Introduction to Food Microbiology - Food Microbiology - Lecture Slides - Document's extract

Slides, Microbiology

Introduction to Food Microbiology, History of Food Microbiology, Sanitation, Foodborne Pathogens, Techniques in Microbiology, Molecular Genetics and Biotechnology, Topics in Food Microbiology are points of this lecture slides about food microbiology subject.

Introduction to food microbiology A brief history Topics in food microbiology Survey of microbes People have “practiced” food microbiology for thousands of years History of food microbiology • 8-10,000 years ago – Food preservation • Ca. 4,000 years ago – Fermented foods • 1600s – Early observations with microscopes • 1700s – Spontaneous generation was challenged (in experiments involving food) 1800s –The Golden Age of Microbiology -Cell theory -Spontaneous generation disproved -Proof that fermentation is a biological process -Germ theory of disease -Canning invented -Discovery of organisms that cause foodborne illness -Techniques for studying microbes Sanitation • 1849 John Snow: cholera spread through water contaminated with feces • Several waterborne pathogens isolated More pathogens isolated from food, diseased animals, feces Foodborne pathogens • Salmonella enteriditis- isolated from meat as well as person who ate it • Staphylococcus • Clostridium botulinum • Isolated in late 19th century • Koch’s postulates in action! Techniques in microbiology • • • • • • • • Pure culture technique Microscopy Staining, esp. Gram stain Sterile microbiological media (liquid and solid) Aseptic technique Methods to control microbial growth Biochemical tests to distinguish microbes Studying beneficial microbes as well as pathogens Molecular genetics and biotechnology • Rapid identification • Genetic engineering • Understanding mechanisms of resistance, biochemical processes, etc. Limitations of microbiological techniques • Most microbes cannot be grown in the laboratory • Microbes do not grow in isolation • Most microbes have not even been discovered! Topics in food microbiology • Fermentation/probiotics – Fermented foods and important metabolites • Making fermenting strains mo

re stable – Resistant to viruses – Enhance fermentation capacity • Understanding probiotics and their effect on the body (the microbiome) Food spoilage • • • • Which microbes, and under what conditions? What are the metabolites (products)? How do they work in the cold? How can they be controlled? Foodborne pathogens • • • • • Detection Identification Control How do we monitor and share information? Are we making the problem worse? – Antibiotic resistance – Are we introducing pathogens through our processes? What kinds of microbes are found in food? • Bacteria • Fungi (yeasts and molds) • Viruses • Protozoans, algae, helminths to a lesser extent • (Helminths=worms) • Protozoans and helminths are considered “accidental” Classification of organisms Where are viruses and prions? Prokaryotes vs eukaryotes prokaryotes • Smaller cells • No nucleus or organelles • Single-celled • Bacteria and archaea eukaryotes • Larger cells • Cells have nucleus and organelles • Can be single-celled or multicellular • Plantae, Animalia, Fungi, Protista • Viruses and prions are not cells so are not considered alive Nomenclature • Binomial name: genus and species – Ex. Salmonella typhimurium; S. typhimurium • Subspecies: – Lactococcus lactis ssp. lactis, (soft cheese) – L. lactis ssp. cremoris (hard cheese) • Serovar, pathovar, biovar Yeasts and molds • Yeasts: single-celled eukaryotes • Molds: multicellular structure (filaments, spores) required for reproductions • Can be used to make foods but also involved in spoilage • Saccharomyces cerevisiae: • Carbon dioxide and ethanol Molds can grow almost anywhere • • • • • Food spoilage Toxins Allergens Food processing Different genera grow on different foods – Rhizopus- fruits, vegetables, bread – Geotrichum- dairy

mold – Penicillium-spoils almost everything, but also used to make cheese Viruses infect cells Can cause disease Interfere with food processing Hepatitis A- infects humans Protozoans, algae, helminths • Protozoans can cause parasitic disease (Giardia, Cryptosporidium, Toxoplasma) • Algae- photosynthetic protists – Contaminants, food products, toxins • Helminths- parasites – Roundworms, tapeworms- contaminated food Life cycle of a tapeworm (helminth) Bacteria (“eubacteria”) • We will spend much lecture time, and most lab time, working with them • Classification is complicated and changing all the time • Most bacterial species have not been described, but many have been very well studied Major classification criteria • Gram-positive or Gram-negative Morphology Bacterial classification, continued • Aerobes, anaerobes, fermenters • Spore formers, non spore formers • What metabolic products do they produce? – Acids, alcohols, gases- and which ones? • What do they use for food? – Carbohydrates, lipids, proteins • Under what conditions do they grow? – Temperature range, pH range, availability of water Do they cause disease? What kind? What should a food microbiologist know? • Characteristics of the different types of microbes • How to identify and enumerate them • Factors that affect their growth (innate and introduced) • Fermentation vs spoilage • How microbes cause disease • That the field of food microbiology is a work in progress!

Like this document? Enter it immediately in your blog or website


Related Notes

Music Information Retrieval-Lecture Slides [Introduction]-Literature

Music Information Retrieval aims at extending the understanding and usefulness of music data, through the research, development and application of computational approaches and tools. Music Informat...
Music Information Retrieval
Literature and Communication

Introduction-Programming For Engineers II-Lecture Slides

This lecture was delivered by Prof. Prabhat Patel at Ankit Institute of Technology and Science for Advanced Programming for Engineers. It includes: Introduction, Programming, Course, Objectives, La...
Advanced Programming for Engineers
Computer science

Introduction - Lecture Slides - Introduction to Information Systems and Technology

Objective of the course Introduction to Information Systems and Technology is to apply information systems solutions to business problems in marketing, finance, accounting, operations, and strategy...
Information Systems
Computer science

Introduction - Basic Statistics for Sociology - Lecture Slides

Introduction, Statistical Applications, Types of Variables, Mathematical Tools, Summarize, Information Expressed, Scores on Variables, Social Class, Numerical Form, States and Nations are the impor...
Statistics for Psychologists
Psychology and Sociology

Food Production, Ecology - Biology - Lecture Slides

These are the lecture slides of Biology. Key important points are: Food Production, Ecology, Action in Plants, Plant Cells, Cytoplasm, Sap-Filled Vacuole, Cell Membrane, Cellulose Cell Wall, Green...
Biology and Chemistry
Docsity is not optimized for the browser you're using. In order to have a better experience please switch to Google Chrome, Firefox, Internet Explorer 9+ or Safari!
Download Google Chrome