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Chemical and physical hazards in food
FS0401 1 2000
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Perception of chemical hazards in food
FS0401 2 2000
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Where chemical hazards arise in the food supply
Vehicle emission Crops Processing Agricultural practices Livestock Retail Cooking Landfills Storage Seafood Industrial emissions and effluents Distribution FS
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Chemical hazards in food
- industrial and environmental contaminants - biologically derived contaminants - contaminants produced during processing - improperly used agrochemicals - improperly used additives FS0401 4 2000
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Contaminants of industrial and environmental origin
Chemical Main source Associated food Transformers By-product Chlor - alkali Fish, animal fat Fish, animal fat Fish PCBs Dioxins Mercury Lead Vehicle emission, smelting, paint, glazes, solder Canned food, acidic foods, drinking water Sludge, smelting Accidental release Fertilizers Grains, molluscs Fish, mushrooms Cadmium Radionuclides Nitrate / nitrite Vegetables, drinking water FS
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Inherent plant food toxicants
Chemical Associated Food oxalates rhubarb, tea, cocoa, spinach, beet glycoalkaloids green potato cyanoglycosides lima bean, cassava phytohaemagglutinin red kidney beans and other beans various carcinogens spices and herbs FS0401 6 2000
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Mycotoxins Chemical Source Associated Food Aflatoxins
Aspergillus flavus and corn, peanuts, tree nuts, milk A. parasiticus Trichothecenes Mainly Fusarium cereals and other foods Ochratoxin A Penicillium verrucosum wheat, barley, corn A. ochraceus Ergot alkaloids Fumonisins Claviceps purpurea Fusarium moniliforme rye, barley, wheat corn apples, pears cereals, oil, starch Patulin P. expansum Zearalenone Fusarium spp FS
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Temperature range for growth of toxigenic moulds
Aspergillus Penicillium Minimum Optimum Maximum FS0401 8 2000
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Minimum water activity for growth of toxigenic moulds
Aspergillus ochraceus 0.78 Penicillium verrucosum 0.79 Aspergillus flavus 0.80 Fusarium moniliforme 0.87 Stachybotrys atra 0.94 FS0401 9 2000
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Target organs of some mycotoxins
Aflatoxin liver Ochratoxin A Trichothecenes Ergot alkaloids kidney mucosa peripheral vascular system Zearalenone uro-genital tract FS
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Contaminants of biological origin
1999
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for mycotoxins in foods
Regulatory limits for mycotoxins in foods Mycotoxin Limit (µg/kg) Commodities No. of Countries Aflatoxins B+G 0 - 50 corn, peanuts, other foods 48 animal feeds milk, dairy 21 Aflatoxin M1 Ochratoxin A 17 rice, corn, 6 barley, beans, pork kidney Deoxynivalenol Patulin wheat 5 apple juice all foods 10 Zearalenone 4 FS
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Risk assessment for mycotoxin in foods Mycotoxin JECFA Benchmark
Aflatoxin B1 cancers per year per people per µg of aflatoxin B1 per kg bw/day 0.4 µg/kg bw/day Patulin 0.1 µg/kg bw/day Ochratoxin A FS
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Regulatory limits for aflatoxins in some Asian and Pacific countries
Country Limit (µ/kg) Commodity Australia/New Zealand China 15 (T) 5 (T) peanuts other foods maize, peanut all 20 (B1) India Japan 30 (B1) 10 (B1) rice 5 (B1) other grains all Malaysia Philippines 35 (T) 20 (B1) coconuts, peanut products (export) all Singapore Sri Lanka Thailand Absence (B1)* all all 30 (T) 20 (T) B1 = Aflatoxin B1 *Limit of detection is around 10 mg/kg T = Total Aflatoxins FS
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Other toxicants of biological origin
Source Associated food Ciguatera dinoflagellates tropical Fish Shellfish toxins: dinoflagellates shellfish paralytic neurotoxic diarrhoeic amnesic cereals, honey fish, cheese Pyrrolizidine alkaloids various toxic plants Histamine spoilage bacteria FS
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Contaminants produced during processing
- polynuclear aromatic hydrocarbons - heterocyclic amines, nitropyrenes - nitrosamines - ethyl carbamate (urethane) - chloropropanols FS 2000
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Improperly used agrochemicals
Insecticides organochlorine insecticides organophosphorus insecticides carbamate insecticides Animal Drugs antimicrobials growth promotants anthelminthics therapeutics fumigants fungicides herbicides fertilizers plant growth regulators rodenticides nematocides molluscicides FS 2000
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Food additives anti-caking agents release agents antimicrobial agents
non-nutritive sweeteners antioxidants nutrient supplements colours nutritive sweeteners curing and pickling agents oxidising and reducing agents emulsifiers pH control agents enzymes propellants and gases firming agents sequestrants flavour enhancers solvents and vehicles flavouring agents stabilisers and thickeners humectants surface-active agents leavening agents texturizers FS 2000
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Other potential hazards
processing Aids ion-exchange resins, filter aids enzyme preparations microorganisms solvents, lubricants, release agents specific function additives food Contact Materials utensils working surfaces equipment packaging Materials cleaning Agents metal, plastic, paper, wood, etc. detergents sanitisers FS
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Improperly used additives
Adulterants - borax - boric acid - formaldehyde - water - unapproved colouring agents FS 2000
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Improper use of food additives
Illegal use in Indonesia Pom Aceh sauce bottles - Rhodamine B Red drinks containing Rhodamine-B : Bogor 15 % Djakarta 8 % Rankasbitung 17 % Pacet 17 % Cikampek 24 % Semarang 55% red drinks contained Rhodamine-B 31% food samples contained Rhodamine-B, Methanyl yellow or orange-RN FS 2000
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Risk analysis of chemicals in foods
Characterisation Hazard Socio-economic/ Characterisation Political End-point Assessment Dose response Risk-Benefit Cost-Benefit Hazard Risk Exposure Identification Communication Assessment Options Level in food Regulatory Dietary intake Voluntary Non-intervention Risk Risk Management Assessment Monitoring and Evaluation FS
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Monitoring points for chemical hazards
- point source - environmental compartments - primary production - import / export - production and processing - wholesale outlets and markets - biomonitoring FS 2000
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Criteria for establishing priorities
- severity of potential effects on health - levels in individual foods and the diet - size and susceptibility of the exposed population - significance in domestic and international trade - nature and cost of management options FS 2000
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Chemical hazards in the home
- metal cookware contaminated with heavy metals - ceramic or enamelled serving dishes with toxic glazes - leaded crystal used with acid foods - copper pans and utensils - miscellaneous home-use chemicals FS 2000
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Chemical hazards in food
Disease and Death Exposure FS 2000
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Potential physical hazards
- glass - slime or scum - metal - bone - plastic - stones and rocks - capsules or crystals - pits or shell - wood - paper - human and animal hair FS 2000
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Potential physical hazards
Distribution of complaints of foreign objects in food soft drinks 19 % infant foods 16 % bakery 14 % chocolate and cocoa products 7 % fruits 7 % cereals 5 % vegetables 4 % fish 3 % others 25 % FS 2000
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Potential physical hazards
Possible control meas-res - vis-al inspection - filters or sieves metal detectors magnets - separation by density - personnel precautions (hair net, gloves) FS 2000
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Effect of thermal processing on nutrients
Vitamin B Vitamin A group* Vitamin C Vitamin E Freezing - M M - Pasteurisation L L M L Boiling L M to H H L Microwaving - L L - Baking/Roasting L L to M M L Ultra High temperature L L M L (UHT) Canning M M to H H M *Comprises a number of water soluble, low molecular weight compounds and includes Thiamine (B1), Riboflavin (B2), Niacin, Folate, B 6 and B12. FS 2000
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Effect of food processes on nutrients
Vitamin B group* Vitamin C Vitamin E M to H - - Vitamin A - Milling M L L to M H M Air drying Freeze drying Salting L M L - L L - - - - - Aw reduction by sugars Fermentation - L L - M - - L - Acid pH (i.e. <4.6) - - Additives H (e.g. sulphite) e.g. B1 - Thiamine - Irradiation L to M L - *Comprises a number of water soluble, low molecular weight compounds and includes Thiamine (B1), Riboflavin (B2), Niacin, Folate, B 6 and B12. FS 2000
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Mineral loss during food processing
Loss may be due to - Physical removal - Leaching into cooking water - Shrinkage during cooking FS 2000
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Factors affecting mineral availability
Processes which may affect mineral availability - Reducing or removing ingredients which inhibit mineral absorption - Fermentation and germination - Heating (increases availability of some minerals, decreases availability of others - Addition of phosphates FS 2000
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Macronutrients - Relatively stable to food processing
- Certain treatments physically remove macronutrients from the food (e.g. milling) - Heat treatments can denature proteins, or cause fats to oxidise and degrade - Certain treatments increase carbohydrate levels (e.g. adding sugar as a preservative) FS 2000
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Effect of nutrient loss on diet
- If a food is a principal source of a particular nutrient, it is important to minimise the loss of this nutrient - Processed foods sometimes retain more nutrients than fresh foods - Strategies to minimise overall nutrient loss must look at each processing stage FS 2000
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Minimising nutrient losses
To reduce nutrient loss - Reduce water in cooking - Minimise the time between harvest and eating - Ensure optimum storage FS 2000
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Free radicals and chronic disease
Free radicals cause oxidative stress Increasing evidence that free radicals may be responsible for and related to - diabetes mellitus - cardiovascular disease - atherosclerosis - tropical diseases FS 2000
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Counteracting oxidative stress
Oxidative stress is counteracted by - antioxidative enzymes - non-enzymic antioxidants (e.g. vitamins A, C, E and beta carotene) FS 2000
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