Case 6 Flashcards
Chemical food safety
Deals with all aspects of risks in the food chain, deals with contaminants, additives and their related toxicology. And ensures that these chemicals are not present in toxic levels in food.
Additives
- Added to foods for a specific technological purpose during manufacture or storage and become an integral part of that food
- Can be natural or synthetic
- Example: Preservatives prevent the growth of bacteria
- Have been blamed for inducing hyperactivity in children
Food additives
Additives are substances used for a variety of reasons - such as preservation, colouring, sweetening, etc.- during the preparation of food.
European Union legislation “any substance not normally consumed as a food in itself and not normally used as a characteristic ingredient of food, whether or not it has nutritive value”
Food flavouring
Flavourings are products added to food in order to impart or modify odour and/or taste.
Contaminants
natural or industrial product, found in food involuntarily
Microbial toxins
- Food containing preformed toxins that originate from bacterial growth, fungal growth, or algal growth
- Bacteria: Toxin is absorbed in the bloodstream via the intestine and → Illness results from intoxication rather than infection
- Fungi: Several species are involved in the production of toxic substances during growth on foodstuffs (Mycotoxins)
- Algal toxins: Associated with seafood, most notably molluscan shellfish
Lead
- found in kidneys, liver
- affects nervous system of children when ingested in toxic quantity
- can also lead to hypertension
- either form environmental exposure such as smoking or by eating
• In children: Effects on nervous system → Interfere with transmission of nervous signals around the body → Reduced IQ and coordination problems
• In adults: Hypertension and other blood effects such as anaemia
Arsenic
- Most often an occupational hazard, but can also be ingested with food → Responsible for acute and chronic poisoning
- Toxicity depends on oxidation state and type of complex that it forms with organic molecules in the body
- Chronic effects: Gastroenteritis, nephritis, liver damage
- Considered to be a carcinogen
Mercury
- about food, fish (especially tuna)
- neurotoxic
- nephrotoxic (kidneys)
associated with neural effects and renal damage
Dioxine
- mainly found in animals fat
- thought to lead to cancer based on animal studies
- broccoli is thought to be a protective factor
Nitrate
- saliva converts it in nitrite and can form carcinogenic compounds
- combination of fish with salads
Plant toxins
- Antinutritional factors: Components of plants that interfere with metabolic processes and can lead to deficiencies of key nutrients in the diet
- Generally classified as enzyme inhibitors (polypeptides and proteins that inhibit the activities of digestive enzymes) and mineral binding agents
- A range of natural plant toxins can cause allergic reactions in humans
e.g. glycosides, glycoalkaloids, pyrrolizidine alkaloids, glucosinolates
Process contaminants
Process contaminants are substances that form in food or in food ingredients when they undergo chemical changes during processing. Processing methods include fermentation, smoking, drying, refining and high-temperature cooking
e.g. acrylamide, PAHs, chloropropanols and nitrosamines.
Environemental contaminants
environmental contaminants refers to harmful chemicals present in soil, air and water. These compounds may come directly from human sources such as industrial manufacturing, agricultural run-off and wastewater discharge, or they may originate from natural sources, such as the taste and odor-causing chemicals in water generated by algae and bacteria blooms.
Food contact materials
Food comes into contact with many materials and articles during its production, processing, storage, preparation and serving, before its eventual consumption.
E.g. containers for transporting food, machinery to process food, packaging materials and kitchenware and tableware
naturally occuring contaminants
Naturally occurring contamination comes from substances already in the environment, rather than from chemicals or other hazardous materials used or manufactured by human
Residues
resulting from the use of a chemical compound that improves production but shouldn’t be present in the final product
Pesticides
Used in agriculture to maximize production
- Important to ensure in production that these pesticides do not stay in the final product because it is thought to interfere with neurological pathways of humans for instance
- It is also said that pesticides accumulate in the body on long-term, creating a chronic intoxication/contamination
Veterinary drug residues
- Include bacterial compounds, hormones, and nonsteroidal anti-inflammatory preparations
- Antibacterial substances increasingly used as growth promoters → Increase feed conversion efficiency, and for prophylaxis and therapy → Prevent outbreaks and diseases
- Veterinary drugs are metabolised in the animal and are excreted in the urine and faeces over time as the detoxification process continues → Residue traces of drugs or their metabolites can be found in major organs, muscles and body fluids
- Excessive use has raised concerns about:
• Development of resistant bacteria
• Risk of allergic reactions in humans to antibacterial residues in food of animal origin
e.g. antibiotics in cows
Acrylamide
- Reactive unsaturated amide that has found several industrial uses
- Occur in variety of fried and baked foods, in particular carbohydrate-rich foods that had been subjected to high-temperature cooking/processing
- Shown to be neurotoxic to humans: Classified as probable human carcinogen
- Formation in foods: Reaction of reducing sugar with asparagine via the Maillard reaction at temperatures above 120°C
- Found in wide range of heat-treated foods: Most prevalent in fried potato products, cereals, bakery wares, and coffee
PAH (polycyclic aromatic hydrocarbons)
- Group of over 100 different chemicals that are formed during certain technological processes and are common environmental contaminants
- Formed during incomplete combustion of coal and oil
- Also formed during barbecuing or grilling meat → Foods most likely to be contaminated by PAHs are grilled or charred meats
- Human exposure usually results from air pollution and from cigarette smoke
- Documented by WHO as genotoxic, immunotoxic, and carcinogenic
Polyhalogenated hydrocarbons
- Certain PHHs are manufactured for use in plastics, paints, transformers and herbicides
- 90% human exposure is through ingestion of contaminated foods (fish and milk)
- Foods rich of fats and oils tend to accumulate PHHs
Metals
- Long been associated with food poisoning, best documented hazards: Lead and mercury
- Released into the environment as result of natural geological action and also as a result of man-made pollution from industrial process
- Affinity for biological tissue and organic compounds → Often easily absorbed into the body and can often accumulate in organs and fat deposits
Cadmium
- Most often accumulated from occupational exposure or smoking -> affect the respiratory system
- bioaccumulate in the kidsney and cause renal damage
Ranking of food hazards, as perceived by the general public
- Additives and food processing residues
- Environmental contaminants (pollutants)
- Nutritional imbalance
- Naturally occurring toxins
- Microbiological contamination
Ranking of food hazards based on objective scientific criteria
Nutritional imbalance
- Microbiological contamination
- Naturally occurring toxins
- Environmental contaminants (pollutants)
- Additives and food processing residues
Risk assessment
- Hazard identification
- Dose-response reaction
- Exposure assessment (quantification)
- Risk characterization (estimated occurrence in a population)
Hazard identification
aims to determine the qualitative nature of the potential adverse consequences of the contaminant and the strength of the evidence it can have that effect. This is done, for chemical hazards, by drawing from the results of the sciences of toxicology and epidemiology.
Dose-response reaction
- Requires describing the quantitative relationship between the amount of exposure to a substance and the extent of toxic injury/disease
- in general as the dose of many toxicants increases, toxicity increases
- Generally requires to extrapolations:
• For species differences in body size, lifespan, and basal metabolic rate
• For differences in doses between animal experiments and human studies
Acceptable daily intake (ADI)
daily intake that, during a lifetime, would pose no appreciable risk to the consumer, on the basis of all facts known at the time (mg/kg)
Tolerable weekly intake (TWI)
The maximum intake of substances in food, such as nutrients or contaminants, that can be consumed weekly over a lifetime without risking adverse health effects.d
Maximum tolerable daily intake (MTDI)
it has been established for food contaminants that are not known to accumulate in the body: Tin, arsenic, styrene
→ Represents permissible human exposure as a result of natural occurrence of the substance in food and drinking water
No observed effect level (NOAEL)
No adverse effect level -> it is the threshold of quantity/dose until which a chemical is safe and has NO effect
Low adverse effect level (LOAEL)
threshold for the dose that is required to start seeing an effect on health
Hazard
The inherent capacity of a chemical or mixture to cause adverse effects on man or the environment under the conditions of exposure
Risk
The probability of occurence of an adverse effect on man or the environment resulting from a given exposure to a chemical or mixture
Exposure assessment
The determination of the emissions, pathways and rates of movement of a substance and its transformation or degradation in order to estimate the concentrations/doses to which human populations or environmental compartments are or may be exposed
Risk management
Decision-making process that entails considerations of political, social, economic, and engineering information with risk-related information to develop, analyze and compare regulatory options and to select the appropriate regulatory response to a potential health or environmental hazard
General food law regulation (EC) 178/2002
It is directly applicable EU legislation and provides the general principles of food safety which include the requirement on food businesses to place safe food on the market, for traceability of food, for presentation of food, for the withdrawal or recall of unsafe food placed on the market and that food and feed imported into, and exported from, the EU shall comply with food law.
The General Food Law Regulation ensures a high level of protection of human life and consumers’ interests in relation to food, while ensuring the effective functioning of the internal market.
- labelling of products
- safe food and animal feed
- food hygiene and animal veterinary
Margin of exposure (by EFSA and JECFA)
- Used to assess the risks to human health of exposure to a substance in the absence of a tolerably daily intake or similar guidance value
- Defined as the reference point on the dose-response curve divided by the estimated intake by humans
→ Enables comparison of the risks posed by different genotoxic and carcinogenic substances - Differences in potency of substances concerned and consumption patterns are taken into account
Regulation EC 1333/2008
sets the rules on food additives: definitions, list of approved additives, conditions of use, labelling and authorization procedures.
New regulation (EU) no 1169/2011
provision of food information to consumers Guideline on daily amounts, substitute ingredients, allergen information
2000/13/EC
Labelling, presentation and advertising of foodstuffs (applicable until 12 December 2014)
90/496/EEC
Nutrition labelling for foodstuffs
Regulation from 2004 on hygiene and food staff ensure standards throughout the whole production chain
- Primary responsibility is with the business operator, can change over time
- Regulation on additives, limits for additives
- Hygiene standards
- HACCP
Uncertainties in toxicity testing
- effects may not show themselves if the number of animals is too small
- time of observation is too short for the manifestation of a particurlar effect
- the experimental design is too limited to obtain conclusive evidence
- the differences in sensitivity to a particular substance between men and experimental animals may not be known
Surveillance
- Estimating average and extreme intakes of foods by the general population or of high-risk groups within it
- Intake of food components can be calculated and compared with recognised safety standards
→ Studies are difficult and costly to carry out effectively → Priorities have to be set
→ Provide an overview of the effectiveness of food control policies and basis for future development
Enforcement
- Concerned with compliance by agriculture and food producers with the legal limits for chemicals in food
- Complete the chain from the safety assessment of foods and their components to the legal limits of chemicals in food established from the results of the assessment
→ Ensure consumer protection
risk evaluation
- Definition: Process of analysis that takes into account value systems that cannot be measured in ways described for risk estimation
- Relies on social and political judgment
- Aim: Determine the importance of hazards and the risk of harm from the point of view of communities and individuals facing that risk
- It is the decision maker or risk manager who must be able to compare risks, risk trade-offs, and risks with the potential benefits of using the material
Role of EFSA
- Carry out scientific assessments on possible hazard associated with the food chain, including potential risks posed by chemicals in food
- Use scientific evidence fore recommendations about varied diet, food safety
- EC uses these guidelines abd applies them
