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
What is “wild” fermentation and examples of these products
• Natural “wild” fermentation
– Creating conditions to inhibit undesirable
microbes and allow desirable microbes
– Using organisms already present
– Example:
• Lambic beer
• Vegetable fermentation (vegetables + salt)
What is controlled fermentation
Deliberate addition of microorganisms
What microorganisms can be directly added and examples of products with them
Isolated single organisms
– baker’s yeast = Saccharomyces cerevisiae
• “backslopping” with starter culture
– Yogurt (LAB), some beer, traditional salami, sourdough
(usually Saccharomyces Exiguus)
• SCOBY
– symbiotic culture/community of bacteria & yeast
– Kombucha, kefir
Why sourdough bread is better for people with gluten intolerance and yogurt for lactose intolerant people
Sourdough bread can be better digested with gluten intolerance, because bacteria break down the gluten
Lactose in yogurt , so people with lactose intolerance can digest better
A requirement for fermentation
Product should be submerged into the liquid totally
There is some evidence that some foods are associated with
– Improved blood lipid profiles, glucose
tolerance, digestive function, tolerance to
lactose (yogurt)
What are probiotics
live microorganisms, which,
when administered in adequate amounts,
confer a health benefit to the host
Example of true probiotic
Activia (Bifidobacterium animalis DN-173 010/CNCM 1-2494)
• If a microorganism is determined to have
health benefits, it is referred to by _____
genus,
species and strain
What are functions of probiotics
- Crowd out pathogens
- Maintain gut barrier
- Produce organic acids that nourish colonic
cells - Enhance immune function
The organism for kombucha production
Acetobacter xylinum
Gluconacetobacter kombuchae
The organism for natto production
Bacillus subtilis
The organism for yogurt and sausage production
Lactobacillus bulgaricus
The organism for olives,sauerkraut,kefir production
L plantarum
Why L plantum produce different products?
Because it uses different substrates
What bacteria are used for sourdough bread
L reuteri and L sanfranciscensis
What bacteria are used for beer
L brevis
What bacteria are used for cheese, sour cream, creme fraiche
Lactococcus lactis
What bacteria are used for cheese, sour cream, sauerkraut, kimchi
Leuconostoc mesenteroides
What bacteria are used for wine
Oenococcus oeni
Pediococcus acidilactici
sausage
Saccharomyces cerevisiae are used for making
wine, beer, kefir, bread starter
Staphylococcus carnosus and S xylosus aare used for
Making sausages
Streptococcus thermophilus is used to make
yogurt
what bacteria are used for soy sauce and miso
Tetragenococcus halophilus
What type of mold and yeast are used for soy sauce and miso
Aspergillus soyae
Zygosaccharomyces rouxii
What yeast is used for making sourdough
Candida humilis
WHat molds/yeast are used for cheese
Debaryomyces hansenii
• Penicillium roqueforti
• Trichosporon ovoides
• Yarrowia lipolytica
What type of mold/yeast is used for making kombucha
Z kombuchaensis
What are examples of fermented foods from Iceland, Japan,Eurasia-caucasus, west africa, korea
Hakarl (Iceland)
Kimchi (Korea)
Natto (Japan)
Kefir (Eurasia – Caucasus) Netetou (West Africa)
What is natto
Fermented soybean product
The process of making natto
Soaking, steaming, cooling, inoculating with
Bacillus subtilis, fermenting, aging
What do B subtilis do
contains proteases that hydrolyze soy proteins into
polypeptides, aas (glu, phe, tyr)
• Volatile fatty acids include butanediol, ethanoic
acid, pentanoic acid
• Produces nattokinase (anti-clotting)
Nattokinase can be used as
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