Food safety Training Course Co-financiado:
Dec 27, 2015
• What are they?• Main characteristics of living
beings?• Functions and applications?
Microorganisms
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• What do you understand by microbial growth?
• What factors affect microbial growth?
• How can we control the growth?
Microbial Growth
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Microbial growing stages in a liquid environment. A – Lag stage; B- log stage; C- stationary stage and D- death stage
Log10células/mL
Tempo
crescimento em condiçõesóptimas
crescimento em outrascondições
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Microbial Growth
Time
Growth in other situations
Growth in optimum conditions
• Intrinsic factors? • Extrinsic factors?• Other factors:
- Biological structures
- Natural antimicrobial substances
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Microbial Growth
Data: Jay, J.M., 1996
Microbial growth
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Microorganisms Minimum pH Optimum pH Maximum pH
Mold 1, 5 to 3,5 4, 5 to 6,8 8 to 11
Yeast 1, 5 to 3,5 4 to 6,5 8 to 8,5
Bacteria (most) 4,5 to 5,5 6,5 to 7,5 8,5 to 9
Lactic Bacteria 3 to 5 5,5 to 7,5 6,5 to 8
Table I – pH level interval for the growth of some microorganisms
Dados de : Jay, J.M., 1996
Microbial Growth
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Product pH Product pH
Egg whites 7,5 to 9 Corn 7 to 7,5
Egg yolk 6,1 Potatoes 5,3 to 5,6
Shellfish 6,8 to 8,2 Carrots 5,2 to 6,2
Fish (most) 6,3 to 6,8 Onion 5,3 to 5,8
Fresh milk 6,3 to 6,5 Tomatoes 4,2 to 5,8
Butter 6,1 to 6,4 Oranges 3,6 to 4,3
Chicken 6,2 to 6,4 Grapes 3,4 to 4,5
Pork 5,3 to 6,4 Apples 2,9 to 3,3
Beef 5,1 to 6,2 Lemons 1,8 to 2,4
Table II - Approximate pH levels of some food products
• Extrinsic factorsMicrobial growth
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TemperatureTemperature is one of the most relevant factors for microbial growth .
Microbial growth
Data: Jay, J., 1996.
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Boiling point
Freezing
Hours N.º of bacteria
Microbial growth
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•Utilization of risk temperatures while conserving food/meals;
•Utilization of inadequate temperatures while preparing/processing those foods (under processing);
These are the two main causes that lead to Intoxications :
Adapted from: Adams, M.R. and Moss, M.O., 1995
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Microbial growth factors – Hurdle effect
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• Main groups with importance for FS:– Bacteria
• Main characteristics
– Fungi (Molds and yeasts)• Main characteristics
Microorganisms
• Unicellular (yeasts);• Multicellular (molds or filamentous
fungi);• Great decomposers of organic matter;• Widely used for making food and
beverages;• Some are eatable (mushrooms);• Responsible for deteriorating most
fruits and vegetables.
Fungi
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Molds and yeasts
Some utilizations of fungi: a) Some eatable mushrooms. b) beer ; c) bread; d) Roquefort cheese with blue mold; e) e f) Camembert an brie cheeses (respectively) with white mold.
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• What are the sources of microorganisms that are present on foods?
– Soil;– Water; – Air;– Handlers;– Utensils and equipments;– Products themselves or raw
materials used in their fabrication.
Main sources
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• Soil- Source of spore forming bacteria, fungi
and yeasts;- Addition of manure – faecal
microorganisms;- Dissemination of microorganisms:
wind, rain, animals, fertilization…
Main sources
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Main sources What measures should be taken to avoid/reduce contamination?
Data: Jay, J.M., 1996 e Lacasse, D.. 1995.
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Type of product Num. of microorganisms
TomatoNot washed > 1 000 000/ cm2
Washed 400-700/cm2
Collards
External leaves not washed 1 000 000 – 2 000 000/g
Internal leaves washed 200 000 – 500 000/g
Internal leaves 100 – 10 000/g
Table III – Effect of washing on the flora of vegetable products
• Water- May contain various types of
microorganisms (origin and level of pollution);
- Utilization of potable water!
How to avoid contamination?
Main sources
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•Air- Non favourable environment for microbial growth;- Excellent conveyer of microorganisms from other sources: sneezing, coughing, agricultural activities …
How to reduce contamination caused by microorganisms transmitted by air?
Main sources
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• Food
Diverse and proper flora :
– Vegetables– Animals
Main sources
Soil Water
Animals
Intestines
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• Handlers- Diverse and own flora (faecal matter
and skin);- Main problems?
• Utensils and Equipments- Do not have own microflora;- Main cause of
CROSS CONTAMINATIONS!!!
Main sources
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• What is “cross contamination”?Microorganisms present in raw foods, utensils and contaminated surfaces are transferred to prepared or washed foods or to clean surfaces..
- What are the main conveyers?- How to prevent/avoid?- Examples
Cross contamination
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• Difference between “Hazard” and “Risk”
- What is the origin of hazards?
- Examples
Risks and hazards
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Risks and hazards
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Types of hazards
Microbiological
Examples of hazards Examples of associated foods Potential illnesses
Bacteria Salmonella Campylobacter
Eggs, poultry, raw milk and milk products
Raw milk, cheese, ice cream, salads
Salmonellosis Campylobacteriosis
Virus Rotavirus Hepatitis A virus
Salads, fruit and appetizers Fish, seafood, vegetables,
water, fruit, milk
Diarrhoea Hepatitis A
Parasites Toxoplasm Giardia
Pork, yearling lamb Water, salads
Toxoplasmosis Giardosis
Prions BSE agent Specific bovine risk materials
Variant of the Creutzfeldt-Jakob disease
Table IV – Classification of hazards related to food safety
Riscos e Perigos
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Table V – Classification of hazards related to food safety
Types of hazardsChemical
Examples of hazards
Examples of associated foods
Potential illnesses
Natural toxins Aflotoxins Solanin Marine toxins
Nuts, corn, milk and milk products
Potato Shellfish, seafood
Cancer, congenital malformations, premature births, alterations of the immune system; nervous system degenerative diseases; hormonal alterations, dysfunction of various organs; fertility alterations; muscle and bone diseases; behaviour alterations.
Pollutants of industrial origin Mercury, Cadmium and lead
Dioxins, PCBs
Fish Fish, animal fat
Contaminants that result from food processing
Acrilamid Polycyclical
aromatic hydrocarbons
French fries, coffee, cookies, bread
Smoked products, vegetable oils, grilled food
Pesticides Insecticides, herbicides, fungicides
Vegetables, fruits and fruit products
Veterinary medicines Anabolics, antibiotics
Poultry, pork, beef
Non authorized additives Sudan I-IV, for red (dyes)
Sauces, spices
Material in contact with food Aluminium, tin, plastic
Canned or plastic packaged food
Other Cleaning products, lubrificants
Riscos e Perigos
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Types of hazards
Examples of hazards
Examples of associated foods
Potential illnesses
Physical Bones, fish bones, glass, metal, stones
lesions
Nutritional Excess salt Table salt, snacks Cardiovascular diseases
Excess fat Butter, fat meat Obesity
Excess sugar Diabetes
Allergens Cow milk, peanut, eggs, crustaceans
Allergies
Table VI – Classification of hazards related to food safety
Intoxications and main agents
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• What are the main factors that determine the occurrence of food intoxications?
• What are the main agents?• What are the symptoms and
characteristics of these illnesses?
• What are the main foods related to food intoxications?
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Food Generally associated microorganisms
Raw seafood Vibrio sp., Hepatitis A virus, Norovirus (Norwalk-like viruses)
Raw eggs Salmonella
Undercooked meat Salmonella and Campylobacter, Escherichia coli STEC, Clostridium perfringens
Unpasteurized milk or juice
Salmonella, Campylobacter, Yersinia, STEC
Unpasteurized soft cheese
Salmonella, Campylobacter, Yersinia, Listeria sp., STEC
Homemade conserves Clostridium botulinum (botulism)
Hotdogs, ham, etc. Listeria sp.
Table VI – Food and agents generally associated to foodborne intoxications
Intoxications and main agents
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Intoxications and main agents
Table VIII – Characteristics of main foodborne Intoxications
Microorganism Type of illness
Symptoms Probable food
Campylobacter jejuni InfectionDiarrhea, sometimes followed by fever; abdominal pain, nausea; headaches and muscle pain
Raw poultry and other food contaminated by raw poultry, unpasteurized milk, untreated water
Clostridium perfringes IntoxicationIntense abdominal cramps;
diarrheaMeat and meat products, sauces, products rich in protein
Escherichia coli (various types:
EPEC; EIEC; ETEC; and
EHEC)
Infection
Watery diarrhea, abdominal cramps, low fever, nausea, MAL ESTAR
Contaminated water, undercooked minced meat, unpasteurized milk and juice; pieces of melon.
Salmonella spp. Infection
Abdominal cramps, diarrhea, fever, headaches
Animal based food; other food contaminated due to the contact with feces, raw animal based food or infected handlers. Poultry, eggs, raw milk and meat are often found contaminated.
Hepatitis A InfectionFatigue, abdominal cramps, anorexia, intermittent nausea, diarrhea, vomiting
Raw or under cooked seafood, food prepared by infected handlers
*Bacillus cereus Poisoning
Watery diarrhea, crampsNausea and vomiting
Cooked products left uncovered; milk, meat, vegetables, fish; rice and food rich in starch.Cooked products left uncovered; milk, meat, vegetables, fish; rice and food rich in starch
Clostridium botulinum Poisoning
Lethargy, weakness, dizziness, double vision; difficulty talking, swallowing and/or breathing, paralysis, possible death
Inadequate processing of homemade conserves; hotdogs, marine products, canned minced garlic; honey
Staphylococcus aureus
Poisoning
Nausea, vomiting, abdominal cramps
Contaminated food due to inadequate handling and storage temperatures – meat and meat products; poultry and egg products; salads rich in proteins, sandwich fillings, pastry products with creams and fillings.