1. Food Toxicology Group A

2. Food Toxicology: Overview  Definition:  Food toxicology is the study of the nature, properties, effects, and detection of toxic substances in food, and their disease manifestation in humans.  Introduction  Historical background

3. Historical Background  “All substances are poisons, there is none which is not a poison. The right dose differentiates a poison from a remedy” ----Paracelsus (1493-1541)  Percival Pott  Orfila  Father of modern toxicology  Developed methods to quantify poisons

4. Causes of Food Toxicity  3 types  Biological  Chemical  Physical

5. Causes of Food Toxicity  Bacteria and Viruses  Parasites  Fungi  Allergens

6. Example  Compylobacteriosis  Causes:  Compylobacter jejuni  Diarrhea, vomiting and abdominal pain  Carrier: Raw poultry, Raw milk, undercooked poultry, Animal feces

7. Intrinsic Toxins  Present naturally in the food  Reduction by the suitable processing  Requires careful Food selection  For example, solanine is present in green part and sprouts of potatoes.

8. Intrinsic Toxins  Different categories of toxin depending upon its harmful effect  Goitrogens:  Direct effect on thyroid gland and cause goiter  Cassava beans contains these toxic compounds  Soaking, prior to cooking, can detoxify food.  Tannins:  Causes astringent and bitter taste  Carcinogen and Genotoxic effect  Careful selection of food can reduce chances of intoxication

9. Intrinsic Toxins  Phytoestrogens:  Non steroid compound  Structural similarity with steroidal which is steroid.  Food source may be rice, apples sesame seeds etc.  Cause cancer, disorders in reproductive system and osteoporosis  Phytates:  Food source are walnuts, paenuts and brown rice  Binds with iron to cause anaemia

10. Intrinsic Toxins  Antivitamins:  Replaces vitamin K due to structural similarity  Works anticoagulant of proteins

11. Extrinsic Toxins  Added externally either during processing or after processing  Contamination  Fungal toxins:  Aspergillus spp, Fusariuam spp, Penicillium spp.  Aflatoxins:  Aflatoxicosis  Produced by Aspergillus spp.  Sources are nuts, rice, meat, cottonseed  Carcinogenic

12. Extrinsic Toxins: Bacterial Toxins  Bacillus cerues:  Present in soil, dust and water  Produce a toxin “ cereulide”  Carrier is poorly cooked food  Causes nausea, abdominal cramps and vomiting  Clostridium perferingens  Present in soil and tract of human and animal  Produces “ lecithenase”  Carriers are turkey, chicken and beefs

13. Extrinsic Toxins: Chemical Toxins  Fertilizers:  Residues are present in food  Soil acidulation  Heavy metal accumulation  May present due to fertilizers residue or nearby industrial waste  Cadmium  Fluorine  Zinc  Calcium- low toxic

14. Principals of Food Toxicology

15. Food Toxicology  Food toxicology is concerned with assessing the injurious effects on living systems of chemicals present in foods and feeds.  Examine adverse effects ranging from acute to long-term  Naturally occurring or added by the environment

16. Toxicants  A poison or toxicant is the chemical that is harmful to living organisms because of its detrimental effects on tissues, organs, or biological processes  Four factors influence toxicity:  The toxic substance itself  The matrix in which it is present  The circumstances of exposure  The organism and its environment.

17. Classification of Toxicants  Heavy metals  Microbial toxins  Pesticides  Mushroom toxins  Plant toxins  Animal toxins  Food Allergens  Cyanides

18. Toxicology Paradigm

19. Toxicokinetics  Toxicokinetics describes the fate of toxic compound in the body.  Absorption  Ditribution  Biotransformation  Excretion of Toxic compounds  Sometimes called as Pharmacokinetics

20. Toxicokinetics

21. Toxicodynamics  Toxicodynamics describes the determination and quantification of the sequence of events at the cellular and molecular levels leading to a toxic response to an environmental agent  Sometimes referred to as pharmacodynamics.

22. Toxicokinetics VS Toxicodynamics

23. Toxicity Testing  To estimate the levels of the substance to which the population is exposed.  Acute Toxicity: to determine the level of the substance which induces mortality in laboratory animals.  Genetic Toxicity: to determine the tendency of the substance to induce mutations in the test organism.  Metabolism: to gain both a general and a quantitative understanding of absorption, biotransformation and disposition of the toxic substance

24. Difference Between Allergies and Toxic Reactions  Toxic effect is directly the result of the toxic chemical acting on cells  Allergic responses are the result of a chemical stimulating the body to release natural chemicals which are in turn directly responsible for the effects seen.

25. Most Common Food Allergens

26. Routes of Toxic Exposure  Ingestion Toxics present in food items, cosmetics, household products  Inhalation Aerosols, toxic gases, vapors  Surface absorption Poison, ivy, oak, cosmetics  Injection Intentional injection of illicit drugs, stings/bites

27. Routes of Toxic Exposure  Ingestion  Common agents:  Household products  Petroleum-based agents  Cleaning agents  Cosmetics  Drugs, plants, or foods Absorption occurs in the stomach and small intestine.

28. Sub-disciplines of Toxicology  Analytical toxicology  Clinical toxicology  Forensic toxicology  Industrial (occupational) toxicology  Environmental toxicology  Regulatory toxicology

29. Dose-Response Relationship:  Fundamental and essential concept.  The higher the dose, the more severe the response.  Based on observed data from experimental animal, human clinical, or cell studies.

30. Dose-Response curve:  Dose-Response relationship is illustrated by Dose-Response curve.

31. LD 50 : 

32. Graphical Representation:

33. Variation is Dose-Response curves:  There is variation in Dose-Response curves in following parameters:  Predictability  Potency  Margin of safety  Potency vs. Efficacy  Interaction of chemicals

34. Potency:

35. Potency Vs. Efficacy:

36. Interaction of Chemicals:  Interaction of chemicals occur in three ways:  Additive Effect  Synergistic Effect  Antagonism

37. Additive Effect :

38. Synergistic Effect:

39. Antagonism: