Unit 5: Food Safety

Question 1

How safe is food in Canada?

Answer 1

one of the safest food supplies in the world

4million Canadians still get sick every year from contaminated foods

Question 2

hazard

Answer 2

o Anything that has potential to cause harm
o Hazards all around us but most are not considered risky
o Ex: rood could collapse but we live under roofs

Question 3

risk

Answer 3

o Likelihood that a hazard will occur and the severity of harm it will cause if it occurs
o Risk= exposure x harm intensity

Question 4

Types of Hazards in Foods

Answer 4

Physical
chemical
biological

Question 5

Physical Hazards

Answer 5

 Ex: fish you are eating has a piece of glass

 Type of harm is physical injury or contamination

Question 6

Chemical hazards

Answer 6

 type of harm: toxicity to organs and tissues

 in our food because…

1. naturally occurring chemical in food
2. additive
   o chemical intentionally added to the food to enhance the quality of the food
3. adulterants
   o chemicals added to deceive consumers is a criminal offence in Canada
4. Residue
   o Chemicals that are asses at stages of food processing but are not intended to be a part of food
   o Ex: pesticide and agricultural chemical residue

5.
• Contaminants
o Chemical’s food was not supposed to be exposed to

Question 7

Biological Hazards

Answer 7

	are
•	bacteria
      o	may not have taste, affect appearance, or smell
•	fungi (molds and yeast)
•	Viruses
•	Prions
•	Parasites

 foodborne illness
• is food with disease- causing microbes can cause foodborne illnesses
• some are probiotics
• 4 million Canadians a year 60% from restraunts
• Affects people with weaker immune systems more ( infants, elderly, pregnant)
- only 4% of bacteria is disease causing

Question 8

Food-borne Illnesses Classifications

Answer 8

• Infections

• Intoxication
o Toxins present in food
o Symptoms after 24 hours

• Toxin induced (or medicated) infections
o Microbes produce toxins in the gut
o Symptoms take 24-72 hours or longer to appear

Question 9

Water Activity (Aw)

Answer 9

o Is the rate of vapor pressure of food
o Harmful bacteria needs at least 0.90 Aw but some can grow at 0.86
o Fungi can grow up to 0.70
o Below 0.60 Aw no microbial growth occurs

Question 10

Potential of hydrogen ions

Answer 10

o 7 is neutral below 7 is acidic and higher is alkaline
o Microorganisms grow better at a pH close to 7
 few can grow at pH below 4

 4.6 pH is used as a limit for food classification
• Low acidity if greater than 4.6
• High acidity if lower than 4.6
o Fungi can grow at pH range of 2-11

Question 11

temperature danger zone

Answer 11

4 C to 60C

Question 12

Psychrophiles

Answer 12

• Grow well at 7C or below and have optimal temperature range of 20-30C

Question 13

Mesophiles

Answer 13

• Grow well between 20 and 45C and have optimal growth at temperature 30-40C

Question 14

Thermophiles

Answer 14

• Grow well 45 C are higher and have optimal growth at 55-65C

Question 15

Aerobes

Answer 15

 Cannot grow without oxygen

Question 16

anaerobes

Answer 16

 Cannot grow in presence of oxygen

Question 17

facultative anaerobes

Answer 17

 Can grow without presence of oxygen but grow best with oxygen

Question 18

facultative aerobes

Answer 18

 Grow better in with no oxygen but can grow with presence of oxygen

Question 19

Chemotrops

Answer 19

o Get energy from chemicals

o May get food from carbs, fats, and proteins

Question 20

Autotrops

Answer 20

o produce food from carbon dioxide

Question 21

how food structure leads to bacteria growth

Answer 21

o More ground the food the higher the surface area

o Higher the surface area the more exposure to air and contaminants

Question 22

Potentially hazardous foods

Answer 22

o Foods that support bacterial growth because they are rich in protein