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Food microbiology is the study of the microorganisms which inhabit, create or contaminate food. Of major importance is the study of microorganisms causing food spoilage. However "good" bacteria such as probiotics are becoming increasingly important in food science. In addition, microorganisms are essential for the production of foods such as cheese, yoghurt, other fermented foods, bread, beer and wine.
Food safety
is a major focus of food microbiology. Pathogenic bacteria,
viruses and toxins
produced by microorganisms are all
possible contaminants of food. However, microorganisms and their products can also
be used to combat these pathogenic microbes. Probiotic
bacteria, including those which produce bacteriocins
can kill and inhibit pathogens.
Alternatively, purified bacteriocins
such as nisin can be added directly to food
products. Finally, bacteriophage,
viruses which only infect bacteria,
can be used to kill bacterial pathogens.
Thorough preparation of food, including proper cooking will eliminate most bacteria and
viruses. However, toxins produced by contaminants may not be heat-labile, and
some will not be eliminated by cooking.
Fermentation is one way
microorganisms can change a food. Yeast,
especially S. cerevisiae,
is used to leaven bread, brew beer
and make wine. Certain bacteria,
including lactic acid
bacteria, are used to make yogurt,
cheese, hot sauce,
pickles.
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Foodborne pathogens
Foodborne pathogens
are the leading causes of illness
and death
Protozoan
Protozoan
parasites associated with food and water can cause illness in humans
Mycotoxins
Molds
produce mycotoxins, which are
secondary metabolites that can cause acute or chronic diseases in humans when ingested from contaminated foods.
Vibrio
Vibrio species are prevalent in marine
environments
Staphylococcus
aureus
Staphylococcus aureus is a common cause of bacterial foodborne
disease worldwide.
Salmonella
infections are commonly acquired by animal to
human
Shigella
Shigella species are members of the family Enterobacteriaceae and
are Gram negative
Escherichia coli
E. coli was considered a commensal of human and animal
intestinal tracts with low virulence potential. Clostridiumbotulinum and Clostridium
perfringens
Clostridium botulinum produces extremely potent neurotoxins that result in the severe
neuroparalytic disease, botulism.
Bacillus cereus
B. cereus is a normal soil inhabitant and is frequently
isolated from a variety of foods, including vegetables, dairy products and
meat.
Water activity
Water activity or aw is a measurement of the energy status
of the water in a system.
Pasteurization
Pasteurization is the process of heating liquids
for the purpose of destroying bacteria, protozoa, molds,
and yeasts.
Sterilization
Sterilization refers to any process that
effectively kills or eliminates transmissible agents
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