Soubra, Lama (2008) Toxic risk assessment of specific chemical substances and contaminants (Food additifs and Mycotoxins). PhD thesis Toxycologie, AgroParistech 2008AGPT0014 p.176.

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Abstract

Following an increasing number of crisis, food hazards entered in the category of major

concerns for humans and thereafter governments and international bodies improved the food

safety systems in order to reduce or prevent food borne illness. In Lebanon the food industry

and intensive agriculture recognized a rapid development that systems ensuring food safety are

deficient or absent, and that climate and storage conditions in addition to local food habits are

favorable to the presence of certain types of hazards that present health risks. The objective of

this research is to assess the level of food safety in relation with certain microbial contaminants

and chemicals (food additives (benzoates, sulphites, BHA and BHT) and mycotoxins

(ochratoxin A, aflatoxinsBG and deoxynivalenol)) in a selection of foods that are available in

the Lebanese market on one hand, and on the other hand to assess the risks related to the

selected food additives and mycotoxins for two subgroups of the Lebanese population

considered to be at risk: children and teenagers, in order to establish a hierarchy of the

importance of the risk that these substances represent to the health of these subgroups.

Available foodstuffs in the Lebanese market that are susceptible to contain these hazards were

identified and analyzed. 596 food samples were analyzed microbiologically. These belonged to

6 food categories: soft drinks, fruit juices, dairy products, potato chips, biscuits and canned

foods that are produced by the Lebanese food industry. 2200 food samples were analyzed

chemically to determine either their content in food additives (421 samples), or the degree of

their contamination by the mycotoxins (1779 samples). The representativness of the samples

was ensured by the fact that those were withdrawn randomly, during two different seasons,

from the major food markets in a way to cover the main brands available in the Lebanese

market. The analyses were performed in the laboratories of Saint Joseph University and of the

National Agricultural Research Institute (IRAL) according to validated methods and on foods

as consumed.

The risk assessment was carried out according to the steps of the scientific process of risk

assessment i.e. hazard identification and characterization, exposure assessment and risk

characterization. Dietary exposures to food additives and mycotoxins was obtained by

combining the food consumption data obtained from an individual food survey specially

developed and carried out during this research, with the contamination data obtained by

chemical analysis. The risk was characterized by comparing the estimated dietary intakes with

the toxicological reference values (TRV) established for these substances by the international

bodies and also by calculating the percentage of individuals that have dietary intakes exceeding

these TRV.

The results of microbial analysis showed that only 9% of the analyzed food did not comply

with current microbial food standards.

The results of chemical analysis showed that the food additives are present in a wide range of

foods including unauthorized foods according to the national standards in 70% of cases for

benzoates, 15% of cases for sulphites, 13% of cases for the BHA and 3.5% of cases for the

BHT, and at levels exceeding the authorized levels in 70% of cases for benzoates, 62% of cases

for sulphites and 37% of cases for BHA. Moreover they showed that the studied mycotoxins

are present at levels conform to the national, international and European standards.

The results of the risk assessment showed that, among the studied hazards, only aflatoxins BG

constituted a risk for the studied subgroups. In fact the mean, the p75 and the p95 of the

distribution of exposure were below the Toxicological Reference Value (TRV) fixed for

benzoates, sulphites, BHA, BHT, OTA and DON, and above the TRV fixed for aflatoxins with

values ranging from 182-769% the TRV for children and 144- 650% of the TRV for the

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teenagers group, and a percentage of individuals exceeding this TRV of 58% for children and

of 52% for teenagers.

Results also showed that it was necessary to bring special attention to the exposure of some

group of the population such as children and high consumers for whom the risk of being

exposed to a level higher than the toxicological reference values for food additives and

mycotoxins exist. The main contributors to the exposures of benzoates, sulphites, BHA, BHT

and the three mycotoxins were found to be, respectively, sodas and fruit juices, dried fruits,

biscuits, chewing gum and cereal products.

Table of content

Dédicace 2

Remerciements. 3

Résumé . 4

Abstract 7

Mots clés . 9

Key words. 10

Table de matières 11

Liste des tableaux . 13

Liste des figures 15

Introduction générale 19

1- Le risque alimentaire : définition et caractéristiques . 20

2- L’analyse du risque alimentaire . 21

2.1- L’évaluation du risque ou appréciation du risque. 22

2.2- La gestion du risque 22

2.3- La communication relative au risque 23

3- L’évaluation du risque alimentaire 23

3.1- L’identification du danger 24

3.2- Caractérisation du danger 33

3.3- Evaluation de L’exposition. 39

3.4- La caractérisation du risque 47

4- Les additifs alimentaires et Les mycotoxines en tant que risques alimentaires. 48

4.1- Les additifs alimentaires. 48

4.2- Les mycotoxines. 50

5- Problématique et méthodologie de la recherche 53

Matériels et méthodes 56

1- première étape: étude microbiologique 57

1.1- Etablissement de la liste d’aliments à échantillonner 57

1.2- Analyses microbiologiques . 57

2- Deuxième étape: enquête de consommation alimentaire. 67

2.1- Sujets 67

2.2- Questionnaires. 68

2.3- Traitement des questionnaires. 69

3- Troisième étape: Evaluation préliminaire des expositions alimentaires à certains additifs

alimentaires (benzoates, sulfites, BHA et BHT): Estimation de la consommation théorique

maximale d’additifs alimentaires . 71

4- quatrième étape: données analytiques pour les additifs alimentaires et les mycotoxines 72

4.1- les additifs alimentaires 72

4.2- les mycotoxines 81

5 - cinquième étape: évaluation scientifique des risques . 83

5.1- Identification et caractérisation du danger 83

5.2- Evaluation de l’exposition 83

5. 3- Caractérisation du risque 84

Résultats 85

1- Etude microbiologique. 86

2- Etude de consommation alimentaire 91

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2.1- Description des sujets 91

2.2- Description des données de consommation. 91

3- Evaluation préliminaire de l’exposition. 94

3.1- Estimation de la consommation théorique maximale des benzoates 94

3.2- Estimation de la consommation théorique maximale des sulfites 97

3.3- Estimation de la consommation théorique maximale du BHA. 99

3.4- Estimation de la consommation théorique maximale du BHT. 101

4- Données analytiques 103

4.1- Les additifs alimentaires. 103

4.2- les mycotoxines 112

5. Evaluation scientifique des risques 117

5.1- Présentation des résultats. 117

5.2- les additifs alimentaires 118

5.3- Les mycotoxines. 141

Discussion, Conclusion et Recommandations générales. 161

1- Evaluation des risques microbiologiques. 162

2- Evaluation préliminaire des expositions aux additifs alimentaires 163

3- données analytiques pour les additifs alimentaires et les mycotoxines . 165

3.1- Les additifs alimentaires 165

3.2- Les mycotoxines 168

4- Evaluation des risques liés à certains additifs alimentaires et à certaines mycotoxines 169

4.1- Considération méthodologique 169

4.2- Interprétation des résultats 170

5- Conclusion et recommandations générales 175

Références bibliographiques . 177

Annexes. 198

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