BGZ2004
Problem 11 toxicology
1. What processes can attribute to food toxicology in food
production?
H36 Toxicology
The 3 objectives of nutritional toxicology are:
- To record any toxic and toxicity modulating properties of foodstuffs
- To increase knowledge and understanding of the toxic and toxicity
modulating properties of foodstuffs by research
- To assess the dangers due to toxic properties of foodstuffs on the basis of
the levels in which they occur in foodstuffs and the dietary habits and
lifestyles of consumers
- To keep society informed of measures aimed at limiting or preventing
toxicological risk
Sources of potentially toxic substances in food
3 broad categories of compounds:
- Natural compounds
- Compounds that may enter food as a result of industrial processes, either
directly (part of processing) or indirectly (via emission to environment)
- Additives, compounds that are deliberately used in food production
Compounds may also originate from various stages in the food production
process.
Food sources; Natural (1st group)
Many food sources naturally contain compounds that are toxic to man. For
example:
- Marine toxins; most are produced by single-cell organisms and occur
secondarily in animals eaten by man (mussels).
- Glycoalkaloids are found in potatoes and tomatoes. Consumption of
varieties with a high content of these compounds may cause poisoning.
o In potatoes, solanine and chaconine constitute 95% of the total
glycoalkaloid content. These are unstable for human production
They are teratogenic, so more attention needs to be paid to possible
chronic toxicity.
- Lectins (hemagglutinins) are toxic proteins found in the seeds of certain
plants. They are rendered harmless by heating (detoxification). Inadequate
heating can cause severe poisoning.
Toxic compounds not naturally occurring in our food: industrial contaminants,
pesticides and veterinary medicines.
- Industrial contaminants can find their way into food sources. The most
familiar compounds are lead, cadmium, PAHs, PCBs, PCDDs;
polychlorinated dibenzodioxins , PCDFs; polychlorinated dibenzofurans .
The last two have been found in breast milk. (2 nd group)
- Pesticides and veterinary medicines are widely used to combat disease
and pests which may adversely affect the production of vegetable and
animal foodstuffs. Residues of these compounds can find their way to the
human consumer (3th group)
Storage and transportation; certain potentially toxic substances can enter
food; myotoxins and pesticides (or raw materials used in food manufacture).
- Myotoxins: formed by funghi
, If certain raw materials used in food industry (vegetable oils) are
transported, the products may be contaminated by compounds previously
transported in the same containers (mineral oils).
- Pesticides are also sometimes used during storage and transportation to
control organisms which might otherwise damage the stock.
Industrial processing and packaging; also here undesirable compounds may
be introduced. For example:
- microbial toxins (salmonella/ staphylococcus/ shigella and exotoxins such
as botulinum toxin).
The manufacture of fermented products may in addition to the desired products,
give rise to products with less desirable properties such as higher alcohols in
alcoholic beverages. Pentanols in particular are toxic, causing damage to the
nervous system, insomnia and headache.
Processing methods such as mechanical treatment, heating and smoking, are
accompanied by changes in chemical composition due to the addition of
compounds (trace of metals) or the formation of new products such as polycyclic
aromatic hydrocarbons (PAH). Compounds may migrate from packaging materials
into packaged foods.
Additives are used above all in this stage. They are designed to improve or at
least influence flavor, texture and storage life (antioxidants, emulsifiers etc).
Solvent residues may also be found as a result of their use in extraction
processes, for example trichloroethylene en methylene chloride used in the
decaffeination of coffee.
, 2. What processes during preparation can attribute to food
toxicology?
Home storage and preparation; the actions performed by the consumer
himself/ herself. Here also is a risk of microbiological contamination (poor
hygiene, products stored for too long or incorrectly).
Nitrite may be formed after preparation and storage in nitrates rich products.
Nitrite is a toxicological hazard but it may also react with nitrogenous compounds
(amines) to form nitroso compounds (in product/ stomach).
Pb; plumbum and Cd; cadmium may reach food or drink via pottery (pigments,
glazes),especially as a result of interaction with acid products such as fruit juices.
Finally; an everyday ingredient such as cooking salt is potentially toxic.
3. What is the role of food additives?
Food additives are substances added to food to preserve flavor or enhance its
taste and appearance. Some additives have been used for centuries; for
example, preserving food by pickling (with vinegar), salting, as with bacon,
preserving sweets or using sulfur dioxide as in some wines. With the advent of
Problem 11 toxicology
1. What processes can attribute to food toxicology in food
production?
H36 Toxicology
The 3 objectives of nutritional toxicology are:
- To record any toxic and toxicity modulating properties of foodstuffs
- To increase knowledge and understanding of the toxic and toxicity
modulating properties of foodstuffs by research
- To assess the dangers due to toxic properties of foodstuffs on the basis of
the levels in which they occur in foodstuffs and the dietary habits and
lifestyles of consumers
- To keep society informed of measures aimed at limiting or preventing
toxicological risk
Sources of potentially toxic substances in food
3 broad categories of compounds:
- Natural compounds
- Compounds that may enter food as a result of industrial processes, either
directly (part of processing) or indirectly (via emission to environment)
- Additives, compounds that are deliberately used in food production
Compounds may also originate from various stages in the food production
process.
Food sources; Natural (1st group)
Many food sources naturally contain compounds that are toxic to man. For
example:
- Marine toxins; most are produced by single-cell organisms and occur
secondarily in animals eaten by man (mussels).
- Glycoalkaloids are found in potatoes and tomatoes. Consumption of
varieties with a high content of these compounds may cause poisoning.
o In potatoes, solanine and chaconine constitute 95% of the total
glycoalkaloid content. These are unstable for human production
They are teratogenic, so more attention needs to be paid to possible
chronic toxicity.
- Lectins (hemagglutinins) are toxic proteins found in the seeds of certain
plants. They are rendered harmless by heating (detoxification). Inadequate
heating can cause severe poisoning.
Toxic compounds not naturally occurring in our food: industrial contaminants,
pesticides and veterinary medicines.
- Industrial contaminants can find their way into food sources. The most
familiar compounds are lead, cadmium, PAHs, PCBs, PCDDs;
polychlorinated dibenzodioxins , PCDFs; polychlorinated dibenzofurans .
The last two have been found in breast milk. (2 nd group)
- Pesticides and veterinary medicines are widely used to combat disease
and pests which may adversely affect the production of vegetable and
animal foodstuffs. Residues of these compounds can find their way to the
human consumer (3th group)
Storage and transportation; certain potentially toxic substances can enter
food; myotoxins and pesticides (or raw materials used in food manufacture).
- Myotoxins: formed by funghi
, If certain raw materials used in food industry (vegetable oils) are
transported, the products may be contaminated by compounds previously
transported in the same containers (mineral oils).
- Pesticides are also sometimes used during storage and transportation to
control organisms which might otherwise damage the stock.
Industrial processing and packaging; also here undesirable compounds may
be introduced. For example:
- microbial toxins (salmonella/ staphylococcus/ shigella and exotoxins such
as botulinum toxin).
The manufacture of fermented products may in addition to the desired products,
give rise to products with less desirable properties such as higher alcohols in
alcoholic beverages. Pentanols in particular are toxic, causing damage to the
nervous system, insomnia and headache.
Processing methods such as mechanical treatment, heating and smoking, are
accompanied by changes in chemical composition due to the addition of
compounds (trace of metals) or the formation of new products such as polycyclic
aromatic hydrocarbons (PAH). Compounds may migrate from packaging materials
into packaged foods.
Additives are used above all in this stage. They are designed to improve or at
least influence flavor, texture and storage life (antioxidants, emulsifiers etc).
Solvent residues may also be found as a result of their use in extraction
processes, for example trichloroethylene en methylene chloride used in the
decaffeination of coffee.
, 2. What processes during preparation can attribute to food
toxicology?
Home storage and preparation; the actions performed by the consumer
himself/ herself. Here also is a risk of microbiological contamination (poor
hygiene, products stored for too long or incorrectly).
Nitrite may be formed after preparation and storage in nitrates rich products.
Nitrite is a toxicological hazard but it may also react with nitrogenous compounds
(amines) to form nitroso compounds (in product/ stomach).
Pb; plumbum and Cd; cadmium may reach food or drink via pottery (pigments,
glazes),especially as a result of interaction with acid products such as fruit juices.
Finally; an everyday ingredient such as cooking salt is potentially toxic.
3. What is the role of food additives?
Food additives are substances added to food to preserve flavor or enhance its
taste and appearance. Some additives have been used for centuries; for
example, preserving food by pickling (with vinegar), salting, as with bacon,
preserving sweets or using sulfur dioxide as in some wines. With the advent of
