the production of alkaloids (such as caffeine, morphine and strychnine ) that are harmful for the human body
The availability of vitamin complexes A, B, C and E and essential minerals is vastly reduced
Microwaving lowers the metabolic behavior and digestibility of fruits and vegetables

8. Effect of microwave on Biological system
Digestive System
Alteration in elemental food substances of microwaved food and its unstable catabolism causes disorders in the digestive system.
Lymphatic System
Due to chemical alterations within food substances, dysfunction occur in the lymphatic system, causing a degeneration of the body’s ability to protect itself against certain forms of neoplasm (cancerous growths).

9. Continue… Endocrine system Loss of vital energies
Due to exposure of microwave, the production of hormones and the maintenance of hormonal balance in both males and females may be destabilized and interrupted.
Loss of vital energies
Humans, animals and plants located within a 500 metre radius of the equipment in operation suffer a long term, cumulative loss of vital energies.

10. Microwave and Food Safety
In the microwave cooking, the rate of heating depends on the power of the equipment i.e. microwave oven and on the water content, density and amount of food being heated.
Microwave energy does not penetrate well in thicker pieces of food, and may produce uneven cooking.
If parts of the food are not heated sufficiently to kill potentially dangerous micro-organisms, this can lead to a health risk.

11. Safety Suggestion for Microwaving
Read the oven manual carefully for recommended handling techniques and cleaning methods.
Arrange food evenly in the dish for proper microwaving.
Use food thermometer to verify whether food have reached a safe temperature or not.
Do not cook food on high power (100%). Use medium power (50%) and a longer cooking time.
Containers use for cooking and reheating should be labeled “microwave safe”. Thick, non-decorative glass is also safe.
NOTE: AVOID using microwave for daily cooking purpose.

12. Thank You………..