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Microorganisms and food intoxications

What are they? Main characteristics of living beings? Functions and applications? Microorganisms 3| 32 Microorganisms and food Intoxications

What do you understand by microbial growth? What factors affect microbial growth? How can we control the growth? Microbial Growth 4| 32 Microorganisms and food Intoxications

Microbial growing stages in a liquid environment. A – Lag stage; B- log stage; C- stationary stage and D- death stage 5| 32 Microorganisms and food Intoxications Microbial Growth Time Growth in other situations Growth in optimum conditions

Intrinsic factors? Extrinsic factors? Other factors: - Biological structures - Natural antimicrobial substances 6| 32 Microorganisms and food Intoxications Microbial Growth

Data: Jay, J.M., 1996 Microbial growth 7| 32 Microorganisms and food Intoxications MicroorganismsMinimum pHOptimum pHMaximum pH Mold1, 5 to 3,54, 5 to 6,88 to 11 Yeast1, 5 to 3,54 to 6,58 to 8,5 Bacteria (most)4,5 to 5,56,5 to 7,58,5 to 9 Lactic Bacteria3 to 55,5 to 7,56,5 to 8 Table I – pH level interval for the growth of some microorganisms

Dados de : Jay, J.M., 1996 Microbial Growth 8| 32 Microorganisms and food Intoxications ProductpHProductpH Egg whites7,5 to 9Corn7 to 7,5 Egg yolk6,1Potatoes5,3 to 5,6 Shellfish6,8 to 8,2Carrots5,2 to 6,2 Fish (most)6,3 to 6,8Onion5,3 to 5,8 Fresh milk6,3 to 6,5Tomatoes4,2 to 5,8 Butter6,1 to 6,4Oranges3,6 to 4,3 Chicken6,2 to 6,4Grapes3,4 to 4,5 Pork5,3 to 6,4Apples2,9 to 3,3 Beef5,1 to 6,2Lemons1,8 to 2,4 Table II - Approximate pH levels of some food products

Extrinsic factors Microbial growth 9| 32 Microorganisms and food Intoxications Temperature Temperature is one of the most relevant factors for microbial growth.

Microbial growth Data: Jay, J., | 32 Microorganisms and food Intoxications Boiling point Freezing HoursN.º of bacteria

Microbial growth 11| 32 Microorganisms and food Intoxications 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., | 32 Microorganisms and food Intoxications Microbial growth factors – Hurdle effect

13| 32 Microorganisms and food Intoxications Main groups with importance for FS: –Bacteria Main characteristics –Fungi (Molds and yeasts) Main characteristics Microorganisms

Bacteria Photos: 14| 32 Microorganisms and food Intoxications

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 15| 32 Microorganisms and food Intoxications

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. 16| 32 Microorganisms and food Intoxications

Molds and yeasts Mold on food 17| 32 Microorganisms and food Intoxications

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 18| 32 Microorganisms and food Intoxications

Soil -Source of spore forming bacteria, fungi and yeasts; -Addition of manure – faecal microorganisms; -Dissemination of microorganisms: wind, rain, animals, fertilization… Main sources 19| 32 Microorganisms and food Intoxications

Main sources What measures should be taken to avoid/reduce contamination? Data: Jay, J.M., 1996 e Lacasse, D | 32 Microorganisms and food Intoxications Type of product Num. of microorganisms Tomato Not washed> / cm2 Washed /cm2 Collards External leaves not washed – /g Internal leaves washed – /g Internal leaves100 – /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 21| 32 Microorganisms and food Intoxications

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 22| 32 Microorganisms and food Intoxications

Food Diverse and proper flora : –Vegetables –Animals Main sources SoilWater Animals Intestines 23| 32 Microorganisms and food Intoxications

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 24| 32 Microorganisms and food Intoxications

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 25| 32 Microorganisms and food Intoxications

Difference between “Hazard” and “Risk” - What is the origin of hazards? - Examples Risks and hazards 26| 32 Microorganisms and food Intoxications

Risks and hazards 27| 32 Microorganisms and food Intoxications Types of hazards Microbiological Examples of hazardsExamples of associated foodsPotential 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 28| 32 Microorganisms and food Intoxications Table V – Classification of hazards related to food safety Types of hazards Chemical Examples of hazardsExamples of associated foodsPotential 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 29| 32 Microorganisms and food Intoxications Types of hazardsExamples of hazardsExamples 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 30| 32 Microorganisms and food Intoxications 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?

31| 32 Microorganisms and food Intoxications FoodGenerally associated microorganisms Raw seafoodVibrio sp., Hepatitis A virus, Norovirus (Norwalk-like viruses) Raw eggsSalmonella Undercooked meatSalmonella and Campylobacter, Escherichia coli STEC, Clostridium perfringens Unpasteurized milk or juice Salmonella, Campylobacter, Yersinia, STEC Unpasteurized soft cheeseSalmonella, Campylobacter, Yersinia, Listeria sp., STEC Homemade conservesClostridium botulinum (botulism) Hotdogs, ham, etc.Listeria sp. Table VI – Food and agents generally associated to foodborne intoxications Intoxications and main agents

32| 32 Microorganisms and food Intoxications Intoxications and main agents Table VIII – Characteristics of main foodborne Intoxications MicroorganismType of illness SymptomsProbable food Campylobacter jejuniInfection 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 Clostridium perfringesIntoxication Intense 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 AInfection Fatigue, abdominal cramps, anorexia, intermittent nausea, diarrhea, vomiting Raw or under cooked seafood, food prepared by infected handlers *Bacillus cereusPoisoning 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 Clostridium botulinumPoisoning 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 aureusPoisoning Nausea, vomiting, abdominal crampsContaminated 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.