Deck 17: Food Preservation

Question 1

Most vegetables are blanched before freezing to halt enzyme action.

Answer 1

True

Question 2

Freezer burn results from:

A) Improperly packaged product
B) Slow freezing rate
C) Sublimation of ice
D) A and C
E) All of the above

Answer 2

D

Question 3

Viscosity of a fruit juice to determine the pectin content and, therefore, the amount of sugar to add, is determined by

A) Linespread
B) Jelmeter
C) Percent sag
D) Syneresis
E) Texturometer

Answer 3

B

Question 4

The preservation achieved in jelly is due primarily to

A) High sugar concentration
B) Barely boiling the ingredients together
C) Peeling the fruit
D) Skimming off the foam during boiling
E) Adequate pectin

Question 5

Low-acid vegetables can be canned safely by:

A) Using a pressure canner
B) Using a steamer
C) Using a boiling water bath
D) Cutting the vegetables in small pieces
E) Adding soda

Question 6

Sublimation is the:

A) Destruction of microorganisms by heat during irradiation
B) Preservation of food by first freezing and then drying
C) Process that occurs during boiling
D) Transition from the frozen state directly to the gaseous state without becoming liquid
E) C and D

Question 7

Toxin from Clostridium botulinum is most likely to form in improperly processed canned:

A) Peaches
B) Sauerkraut
C) Beans
D) Tomatoes
E) Cranberries

Question 8

Jams and pickles, which rely on osmotic pressure and a low pH respectively, to destroy microorganisms also need to be processed by

A) Cold pack
B) Hot pack
C) Open kettle canning
D) Pressure canning
E) Water bath canning

Question 9

Killing of microorganisms during canning is dependent on:

A) Presence of calcium ions
B) Temperature reached
C) Time held at the highest temperature
D) A and B
E) B and C

Question 10

Kimchi is preserved because:

A) The high salt content kills bacteria
B) Fermentation creates too acidic an environment for harmful microorganisms,
C) Cool storage inhibits microorganisms
D) A, B, and C
E) None of these

Question 11

Freezing of emulsions causes:

A) No change
B) Thickening of the thawed product
C) Changes in flavor
D) A broken emulsion
E) None of these

Question 12

The rate of freezing is important when freezing meats because:

A) Large crystals that form during slow freezing promote greater drip loss
B) Large crystals that form during very rapid freezing promote greater drip loss
C) Spoilage is decreased with fast freezing
D) Spoilage is a problem with slow freezing
E) None of these

Question 13

All of the following are needed for jelly formation except:

A) Acid
B) Fat,
C) Juice
D) Pectin
E) Sugar

Question 14

Blanching is recommended before freezing:

A) Low-acid fruits
B) Vegetables
C) Meats
D) Orange juice
E) None of these

Question 15

To be canned in a water bath canner, a food needs to be:

A) Cut in small pieces
B) Processed with salt
C) pH 4.5 or lower
D) pH 5 to pH 6
E) pH 7 or higher

Question 16

Fruits and vegetables usually are blanched in preparation for freezing.

Question 17

The network for the gel structure of strawberry jam is provided by"

A) The berries
B) Acid
C) Sugar
D) Pectin
E) Gelatin

Question 18

Flat-sour spoilage in canned foods can be detected because of bulging
lids.

Question 19

The type of microorganism that can exist at the lowest moisture level is:

A) Bacteria
B) Virus
C) Mold
D) Microalgae
E) Nematode

Question 20

All microorganisms are destroyed on freezing.

Question 21

If a consumer asked you about canning home-grown tomatoes, what advice would you give?

Question 22

Ice crystals are larger and drip loss is greater with rapid freezing than with slow freezing.

Question 23

Cheeses that are frozen may become crumbly.

Question 24

Explain in layman's terms the process of canning peaches and green beans. This involves discussion of sterilization, acid vs. low acid products, raw vs. hot pack, water bath vs. pressure canning, storage time, cooking procedures.

Question 25

Thermal death times in canning are much shorter at high processing temperatures than at lower ones.

Question 26

Freezing egg whites presents no problems, but freezing egg yolks is another matter.
Why?

Question 27

You read a research article that states that frozen fish and poultry become rancid through oxidative rancidity faster than beef does. After studying fats and oxidative rancidity, explain the reasons for this.

Question 28

A consumer asks why she can't can green beans using a water bath canner. Explain this to her, making sure to include what bacteria need to grow and, therefore, how canning acts to preserve food; the two types of canning processes and how each functions to preserve food; the type of food that green beans are; and why it is unsafe to can green beans by water bath.

Question 29

The pH of a jelly mixture must be below 3.5 for gel formation.

Question 30

You are in the grocery store when a package of bright orange dried apricots catches your eye. Your friend, who is extremely health conscious and reads all the health magazines, says he would not eat those processed dried apricots. He buys his in the health food store.

Question 31

Mrs. Jones freezes peaches in a simple (plain) sugar syrup. The peaches that float to the top of the package are brown. Mrs. Jones wants to know why. What would you tell her? (Use specific terms, but translate to understandable language.) How could she have prevented it?

Question 32

Select one of the following foods and explain the problems associated with it on freezing and how to prevent them: mayonnaise, meringues, or starch-thickened mixture.

Question 33

The packaging material used on over-the-counter meats is acceptable for long-term freezer storage of meat.

Question 34

Explain in layman's terms the process of freezing peaches and green beans. This involves discussion of prevention of enzymatic browning, blanching, packaging, rate of freezing, storage time, thawing and cooking procedures.

Question 35

For each of the three major ingredients in jellies listed below identify one fact that elates it to making good quality jelly.

Question 36

In canning, either the hot or cold pack can be used. The cold pack fruits or vegetables tend to float above the bottom of the jar. What part of the plant cell structure causes this? [Intercellular air space.]

Question 37

Describe when the water bath canner and the pressure canner would be used.

Question 38

In canning, the innermost part of the food must reach the desired temperature for the canning procedure to be safe.

Question 39

Discuss optimal growth conditions for molds, yeasts, and bacteria in general terms.

Question 40

Dennis' mother fixes him a peanut butter and mayonnaise sandwich for his school lunch. She freezes it, takes it out, and puts it in his lunch box. Describe what the sandwich is like by lunch time?

Question 41

You are adding acid to either a pectin or starch mixture. If you add the acid at the beginning of the cooking process, what will happen to the pectin and starch and why?