FIM Les 1-2

Molds

Import in food because they can grow even in conditions in which many bacteria cannot grow, such as low pH, low water activity, and high osmotic pressure

Aspergillus

A type of mold that is widely distributed, have septate hyphae and produce black-colored asexual spores on conidia. Some species or strains produce mycotoxins

Alternaria

A mold with members are septate and form dark-colored spores or conidia. Some species or steains produce mycotoxins

Jams, cured ham, nuts, fruits and vegetables (rot)

Aspergillus are associated with spoilage of which foods?

Tomatoes and rancid flavor in dairy products

Foods associated with Alternaria

Fusarium

Mold that has cottony growth and produce septate, sickle-shaped conidia and produces mycotoxins

Citrus fruits, potatoes, and grains

Fusarium causes rot in which foods?

Geotrichum

Mold that has septate and form rectangular arthrospores, with yeast-like cottony, creamy colony

Equipments and dairy products

Where does Geotrichum often grow

Mucor

A widely distributed mold, have nonseptate hyphae and produce sporangiophores with cottony colonies.

Penicillium

A widely distributed mold that has many species. Have septate hyphae and for, conidiophores on a blue-green, brush-like conidia head. Some strains produce mycotoxin

Penicillium roquefortii

Species of penicillium used in production of cheese

Rhizopus

Mold whose hyphae are aseptate and form sporangiophores in sporangium.

Rhizopus stolonifer

Common black bread mold

Fruits and vegetables

Rhizopus causes spoilage of which foods?

Yeasts

Important in food because of their ability to cause spoilage, used for food bioprocessing, and producing food additives

Saccharomyces

Type of yeast with round, oval, or elongated cells.

Saccharomyces cerevisiae

Used in baking for leavening bread and for alcoholic fermentation. Also cause spoilage of food, producing alcohol and CO2

Pichia

Yeast with oval to cylindrical cells and form pellicles in beer, wine, and brine to cause spoilage.

Pichia membranaefaciens

Yeast used in oriental food fermentation

Rhodotorula

Pigment-forming yeasts and can cause discoloration of foods such as meat, fish, and sauerkraut.

Torulopsis

Yeast with spherical to oval cells. Causes spoilage of milk, fruit juice, and acid foods

Torulopsis

Yeast that can ferment lactose, causing spoilage of milk

Candida

Yeast that spoil food with high acid, salt, and sugar, and form pellicles on the surface of liquids.

Rancidity in butter and dairy products

Which food does Candida affect and what is the effect?

Zygosaccharomyces

Yeast that cause spoilage of high-acid foods, such as sauces, ketchups, pickles, mustard, mayonnaise, salad dressings, and food with less acid, salt and sugar.

Lactic Acid Bacteria

These bacteria produce large quantities of lactic acid from carbohydrates

Lactococcus, leuconostoc, pediococcus, lactobacillus, and streptococcus thermophilus

Lactic acid bacteria (genera)

Acetic Acid Bacteria

These are bacteria that produce acetic acid

Fruits and vegetables, grains, breads, and meat

Penicillium causes rot and spoilage in which foods?

Acetobacter aceti

Example of acetic acid bacteria

Propionic Acid Bacteria

These bacteria produce propionic acid and are used in dairy fermentation

Propionibacterium freudenreichii

Example of propionic acid bacteria

Clostridium butyricum

Example of Butyric Acid Bacteria

Proteolytic Bacteria

These bacteria can hydrolyze proteins because they produce extracellular proteinases.

Lipolytic bacteria

These bacteria hydrolyze triglycerides because they produce extracellular lipases

Staphylococcus, bacillus, clostridium, pseudomonas, alteromonas, flavonacterium, brevibacterium

Examples of proteolytic bacteria

Generamicrococcus, Staphylococcus, Pseudomonas, Alteromonas, flavonacterium

Examples of lipolytic bacteria

Saccharolytic bacteria

These are bacteria that hydrolyze complex carbohydrates

Bacillus, Clostridium, Aeromonas, Pseudomonas, and Enterobacter

Examples of Saccharolytic bacteria

Thermophilic bacteria

These are bacteria that can grow at 50C and above.

Bacillus, Clostridium, Pediococcus, Streptococcus, Lactobacillus

Examples of Thermophilic bacteria

Spore formers

These are bacteria that can produce spores

Bacillus, Clostridium, Desulfomaculum

Examples of Spore formers bacteria

Aerobes

Bacteria that require oxygen for growth and multiplification

Anaerobes

These are bacteria that cannot grow in the presence of oxygen

Facultative Anaerobes

These are bacteria that can grow both in presence and absence of oxygen

Coliforms

Bacteria used as an index sanitation

Pseudomonas, Bacillus, Flavobacterium

Example of Aerobes bacteria

Clostridium

Example of Anaerobes bacteria

Lactobacillus, Pediococcus, Leuoconostoc, Bacillus, Listeria, Salmonella, Serratia

Examples of Facultative Anaerobes

Escherichia, Enterobacter, Citrobacter, Klebsiella

Examples of Coliforms