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Unformatted text preview: * Pasteurization: Method Params Approx Shelf Life- Batch 145˚F for 30min ~ 12 days- ↑ Tempt, Short Time 161˚F for 15sec ~ 14 days- Ultra Pasteurized 280˚F for 2sec; conv pack ~ 45-60 days- Ultra High Temp 280˚F for 2sec; aseptic pack ~ 6mo at room temp, 1 yr in fridge * Shelf life of food depends on: composition of the food, microbiological quality, processing method, packaging system, storage conditions * Roles of microorganisms in food:- Beneficial: fermented dairy, meat, veggies and other - Food Spoilage: off flavors & physical defects- Harmful: food borne illness * Major food incidents result from: mishandling, incorrect ingredients, packaging problems, lack of attention to detail, malicious contamination * Factors affecting rise in food borne illnesses:- Changes in food processing technologies- Increase in food prepared outside the home- Changes in microorganisms (fewer cells needed to cause illness/some are more sever) …However, there are improved diagnostic techniques * Food borne pathogens: EColi, listeria monocytogenes (can grow in fridge), salmonella, hep A, norovirus * Factors increasing the risk of food borne infection/severity:- Age <5yrs: lack of developed immune system- Age >50-60yrs: immune system failing- Pregnancy: altered immune system during pregnancy - Hospitalized people: individuals already debilitated by illness- Poor hygiene * Physical hazards: glass, plastic, metal fragments… can cause injury * Chemical hazards: toxic metals, poisonous chemicals, intentional food additives (Niacin: B 12 in Rochester bagels), poisonous plants, marine (seafood) toxins * PSP: Paralytic Shellfish Poisoning: can occur in shellfish, clams, scallops, and oysters. With the right combination of factors, dinoflagellates reproduce rapidly and produce a red-brown color on water → “red tide”. Molluskin shellfish infected. Here the saxitoxin blocks the sodium pores of nerve and muscle membranes and prevents sodium ions from entering the cells. * Scombroid Poisoning: A histamine intoxication that occurs in scombroid and related fish. With temp abuse, these organisms convert AA’s to histamine. Cooking/canning/freezing has no effect on scombrotoxin so the only way to prevent it is to put the fish in <40˚F ASAP * Cigueatera Fish Poisoning: Caused by consumption of tropical and subtropical reef fish that have accumulated naturally-occurring toxins in their diet. The fish do not food directly on plankton, but on smaller fish that feed on poisonous algae or plankton. Ciguatoxin is heat-stable so salting, drying, and cooking won’t inactivate the toxin. * Food borne illnesses:- Intoxications: caused by eating TOXINS produced by the growth of bacteria/mold ~ Bacterial intoxications: staphylococcus aureus & bacillus cereus (vomiting type)- Infections: caused by eating food w/ LIVING PATHOGENIC MICROorganisms ~ Bacterial infections: salmonella- Toxin-mediated infections: from eating food with bacteria that PRODUCE TOXIN in human intestine ~ Ex: bacillus cereus (diarrheal type), EColi O157:H7 * Steps necessary for food borne illness: Chain of infection for bacteria food borne illness: CS,DG,TQ...
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- Spring '07
- Bacteria, Foodborne illness, food additives