Food safety Training Course

1. Food safety Training Course Co-financiado:

2. Microorganisms and food intoxications

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

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

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

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

7. 7| 32 Microorganisms and food Intoxications Microbial growth Table I – pH level interval for the growth of some microorganisms Data: Jay, J.M., 1996

8. 8| 32 Microorganisms and food Intoxications Microbial Growth Table II - Approximate pH levels of some food products Dados de : Jay, J.M., 1996

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

10. 10| 32 Microorganisms and food Intoxications Microbial growth Hours N.º of bacteria Boiling point Freezing • Data: Jay, J., 1996.

11. 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 : Microbial growth

12. 12| 32 Microorganisms and food Intoxications Microbial growth factors – Hurdle effect Adapted from: Adams, M.R. and Moss, M.O.,1995

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

14. 14| 32 Microorganisms and food Intoxications Bacteria • Photos: www.denniskunkel.com

15. 15| 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

16. 16| 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.

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

18. 18| 32 Microorganisms and food Intoxications 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.

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

20. 20| 32 Microorganisms and food Intoxications • What measures should be taken to avoid/reduce contamination? Main sources Table III – Effect of washing on the flora of vegetable products Data: Jay, J.M., 1996 e Lacasse, D.. 1995.

21. 21| 32 Microorganisms and food Intoxications Main sources • Water • - May contain various types of microorganisms (origin and level of pollution); • - Utilization of potable water! • How to avoid contamination?

22. 22| 32 Microorganisms and food Intoxications 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?

23. Intestines Soil Water Animals 23| 32 Microorganisms and food Intoxications Main sources • Food • Diverse and proper flora : • Vegetables • Animals

24. 24| 32 Microorganisms and food Intoxications 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!!!

25. 25| 32 Microorganisms and food Intoxications 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

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

27. 27| 32 Microorganisms and food Intoxications Risks and hazards Table IV – Classification of hazards related to food safety

28. 28| 32 Microorganisms and food Intoxications Riscos e Perigos Table V – Classification of hazards related to food safety

29. 29| 32 Microorganisms and food Intoxications Riscos e Perigos Table VI – Classification of hazards related to food safety

30. 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? Intoxications and main agents

31. 31| 32 Microorganisms and food Intoxications Intoxications and main agents Table VI – Food and agents generally associated to foodborne intoxications

32. 32| 32 Microorganisms and food Intoxications Intoxications and main agents