CHEMICALS IN FOODS 2. Food Contaminantschemia.us.edu.pl/chemia/attachments/article/6737/Lecture...

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