Deck 3: Chemistry of Food Composition

Question 1

A process in which colloid particles come out of suspension and solidify is called

A) suspension.
B) flocculation.
C) ionization.
D) salt formation.
E) None of these are correct.

Answer 1

B

Question 2

How does increasing elevation affect the boiling point of water?

A) It decreases the boiling point of water.
B) It doubles the boiling point of water.
C) It triples the boiling point of water.
D) It does not affect the boiling point of water.

Answer 2

A

Question 3

The amount of energy in calories per gram that is absorbed or emitted as a substance undergoes a change from a solid to a liquid or gas is called

A) latent heat.
B) specific heat.
C) melting point.
D) heat of vaporization.
E) heat of solidification.

Answer 3

A

Question 4

Organic materials are those that contain

A) magnesium.
B) carbon.
C) molybdenum.
D) selenium.

Question 5

The primary six-carbon monosaccharides in foods are

A) sucrose, maltose, and lactose.
B) sucrose, glucose, and galactose.
C) glucose, raffinose, and sucrose.
D) glucose, fructose, and galactose.
E) lactose, stachyose, and raffinose.

Question 6

Which of the following foods contains the lowest percentage of water?

A) butter
B) peanut butter
C) Swiss cheese
D) baked potato
E) cooked hamburger

Question 7

In addition to eating foods and drinking fluids, water balance is maintained by

A) metabolic processes.
B) elimination.
C) tears.
D) sneezing.

Question 8

As free water within a food decreases,

A) so does water activity.
B) water activity increases.
C) water activity remains constant.
D) bacterial growth increases as a result.

Question 9

The human body averages _____% water.

A) 20 to 40
B) 40 to 50
C) 50 to 60
D) 60 to 70

Question 10

The caloric contribution of foods is dependent on the amounts of proteins, fats, carbohydrates, and alcohol in the food. Protein provides _____ kcal/g, fats provide _____, carbohydrates provide _____, and alcohol provides _____.

A) 4, 4, 9, 7
B) 7, 9, 6, 10
C) 4, 7, 9, 10
D) 4, 9, 4, 7

Question 11

The smallest proportion of nutrients in the human body is comprised of

A) water.
B) fat.
C) minerals.
D) protein.

Question 12

A pressure cooker speeds up heating time by _____.

A) decreasing atmospheric pressure to 5 pounds
B) decreasing the boiling point by 10 degrees
C) increasing atmospheric pressure to 15 pounds
D) increasing the boiling point by 20 degrees

Question 13

All living things contain six key elements (or atoms). Which element is not part of this list?

A) carbon
B) nitrogen
C) hydrogen
D) helium
E) phosphorus
F) sulfur

Question 14

Hard water contains a greater concentration of calcium and magnesium compounds, whereas soft water has a higher _____ concentration.

A) sodium
B) potassium
C) chloride
D) copper

Question 15

All foods consist of one or more of six basic nutrient groups that include

A) water, amino acids, fatty acids, sugars, vitamins, and minerals.
B) proteins, fats, and carbohydrates.
C) water, proteins, carbohydrates, and lipids.
D) proteins, vitamins, minerals, fatty acids, and amino acids.
E) water, carbohydrates, proteins, lipids, vitamins, and minerals.

Question 16

Which of the following food items is an example of a suspension?

A) milk
B) egg yolk
C) cornstarch mixed in water
D) oil mixed with vinegar
E) ice cream

Question 17

Losing as little as ____% water can result in death.

A) 1
B) 0.1
C) 5
D) 10
E) 15

Question 18

Which of the following substances is/are not used in the food industry to reduce a food's water activity (aw) level?

A) salt and sugar
B) glycerol
C) propylene glycol
D) modified corn syrups
E) All of these substances are used by the food industry for this purpose.

Question 19

Which of the following is not an example of hydrolysis?

A) Hydrolysis of glucose to sucrose and maltose
B) Hydrolysis of maltose to two glucose molecules
C) Hydrolysis of cornstarch to yield corn syrup
D) Hydrolysis of table sugar to another sugar helpful in the manufacture of candy

Question 20

Which of the following food items is/are not a colloidal dispersion?

A) salad dressings
B) jam, gelatin, cheese, and butter
C) whipped egg white and whipped cream foams
D) marshmallows
E) All of these are colloidal dispersions.

Question 21

The definition of protein complementation is

A) an increase in the effectiveness of two complete proteins when combined.
B) the combination of two incomplete protein foods to yield a complete protein profile.
C) any combination of nonessential amino acids that makes a complete protein.
D) the supplementation of the diet with a complete protein source.

Question 22

As plants like celery and carrots mature, their cell walls increase in _____ concentration, resulting in a tough, stringy texture.

A) cellulose
B) gums
C) hemicellulose
D) lignin
E) pectin
F) All of these are correct.

Question 23

Starch is a polysaccharide that does provide energy to the body.

Question 24

All of the following foods are made up of mostly unsaturated fatty acids except

A) avocado.
B) chocolate.
C) peanuts.
D) olives.
E) canola oil.

Question 25

The difference between fats and oils is based on

A) solubility in water and melting temperature.
B) consistency (liquid or solid) at room temperature and source.
C) the fatty acid content and the percentage of unsaturates.
D) the number of unsaturated bonds and the alcohol to which they are attached.

Question 26

Which of the following foods has been fortified?

A) salt with iodine
B) milk with vitamins A and D
C) orange juice with calcium
D) cereals with folate
E) All of these are correct.

Question 27

All of the following are fat-soluble vitamins except

A) vitamin A.
B) vitamin B6.
C) vitamin E.
D) vitamin D.
E) vitamin K.
F) All of these are fat-soluble vitamins.

Question 28

Proteins are unique from the other macronutrients because the molecular structure of protein includes

A) hydrogen.
B) carbon.
C) oxygen.
D) nitrogen.

Question 29

The most important of all the nutrients is water.

Question 30

All of the following polysaccharides are indigestible except

A) inulin.
B) pectin.
C) amylopectin.
D) cellulose.

Question 31

All compounds are minerals, but not all minerals are compounds.

Question 32

What is the source of the gum carrageenan?

A) plant fibers
B) plant exudates
C) seeds
D) seaweed

Question 33

Which process is the proper representation of photosynthesis?

A) carbon + water + sun energy + glucose + oxygen
B) carbon dioxide + hydrogen + sun energy + glucose + oxygen
C) carbon dioxide + water + sun energy + glucose + oxygen
D) carbon dioxide + water + nitrogen + nitrogen dioxide + glucose

Question 34

The two essential fatty acids are

A) butyric and histidine.
B) linoleic and linolenic.
C) leucine and isoleucine.
D) threonine and tryptophan.

Question 35

Which of the following foods is/are a plant source that is primarily made up of saturated fatty acids?

A) avocados
B) coconuts and coconut oil
C) olives and olive oil
D) peanuts and peanut butter

Question 36

Meats can be tenderized with all of the following enzymes except

A) papain.
B) bromelain.
C) ficin.
D) rennin.

Question 37

All of the following are essential amino acids for humans except

A) isoleucine.
B) tryptophan.
C) cysteine.
D) lysine.
E) All of these are essential amino acids.

Question 38

Which of the following proteins is classified as incomplete?

A) amaranth
B) quinoa
C) soybeans
D) wheat berries

Question 39

Triglycerides consist of three fatty acids attached to a _______ molecule.

A) water
B) glycogen
C) glucose
D) glycerol
E) carbon dioxide

Question 40

The nutrient content of a food is related to the water activity of the food.

Question 41

What makes water so important to humans? Discuss not only the nutritional functions of water but also the function of water in food preservation and preparation.

Question 42

Explain how a person who follows a predominantly vegetarian diet can ensure that he or she is obtaining all of the important, essential amino acids and complete protein without eating animal foods. Give examples of foods that should be included in the diet to fill any potential nutrient gaps.

Question 44

Among the beneficial compounds naturally found in foods are those that provide calories and flavor.

Question 45

Discuss the following functions of proteins in foods: hydration, denaturation/coagulation, enzymatic reactions, buffering, and browning. What are the differences among a complete, an incomplete, and a complementary protein food?

Question 46

Approximately 95% of all food lipids are sterols.

Question 47

Discuss lipid composition and how fatty acid structure influences the application of fats from both a health and culinary standpoint. Discuss cis , trans , and omega-three fatty acids. What is a phospholipid? What component in fats allows hydrophilic and hydrophobic compounds to mix? Why is this food ingredient so important in the kitchen?

Question 48

Why do some vegetables like celery and carrots get tougher as they age? Why don't they get soft even when they are boiled in water?

Question 49

You are in the process of beginning to make a fresh fruit cobbler and cutting up the fruits. The phone rings and you proceed to talk for about 45 minutes. When you return to your preparation area your fruit has begun to turn brownish in color. What may have happened? Why do pears, apples, or bananas turn brown when cut into and then allowed to sit? What could you have done to prevent or reduce this browning?

Question 50

The presence of a broad spectrum of colors in food makes it more appetizing.

Question 51

Fiber is a polysaccharide that does not provide energy to the body.

Question 52

Food appeal can be improved by the addition of coloring, flavoring, and texture-enhancing agents.

Question 53

Most of the incomplete proteins come from animals; exceptions are those from soybeans and certain grains.

Question 54

What foods are high in saturated fats? Discuss the classification of saturated fatty acids and what sorts of unsaturated fatty acid containing foods could be used in the diet to replace saturated fatty acids.

Question 55

Discuss the importance of understanding the roles of water activity (aw), osmosis, and osmotic pressure in food preservation.

Question 56

Discuss the differences and similarities between soluble and insoluble fibers. What benefits do these functional fibers provide from a nutritional/health standpoint and what properties do they contribute to food processing? Be sure to include cellulose, hemicellulose, pectic substances, gums, inulin, and lignin in your discussion.