Transcript HSA - EPRALIMA

Food safety
Training Course
Co-financiado:
Microorganisms and
food intoxications
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Microorganisms • What are they?
• Main characteristics of living beings?
• Functions and applications?
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Microbial Growth • What do you understand by microbial
growth?
• What factors affect microbial growth?
• How can we control the growth?
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Microbial Growth
crescimento
em condições
Growth in optimum
óptimas
conditions
crescimento em outras
Growth in other
condições
situations
Log10
células
/mL
Tempo
Time
Microbial growing stages in a liquid environment. A – Lag stage; B- log stage; C- stationary
stage and D- death stage
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Microbial Growth • Intrinsic factors?
• Extrinsic factors?
• Other factors:
- Biological structures
- Natural antimicrobial substances
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Microbial
growth
Table I – pH level interval for the growth of some microorganisms
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
Data: Jay, J.M., 1996
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Microbial
Growth
Table II - Approximate pH levels of some food products
Product
Egg whites
pH
7,5 to 9
Egg yolk
6,1
Shellfish
Product
Corn
pH
7 to 7,5
Potatoes
5,3 to 5,6
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
Dados de : Jay, J.M., 1996
5,1 to 6,2
Lemons
1,8 to 2,4
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Microbial
growth
• Extrinsic factors
Temperature
Temperature is one of the most relevant
factors for microbial growth .
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Microbial
growth
Hours
Boiling point
Freezing
Data: Jay, J., 1996.
N.º of bacteria
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Microbial
growth
•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 :
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Microbial
growth factors –
Hurdle effect
Adapted from: Adams, M.R. and Moss, M.O., 1995
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Microorganisms • Main groups with importance for FS:
–
Bacteria
• Main characteristics
–
Fungi (Molds and yeasts)
• Main characteristics
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Bacteria
Photos: www.denniskunkel.com
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Fungi
•
•
•
•
•
•
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.
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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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Molds and
yeasts
Mold on food
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Main sources
• 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.
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Main sources
• Soil
- Source of spore forming bacteria, fungi and
yeasts;
- Addition of manure – faecal
microorganisms;
- Dissemination of microorganisms:
wind, rain, animals, fertilization…
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Main sources
What measures should be taken to
avoid/reduce contamination?
Table III – Effect of washing on the flora of vegetable products
Type of product
Tomato
Collards
Num. of microorganisms
Not washed
> 1 000 000/ cm2
Washed
400-700/cm2
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
Data: Jay, J.M., 1996 e Lacasse, D.. 1995.
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Main sources
• Water
- May contain various types of microorganisms
(origin and level of pollution);
- Utilization of potable water!
How to avoid contamination?
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Main sources
•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?
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Main sources
• Food
Diverse and proper flora :
– Vegetables
– Animals
Intestines
Soil
Animals
Water
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Main sources
• Handlers
- Diverse and own flora (faecal matter and
skin);
- Main problems?
• Utensils and Equipments
- Do not have own microflora;
- Main cause of
CROSS CONTAMINATIONS!!!
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Cross
contamination
• 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
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Risks and
hazards
• Difference between “Hazard” and “Risk”
- What is the origin of hazards?
- Examples
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Risks and
hazards
Table IV – Classification of hazards related to food safety
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
Creutzfeldt-Jakob
disease

the
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Riscos e
Perigos
Table V – Classification of hazards related to food safety
Types of hazards
Chemical
Examples of hazards
Examples of associated foods
Potential illnesses
Natural toxins



Aflotoxins
Solanin
Marine toxins




Nuts, corn, milk and milk
products
Potato
Shellfish, seafood

Mercury,
Cadmium
and
lead
Dioxins, PCBs


Fish
Fish, animal fat
French
fries,
coffee,
cookies, bread
Smoked
products,
vegetable oils, grilled
food
Pollutants of industrial origin

Contaminants that result from food
processing


Acrilamid
Polycyclical
aromatic
hydrocarbons

Pesticides

Insecticides,
herbicides,
fungicides

Vegetables, fruits
fruit products
Veterinary medicines

Anabolics,
antibiotics

Poultry, pork, beef
Non authorized additives

Sudan I-IV,
red (dyes)
for

Sauces, spices
Material in contact with food

Aluminium,
plastic
tin,

Canned
or
packaged food
Other

Cleaning
products,
lubrificants

and
plastic
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.
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Riscos e
Perigos
Table VI – Classification of hazards related to food safety
Types of hazards
Examples of hazards
Examples of associated
foods
Physical
Bones, fish bones,
glass, metal, stones
Nutritional
Excess salt
Table salt, snacks
Cardiovascular diseases
Excess fat
Butter, fat meat
Obesity
lesions
Excess sugar
Allergens
Potential illnesses
Diabetes
Cow
milk,
peanut,
eggs, crustaceans
Allergies
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• What are the main factors that
Intoxications
and main agents
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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Intoxications
Table VI – Food and agents generally associated to foodborne intoxications
and main agents
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
juice
milk
or
Salmonella, Campylobacter, Yersinia, STEC
Unpasteurized soft cheese
Salmonella, Campylobacter, Yersinia, Listeria sp., STEC
Homemade conserves
Clostridium botulinum (botulism)
Hotdogs, ham, etc.
Listeria sp.
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Table VIII – Characteristics of main foodborne Intoxications
Microorganism
Intoxications
and main
agents
Type of
illness
Campylobacter jejuni
Infection
Clostridium perfringes
Intoxication
Escherichia coli (various
types: EPEC; EIEC;
ETEC; and EHEC)
Infection
Salmonella spp.
Infection
Hepatitis A
Infection
*Bacillus cereus
Clostridium botulinum
Staphylococcus aureus
Poisoning
Poisoning
Poisoning
Symptoms
Probable food
Diarrhea, sometimes followed by
fever;
abdominal
pain,
nausea;
headaches and muscle pain
Raw poultry and other food contaminated by raw
poultry, unpasteurized milk, untreated water
Intense abdominal cramps; diarrhea
Meat and meat products, sauces, products rich in
protein
Watery diarrhea, abdominal cramps,
low fever, nausea, MAL ESTAR
Contaminated water, undercooked minced meat,
unpasteurized milk and juice; pieces of
melon.
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.
Fatigue, abdominal cramps, anorexia,
intermittent
nausea,
diarrhea,
vomiting
Raw or under cooked seafood, food prepared by
infected handlers
Watery diarrhea, cramps
Nausea 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
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
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.