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Lectures term

34 important questions on Lectures term

Explain the following letters: n, c, m

n = the number of sampling units from the lot
c = the maximum allowance number of sample units that exceed the microbiological criterion
m = the maximum number or level of relevant bacteria

How can you make a plan more stringent?

1. Increasing number of unit (n)
2. Reducing the maximum allowance number (c)

Where is the 3 class plan used for?

Used to designate acceptible/ marginally acceptible and unacceptible food.

What is the cause of increasing food poisoning?

1. More intensive methods of rearing animals
2. Unsafe animal feed
3. (Partly) cooked products

What is going wrong on the consumer side?

1. Consumers don't want addetives anymore
2. Less cooking skills
3. Increased processed food consumption
4. Increased take away consumption
5. Miss use of equipment like a microwave
6. Different types of food are eaten

What causes a seemingly increase?

1. More awareness
2. Media
3. Increased reporting

What are examples of chemical contamination?

- Antibiotics
- Incorrect storage of cleaning chemicals
- Miss use of cleaning chemicals
- Pesticides
- Fraud
- Deliberate

Which metals can cause food poisoning?

- Copper
- Lead
- Tin
- Iron
- Zinc

Which fish types can contain scrombotoxin?

- Mackerel
- Tuna
- Sardines

Which two types poisoning can shell fish cause?

Paralytic poisoning and diarrhetic. Mussels can be contaminated from neurotoxins by eating contaminated plankton.

Which micro-organisms can contaminate a product?

- Viruses
- Spoilage bacteria
- Pathogenic bacteria

What is the source of Salmonella?

It comes from the gut and excreta of animals.

What are the characteristics of Salmonella?

- Dormant when in fridge
- Relatively takes many to cause infection

What are the symptoms of Salmonella?

- Incubation period is 12 to 72 hours
- Symptoms: fever, diarrhoea, vomiting and abdominal pain
- Infections are most of the time mild, but sometimes severe and can cause death
- Symptoms may stay for 7 days

Staphylococcus aureus (source)

Skin/ in the nose/ unpasteurised milk

Bacillus cereus (source)

- Soil and dust
- Cooked foods subjected to inadequete post-cooking temperature control

Bacillus cereus (characteristics)

Spores survive cooking, if kept warm until consumption or not cooled at low temperture then spores germinate forming new bacteria and make more heat-resistant toxin.

Bacillus cereus (symptoms)

Incubation time is 1 to 5 hours. Symptoms include nausea, vomiting, diarrhoea and abdominal pain. Can appear very sudden but is over really quickly and unlikely to be fatal.

E.coli (source)

Bowels of animals and humans.E.coli type 0157 is dangerous. It produces verocytotoxins. In raw meat, unpasteurised milk, dairy, raw vegetables.

E.coli (characteristics)

Infective dose is low.

E.coli (symptoms)

Incubation period 1-6 days. Diarrhoea, kidney failure, sometimes death.

Clostridium perfringes (source)

Soil, excreta, raw meat, insects

Clostridium perfringes (characteristics)

Multiplies during long low heat cooking and during long cooling periods. Forms spores so if it is not immediatly consumed is must be quickly frozen to prevent germination of spores.

How are SRSV's spread?

By the feacal-oral route. Also by aerosols of projectile vomit and environmental contamination like by means of a toilet visit of from food or water.

What is the incubation period?

24-28 hours. It stays infectable another 48 hours when the symptoms are over.

What are sources of microbiological contamination?

- Raw foods
- People
- Pets and pests
- Air and dust
- Water
- Soil
- Food waste

What is direct contamination?

When raw food touches ready to eat food.

What is indirect contamination?

When liquid or juices from raw food drip into high risk products.

What are vehicles of contamination?

- Hands
- Work surfaces, containers, crockery and cutlery
- Utensils and equipment
- Any food contact surface that has not been cleaned properly

What is considered to be the danger zone?

5 to 63 degrees Celsius.

What are the 5 principles of microbial safety?

1 Micro-organisms in food
2 Pathogen micro-organisms in food
3 Heat inactivation of MO
4 Microbial safety of heat treated foods
5 Optimizing of heat treatment

What is the pH at which bacteria can't multiply but survive?

4,5

What is the minimal temperature for mesophiles and psycrotrophes to grow?

Mesophiles: >4
Psychrotrophes: <-4 and =-4

Which pathogens make toxins?

- Clostridium botulinum
- Bacillus cereus
- Staphylococcus aureus

The question on the page originate from the summary of the following study material:

Lectures term 4

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