Food Toxicology Group A Food Toxicology Overview Definition

Food Toxicology Group A

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

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

Causes of Food Toxicity 3 types Biological Chemical Physical

Causes of Food Toxicity Bacteria and Viruses Parasites Fungi Allergens

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

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.

Intrinsic Toxins Different categories of toxin depending upon its harmful effect Goitrogens: Direct effect on thyroid gland 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

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

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

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

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

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

Principals of Food Toxicology

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

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.

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

Toxicology Paradigm

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

Toxicokinetics

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.

Toxicokinetics VS Toxicodynamics

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

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.

Most Common Food Allergens

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

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

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

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.

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

LD 50:

Graphical Representation:

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

Potency:

Potency Vs. Efficacy:

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

Additive Effect:

Synergistic Effect:

Antagonism: