microbiology of food fermentation

8/13/2019 Microbiology of food fermentation

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IndustrialMicrobiology

Applications in the Industry


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Brief Overview Industrial microbiology includes the use

of microorganisms to manufacture food

or industrial products in large quantities.

Numerous microorganisms are usedwithin industrial microbiology

naturally occurring organisms laboratory selected mutants

genetically modified organisms (GMOs).


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Microorganisms in thefood industry


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Use of Microorganisms inFood Industry

Fermentation

Processing of raw materials (e.g. coffeeand cocoa)

Manufacture of food additives

Vinegar production and other processes


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Importance of Fermentation

Physiologic effect of alcohol

Improved stability and preservation offoods

Acidulation of flaveor

Change in texture


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Role of Microorganisms inManufacture of Dairy Products

Homolactic Fermentation

Butter pasteurized cream with lactic acid starter

culture

Lactococcus cremoris/ L. lactisas mainlactic acid producers

L. lactis subsp diacetylactisor Leuconostoccremorisas diacetyl contributor


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Cheese

Coagulation and fermentation of milk

Commonly used are LactobacillusandLactococcus

Cheddar cheese: Lysteria monocytogenesAEM 64

Swiss cheese: Propionibacterium


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Yoghurt

Pasteurized low fat milk high in milk solids

Lactobacillus bulgaricus breaks down milkproteins and produce lactic acid

Streptococcus thermophillusconsumes thedigested milk proteins and produces formic

acid


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Other fermented foods Sausages Pediococcus cerevisiaeand P.

acidilactici

Sauerkraut and pickles natural fauna(mixed culture) and salt

Cocoa choice of microorganism changesthe subtle flavor

Coffee fermentation to remove themucilages covering the seed


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Brewing

Beer

Dextrins AlcoholCarbon

dioxideHop resin

Aromatics,

etc.

Boiled with hops, cooled and fermented

Wort

Enzymatic conversion of starch to maltose and dextrin

Malt Rice Corn


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Wine productionJuice is extracted from grapes and other

similar fruits

Saccharomyces cerevisiae Glucose CO2+ Ethanol

Malic acid Lactic Acid

Acetobactersp. May convert the juice tosugar


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Food AdditivesMonosodium glutamate

Corynebacterium glutamicum


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Food Additives Xanthan gum

Xanthomonas capestris


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Vinegar Produced through acetificatio of ethanol

products (wine, cider and beer)

Acetobacter sp.


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Food Spoilage andPreservation


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PasteurizationHTST pasteurization

Kills salmonellosis and tuberculosis in milk

but not Coxiella burnetii) UHT processing

Increases shelf life to 6 mos


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Canning Temperature conditions depend on type

Clostridium botulinum

Bacillus stearothermophilus


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Food Poisoning agents Bacillus cereusunrefrigerated meat, spices Campylobacter jejuni, C. coliundercooked

meat, milk Clostridium botulinum, C. perfinges Salmonella poultry, eggs Escherichia coli Staphylococcus aureus

Vibrio parahaemolyticus shellfish Yersinia enterocolitica Listeria monocytogenes cause Listeriosis

microbiology of food fermentation

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