Topic 4 : Materials management & Measures for prevention of cross contamination Flashcards
PRP : Materials management
What are specifications and its purposes in the food industry? [2]
Specifications are requirements that a product/ service has to conform to.
Purposes in food industry:
1. Used as standards for quality checks
2. Communication tools with third party suppliers and ensuring that the raw materials meets the requirements
PRP : Materials management
What are some information that can appear in specifications ? [9]
Not important
1) Supplier name / info
2) Sensory info (appearance / flavour)
3) Ingredients list
4) Composition of food
- Chemical and nutritional composition
- Brix, specific gravity → for liquids (e.g. syrup), ensure that supplier don’t make it too dilute and conform to specs
5) Certifications
- Food safety management system / quality management system
- Sustainability certification
- Halal / kosher
6) Contaminants (physical, chemical, microbiological)
7) Allergens
8) Microbiological quality
9) Analytical methods used to measure each parameter (e.g. Brix, microbial count etc) → manufactuer should use similar method as supplier to minimise discrepancy
PRP : Materials management
What kinds of microbes could a company target to test and sample raw materials? [5]
- Utility microbes
- Indicator organisms
- Moderate hazard pathogens
- Serious hazard pathogens
- Severe hazard pathogens
PRP : Materials management
What do utility microbes indicate? Give some examples [4].
Utility microbes are general indiators of hygiene and possible risk of spoilage, indicative of quality rather than safety.
Examples:
1. Total plate count
2. Yeast and mould count
3. Thermophilic count (e.g. syrups, sugars, canned foods)
4. Psychotropic count (e.g. chilled foods)
PRP : Materials management
What do indicator organisms indicate? [3]. Give 2 examples and which is more commonly used.
Indicator organisms indicate poor hygiene, insufficient processing or post-processing contamination.
Examples
1. Coliform – not widely used because no correlation between coliform count and pathogen presence
- Enterobacteriaceae (includes enteric pathogenic strands and non-pathogenic strands) → more accepted and commonly used indicator microbes.
PRP : Materials management
Under what circumstances are pathogens monitored (on top of indicator organisms)?
When having acceptable indicator microbes does not guarantee low risk for food safety issues
PRP : Materials management
State the difference in how moderate/serious/severe hazard pathogens are classified. Give some examples.
1) Moderate hazard pathogens : short-term illness, no long-term (chronic) effects and non life threatening
- e.g. Bacillus Cereus, Clostridium Perfringens, Staphylococcus aureus, Vibrio parahaemolyticus
2) Serious hazard pathogens : longer-term illness lasting several weeks, rarely have chronic effects and non life threatening
- Listeria monocytogenes : low frequency but severe
- Salmonella Enteritidies: widespread, serious in vulnerable populations
3) Severe hazard pathogens : life threatening
- Cronobacter : rare but life threatening in infants
- Listeria monocytogenes : rare but life threatening among vulnerable groups (YOPI)
- Salmonella spp : rare but life threatening among infants
PRP : Materials management
Attribute sampling plan : What is the difference (in terms of classification) between two-class attribute plan and three-class attribute plan?
Two-class attribute plan : only 2 categories (acceptable / unacceptable)
Three-class attribute plan : 3 categories (acceptable / marginally acceptable / unacceptable)
PRP : Materials management
For two-class sampling plan:
m = microbial limit
c = maximum allowable no of samples that yield unsatisfactory results
n = total no of samples
State the 3 possible outcomes and whether the lot will be accepted or rejected.
- All samples ≤ m → accept lot
- ≤ c out of n samples ≤ m → accept lot
- > c out of n samples > m → reject lot
PRP : Materials management
Example of 3 class sampling plan
For enterobacteriaceae
n = 5
c = 2
m = 1 cfu/ml
M = 5 cfu/ml
What does this sampling plan mean?
- Less than or 2 samples should have microbial count within 1-5 cfu/ml before lot is accepted.
- If any sample > 5 cfu/ml, or more than 2 samples have microbial count within 1-5 cfu/ml, the lot is rejected.
PRP : Materials management
For three-class sampling plan:
m = marginally acceptable microbial limit
M = maximum unacceptable microbial limit
c = maximum allowable no of samples that yield unsatisfactory results
n = total no of samples
State the 4 possible outcomes and whether the lot will be accepted or rejected.
Note : m < M
- All samples ≤ m → accept lot
- ≤ c out of n samples fall within the range, > m and ≤ M → accept lot
- > c out of n samples fall within the range, > m and ≤ M → reject lot
- Any one out of n samples > M : reject lot
PRP : Materials management
Example of 3 class sampling plan
For Salmonella
n = 5
c = 0
m = absence in 25 g
M = absence in 25 g
What does this sampling plan mean?
All samples should have absence of Salmonella in 25 g of food, or else lot is rejected.
PRP : Materials management
When to use a two-class and three-class sampling plan?
Thus, what sampling plan do these fall under
- Utility microbes
- Indicator organisms
- Moderate hazard pathogens
- Serious hazard pathogens
- Severe hazard pathogens
Two-class sampling plan is used when the microbe is strictly not allowed in food (pathogens) and there is no room for error / negotiation, whereas three-class sampling plan is used when microbe is allowable to be present within the food within acceptable limits.
Two-class sampling plan :
- serious hazard pathogens
- severe hazard pathogens
Three-class sampling plan
- utility
- indicator organisms
- moderate hazard pathogens (non life threatening and mild illness)
PRP : Measures for prevention of cross contamination – allergen
What main group of compounds typically trigger allergic reactions?
Proteins (and glycoproteins)
PRP : Measures for prevention of cross contamination – allergen
What are the 9 major common allergens as outlined by SFA / US FDA?
- Egg
- Milk
- Fish
- Crustaceans / shellfish
- Tree nuts
- Peanuts
- Soybean
- Gluten / wheat
- Sesame
1-2 : Foods that animals produce
3- 4 : Animal meat
5 - 6 : Nuts
7 - 9 : Crops
PRP : Measures for prevention of cross contamination – allergen
True food allergies are IgE-mediated. Explain how allergens lead to IgE-mediated allergies.
Sensitisation phase (no allergic reaction yet)
- When consuming a food with an allergen, B cells recognise the allergens as foreign substances.
- Thus, B cells produce Immunoglobulin E (IgE), an antibody, which attaches itself to mast cells / basophils
Elicitation phase
- Subsequent exposure to allergen results in antigen binding to IgE antibody.
- This causes mast cells / basophils to degranulate, releasing granules containing histamine and other mediators
- This leads to triggering of allergic symptoms
Mast cells = immune cells derived from the myeloid lineage
Basophils = WBC in immune system that protect body from allergen and infection (granulocytes)
PRP : Measures for prevention of cross contamination – allergen
An IgE antibody can only recognise the antigen of 1 specific type of allergen. True or False?
False, 1 antibody may recognise multiple antigens (from same type of food)
PRP : Measures for prevention of cross contamination – allergen
What is cross allergy? Give example of cross allergies.[3]
Cross allergies occur when proteins in substance A is similar to protein in substance B, thus when one is allergic to substance A, he/she is likely to be allergic to substance B.
- Cross allergy between different types of animal milk
- Cross allergy between cashew and pistachio (tree nuts)
- Cross allergy between hazelnut and walnut (tree nuts)
PRP : Measures for prevention of cross contamination – allergen
What is the difference between allergy, hypersensitivity and intolerance.
Allergy : involves the immune system and proteins
Hypersensitivity : may or may not involve proteins.
Intolerance : inability to metabolise a specific substance due to the lack of enzymes. (e.g. lactose intolerance)
PRP : Measures for prevention of cross contamination – allergen
What is the current approach to allergen labelling and what is its limitation?
Current approach : as long as a product contains / may contain allergens, it must include a precautionary allergen label. However, it could greatly limit the choices of consumers. (e.g. soy sauce may not have soy allergen in it as proteins are broken down via fermentation)
PRP : Measures for prevention of cross contamination – allergen
What does risk assessment of allergens consist of ? [3]
- Establishing frequency of allergic reaction (e.g. milks, eggs, peanuts are most common allergens worldwide)
- Severity of allergic reaction
- Potency of allergen : minimum amount of allergen that triggers an allergic reaction.
Rmb : risk assessment = risk x likelihood
PRP : Measures for prevention of cross contamination – allergen
____ curves can help to determine the thresholds and thus, potency of an allergen.
What is meant by the potency of an allergen?
Dose-response.
Potency of an allergen is the minimum concentration of an allergen that triggers a (visible) reaction.
PRP : Measures for prevention of cross contamination – allergen
Since precautionary labelling of every single allergen could limit consumer choice, the industry is moving towards a reference dose regulation to determine when precautionary labelling is necessary (via risk assessment). Reference doses such as ED5 can be used. What does ED5 mean?
ED5 : Elicit dose (5%).
- The elicit dose is the dosage of an allergen that triggers a certain response
- Thus, ED5 is the elicit dose that triggers an allergic response in 5% of the population.
PRP : Measures for prevention of cross contamination – allergen
Under the new approach of establishing a reference dosage, why is precautionary allergen labeling not required even if mild allergic reactions can still occur below the reference dose (e.g., ED₅)?
Even if allergic reactions to unlabelled allergens occur from exposure below the reference dose, these reactions will be mild and transient and do not require emergency medical intervention.
**When to conduct the testing** 1. After cleaning 2. Before product changeover
