Microwaves

Question 1

what were microwave radio signals used for during ww2

Answer 1

tracking enemy & as a means of communication

Question 2

what are microwaves

Answer 2

nonioninzing waves of energy that create thermal charges

Question 3

can microwaves cause dangerous chemical changes

Answer 3

no

Question 4

what are the 3 possible applications of microwaves

Answer 4

they can be

1. absorbed
2. transferred
3. reflected

Question 5

how does a microwave oven function?

Answer 5

it converts household electricity into microwaves by using a vacuum electron tube.

Question 6

what are the 2 power outputs of microwaves and in what setting are they used?

Answer 6

household: 500-750 watts
commercial: 1000-1300 watts

Question 7

how are the microwaved reflected in a microwave oven?

Answer 7

waves are emitted from an opening in the metal case and get reflected off the sides and penetrate the food located in the center.

Question 8

what are the 2 major interactions in dielectric heating?

Answer 8

dipolar rotation of molecules–> occurs to the water molecules found in foods.
ionic conduction that occurs to the charged particles in food.

Question 9

what do the 2 types of interactions generate in dielectric heating?

Answer 9

they both generate heat caused by friction which gets transferred to other molecules through conduction.

Question 10

what type of containers should be used in microwave heating?

Answer 10

1- it must be a container that will transfer the waves as opposed to absorbing or reflecting them (glass, china & ceramic… plastic if heat tempered)
2- round & not to tall –> allows for greater wave distribution

Question 11

what should metal dished not be added in the microwave?

Answer 11

if any sharp edges, it will cause charges to be less well distributed causing for sparking to happen. chances are greater for a fork to spark than a spoon.

Question 12

if metal is used in the microwave, what needs to be followed?

Answer 12

1- needs to be of reasonably large size

2- needs to be kept away from the side walls as this is where the rays bounce off of.

Question 13

should food added to the microwave be stirred?

Answer 13

yes as this will allow the food to be evenly heated.

Question 14

does food cook from inside to outside or outside to inside?

Answer 14

outside to inside.

hence foods that are heavier of more dense should be place on the outside.

Question 15

how should a microwave be arranged when heating multiple items

Answer 15

spaced apart and in a circle(5+) square (4) or triangle (3).

nothing in the center.

Question 16

what should you do to foods enclosed in a skin or peel?

Answer 16

pieced to prevent them from exploding.

Question 17

what trick can you use to keep moisture in foods

Answer 17

place a cup of water in the center and allow it to steam to keep moisture as high as possible.

Question 18

does the food continue to cook through even when removed from the microwave?

Answer 18

yes. this is known as the standing time, where the particles continue to vibrate even after haven been taken out.

Question 19

what factors affect microwave cooking?

Answer 19

1- density: a whole potato will cook longer than mashed potato
2- volume: shallow & wide will cook faster and more evenly than narrow and tall.
3- the starting temperature of food.
4-shape of the food: thickness will determine cooking time
5- food composition:
sugar and fat help absorb heat.
state of water in the food: thawed or frozen.

Question 20

how to cook vegetables in the microwave

Answer 20

pro: retains vitamins and minerals
tips: add a little water to retain moisture & cut evenly & arrange in a single layer.

Question 21

how to cook meats in the microwave

Answer 21

not ideal as it will dry it out and make it lose its flavour.
temperature is not high enough to kill pathogens.
not good for large cuts of meat
tender cuts will produce better results
should be covered and liquid should be added
so not add salt until the end as this will result in a toughening effect.
ok to be used for thawing and reheating leftovers.

Question 22

cooking fish in the microwave

Answer 22

good as they are thin and require short cooking time.
should be covered to prevent surface from drying up.
to avoid overcooking of thin pieces they could be overlapped
not ideal for deep fried fished and live lobster nor for reheating.

Question 23

cooking eggs in the microwave?

Answer 23

they can cook very quickly… be careful
best used for scrambled, poached or omelet
fried and whole eggs will not work.

Question 24

microwaves for baking cakes & cookies?

Answer 24

not recommended
no browning effect
angel food cake, chiffon cake and meringues are too sensitive to heat
some microwave mixes are available.

Question 25

microwaves for beaking breads

Answer 25

not recommended

no maillard reaction, dexterization & caramelization.

Question 26

what happens to yeast bread in the microwave

Answer 26

yeast bread will result in a through, pale & low volume bread

Question 27

what happens to quick breads in the microwaves

Answer 27

quick breads will be pale & rise unevenly.

Question 28

cereals in the microwave?

Answer 28

ideal for instant hot cereal

the cooking time for other grains is not significantly reduced.

Question 29

does food in the microwave undergo browning effect?

Answer 29

no the foods will not brown or crisp

Question 30

what additional ingredients may be added to foods to cause a fake “browning effect:

Answer 30

soy sauce, bbq sauce, steak sauce

bread crumbs, shredded cheese, nuts, jellies, brown sugars etc.

Question 31

should a microwave be used when empty?

Answer 31

no it may cause for overheating

Question 32

are microwaves recommended for home canning?

Answer 32

No

Question 33

greater survival of bacteria and parasites results from what?

Answer 33

quick and uneven increase of temperature when using the microwave.

Question 34

what are some advantages of using microwaves

Answer 34

cooking time is decreased (3-4 minutes faster)
absence of cooking heat in the kitchen
saves energy
quick and easy to clean up

Question 35

what are some disadvantages of using microwaves

Answer 35

no browning effect
may dry up the foods
cannot cook foods slowly
not practical for large portions