Descriptive assessment of risks in meat products

Question 1

What are some of the main groups of meat products?

Answer 1

• Uncooked (raw), dried meat products
• Cooked, uncured meats
• Cooked, cured meats

Question 2

What are the considerations when thinking about the fate of microorganisms in meat products

Answer 2

• Contamination events during primary production, meat processing
• Whether processing includes a microbicidal step and if any survivors exist
• Whether post-microbiocidal step contamination can occur
• Identification of antimicrobial factors acting in the final product
• Whether conditions during storage and retail stages may enable growth of, or toxin production by, pathogens

Question 3

Which Antimicrobial factors are associated with fermented sausages

Answer 3

• Low pH (dry sausages 5.3-6; semi-dry with acidulants 4.8-5.2)
• Salt 3-5%
• Nitrites (~200 ppm)
• Starters/protective cultures (via competition, bacteriocins)
• Low aw value (dry 0.8-0.9, semi-dry 0.9-0.95)
• Smoke (on the surface)

Question 4

Name two halotolerant pathogens

Answer 4

Listeria monocytogenes

Staphylococcus aureus

Question 5

Which pathogen can survive fermentation and drying?

Answer 5

Trichinella

Question 6

Which pathogens cause problems in products with higher water activity?

Answer 6

L. monocytogenes, Salmonella and S. aureus

Question 7

Which pathogens cause problems in products with lower water activity?

Answer 7

S. aureus enterotoxin, aflatoxin B1 surface contaminated with toxigenic fungi

Question 8

Which Antimicrobial factors are associated with dry, raw meat products?

Answer 8

• Salt 5-11%
• Nitrites (optional)
• Low aw value (0.7-0.9)
• Smoke (on the surface)

Question 9

Which pathogen is a potential hazard in dry, raw meats?

Answer 9

Clostridium botulinum

Question 10

Which pathogens are hazardous in undercooked, uncured meats?

Answer 10

E. coli
Listeria monocytogenes
Salmonella
Parasites (Trichinella)

Question 11

What are the conditions required for the inactivation of most aerobic mesophilic bacteria?

Answer 11

72oC for 2 minutes

Question 12

Which antimicrobial factors are associated with roasted meats (Lightly cooked (pasteurized) uncured meats)

Answer 12

• Higher temperatures achieved only on the product’s surface (150-180oC), in the centre <100oC
• Slightly low natural pH (beef ~ 5.2-5.5)

Question 13

Which pathogen is hazardous with roasted meats (Lightly cooked (pasteurized) uncured meats)

Answer 13

Clostridium perfringens

Salmonella and L. monocytogenes – post-cooking cross-contamination

Question 14

Which antimicrobial factors are associated with self-stable uncured sterilized cans?

Answer 14

• High temperature, sterilisation - > 120oC, 20 minutes, high pressure
• salt 1-2%

Question 15

Which pathogens are hazardous with lightly cooked (pasteurized) or uncooked cured meat joints?

Answer 15

Listeria monocytogenes and S. aureus (halotolerant), % of salt and nitrites insufficient to prevent growth