Upload
others
View
5
Download
0
Embed Size (px)
Citation preview
CHEMICALS IN FOODS
2. Food Contaminants
Prof. dr. ir. Hubert Paelinck
KULEUVEN – Technology Campus Ghent
Gebroeders Desmetstraat 1
B-9000 Gent
Belgium
CHEMICALS IN FOODS
Theme 1: Food Contaminants
Introduction: Food safety aspects
1 Toxic trace elements
2 Toxic compounds of (micro)biological origin
3 Pesticides
4 Veterinary medicines
5 Polychlorinated biphenils (PCB’s)
6* Polycyclic aromatic hydrocarbons (PAH’s)
7* Lipid oxidation products
8* Nitrosamines
* Produced during processing
INTRODUCTION: FOOD SAFETY ASPECTS
● Acute toxicity
LD 50 (median lethal dose/rats): mg/kg BM
Introduction
Substance LD 50 LD 50 (g/kg)
Water 90 g/kg 90
Ethanol 7 060 mg/kg 7.06
Salt 3 000 mg/kg 3
Aspirin 200 mg/kg 0.2
DDT 113 mg/kg 0.113
Nicotine 0.5 mg/kg 0.0005
Aflatoxin B1 0.48 mg/kg 0.00048
TCDD (a dioxin) 20 µg/kg 0.00002
Polonium-210 10 ng/kg 0.00000001
Botulinum toxin 1 ng/kg 0.000000001
1. TOXIC TRACE ELEMENTS
- Mercury
Minamata disease (‘50)
- Lead
- Cd
No acute health hazard
- Radionuclides
137 Cs, 90 Sr
No acute health hazard
(methylmercury)
1. Toxic trace elements
tetraethyllead
2. TOXIC COMPOUNDS OF (MICRO)BIOLOGICAL ORIGIN
2. Toxic compounds of (micro)biological origin
Remark:
60 – 90 % of food poisonings are bacterial in nature !!!!!!!!!
● Intoxications: Clostridium botulinum, Staphyllococcus
aureus, Clostridium perfringens, Bacillus cereus
● Infections: Salmonella* spp, Shigella spp, Escherichia coli,
Listeria monocytogenes
+ Mycotoxins (fungi, molds)
+ Plant toxins
* Salmonella typhi, S. paratyphi
Staphylococcus aureus α-toxin
C6760H10447N1743O2010S32
Botulinetoxine
BACTERIAL TOXINS
2. Toxic compounds of (micro)biological origin
2. Toxic compounds of (micro)biological origin
MYCOTOXINS Ergocristine
(Claviceps purpurea)
Aflatoxin B1 (Aspergillus spp)
Patuline
(Penicillium spp) Ochratoxin A (Aspergillus and Penicillinum species)
PLANT TOXINS
2. Toxic compounds of (micro)biological origin
Glycoalkaloids (Solanaceae)
+ Allergens :
gluten, milk, egg, tree nuts, peanuts, soybeans, fish, and crustacea
3. PESTICIDES
- Herbicides
- Fungicides
- Insecticides
-
- Acaricides
- Nematocides
- …..
- Rodenticides
3. Pesticides
3. PESTICIDES
3. Pesticides
Crop harvest losses:
World wide: 35 %
Europe: 25 %
Asia: 43 %
Africa: 60 %
??????????????????????????????????
??? Organic
is a crime
3. Pesticides
3. PESTICIDES
3. Pesticides
EFSA:
Conventional crops: 45 % contaminated with traces of pesticides
Organic crops: 15.5 % contaminated with traces of (allowed) pesticides
HERBICIDES
3. Pesticides
Glyphosate (Roundup)
Atrazine 2,4-Dichlorophenoxyacetic acid
U.S. insecticide use in 2001 in millions of acres
PYR=pyrethroid, CARB=carbamate, OP=orthophosphate.
INSECTICIDES
Cyfluthrin
aldicarb
parathion
zineb
benomyl
phenylmercury acetate
captan
dichlofluanide (euparen)
FUNGICIDES
sulfur
copper (II) sulfate:
Cu2+ + SO42- + Ca2++ 2(OH)- →Cu(OH)2+CaSO4
3. Pesticides
4. VETERINARY MEDICINES
4. Veterinary medicines
- Antibiotics
- Glucocorticoïds
- Sex Hormones
- Thyreostatica
- Psychosomatic agents
- ……..
ANTIBIOTICS: problem
antibiotics
antibiotic growth promotor
4. Veterinary medicines
Use of antibiotics in stock breeding
NL EU
ANTIBIOTICS
(human) pharmaceuticals
4. Veterinary medicines
EU ban: antibiotic growth promotors
benzylpenicillin streptomycin
tetracycline
chloramphenicol
adrenalin
cortison
aldosteron
GLUCOCORTICOÏDS
(inflammatory agents)
4. Veterinary medicines
Adrenal gland cortex
SEX HORMONES (anabolic steroids)
testosterone progesterone
trenbolone
diethylstilbestrol
(DES) zeranol
4. Veterinary medicines
Synthetic compounds
THYREOSTATICA
4. Veterinary medicines
- Growth promoting agents: clenbuterol
- β- agonists: carbimazole
PSYCHOSOMATIC AGENTS
Sedatives: librium, valium
4. Veterinary medicines
chloordiazepoxide
diazepam
5. POLYCHLORINATED BIPHENILS (PCB’S)
2,3,7,8 tetrachloordibenzo-p-dioxine
Ban: industrial applications (e.g. as transformer oil)
Belgium Dioxin Affair (1999):
50 kg PCB transformer oil
500 tonnes of animal feed
2 500 farms affected (in several countries)
60 000 pigs destroyed
9 000 000 chickens destroyed
+ 20 000 extra cancers ???????????????????
Total cost: 400 million euro
5. polychlorinated biphenils
6. POLYCYCLIC AROMATIC HYDROCARBONS (PAH’S)
6. Polycyclic aromatic hydrocarbons
C – H containing substances formed during processing
benzo[a]pyrene
chrysene
benzo[a]anthracene
benzo[k]fluoranthene
Carcinogenic, mutagenic and teratogenic properties
Metabolism of benzo[a]pyrene yielding the carcinogenic
benzo[a]pyren-7,8-dihydrodiol-9,10-epoxide.
6. Polycyclic aromatic hydrocarbons
6. POLYCYCLIC AROMATIC HYDROCARBONS (PAH’S)
6. Polycyclic aromatic hydrocarbons
C – H containing substances formed during processing
Formed during burning* of carbon containing materials:
1. Fuels (coal) TAR !!!!! charcoal
* Pyrolysis
6. POLYCYCLIC AROMATIC HYDROCARBONS (PAH’S)
6. Polycyclic aromatic hydrocarbons
C – H containing substances formed during processing
Formed during burning* of carbon containing materials:
1. Fuels (coal)
2. Wood: SMOKE !!!!!!!!!!
6. POLYCYCLIC AROMATIC HYDROCARBONS (PAH’S)
6. Polycyclic aromatic hydrocarbons
C – H containing substances formed during processing
Formed during burning* of carbon containing materials:
1. Fuels (coal)
2. Wood: SMOKING MEATS/FISH (foods)
benzo[a]pyrene < 50 µg/kg
Liquid Smoke
6. Polycyclic aromatic hydrocarbons
SMOKING: Traditional process (Lab scale)
6. Polycyclic aromatic hydrocarbons
Liquid smoke installation
6. POLYCYCLIC AROMATIC HYDROCARBONS (PAH’S)
6. Polycyclic aromatic hydrocarbons
C – H containing substances formed during processing
Formed during burning* of carbon containing materials:
1. Fuels (coal)
2. Wood
3. Fat FRYING !!!! (+ BBQ)
* Pyrolysis
6. POLYCYCLIC AROMATIC HYDROCARBONS (PAH’S)
6. Polycyclic aromatic hydrocarbons
C – H containing substances formed during processing
Formed during burning* of carbon containing materials:
1. Fuels (coal)
…..
4. Foods of vegetable and /or animal origin:
GRILL, BBQ, TANDOORI OVEN
6. POLYCYCLIC AROMATIC HYDROCARBONS (PAH’S)
6. Polycyclic aromatic hydrocarbons
C – H containing substances formed during processing
Formed during burning* of carbon containing materials:
1. Fuels (coal)
2. Wood
3. Fat
4. Foods
5. Incense (spices, herbs) + BBQ !!!!!
* Pyrolysis
6. POLYCYCLIC AROMATIC HYDROCARBONS (PAH’S)
6. Polycyclic aromatic hydrocarbons
C – H containing substances formed during processing
Formed during burning* of carbon containing materials:
1. Fuels (coal)
2. Wood
3. Fat
4. Foods
5. Incense
6. Tabacco
* Pyrolysis
R*
ROO*RH
Initiatie
O2 Dimeren; polymeren;cyclische peroxiden;hydroperoxverbindingen
RH
splitsen
Aldehyden; ketonen;koolwaterstoffen; furanen;zuren
ROOH
HO*
RO*ROOR,ROR dimeren
Aldehyden Alkylradicalen Semi-aldehyden
O2
Koolwaterstoffen;kortketenige aldehyden;zuren;epoxiden
Condensatie-producten
Koolwaterstoffen
O2
ROOH
Koolwaterstoffen;aldehyden;alcoholen
ofoxo-esters
Propagatie
Xxxxxxxx
Xxxxxxxx
AH
Fe2+
Fe2+
O2 scravenger
7. LIPID OXIDATION PRODUCTS
7 Lipid oxidation products
O2*
7. LIPID OXIDATION PRODUCTS
7 Lipid oxidation products
REACTIVE OXYGEN SPECIES
O2 O2* H2O2 HO* H2O
e- e- e- e-
H+ H+ H+
1 – 5 % of consumed oxygen is converted to reactive
oxygen species
Gastro intestinal Eye Skin Heart
Hepatitis Liver injury Cataractogenesis
Retinal damage
Dermatitis Age
pigment
Heart attack
Teeth
Periodontis
Joints
Arthritis Reactive Oxygen Species
Vessels Multiorgan failure Brain Lung
Atherosclerosis Cancer Trauma Asthma
Vasopasms Stroke Hyperoxiia
EFFECT OF ROS ON DEGENERATIVE DISEASES
7 Lipid oxidation products
Lipid Peroxides
Catalysts (Fe, Fe-O2) Decomposit Decomposition
Polyunsaturated Fatty Acids
Free Radical Initiation H-abstraction Diene Conjugation O2 uptake
Polymerization Secondary By-products Insolublization
(dark color, possibly toxic) including rancid off-flavor of proteins
AUTO-OXIDATION OF LIPIDS
7 Lipid oxidation products
LIPID OXIDATION IN COOKED HAM
7 Lipid oxidation products
PRODUCTION OF TOXIC COMPOUNDS
● Many secondary by-products of lipid oxidation are
xxpotential carcinogens
● Hydroperoxides are known to damage DNA ● Carbonyl compounds may affect cellular signal
xxtransduction
● Aldehydes: 4-HNE and MDA, toxic compounds ● Epoxides and hydrogen peroxide by-products are
xxknown carcinogens
7 Lipid oxidation products
CH3 - CH2
CH3 - CH2
N – N = O
CH3
CH3
N – N = O
2A Probably carcinogenic for humans
N
NO
N
NO
O
N
NO
2B Possibly carcinogenic for humans
N-nitrosodimethylamine (NDMA) N-nitrosodiethylamine
(NDEA) N-nitrosodibutylamine (NDBA)
N-nitrosopiperidine (NPIP)
N-nitrosopyrrolidine (NPYR)
N-nitrosomorpholine (NMOR)
CH3 – (CH2)3
N – N = O
CH3 – (CH2)3
(IARC, 1987)
8 NITROSAMINES
8 Nitrosamines
Nitrite, nitrate,
smoke, air,…
NO, NO2, N2O3
Amino acids,
peptides & protein
degradation products,
chemicals
Nitrosating agent
NO+
N-nitrosamine
Amine
+
(Loeppky et al., 1994)
43
SAFETY ASPECTS
8 Nitrosamines
Nitrosating agent
NO+
N-nitrosamine
Amine
+
GC-TEA
NDMA
NDEA
NDPA (IS)
NP IP
NPYR NMOR
NDBA
IC-HPLC-UV
RP-HPLC-UV
44
SAFETY ASPECTS
8 Nitrosamines
Gas chromatograph
- Thermo Electron Corp., Rodano, Italy
- GC column: glass, 1.8 m by 2 mm ID, packed with
10% Carbowax 20 M + 2% KOH on Chromosorb WAW, 80/100 mesh
- Carrier gas: argon, constant column flow rate: 25 mL/min
- Temperature injector: 175˚C
- Oven temp. program: Initial: 110˚C for 1 min
Ramping: 5˚C/min to 180˚C
Hold time: 5 min
Gas chromatography – thermal energy analyser (GC-TEA)
Thermal energy analyser (detector)
Thermo Electron Corp., model 610; Breda,
Nederland
Attenuation: 4
GC operate mode pressure: 1.2 mmHg
Interface temperature: 250˚C
Pyrolizer temperature: 500˚C
Vent mode pressure: 0.6 mmHg
8 Nitrosamines
GC-TEA chromatogram
NDMA: N-nitrosodimethylamine; NDEA: N-nitrosodiethylamine; NDPA: N-nitrosodipropylamine;
NDBA: N-nitrosodibutylamine; NPIP: N-nitrosopiperidine; NPYR: N-nitrosopyrrolidine
retention time, tR [min]
0 5 10 15 20
signal
[mVolt]
ND
MA
ND
EA
ND
PA (
IS)
ND
BA
NP
IP
NP
YR
8 Nitrosamines
HEATED CURED LEAN MEAT
BRINE:
2% NaCl
0.3% Na5P3O10
LEAN MEAT
(M. longissimus dorsi)
NaNO2:
0 mg kg-1
120 mg kg-1
480 mg kg-1
OR
OR
BLANK (0 mg kg-1)
PROLINE (1000 mg kg-1)
HYDROXYPROLINE (1000 mg kg-1)
PYRROLIDINE (10 mg kg-1)
PUTRESCINE (1000 mg kg-1)
CADAVERINE (1000 mg kg-1)
SPERMIDINE (1000 mg kg-1)
SPERMINE (1000 mg kg-1)
PIPERIDINE (10 mg kg-1)
HEATING:
• 85°C/30 min (pasteurization)
• 120°C/30 min (sterilization)
• 160°C/30 min (baking)
• 220°C/30 min (roasting)
8 Nitrosamines
Proline (1000 mg/kg)
N COOH
8 Nitrosamines
Piperidine (10 mg/kg)
N
8 Nitrosamines
50
Raw material
Cutting
Mixing
Stuffing
Resting
Fermentation
1st ripening/drying
2nd ripening/drying
Final product
Slow process
Rapid process
Day 0
Day 4 - 21
Day 0 - 3
DRY FERMENTED
MEAT PRODUCTS
8 Nitrosamines
Sarcoplasmic and myofibrillar proteins
Free amino acids
Oligopeptides
Small peptides
Cathepsines Calpains
Tripeptidylpeptidases Dipeptidylpeptidases
Dipeptidases Aminopeptidases Carboxylpeptidases
(Toldrá, 2002)
(Biogenic) Amines
Tryptamine Phenethylamine
Cadaverine Putrescine Histamine Serotonine Tyramine Spermine
Spermidine
51
SAFETY ASPECTS
8 Nitrosamines
52
SAFETY ASPECTS
8 Nitrosamines
N-nitrosamines (µg/kg)
Type n NDMA NDEA NDBA NPIP NPYR NMOR
Boerenring 3 nd nd nd nd-0.9 nd nd-0.6
Boulogne 3 nd nd nd nd-0.3 nd nd-0.6
Chorizo 10 nd-0.7 nd nd-1.4 nd-1.7 nd-0.8 nd-1.6
Dry sausage 6 nd nd nd nd-0.5 nd nd
French types 6 nd-0.2 nd nd nd-0.3 nd nd-0.5
Garlic salami 6 nd nd nd nd-0.3 nd-0.3 nd-0.5
German types 2 nd nd nd nd nd nd-0.8
Italian types 9 nd-0.6 nd nd nd-2.4 nd nd-1.2
Light salami 5 nd-1.0 nd nd nd-0.5 nd nd
Pepper salami 4 nd-0.3 nd nd 0.3-12.3 nd-1.5 nd
Salami 10 nd nd nd nd-0.6 nd nd-0.7
Saucisson
d’Ardennes
6 nd nd nd-0.4 nd nd nd-0.8
Smoked salami 10 nd nd nd nd-5.2 nd nd-0.5
Snack 15 nd-0.31 nd nd nd-2.6 nd nd-0.8
Turkey salami 6 nd-0.8 nd nd nd-1.4 nd nd-0.9
53
8 Nitrosamines
SPICES:
Samples Piperine (mg/g)
PIP (mg/g)
White and black pepper max. 21 max. 11
Paprika and chili ± 2 nd
Allspice and nutmeg ± 2 traces
3 g spices + 100 g NPZ
(NaCl + 0.6% NaNO2)
Pepper (g/kg)
Piperine (mg/kg)
PIP (mg/kg)
2 (average)
42 12 22 34
5 (high)
105 31 55 86
Calculated in dry fermented sausages:
Worst case scenario: still < 100 mg/kg PIP
+
+
• Curing mixtures:
54
NPIP (ng/g)
8 Nitrosamines
THANK YOU FOR YOUR ATTENTION
THANKS FOR ALL