Food Fermentation 2

Question 1

what are the two key biological molecules in fermentation?

Answer 1

Starch amylase

Cellulose NO B1-4 in humans.

Question 2

Starch analysis method 1?

Answer 2

1. Enzyme methods use alpha-amylase and amyloglucosidase

Question 3

Starch anaylsis method 2?

Answer 3

2. Acid hydrolysis
   - non-specific
   - GOPOD

Question 4

Yeast fermentation aka brewing.. potable alcochol has three stages..what are they?

Answer 4

1. Conversion of biomass to fermentable sugars
   a) Sugar crops (sugar cane- extraction of juice)
   b) Starches (wheat, barley- enzyme hydrolysis)
   c) Lignocellulose ( acid hydrolysis-milling)

Question 5

2nd stage?

Answer 5

2. Fermentation
   Predominately Saccharomyces spp. (yeast)
   use glucose, fructose, galactose, maltose,

Question 6

3rd stage?

Answer 6

Alcohol recovery/ product fermentation

Question 7

Fermentation with oxygen and without oxygen

Answer 7

WITH oxygen: grows well, glucose–> CO2 and H2O
without O2–> Glucose~ 51% ethanol + CO2.
Side products are toxic. 5% glycerol, butyl alcohols and esters.
Flavors such as acetic and lactic acids.

Question 8

Toxicty?

Answer 8

Ethanol can be. leaky at 4%, which can cause ethanol to go into cells. soluble metabolites ar elost.

Question 9

Distillation of ethanol

Answer 9

1. Primary distillation–> beer wich is >85% (removes volitiles ether and aldehydes)
2. Rectification 96% ehtanol 3.5% water
3. dehydration benzene or cyclohexane 99.9%

Question 10

What are the types of potable ethanol?

Answer 10

1. unforitified
2. Fortified
3. Distilled

Question 11

Unforitifed what type of drinks

Answer 11

beers, wines

Question 12

fortifeid

Answer 12

ports, sherry

Question 13

distilled

Answer 13

Whiskey, gin, vodka, rum.

Question 14

What is the difference between ales and lager beer?

Answer 14

ales beer is bottled for 3 weeks at 18-20C, while lager is bottled for 7 weeks at 13-17C bottom yeast

Question 15

What is a cider?

Answer 15

yeast + Lactobacillus planetarium, L. mali. HOMOlactics

- fermented apple juice

Question 16

What are wines?

Answer 16

fermented grape juice.
10-11% ethanol.
Ferment for 10 days, solids prepicipate for about 6 weeks, add acids. clear “must” for 6months to two years.

Question 17

What is a difference if you dry the grapes in the sun?

Answer 17

Increase sugar content.