MICROWAVES: CHAPTER 7

I. HISTORY OF MICROWAVES

Started during World War II Large, heavy and very expensive $1,300 Modern microwaves Convenient, and available in different

sizes

II. FOOD-RELATED USES OF MICROWAVES

3 different places of use1. Home

Used to boil water, heat frozen foods, defrost foods, or to make popcorn

Consumers use it because of convenience

2. FoodserviceHave high-output capabilitiesUsed to reheat foodsNot frequently used, unless for individual

portionsNot a time saver with large quantities

3. Food Industrya. Meat tempering

Largest use of microwaves in food industry As food is tempered, it is brought to

temperature below freezing Not frozen, but still firm Conventional thawing would take several days Microwave tempering takes a few minutes Less drip loss and microbial growth

b. Microwave DryingSaved time and energyCan be used for pasta, fruit juice

concentrates, herbs, breadcrumbs, chips, and snack foods

c. PasteurizationFresh pasta, bread, granola, yogurt, meat

products, and prepared meals

d. Sterilization --Using overpressure conditions

--Produces temperatures 230 to 266 degrees F.

e. Proofing-- Used for baking bread, pizza, cake, and

pastry products. --Usually used with conventional baking

III. WHAT ARE MICROWAVES?

High-frequency electromagnetic waves of radiant energy.

a. How do they heat food? i. Interact with electrically polarized molecules

(dipolar molecules) Include water, protein, and CHO. ii. Dipolar molecules act like tiny magnets and

align in the microwave electromagnetic field. iii. Field alternates rapidly iv. Causing polarized molecules in the food to

rotate rapidly v. Heat is produced by the friction that is

created.

IV. ADVANTAGES OF MICROWAVE COOKING

Speed of Cooking and Reheating of Food Reduction of Nutrient Loss Energy Conservation

V. LIMITATIONS OF MICROWAVE COOKING

a. Surface Browning of Foods b. Overcooking c. Unevenness of Heating d. Food Safety

May not destroy all of the Salmonella or Trichinella spiralis

VI. COOKING SUGGESTIONS

a. BrowningLarge pieces of food are able to brown in

the microwaveSmall pieces of food need another way

b. Stirring and TurningPower is unevenly distributedNeeds to be turned around, turned over,

and stirred

c. Standing Time i. Foods still cook after a few minutes after

being removed ii. Take this into consideration to avoid

overcooking

d. Defrostinge. Combine Microwaves and Conventional

CookingFood can be prepared more efficiently

f. Heating Meals