Unit 5 : Food Safety Flashcards
What is a hazard and a risk ?
- Hazard: Anything that has a potential to cause harm
- Risk: A product of the likelihood that a hazard will occur
What type of hazards are there?
- Physical
- Chemical
- Biological
What are 5 ways that chemical hazards could occur ?
- Naturally occurring chemicals in foods
- Additives - intentionally added to enhance the quality
- Adulterants - intentionally added to deceive the consumers
- Residues - intentionally used at certain stage of food processing
- Contaminants - Unintentionally exposed
What are some examples of chemicals that are naturally present in foods?
- Solanine
- Glucosinolates
- Phytates
- Psoralens
What are some toxins that are produced while cooking and what foods are they found in ?
- Acrylamide - created when starch and amino acids asparagine combine , e.g bread
- Heterocyclic aromatic amines - produced by chemical reaction of amino acids at high temp with reducing sugars - found in well cooked meat
- Polycyclic aromatic hydrocarbons(PAHs) - dripping of meat fat onto the fire creates smoke which is PAHs
What are some examples of biological hazards?
- Bacteria
- Fungi
- Viruses
- Prions
- Parasites
Define infections , intoxications and toxin induced (or mediated infections
Infections:
- When microbes are ingested and they survive the acidic environment , they reach small intestine, once absorbed into blood they cause harm.
Intoxications:
- when microbes produce toxins in food, and such food is ingested , these toxin cause harm to our tissues and organs.
Toxin induced (or mediated) infections:
- When microbes are ingest with the food and produce toxins in our gut
How does water activity affect microbial growth ?
- all microbes require adequate available water for growth
- most harmful bacteria need at least 0.90 water activity
- Fungi can grow at 0.7 water activity
- below 0.6 water activity no microbial growth occurs
How does potential of hydrogen ions (pH) affect the microbial growth ?
- Most micro-organism grow better in pH values close to 7.0 but a few go can grow below 4.
- bacteria tend to be more sensitive to pH than fungi and yeasts
- Fungi and yeast can grow at much wider pH range , 2-11.
What are the four groups of microorganism according to their growth temperature domains and at what temperatures do they grow well and at what temperatures do they grow optimally ?
- Psychrophiles - grow well at 7°C or below and optimal at 0-10°C
- Mesophiles - grow well at 20-45°C and optimal at 30-40°C
- Thermophiles - grow well at 45°C and have optimal at 55-65 °C
- Psychrotrophs - grow well at psychrophillic conditions but optimal at mesophyllic conditions
At what temperature does bacteria grow the quickest or other wise known as the temperature danger zone ?
- 4°C to 60°C
What cells do microbes have that multiply when conditions are favourable to their growth ?
- vegetative cells
What do some microbes produce that can tolerate much harsher conditions and germinate when the conditions become favourable ?
- Spores ( dormant cells )
Name the different type of microbes according to their oxygen needs for microbial growth
- Obligate aerobes : they can’t grow in the absence oxygen
- Obligate anaerobes : they can’t grow in the presence oxygen
- Facultative anaerobes : they can grow in anaerobic environment but optimal in aerobic
- Facultative aerobes : they grow better in anaerobic environment but also can grow in aerobic environment
Define Chemotrophs and Autotrophs
- Chemotrophs : obtain their energy from chemicals
- Autotrophs : produce their own from food from CO2
Define fermentation
- its when chemotropic microbes breakdown carbs in the absence of oxygen
Define hydrolysis
- Its when chemotropic microbes breakdown lipids with the help of water
Define Putrefaction
- Its when chemotropic microbes breakdown proteins
Explain how the food structure can affect microbial growth
- The higher the surface area the faster the microbe will grow
What are potentially hazardous foods (PHF)?
- Foods that support bacterial growth because they are rich in protein low acid foods and have high moisture content with pH above 4.5
Describe Salmonellosis and what type of microbe it is according to its oxygen needs and does it produce spores and what are the symptoms ?
- it is an infection caused by some strains of bacterium salmonella enterica
- Its a facultative anaerobic and it does not produce spores
- Symptoms : diarrhea , fever , vomiting and abdominal cramps 12to 72 hours after infection
Describe Botulism and the environment it needs to grow and does It produce spores ?
- it Is an intoxication caused by the neurotoxin , botulinum.
- It is a mesophilic obligate anaerobe
- They produce spores
Describe Listeriosis and the environment it needs to grow and does it produces spores?
- It is an infection caused by listeria monocytogenes
- They don’t produce spores
- Psychrotrophic and facultative anaerobes
Describe Escherichia coli (E.coli) and the illness it can cause
- it is an infection found in the gut go humans
- It is an important cause of bacterial diarrheal illness
Describe Shiga toxin producing E.coli (STEC) and what temp it grows in and what are some symptoms ?
- It can cause severe toxin mediated infection
- grows in temp ranging from 7°C to 50°C, optimal in 37°C.
- Abdominal cramps , diarrhea , some cases of bloody diarrhea , fever and vomiting
What 2 bacterias can cause intoxication ?
- Staphylococcus aureus intoxication
- Botulism
Describe Staphylococcus aureus intoxication and the symptoms it can cause
- it is an intoxication and the toxins are resistant to heat and cannot be destroyed by cooking
- Symptoms : Nausea , Vomiting , stomach cramps and diarrhea
What is the Norovirus and how does it grow and how can it be transmitted and what can It cause?
- it is a leading cause of food borne illness
- transmitted by contaminated food or water, an infected person, or by touchingcontaminated surfaces.
- it is a virus so it needs a host to grow on
- Causes inflammation of the stomach, intestines or both . leads to stomach pain , nausea, diarrhea and vomiting
What does the prion disease do and who can it effect and how is it spread?
- A prion is a protein that can trigger normal proteins in the brain to fold abnormally.
- Can affect both humans and animals
- Spread to humans by infected meat products
In the Canada’s Food and Drug Act (Law) what are Novel Foods?
- Food that have been produced by novel technology or ingredients that do not have a long history of use
What is the role of Canadian Food Inspection Agency (CFIA) in food safety ?
- Enforces all federal laws and regulations dealing with food
- Ensures industry compliance with food safety refutations through inspection/compliance verification of food products
- Investigates food responsible for food borne illness outbreaks with food safety partners
- Initiates food recalls
What is the role of Health Canada (HC) in food safety ?
- Sets food safety standards/ policies
- Makes health risk assessment
- Communications to public on food safety issues
What is the role of Public Health Agency of Canada (PHAC) in food safety ?
- Acts as first point of contact for federal government for human health impact of food borne outbreaks
- Conducts public health surveillance
- Leads epidemiological investigations when investigation is in more than one province
What is the 5 step process the CFIA uses to investigate and determine if a food recall is necessary ?
- Trigger
- Food safety investigation
- Risk assessment
- Recall process
- Follow up
