Food Preservation and Spoilage

Question 1

Food spoilage results from…

Answer 1

The growth of microbes in food which alter the food visibility and renders it unsuitable for consumption

Question 2

Microbial growth is controlled by… (2)

Answer 2

1. Intrinsic Factors

2. Extrinsic Factors

Question 3

Factors that are related to the food itself

Answer 3

Intrinsic Factors

Question 4

Factors that are effected by the environment in which they are stored

Answer 4

Extrinsic Factors

Question 5

Intrinsic factors for carbohydrates

Answer 5

• Mold predominates
• Degrades food by hydrolysis
• Little odor
• Ergotism

Question 6

What is ergotism?

Answer 6

• Hallucinogenic alkaloids released by Claviceps purpurea

- May cause death

Question 7

Intrinsic Factors of Fats and Proteins. What dominates?

Answer 7

-Bacterial growth predominates

-

Question 8

What are the 3 types of Bacterial growth in Proteins or Fats?

Answer 8

1. Putrefaction
2. Unpasteurized Milk Spoilage
3. Butter

Question 9

• Proteolysis and anaerobic breakdown of proteins

- Foul smelling amine compounds

Answer 9

Putrefaction

Question 10

Acid production followed by putrefaction

Answer 10

Unpasteurized milk spoilage

Question 11

Short chained fatty acid production

Ex. Rancid Butter

Answer 11

Butter

Question 12

What are other intrinsic factors?

Answer 12

1. pH
2. Water availability
3. Physical Structure

Question 13

• Impacts make up of microbial community and therefore types of chemical reactions that occur when microbes grow in food
• Ex. Low levels of this favor yeast and mold

Answer 13

pH

Question 14

Lower water activity (promotes/inhibits) microbial growth?

Answer 14

Inhibits

Question 15

Grinding, mixing, and distributing of microbes (promotes/inhibits) microbial growth?

Answer 15

Promotes

Question 16

The outer skin of fruits and vegetables (promotes/inhibits) microbial growth?

Answer 16

Inhibits

Question 17

What are examples of antimicrobial substances? (5)

Answer 17

1. Coumarins
2. Lysozyme
3. Aldehydic and phenolic compounds
4. Allicin
5. Polyphenols

Question 18

Examples of extrinsic factors (3)

Answer 18

1. Temperature
2. Relative humidity
3. Atmosphere

Question 19

Temperatures effect on growth…

Answer 19

Lower temperatures retard microbial growth

Question 20

Relative humidity effect on growth…

Answer 20

Higher relative humidity promote microbial growth

Question 21

How does the atmosphere effect growth…

Answer 21

-Oxygen promotes growth

Question 22

Use of shrink wrap and vacuum technologies to package food in controlled atmospheres

Answer 22

Modified Atmosphere Packaging

Question 23

Methods for controlling Food Spoilage (6)

Answer 23

1. Filtration
2. Low Temperature
3. Pasteurization
4. Water Availability
5. Chemical based preservation
6. Radiation

Question 24

What is the goal of preservation?

Answer 24

To eliminate or reduce the populations of spoilage and disease causing microbes while maintaining food quality

Question 25

Refrigeration's effect on growth?

Answer 25

5 degrees retards but does not stop microbial growth, microorganisms can still cause spoilage with extended storage

Question 26

- This method kills most human pathogens and substantially reduces the number of spoilage of organisms - Shorter heating times results in improved flavor

Answer 26

Pasteurization

Question 27

Type of chemical based preservation

Answer 27

- GRAS "Generally recognized as safe" | - agents include organic acids, sulfite, ethylene oxide gas, ethyl formate, sodium nitrate

Question 28

Use of ionizing radiation (gamma radiation) to extend shelf life of sterilized meat, seafoods, fruits, and veggies -excellent penetrating power

Answer 28

Radiation

Question 29

2 major types of Food Borne Diseases

Answer 29

1. Food born infections | 2. Food intoxications

Question 30

How are food borne diseases transmitted?

Answer 30

1. Breakdown in hygiene 2. Fecal-oral route is key 3. Fomites also important

Question 31

Life pathway of food borne diseases (4)

Answer 31

1. Ingestion of pathogen 2. Growth of pathogen 3. Tissue invasion 4. Release of toxins

Question 32

Characteristics of food borne intoxications

Answer 32

1. Ingestion of food in which microbe have been growing | 2. Produce symptoms shortly after the food has been consumed

Question 33

Enterohemorrhagic E. coli disease characteristics

Answer 33

1. Normal inhabitant of the intestines | 2. Contamination of meat during slaughter