Probiotics, Wine, and Beer

Question 1

fermentation in food

Answer 1

• used for food preservation
• may involve a succession of microbes
• a self-limiting process (fermentation products inhibit what was fermenting)
• an extension of glycolysis
• recycles NADH
• changes the flavor, texture, and odor of the food

Question 2

fermented food examples

Answer 2

• dairy products
• meat products
• vegetables and vegetable products
• yeast bread
• chocolate
• alcoholic beverages

Question 3

What is the role of fermentation in the production of chocolate?

Answer 3

fermentation allows the bitter, tasteless cacao seeds to develop rich flavors associated with chocolate

Question 4

lactic acid bacteria

Answer 4

• gram positives that tolerate acidic conditions
• non-spore forming
• aerotolerant
• strictly fermentative metabolism
• used to make fermented dairy products
• ex: lactobacillus, lactococcus, leuconostoc, streptococcus

Question 5

probiotics

Answer 5

• live organisms. which when administered in adequate amounts, confer a health benefit to the host
• ex: fermented food, dietary supplements, non-oral supplements

Question 6

prebiotics

Answer 6

• substances that promote the growth of probiotics

- food for probiotics

Question 7

pros of probiotics

Answer 7

• considered safe for healthy individuals
• improve general intestinal health and balance
• improve lactose intolerance, control of diarrhea, anticancer effects, treatment of enteric disease, colonization resistance
• may lower blood pressure and serum cholesterol
• immunomodulation (building up gut microflora)
• improve oral health

Question 8

cons of probiotics

Answer 8

• difficult to accurately assess effectiveness because each probiotic and each individual is different
• not regulated by the FDA
• most yogurts have relatively low CFU counts
• voluntary “Live Active Culture” seal
• may cause mild side effects and systematic infection and severely immunocompromised individuals

Question 9

production of alcoholic beverages

Answer 9

• produced by yeast from the fermentation of sugar to ethyl alcohol and CO2
• begins with the formation of liquid containing carbohydrates in readily fermentable form
• wine= fermented grape juice
• beer= fermented malted grain
• distilled beverages= distillation of fermented solutions

Question 10

production of wine (enology)

Answer 10

1. must preparation
   - grapes are crushed to yield must
   - treated with sulfur dioxide fumigant
   - S. cerevisiae or S. elliposideus added
2. fermentation
   - primary (3-5 days at 20-28 C)
   - secondary, malolactic (1-3 weeks at 20 C)
3. aging
4. racking
   - removes sediment produced during fermentation

Question 11

production of beer/ale

Answer 11

1. mashing is done to release fermentable sugars from brains
2. germination of grains (barley, wheat, rice) and activation of enzymes to yield malt
3. malt mixed with water to yield mash
4. mash is heated with hops in a brew kettle
5. heating inactivates hydrolytic enzymes
6. hops removed
7. wort results (clear liquid containing fermentable carbohydrates)
8. wort inoculated with bottom yeasts (beer) or top yeasts (ale)
9. fermentation of 7-12 days at 6-12 C (beer) or 5-7 days at 14-23 C (ale)
10. storage and bottling (CO2 typically added, beer can be pasteurized or sterilized by filtration)

Question 12

production of distilled beverages

Answer 12

1. whiskey and bourbon begin with sour mash (mash inoculated with homolactic bacteria)
2. following fermentation, distilled to concentrate alcohol (alcohol and water have different boiling points)
3. color of distillate develops during aging