Class 3 Flashcards
What is a key step in decomposition?
fermentation
How old is the culture of fermentation
5000 years
Name some widely familiar fermented products
Bread Olives Yogurt, kefir Wine, beer Sausages Cocoa,coffee, vanilla Vinegar
Culturally-specific fermented food
Natto, soya sauce
Fermented fish
kimchi, sauerkraut
What is fermentation as food preparation technique a short definition
The enzymatic transformative action of microorganisms on food and beverages to produce a desirable food product
What is fermentation a broader definition
Fermented foods are food substrates are invaded or overgrown by edible microorganisms whose enzymes, particularly amylases, proteases and hydrolyze the polysaccharides, proteins and lipids to non-toxic products with flavors,aromas and textures pleasant and attractive to the human consumer
Bicohemical definition of fermentation
The conversion of CHO to CO2 and alcohol by yeast and bacteria
What is anaerobic metabolism
Extraction of energy from CHO in the absence of oxygen
Fermentation results in
– Food preservation • inhibition of pathogens, spoilage organisms, extending shelf-life – Enhanced organoleptic properties • Flavour, texture, odor
What are benefits of fermentation
– Increased nutrient density digestibility
• Complex nutrients into simple, more digestible
• Breakdown plant structures
• Synthesize, improve bioavailability of vitamins
– Production of beneficial, new compounds
– Removal of antinutrients
• e.g. phytic acid
– Enhanced content of probiotic bacteria
Examples of production of beneficial, new compounds during fermentation
- e.g. bioactive isoflavones genistein, daidzein in soy
* e.g. convert w-3 to CLA
What is the differences in rotten vs delicious products if both use microorganisms
Time Temp Heat Acidity Water activity/salinity O2 Substrates
Three types of fermentation classification
By food group
By viability of microorganism
By type of fermentation
Categories in food group classification
– Cereal products – Dairy products – Fish products – Fruit and vegetable products – Legumes – Meat products – Beverages
Categories in viability of microorganisms classification
– Containing viable microorganism
– Not containing viable microorganism
– Microorganism used in early step of
production
• e.g. cocoa, coffee, cassava product
Examples of food containing viable microorganisms
• e.g. many yogurts, fresh, unprocessed kimchi/
sauerkraut/pickles, kombucha, unpasteurized
miso/cheese, olives, traditional salami, beer not
filtered or heated
Examples of food not containing viable microorganisms
• e.g. most soy sauce, bread, most beer, wine,
tempeh, many aged cheeses
Categories in type of fermentation classification
-Production of textured vegetable protein
– High salt/meat-flavoured aa/peptide sauce & pastes
– Lactic acid fermentations
– Alcoholic fermentations e.g. wine, beer, bread
– Acetic acid fermentations e.g. vinegars
– Alkaline fermentations
• e.g. natto
– Leavened breads
What product is classified as production of textured vegetable protein
Tempeh
What product is classified as High salt/meat-flavoured aa/peptide sauce & pastes
• e.g. soy sauce, fish sauces and pastes
What product is classified as lactic acid fermentations
• e.g. vegetables, milk, some breads (injera)
What is happening during anaerobic metabolism and two types of fermentation
-extraction of energy from CHOs in the absence of
oxygen
• Pyruvic acid is broken down, NAD+, an electron
acceptor used in glycolysis, is regenerated
• Two types:
– Lactic Acid Fermentation
– Alcoholic Fermentation
What is happening during alcohol fermentation and examples of organisms doing it
• Pyruvic acid converted to ethyl alcohol + CO2+2ATP • Microbe example: different strains of the yeast Saccharomyces cerevisiae
What is happening during lactic fermentation and examples of organisms doing it
• Pyruvic acid converted to lactic acid • Microbe example: Lactic acid bacteria (LAB) Lactobacillus streptococcus, enterococcus, lactococcus and Bifidobacterium
