Download Egg quality: Chemical residues in respect to food safety

Egg quality:
Chemical residues in respect
to food safety
E. Esteve-Garcia1 and J.A. García-Regueiro2
1Department
of Animal Nutrition, Centre de Mas Bové,
Apartat 415, 43280 Reus, Spain
2Meat Technology Centre, Food Chemistry Unit, Granja
Camps i Armet, 17121 Monells, Spain
Egg is a very valuable source of
nutrients
• Essential amino acids
• Vitamins (except vitamin C) and other
interesting carotenoids (lutein, zeaxanthin)
• Essential minerals
• Linoleic and linolenic acid
Monitoring
Comission Decission 97/747/EC
Directive 96/23/EC
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Sample should allow tracking
Taken at farm level or at packing centre
12 eggs or more
1 sample per 1000 Tonnes of annual
production. Minimum 200 samples.
• 30 % taken at packing centres
Monitoring
Comission Decission 97/747/EC
Directive 96/23/EC
Groups tested:
• 70 % tested for groups A6, B1 and B2(b)
– A6 :pharmacologically active substances for which no
maximum levels can be fixed (banned)
– B1 :antibacterial substances, including sulfonamides
and quinolones
– B2 (b ) Anticoccidials, including nitroimidazoles
• 30 % according to situation, but must include B3 (a)
– Organochlorine compounds, including PCBs
Limits
• Drugs: MRLs in Unofficial consolidated version
of Annexes I to IV of Council Regulation 2377/90.
Updated 22/12/2004.
• Limits for pesticides. Directive 2002/32/CE.
• Limits for Dioxins. Directive 2001/102/CE.
Undesirable (SCAN, 2003)
• Ions or elements
– heavy metals
– other trace elements, coming from feeds or
water
– radionuclides
• Mycotoxins
Undesirable (SCAN, 2003)
• Other organic contaminants including:
– organochlorine compounds
• pesticides
• Dioxins
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other pesticides
polychlorinated biphenyls
brominated flame retardans
mineral oil hydrocarbons
• Plant and natural plant products
• Drugs
Heavy metals
• In general levels are greater in albumin
Lead
• Chronic and cumulative
• Accidental contamination:
– airborne deposition in plants.
– Drinking water. Soft waters and leaded pipes.
– Paints,
• Affects enzymes, anemia, renal toxicity,
carcinogen, cardiovascular and neurobiological
impact
• Levels are low in eggs (0.003 to 0.259 mg/kg in
European surveys)
• PTWI= 0.020-0.025 mg/kg body weight
Mercury
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Chronic and cumulative
Teratogenic and carcinogenic, damages CNS
Organic is more toxic.
Feeding seed grains treated with methylmercuric chloride
to prevent insect infestation. 93 mg/kg in albumen and 5.8
mg/kg in yolk.
Accidental contamination in Washington State in 1979 by
mercurial fungicides. Nowadays are banned
Maximum EU 0.3 mg Hg/kg in calcium carbonate
European survey. Avg=0.0013- 0.005 mg/kg. Max= 0.01
mg/kg
PTWI= 0.005 mg/kg body weight/week.
– < 0.0033 mg/kg body weight/weeek as methyl mercury
Cadmium
• Toxicity: long term exposure
• Teratogenic and carcinogenic, kidney, bones,
neurotoxic
• Sources: plants grown in Cd rich soils, impurities
in minerals, drinking water
• Present in egg yolk. Transfer is low, retained in
follicle walls.
• Low levels in eggs in surveys (0.001-0.01 mg/kg).
• PTWI = 0.42 mg/person/week
Arsenic
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Skin lesions and neurological effects
Water, arsenicals (discontinued), pesticides
As3 more toxic than As5
In the egg, yolk/albumen=1/3
At increasing levels in feed a plateau is reached
rapidly
• Low levels in eggs in surveys (0.001-0.006 µg/g).
• PTWI= 0.015 mg/kg body weight/week
Fluorine
• In phosphate supplements (should be
defluorinated).
• Genotoxic, skeleton (bone fracture), dental
fluorosis and hypomineralization of enamel.
• Transferred to eggshell.
• High F diets result in 0.4-1.0 mg F/kg fresh
albumen, and 3.1-8.4 mg F/kg dry fat free yolk.
• Risk of bone effects > 5 mg F/day
Nitrates
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Present in water and vegetables
Anaemia
Nitrites in water. Formation of methaemoglobin
Fast excretion in urine. No bioaccumulation.
Little information in eggs. Content probably low?
Low compared to other sources (water)
Limits for feeds (mg/kg)
EU (1999-2002)
Arsenic
2
Lead
5
Fluorine
350
Mercury
0.1
Cadmium
0.5
Radionuclides
• Transfer is higher than for other animal products
• Experience from Chernobyl accident: 137Cs and 131I from
contaminated cereals.
• Countermeasures: Iron (III) hexacyanoferrates
• U and Po in phosphates in Israel. Dose equivalent for all
poultry products (70% of meat) is 0.04 mSv/year.
• (According to ICRP individual doses of less than 10
μSv/year are negligible)
Limits according to Council Regulation (EURATOM) No
2218/89 (Bq/kg)
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90Sr:
125; 131I: 500; 239Pu and 241Am: 20; 134Cs and 137Cs and all t1/2
> 10 days: 1000
– 3H, 14C and 40K are excluded
Mycotoxins
• Eggs < animal feeds. Unlikely acute toxicity
• Aflatoxin B1, M, ochratoxin A are
carcinogenic and must be monitored.
• Fumonisin, Vomitoxin, and zearalenone
found at very low levels or not found ata all
when contaminated feeds are given to hens.
Ochratoxin A
• No information in eggs of laying hens
• In Japanese quail there is transfer to eggs.
• Contribution of products of animal origin is
not more than 3 % of the burden
Aflatoxin B1
• Residues when feed is 500 µg B1/kg feed but not
at 300 µg B1/kg feed
• Transfer 4615:1 in yolk, 3846:1 in albumen
• In Japanese quail transfer is higher
• After 7 days withdrawal only traces in eggs
• Limit in feeds is 0.02 mg B1/kg feed
• Limit in eggs is 3 pg WHO-PCDD/F-TEQ/ g fat
• Maximum level based on ALARA
T2 Toxin
• Inmunosupresive and carcinogenic
• 1 mg T2 for 8 days
0.9 µgT2/egg
• Limits in Israel and Russia: 0.1 mg T2/kg
feed
Organochlorine pesticides
• Transferred to eggs in many cases
• Very persistent. DDT (metabolites) still can be
found in eggs more than 25 years after use was
discontinued.
• Banned for most applications in Europe and USA
but still used in some third world countries:
Monitoring of eggs and feed ingredients
• Limits for complete feeds and supplemental fats:
see manuscript, adapted from EU 1999
Brominated flame retardants
• Accumulated like PCBs. From landfill and
industry emissions
• Transferred to eggs
• Weight loss, liver damage, inmunity and
reproduction. Carcinogenic
• Banned in Europe.
• Survey in Catalonia (Spain) PBDEs 58.3-64.5
ng/kg of wet weight in eggs
• NOAEL is 0.15 mg/kg BW (WHO, 1994)
Plant and natural plant products
• EU list of 1999 includes 17 plant species
and 5 natural products
• According to SCAN risk is low.
• Affect health of animals rather than the
products derived from them
Mineral oil hydrocarbons
• Carcinogen
• Accidental contamination of fats and oils from gas
oils (C18-C35) or synthetic oils (C25 and beyond
C45) by discharge of waste oils.
• FDA maximum in cereals is 100 mg/kg
• Survey in Switzerland in fats for animal feeds
levels between 100 and 1000 mg/kg.
– In 1999 in the fat phase of eggs average 30 mg/kg, and
maximum 80 mg/kg.
Prevention
• At farm level:
– Good production practices.
• Control and traceability of feeds
• Wtihdrawal time for drugs
• Control of drinking water
• Feed
– Monitoring of ingredients. European legislation
• HACCP
• Traceability
Eggs are very valuable sources of
nutrients
• Knowledge of risks is necessary to prevent
contamination