Food Safety Training Course

1. Food Safety Training Course Co-financiado:

2. Microorganisms and food

3. 5| 25 Microorganisms and food Microorganisms • What are they? • Main characteristics of living beings? • Functions and applications?

4. 4| 25 Microorganisms and food Microbial Growth • What do you understand by microbial growth? • What factors affect microbial growth? • How can we control the growth?

5. 5| 25 Microorganisms and food 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| 25 Microorganisms and food • Intrinsic factors • - Nutrients • - pH • - Water activity • - Available oxygen • Extrinsic factors • - Temperature • - Relative humidity • - Atmospheric oxygen • Other factors: • - Biological structures • - Natural antimicrobial substances Microbial growth factors

7. 7| 25 Microorganisms and food Microbial growth factors - Temperature Temperature Temperature is one of the most relevant factors for microbial growth.

8. 8| 25 Microorganisms and food Microbial growth factors - Temperature • Main cause that lead to Intoxications : • Utilization of risk temperatures while conserving food/meals; • Utilization of inadequate temperatures while preparing/processing those foods (under processing);

9. 9| 25 Microorganisms and food Microbial growth factors – Hurdle effect Adapted from: Adams, M.R. and Moss, M.O.,1995

10. 10| 25 Microorganisms and food Microorganisms • Main groups with importance for FS: • Bacteria • Main characteristics • Fungi (Molds and yeasts) • Main characteristics

11. 11| 25 Microorganisms and food Bacteria • Unicellular; • Various forms (cocci, bacilli, spirilla); • Some develop resistant structures (spores); • Main cause of food intoxications of biological origin.

12. 12| 25 Microorganisms and food Bacteria • Photos: www.denniskunkel.com

13. 13| 25 Microorganisms and food • 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(molds and yeasts)

14. 14| 25 Microorganisms and food 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.

15. 15| 25 Microorganisms and food Molds and yeasts • Mold on food

16. 16| 25 Microorganisms and food 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.

17. 17| 25 Microorganisms and food Main sources • Soil • Source of spore forming bacteria, fungi and yeasts; • Addition of manure – faecal microorganisms; • Dissemination of microorganisms: • wind, rain, animals, fertilization…

18. 18| 25 Microorganisms and food • What measures should be taken to avoid/reduce contamination? Main sources Table I – Effect of washing on the flora of vegetable products Data: Jay, J.M., 1996 e Lacasse, D.. 1995.

19. 19| 25 Microorganisms and food Main sources • Water • - May contain various types of microorganisms (origin and level of pollution); • - Utilization of potable water! • How to avoid contamination?

20. 20| 25 Microorganisms and food 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?

21. Intestines Soil Water Animals 21| 25 Microorganisms and food Main sources • Food • Diverse and proper flora : • Vegetables • Animals

22. 22| 25 Microorganisms and food 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!!!

23. 23| 25 Microorganisms and food 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

24. 24| 25 Microorganisms and food Risks and hazards • Difference between “Hazard” and “Risk” • - What is the origin of hazards? • - Examples

25. 25| 25 Microorganisms and food Riscos e Perigos Table II – Classification of hazards related to food safety