LAB Flashcards
LAB
Why do we ferment food?
Preserve food
Climate with long winter
Detoxification
Grains and Legumes poorly digested without processing
Remove bitter-tasting polyphenols
Improve palatability
Health Benefits
What is fermentation?
Biochemical: a process that bacteria use to make energy from carbohydrates in the absence of oxygen
What is the most efficient fermentative pathway?
EMP pathways
What catabolic pathway is important for dairy fermentation?
Embden-Douboroff Pathway
What pathway generates one 3-carbon intermediate, CO2, and 1 ATP?
Heterofementative Pathway
What factors determine which pathway organisms use?
Genetic Makeup
Sugar Availability
Membrane Proteins
What kills most of the natural LAB and other bacteria in the raw product?
Pasteurization
What is a starter culture?
A defined set of bacteria is added at the beginning of the fermented process resulting in a predictable rate of acid and flavor profile development.
What is a secondary microbiota?
Bacteria added to some fermented products to influence texture and profile
Is non-starter lactic acid bacteria a part of the starter culture?
No
What are the 2 classifications of cheese starters?
Lactic Starters and Non-lactic starters
What temp are mesophilic starters?
20-30 °C
What temp are thermophilic starters?
37-45 °C
What is homogenization?
The even distribution of fat in milk products
What is the clarification of milk?
Removal of sediments from milk
What are the benefits of starter cultures?
Rapid acid production
decreased rate of contamination
production of flavor compounds
more consistent product
greater process predictability
______ and _______ fermentative strains are usually mixed in a fixed ratio to generate a flavor profile in a fermented product
homo and hetero
What type of fermentation is responsible for flavor and aroma compounds?
Heterofermenatation
What effects does acidity have on starter cultures?
Moisture content
protein retention
mineral loss
sensory characteristics
What two things affect starter culture?
Bacteriophage attack
Presences of Antibiotics in Milk
What only contributes to taste and not aroma?
Lactic Acid
What compound produces a buttery flavor?
Diacetyl
What is utilized by heterofermative strains to make diacetyl, acetic acid, and CO2 in gouda and Adam cheese?
Citric acid
What is the green apple defect?
The increased level of acetaldehyde as a result of prolonged fermentation
What is the starter culture for yogurt?
Lactobacillus bulgaricus and Steptococcus thermophilus
What is commonly used for veggie fermentation in the US and Europe?
LAB and yeast
What is commonly used for veggie fermentation in Asia?
Mold
What is the purpose of blanching?
inactivate enzymes
What is the role of salt in fermented veggies?
Flavor, moisture loss, and creation of anaerobic condition, selective agent
LAB during __________ of meat prevents spoilage and converts meat into different products.
Fermentation
What is the purpose of nitrite?
inhibit clostridium botulinum, generates color and taste
What bacteria is associated with meat?
LAB, lactobacillus, coagulase-negative staphylococci, micrococci.
