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1 Definition of Terms Food contamination – presence of harmful substances in food; tasteless & odorless Food Contamination & Spoilage

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Food Contamination & SpoilageDefinition of TermsFood contamination ± presence of harmful substances in food; tasteless & odorless1Definition of TermsFood spoilage ± damage to the edible quality of food; unacceptable taste & appearanceSpoilage affects the aroma, texture and/or appearance of food. Examples: sour milk, moldy cheese, slimy, rancid meat, or mushy, discolored vegetables2When food spoils, the following may change: ‡ appearance ‡ taste ‡ texture ‡ odour Food may becom

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Page 1: Food Contamination

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Definition of Terms

Food contamination – presence of harmful substances in food; tasteless & odorless

Food Contamination & Spoilage

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Food spoilage – damage to the edible quality of food; unacceptable taste & appearance

Spoilage affects the aroma, texture and/or appearance of food.

Examples: sour milk, moldy cheese, slimy, rancid meat, or mushy,discolored vegetables

Definition of Terms

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When food spoils, the following may change:

• appearance

• taste

• texture

• odour Food may become unsafe to eat.

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Color can often indicate the type of microbe involved in the spoilage: Black spots on meat are the result of Cladosporium

species. White spots are from Sporotrichum carnis. Yellow or green spots form as a result of the Penicillium

species. A rainbow effect, often seen on bacon and fish, is

caused by a spoilage bacteria known as Photobacteria that can break down ATP to produce visible light. After a couple of days, this bacterium can grow sufficiently to enable raw fish to glow in the dark!

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Food infection – caused by harmful live microorganisms that are present in food when consumed

Definition of Terms

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Definition of Terms

Food intoxication – caused by food containing toxins produced by harmful microorganisms

Food toxicoinfections – foodborne illness caused by a combination of food intoxication and food infection

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Definition of Terms

Foodborne illness – disease occurring as a result of consumption of contaminated food

Foodborne outbreak – development of foodborne illness in two or more people who have eaten a common food that is shown by laboratory analysis to be the source of the illness

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Potentially Hazardous Foods

Any natural or synthetic food or food ingredient that supports the rapid growth of infectious or toxigenic microorganisms or the slower growth of C.botulinum

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Potentially Hazardous Foods

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Potentially Hazardous Foods

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Not Potentially Hazardous Foods Hard-boiled eggs with shells intact, which

have been air dried Foods with Aw ≤0.85 Foods with pH ≤4.6 Foods that have been adequately

commercially processed & remain in hermetically sealed containers

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Not Potentially Hazardous Foods Foods for which laboratory evidence

(acceptable to the regulatory authority) demonstrates that rapid & progressive growth of infectious & toxigenic microorganisms or the slower growth of C. botulinum cannot occur.

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Sources of Food Contamination

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Types of Sources of Food Contamination Primary contamination

Infected animalsFecal pollution

Secondary contamination Infected humansOther animalsFomites (water, soil, plants, air)Food additives

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Types of Contamination

BiologicalChemicalPhysical

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Biological Contamination

Cause of most foodborne illness Caused by bacteria, viruses, parasites, &

fungi Can be spread by the air, through direct

contact, & through food itself Most are destroyed by adequate cooking, &

proper cooling during distribution & storage

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Foodborne infection

Salmonella sp.(chicken) Shigella sp. (fecal contamination) Campylobacter jejuni (chicken) Listeria monocytogenes (soil, chicken)

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Foodborne Intoxication

Bacillus cereus (rice) Staphylococcus aureus (infected food

handler) Clostridium botulinum (product, soil)

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Viral Infection

Hepadnavirus (water) Norwalk virus (fecal contamination)

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Biological Toxins

Seafood ToxinsCiguateraScombroidShellfish (histamine)Systemic fish toxins (e.g. pufferfish)

Plant Toxins Fungal Toxins

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Parasites Associated with Foodborne Diseases Taenia spp. Trichinella spiralis Toxoplasma gondii

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Chemical Contamination

Toxic substances that may occur naturally or may be added during the processing of food

Substances such as food additives & preservatives, pesticides, toxic metals, & toxic cleaning products

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Man-made Chemical Contaminants Cleaning solutions Food additives – nitrites, sulfites & MSG Pesticides – plant sprays Heavy metals – Cu, Cd, Pb, Zn, & brass Drugs – growth hormones, antibiotics

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Physical Contamination

Results from the accidental introduction of foreign objects into foods

Includes metal shavings, staples, glass, blades, fingernails, hair, bandages, pieces of wood, etc.

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Common Causes of Food Spoilage

Improper storage temperatures Incorrect storage times Improper ventilation Failure to separate foods Excessive delays between receiving and

storing Inadequate food safety standards

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Factors contributing to food poisoning outbreaks 1980 - 1995

Other 6%Poor personal

hygiene 9%

Inadequate cooking 27%

Temperature control 20%

Contaminated equipment 19%

Unsafe food source 19%

Source: Crerar, S.K. et al 19967.

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The food poisoning time bomb

8.

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Low-Temperature Food Preservation

Chilled storage: 50˚F (10˚C) to 59˚F (15˚C)

Refrigerated storage: 32˚F (0˚C) to 45˚F (7˚C)

Freezer storage: 0˚F (–18˚C) or below

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Pasteurization

High-temperature food preservation

Food product heated to 145˚F (63˚C) for 30 minutes or to 161˚F (72˚C) for 15 seconds then immediately cooled to 50˚F (10˚C) or less.

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Sterilization

High-temperature food preservationVirtually kills all microorganisms and their spores.

Heating usually takes place in a large container which is pressurized according to the food product, its ability to withstand heat, and packaging.