Deck 7: Vegetables and Fruit

Question 1

To maintain high quality, potatoes should be stored:

A) At room temperature
B) In cold storage
C) In crisper unit of refrigerator
D) In a moist place
E) Any of the above.

Answer 1

A

Question 2

Plant tissue becomes mushy when treated with alkali due to the breakdown of :

A) Cellulose
B) Cell wall
C) Hemicellulose
D) Lignin
E) Pectin

Answer 2

C

Question 3

When cooked in an alkaline medium, anthocyanins become more

A) Bleached
B) Blue
C) Green
D) Orange
E) Red

Answer 3

B

Question 4

The unique texture of pears is due to:

A) Sclereid cells
B) Parenchyma cells
C) Collenchyma cells
D) Vacuoles
E) Middle lamella

Question 5

Carbohydrate gums for use in food products are obtained from:

A) Seeds
B) Plant exudates
C) Seaweed extracts
D) Microorganisms
E) All of the above

Question 6

When cooked in an acidic medium, anthoxanthins become more:

A) White
B) Blue
C) Red
D) Orange
E) Yellow

Question 7

Which of the following does not happen when cooking vegetables?

A)Acids are released
B) Cells separate, and texture becomes softer
C) Loss of water and turgor occur
D) Starch is gelatinized
E) Sugars increase as starch decreases

Question 8

Pectic substances are in the middle lamella between parenchyma cells.

Question 9

As fruit ripens, the pectic substances undergo the following sequence of changes:

A) Protopectin, pectin, pectinic acid
B) Pectic acid, protopectin, pectinic acid
C) Protopectin, pectinic acid, pecturonic acid
D) Protopectin, pectin, pectic acid
E) Pectic acid, pectin, protopectin.

Question 10

Chlorophyll and carotenoid pigments are found in the plastids in which part of the plant cell:

A) Cell sap
B) Cell wall
C) Cytoplasm
D) Nucleus
E) Vacuoles

Question 11

T or F It is impossible to convert anthoxanthins to anthocyanins by adding acid.

Question 12

Which of the following does not occur when fruit ripens?

A) Flavor becomes more tart and astringent
B) Organic acids decrease and change
C) Pectin changes to water soluble form, causing a softening of texture
D) Starch is converted to sugar
E) None of the above

Question 13

The precursor of the typical flavor of garlic is:

A) Sinigrin
B) Disulfide
C) Alliin
D) Hydrogen sulfide
E) Carbonic acid

Question 14

When cooked in an acidic medium, anthocyanins become more:

A) Bleached
B) Blue
C) White
D) Orange
E) Red

Question 15

Vegetable gums are used in foods to

A) Act as a bulking agent
B)Give body
C) Stabilize
D) Thicken
E) All of the above

Question 16

The color change that occurs when chlorophyll is heated in an acidic medium is caused when the magnesium ion is replaced by hydrogen.

Question 17

For enzymatic browning to take place, the following substances are needed:

A) Enzyme
B) Oxygen
C) Substrate
D) All of the above ,
E) 1 and 2

Question 18

Ethylene gas may be used in the home to speed ripening of fruit by:

A) Decreasing carbon dioxide in the atmosphere
B) Decreasing the oxygen content in which fruit is stored
C) Placing the fruit in a paper bag or other closed container
D) Storing the fruit in a high humidity condition
E) Storing fruit at a low temperature

Question 19

The strings in celery are composed of:

A) Parenchyma cells
B) Collenchyma cells
C) Plastids
D) Chromoplasts
E) Vacuoles

Question 20

Protopectin in the immature plant is converted to the gel former

A) Gelatin
B) Pectic acid
C) Pectin
D) Protein
E) None of the above

Question 21

Sulfur compounds are responsible for flavors in garlic and cabbage.

Question 22

You conducted an experiment on the effect of the form of sweetener on fruit texture with the objective measurement of cooking time. The heavy syrup variation is expected to cook in the shortest time, followed by the thin syrup variation, and then the control (no sugar). Using the terms nonvolatile, non-ionizing solute, explain these results. Then imagine that salt was substituted for sugar, and using the term nonvolatile, ionizing solute, explain these results.

Question 23

In making a fresh fruit salad, how would enzymatic browning be prevented naturally
(by the use of certain key fruits)?

Question 24

List five uses of gums.

Question 25

An increase in the number of hydroxyl groups on the right ring on anthocyanins shifts the color from red to blue.

Question 26

Propenylsulfenic acid makes us "cry" when chopping onions.

Question 27

A decrease in pH such as adding cream of tartar to cooking water prevents darkening of potatoes.

Question 28

Distinguish between:
e.g., bananas and tomatoes. Nonclimateric fruit does not ripen after picking. It needs to be harvested when ripe;
e.g., grapes and oranges.
Mealy and waxy potatoes - [Mealy potatoes are characterized by large starch granules, have a high specific gravity, a high starch content, and are best used for baking, mashing, and frying. Waxy potatoes have smaller starch granules and starch content, a wet, pasty feel, and are suitable for boiled or scalloped potatoes.]
Anthocyanins and anthoxanthins - [Both are flavonoid, ring compounds. Anthocyanins are reddish-blue, whereas anthoxanthins are white.]
Pheophytin and chlorophyllin - [Both are forms of the chlorophyll pigment. Pheophytin is formed by the reaction with acid and the loss of the magnesium from the center of the molecule. It is an olive green color. Chlorophyllin is formed with the reaction with alkali and the loss of the phytyl and methyl group. This is a "nonfood green."]
Protopectin and pectin - [Both are forms of pectic substances. Protopectin is found in underripe fruit, is a large molecule, is methylated, and yields firm fruit. Pectin
is a gel former, a large molecule, partially methylated, found in ripe fruit.]

Question 29

Explain why one can tell if onions have been cooking the moment you walk in the door.

Question 30

Acid causes a mushy texture in cooked vegetables plus a loss of nutrients.

Question 31

Pectic substances are classified as insoluble fiber.

Question 32

The edible part of the plant cell is the parenchyma cells.

Question 33

A German dish uses red cabbage and apples, in a sweet-sour sauce. Why are these ingredients beneficial in combination?

Question 34

Cold storage of potatoes causes an accumulation of starch and yields high quality potato chips.

Question 35

Inulin is a fructooligosaccharide that sometimes is added to foods to improve mouthfeel and increase fiber content.

Question 36

An acid medium greatly accelerates softening.

Question 37

A consumer states that she/he always adds a touch of baking soda when cooking green beans in order to preserve the nice green color. What are three dangers in doing this?

Question 38

Plant gums are classified as soluble fiber.

Question 39

Citric acid prevents browning in potatoes by lowering pH and also ties up iron to prevent bluish-grey discoloration.

Question 40

The main constituent of plant cells is carbohydrate.