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Quality and Consumer acceptability Prof. I.E.Psomas Laboratory of Food Hygiene School of Veterinary Medicine Aristotle University of Thessaloniki GREECE 1 Chemical contaminants in crop production Pesticides Naturally occurring toxicants (mycotoxins, higher plant toxicants) Nitrate Metals 2 Routes by which pesticides reach the food chain Treatment of crops Veterinary use In food manufacture and retailing In the general environment In the home 3 EC Legislation governing pesticide MRLs in products of plant origin (Council Directive 2000/24/EC) Council Directive 76/895/EEC Council Directive 86/362/EEC Council Directive 86/363/EEC Council Directive 90/642/EEC 4 Control of pesticides according to the “Farm to Table” Approach Farming (1,2,3,4) Food manufacture (1,2,3,4) Food retailing (1,2,3,4) Food preparation in the home (1,2,5) Types of control: 1.Control the availability and/or use of pesticides 2. Limit contamination from the general environment 3. Halt the supply of contaminated food 4. Limit the concentrations of pesticides allowed in food 5. Advise consumers on how to avoid pesticide contamination of food 5 in the home General scheme for pesticide risk assessment Consumption Occurrence Hazard evaluation estimation (how much assessment (how dangerous is the of the food is eaten?) (what foods pesticide?) contain pesticides, at what levels?) Intake estimation (what is the high intake of consumers?) Risk estimation (how does the risk 6 intake compare to acceptable level?) Major mycotoxins in feed/foodstuffs Aflatoxins Ochratoxins Fumonisins Trichothecenes Zearalenone 7 Phases of a food safety management programme for mycotoxins 1. Setting of regulatory limits 2. Establishment of a monitoring programme 3. Control through good agricultural practices 4. Control through processing 5. Decontamination through specific treatments 6. Consumer/Producer education 8 Pre-harvest control Management of insect infestation (Integrated Pest Management control programmes) Management of crop residues and crop rotation Irrigation and soil condition Development of resistant plant varieties 9 Post-harvest control and Decontamination Physical methods of decontamination Biological Decontamination Chemical Inactivation 10 Physical methods of decontamination Cleaning Segregation and sorting Thermal degradation Microwave treatment Solar degradation Extrusion cooking (promising) 11 Microbiological Decontamination Ethanol fermentation Probiotic mixtures (Lactobacillus, Propionibacterium) 12 Chemical Inactivation Nixtamalization/alkaline hydrolysis Bisulfite Ammoniation Hydrogen peroxide/sodium bicarbonate Ozonation Activated charcoal 13 Ranges in 1987 and 1996 of maximum tolerated levels (ng/g) for some aflatoxins and countries that have regulations for these B1 in foodstuffs 0-50 (1987)-(29)* 0-30 (1996)-(33)* B1+B2+G1+G2 in 0-50 (1987)-(30)* foodstuffs 0-50 (1996)-(48)* B1 in feedstuffs 5-1000 (1987)-(16)* 5-1000 (1996)-(19)* B1+B2+G1+G2 in 10-1000-(8)* feedstuffs 0-1000-(21)* *countries with legislation for mycotoxins 14 Types of higher plant toxicants Pyrrolizidine alkaloids (several plant species) Psoralens (celery, legumes, citrus fruits) “Bracken carcinogen” (bracken) Glycoalkaloids (potatoes, tomatoes) Glycosinolates (Brassicas,vegetables, rapeseed) 15 Factors that influence the levels of nitrate in crops The season in which the crops are grown Increased irrigation may decrease nitrate concentrations in crops Storage of vegetables has unpredictable effects Cooking may reduce levels of nitrite in vegetables Lengthening the period between nitrogen fertiliser usage and crops harvesting may decrease nitrate levels in crops The effects of organic farming on nitrate levels are not established 16 Heavy metals in plants Lead Cadmium Mercury Arsenic Aluminium 17 References Official Journal of the European Communities, Commission Directive 2000/24/EC of April 2000 (L 107/28, 4.5.2000) European Commission, Opinion of the Scientific Committee on Plants regarding variable pesticide residues in fruit and vegetables (Opinion expressed by SCP on 14 July 1998) Third Joint FAO/WHO/UNEP International Conference on mycotoxins (Tunis, Tunisia, 3-6 March 1999) Safety of Chemicals in Food (chemical contaminants) Ed. David Watson, Ellis Horwood series in Food Science and Technology (1993) 18
"Phases of a food safety management programme for naturally "