Deck 3: Physical Aspects of Food Preparation

Question 1

Water in a sol is the

A) Dispersed phase
B) Continuous phase
C) Emulsifier
D) Hydrophilic protein
E) Protein

Answer 1

B

Question 2

The type of cooking using radiation is

A) Broiling
B) Boiling
C) Steaming
D) Baking
E) Roasting

Answer 2

A

Question 3

Starch in a sol is the

A) Dispersed phase
B) Continuous phase
C) Emulsifier
D) Hydrophilic protein
E) Protein.

Answer 3

A

Question 4

.Water drops tend to draw up into a flattened ball because of

A) Water vapor
B) Evaporation
C) Surface tension
D) Atmospheric pressure
E) Heat energy

Question 5

French fries brown gradually during frying because of

A) Absorption of water
B) Cooling on the surface due to vaporization of water
C) Lack of sugar in the potatoes
D) Removal of the potato skins
E) None of these

Question 6

A thickened starch mixture that no longer flows is called a

A) Gel
B) Coagulum
C) Gum
D) Precipitate
E) Sol

Question 7

Microwaves heat food by

A) Radiant heat
B) Visible energy
C) Vibration of water molecules due to their occurring as dipoles
D) Surface heating
E) None of these

Question 8

When water is heated in a pan on a surface unit, the pan is heated by

A) Irradiation
B) Visible energy
C) Vibration of water molecules due to their occurring as dipoles
D) Conduction
E) None of these

Question 9

Standing time is needed for some foods cooked by microwave energy. This allows the food to continue cooking by

A) Conduction
B) Convection
C) Microwave energy
D) Radiation
E) None of these

Question 10

The type of wave used for irradiating food is

A) Alpha
B) Irridon
C) Delta
D) Gamma
E) None of these

Question 11

The pressure exerted as molecules of a compound attempt to be in the gaseous state instead of the liquid state is called

A) Atmospheric pressure
B) Boiling point
C) Interfacial tension
D) Surface tension
E) Vapor pressure

Question 12

Colloidal dispersions are stabilized by all the following except:

A) Antioxidants
B) Brownian movement
C) Electric charges
D) Water of hydration
E) A and b

Question 13

Microwaves heat food by

A) Radiant heat
B) Visible energy
C) Vibration of water molecules due to their occurring as dipoles
D) Surface heating
E) None of the above

Question 14

For an emulsifying agent to be effective it must be

A) Attracted only to water
B) Attracted only to oil
C) Attracted to both water and oil
D) A fat
E) None of these.

Question 15

An emulsion is an example of a

A) True solution
B) Coarse suspension
C) Colloidal dispersion
D) Foam
E) Protein-protein interface.

Question 16

The cooking method in which heat is generated within the food and then conducted toward the surface and other areas is

A) Irradiation
B) Microwaving
C) Broiling
D) Roasting
E) Drying

Question 17

A major drawback of microwave cookery is

A) Lack of surface browning
B) Lack of flavor
C) Dehydration
D) Burning
E) Scorching

Question 18

A thickened starch mixture that has flow properties is called a

A) Gel
B) Coagulum
C) Gum
D) Precipitate
E) Sol

Question 19

When water is heated in a pan on a surface unit, the water is heated by

A) Irradiation
B) Convection
C) Conduction
D) A and c
E) B and c

Question 20

Bread baking in an oven is heated by

A) Irradiation
B) Convection
C) Conduction
D) B and c
E) None of these

Question 21

Like charges repel and thus help to stabilize colloidal dispersions.

Question 22

An example of a water-in-oil emulsion would be

A) Butter
B) Cake batter
C) Ice cream
D) Mayonnaise
E) White sauce

Question 23

Radiant energy of very short wavelength capable of penetrating food, but not lead is called:

A) Beta ray
B) Gamma ray
C) Electromagnetic waves
D) Irradiation
E) Microwave

Question 24

Low surface tension is necessary for a liquid to spread out to form the
continuous phase of a foam.

Question 25

Movement of a food component into or out of a food that is being heated is referred to as:

A) Mass transfer
B) Endothermic Reaction
C) Glassy state
D) Induction cooking
E) Glass transition

Question 26

A supersaturated solution exists when a sugar solution is heated to the
boiling point.

Question 27

A sol is a dispersion of a solid in a liquid, whereas a gel is a dispersion of
a liquid in a solid.

Question 28

Substances that do not flow under moderate stress:

A) Amorphous
B) Sol
C) Gel
D) Solid
E) Gas

Question 29

Very hot materials that are glowing a deep red are emitting some radiant
energy.

Question 30

Clumping of dried milk can be reduced by controlling glass transition
temperature during drying.

Question 31

How many people, worldwide, are cooking indoors over fires fueled by firewood or dung?

A) 1 billion
B) 2 billion
C) 3 billion
D) 4 billion
E) 5 billion

Question 32

The surface active agent in a foam is

A) Carbohydrates
B) Fats
C) Proteins
D) Sugar
E) Egg yolk

Question 33

An emulsion is a dispersion of a solid in a liquid, whereas a foam is a
dispersion of a gas in a liquid.

Question 34

Sols and gels are classified as colloidal systems.

Question 35

Which of the following is not true about emulsifiers?

A) They are added in both oil-in-water and water-in-oil emulsions
B) Emulsifiers are concentrated to form a tight film around the suspended globules
C) The hydrophilic portion of the emulsifier is oriented toward the oil and the hydrophobic portion is oriented toward the water
D) They aid emulsion formation and increase the emulsion stability
E) They decrease the surface tension of one liquid more than the other

Question 36

The waves used to irradiate food are the same waves as are produced in a
microwave oven.

Question 37

Form of solid lacking an organized, crystalline structure.

A) Crystalline
B) Amorphous
C) Sol
D) Gel
E) Coagulate

Question 38

Syneresis is the weeping of water from a foam or gel.

Question 39

The circulation or convection of the heated material is the natural result of its:

A) Increased density
B) Transfer energy
C) Reduced density
D) Increased density
E) Mass transfer

Question 40

The attraction between molecules at the surface of a liquid is:

A) Evaporation
B) Vapor pressure
C) Glass transition
D) Surface tension
E) Endothermic Reaction

Question 41

Using the three states of matter in your answer, distinguish among a sol, a gel, an emulsion, and foam.

Question 42

Explain the terms hydrophilic and hydrophobic as they relate to emusifiers.

Question 43

Using the candy lab experience, explain the concept of supersaturation and what happens in this state.

Question 44

Explain what is happening to the colloidal dispersion when tomato juice is added to milk in making tomato soup.

Question 45

Describe the colloidal structure (from a dispersion standpoint including each ingredient) of the following food systems:

Question 46

Describe the factors that stabilize a colloidal dispersion.

Question 47

Distinguish between:

Question 48

A change of state from water to steam has no effect on the volume of
batters and doughs when they are being baked or fried.

Question 49

Explain how an emulsifier or a foaming agent works to stabilize an emulsion or a foam.