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FOOD POISONING. (c) PDST Home Economics. FOOD POISONING. Food poisoning is caused by eating food containing harmful substances. There are 3 types of food poisoning Chemical food poisoning: caused by chemicals such as antibiotics or pesticides in the food.
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FOOD POISONING (c) PDST Home Economics
FOOD POISONING • Food poisoning is caused by eating food containing harmful substances. • There are 3 types of food poisoning • Chemical food poisoning: caused by chemicals such as antibiotics or pesticides in the food. • Biological food poisoning: caused by chemicals that occur naturally in the food e.g. solanine in green potatoes or toxins in red kidney beans. • Bacterial food poisoning: caused by the presence of pathogenic bacteria in the food.
SYMPTOMS OF FOOD POISONING • Nausea • Vomiting • Abdominal cramps • Diarrhoea • Fever • Headache • Loss of appetite • Very serious for infants, invalids, pregnant women and elderly.
(H) BACTERIAL FOOD POISONING There are 2 types of bacterial food poisoning: • 1. Toxic food poisoning • 2. Infectious food poisoning
(H) 1. TOXIC FOOD POISONING • Some bacteria produce exotoxins as they grow in food both before and after its eaten. • Exotoxins are hard to destroy. Boiling for 30 mins is required. • Symptoms develop quickly- often within 2 hours • Examples: staphylococci and clostridium botulinum
(H) 2. INFECTIOUS FOOD POISONING • Caused by eating food containing large numbers of live pathogenic bacteria. • These bacteria make endotoxins which are released when they die. • Endotoxins are easy to destroy. Proper cooking and reheating will destroy both toxins and bacteria. • If not destroyed symptoms will appear after approx. 12 hours • Salmonella and listeria cause infectious food poisoning.
(H) HIGH RISK FOODS • Liquid protein foods are at high risk of contamination • Milk, cream • Eggs & egg dishes e.g. custard, mayonnaise • Meat, poultry, fish, shellfish • Meat pies, gravies, sauces, soups and stock • Reheated dishes
(H) FOOD POISONING BACTERIA • Learn 3 common strains of food poisoning bacteria: e.g. Salmonella, Staphylococcus aureus, Listeria monocytogenes. • Habitat /Sources • Factors affecting growth • High risk foods • Incubation period • Toxic or infectious • Symptoms
OTHER FOOD & WATER BORNE DISEASES • Here the food acts only as a means of transport for the organism. They do not grow in it. • Incubation longer. • Only small number of organisms can cause illness. • Organism enters bloodstream. • Symptoms varied - may not include vomiting or diarrhoea.