Lecture 17 Microbiology In Food Indistry Fermentations

Question 1

Fermentation is critical for the production of what

Answer 1

•Beer
•Wine
•Many dairy products

Question 2

Yeast prefers what type of pathway

Answer 2

Aerobic pathway

need to keep oxygen low to force fermentation and production of alcohol.

Question 3

What is the sugar source for wine making

Answer 3

Grapes

Question 4

Why is barley unsuitable as a sugar source

Answer 4

65% starch

Question 5

What is malting process used to generate

Answer 5

enzymes (amylases) and carbon source useful for fermentation

Question 6

How is malt preserved

Answer 6

By Kilning

Question 7

What happens when wort is boiled

Answer 7

•Amylases inactivated
•Starch breakdown now stopped
•alpha acids and oils from hops Kills microbes in the wort
•Sugars are caramelized

Question 8

What temperature does alcohol boil at

Answer 8

78 degrees Celsius

Question 9

Name the main organisms involved in dairy fermentations

Answer 9

Lactococci, Lactobacilli and S. thermophilus

Question 10

Name the enzyme mix that promotes milk curdling

Answer 10

Rennet

Question 11

Who begin the “Good bacteria” theory

Answer 11

Elie Metchnikoff

Question 12

Fermentation for Beer and Wine

Answer 12

Primarily S. cerevisiae but occasionally Zymomonas