Food Safety II

Question 1

Clostridium bolulinum (botulism)
Infection or intoxication?
Bacteria, virus or protozoa?
How does organism get on food?
Aerobic, anaerobic or facultative anaerobic?

Answer 1

Found in animal and fish intestines. Also soil. Assumed present in all foods.
Spores are heat resistant.
Intoxication-Toxin can be destroyed by heat
Anaerobic
Control w pH<4.6, heat, canning, nitrites

Question 2

Staphylococcus aureus  (Staph)
Infection or intoxication?
Bacteria, virus or protozoa?
How does organism get on food?
Aerobic, anaerobic or facultative anaerobic?

Answer 2

Found on humans and animals. Nasal passages and genitals. Also on skin
Intoxication -

Question 3

What is a chemical hazard?

Answer 3

Toxic substance or other substance that renders food unsafe for consumption

Question 4

What is classified as a chemical hazard?

Answer 4

Natural toxins - mushrooms, shellfish,

Microbial toxins - fish, molds from grain, nuts, cottonseed and other plants

Question 5

List all 8 major allergens

Answer 5

Milk - Eggs - Peanuts - Tree nuts

Soy - Wheat - Fish - Shellfish

Question 6

What percentage of food allergic reactions are caused by the 8 major food allergens?

Answer 6

90%

Question 7

Describe water activity in simplified terms

Answer 7

Measure of how tightly water is structurally or chemically bound within food product.
NOT moisture content

Question 8

What is the abbreviation for water activity?

Answer 8

W

Question 9

Water activity of 0.85 means what for the food product?

Answer 9

It is shelf-stable and does NOT require refrigeration.

Staph is controlled. Food can still spoil due to microbes but pathogens controlled

Question 10

How is water activity controlled?

Answer 10

• Dehydration Remove moisture Pasta, jerky, cereal bars
• Bind water chemically. Add salt or sugar
  i. e. pickling products

Question 11

What are the upper and lower limits of the pH scale?

Answer 11

Acid 0————————14 Alkaline

Question 12

For each unit change in pH, what is the change in hydrogen concentration or how many times more acidic is it?

Answer 12

Log scale (base 10)
pH of 6.0 has 10x hydrogen ions present at 7.0    5.0 has 100x compared to 70 (10x10)

Question 13

Why is pH important? What is the significance of 4.6 pH for food safety?

Answer 13

Affects
- food safety - product development
- shelf life - affects taste Acid-sour
<4.6pH is shelf stable

Question 14

Why are yeast and molds a concern for acid and acidified products?

Answer 14

Can and will grow on acid/acidified foods at pH around 2.0

Will consume acids and raise pH to levels where C. botulinum germinates