Hygiene Flashcards
What are potential strategies to assure food safety?
Sterilise everything and process line are impossible
Test everything before clearance
Regular cleaning
Control critical steps during processing
What are the cons of testing the final product?
High possibility of not finding the pathogen
Takes days
Expensive
Doesn’t give information on process
What is the best way of safeguarding the product during processing?
Control critical steps during processing and regular cleaning->good practices
How does codex Alimentarius define food handling?
Operations in growing, harvesting, preparation processing packaging storage transport and distribution and sale of food
How does codex Alimentarius define food hygiene?
All conditions and measures necessary to ensure safety of food at all stages
What is hygiene?
Preventing spoilage and pathogen microorganisms from raw materials contaminating food products
What tools assure the most food safety? Which ones the least?
ISO and total quality management
Worse: General principles of food hygiene
What is the relation between Good manufacturing practices and their impact on undesirable actions?
They should make undesirable actions impossible or unlikely
Why should pests be avoided?
Entry of contamination into raw material/facilities
Damage to raw materials and products
How are pests prevented?
Prevent access to factory
Prevent access to food and water including waste
How are pests controlled?
Killing and trapping
What are potential sources of contamination of food?
Raw materials
Air and water
Employees
Pests
Equipment
According to what should care areas be determined?
Product vulnerability
What is zoning?
Separation of the factory in different zones
What is hygienic equipment?
Equipment that can be cleaned and freed from microorganisms
What is hygienic equipment class 1?
Can be cleaned without dismantling
What is hygienic equipment class 2?
Can be cleaned after dismantling
When does cleaning and disinfection fail?
When the equipment cannot be cleaned
What is aseptic equipment?
Hygienically designed equipment sterilizable and impermeable to microorganisms
What is the biggest reason for transmission in the kitchen?
Cross contamination
What three factors does transmission depend on?
Contact time
Pressure
Organism
True or false: the presence of food debris on kitchen equipment provides protection for pathogens?
True
What is the codex alimentarius definition of cleaning?
Removal of soil, food residue, dirt, grease or other matter
What are the effects of food residue on m.o.’s?
Source of nutrients
Protect microorganisms physically
Diminish effect of disinfectants
Decrease performance
What is the difference in log reduction between cleaning and disinfection?
Cleaning <1 log
Disinfection 5 log
What are the three main types of cleaning aspects?
Mechanical and chemical force and process parameters
What are the two things that you need to base your cleaning on?
Suitable and in time
True or false: before disinfection the surface doesn’t have to be cleaned?
False
What is the difference in the removal of m.o. between cleaning and disinfection?
Cleaning 50-90% removed
Disinfection 99.999% killed
What are the three methods of disinfection?
Heat
UV radiation
Chemical
What are the main principles of heat and UV radiation disinfection?
Heat: denaturation of proteins
Radiation: DNA/RNA damage
What are the six types of chemical disinfectants and what are their principles?
Oxidizers: oxidation
Alcohols: membrane leakage
Aldehydes: cell disturbance
Phenols: disturb enzyme activity
QUATS: permeability of cells
Ampholytes: disturb protein synthesis
What are transient flora?
Temporary
What are resident flora?
Part of skin
How long do you need to wash your hands?
At least 20 seconds
Do gloved hands need to be washed too?
Yes
What are the disadvantages of the direct examination of food?
High detection limit
Food interference
Dead/alive
What are the types of culturing techniques?
Pour plate
Surface plate: spread and spiral plate
How do you calculate the concentration of m.o.’s?
Number1/dilution factor1/volume
What are selective and non-selective media?
Non selective: favourable for a wide range of microorganism
Selective: favourable for target organism
What are chromogenic media?
Specific colouring to enhance electivity
What are the three criteria for culturing media?
Selectivity
Specificity
Electivity
What are four ways to environmentally sample?
Surface sampling:
Dipslide
Rodac plates
Swabs
Air sampling
