Transcript Fermentation

Fermentation
The good, the bad,
and the smelly
History of Fermentation
Age old applications:
1. Wine/ Beer/ Spirits
2. Cheese and Yoghurt
Louis Pasteur:
 Hypothesised that bacteria spoils wine
 Suggested that wine be heated to kill bacteria
 Hence: pasteurization of milk
Fermentation’s
Pros
and
Cons



Extended shelf life of
food (ex. Cheese)
Eases Digestion (ex.
Wild rice)
New [better] flavours (ex.
Chocolate)


Can be unpredictable
(i.e. bad bacteria win the
battle)
New [worse] flavours
(ex. Mouldy bread tastes
terrible)
The Process



Aerobic respiration
release of energy from
glucose or another
organic substrate in the
presence of Oxygen
CO2, H2O, an energy
produced



Anaerobic respiration
release of energy from
glucose or another
organic substrate in the
absence of Oxygen
Products: CO2, energy,
and alcohol or various
organic acids
Fermentation Definition:
Anaerobic respiration of food by
micro organisms
Types of fermentation:
1. Bacterial fermentation
2. Yeast fermentation
3. Mold and Enzyme fermentation
1. Bacterial Fermentation (4 types)
a)
b)
c)
d)
Lactic Acid Bacteria
(pickles, sauerkraut)
Acetic Acid Bacteria
(vinegar)
Carbon Dioxide
Bacteria (Edam, Gouda,
Swiss)
Proteolytic Bacteria
(cocoa, chocolate)
bacteria
2. Yeast Fermentation
Glu Ethyl alcohol +
CO2
 Best temperature: 27
degree C (warm)
 Other sugars will ferment
(mal, suc, fru)
 Too much salt ruins the
process
When baking: follow the
recipe

3. Mold and Enzyme Fermentation

Enzymes in Mold can be useful:
-Break down cellulose thus grains easier to
chew
-Add flavour and texture to cheeses (ex- blue)
Wine




Dates back to Middle
east 3000 bc
Fermentation of grapes
Scientific process yet so
many variables
Growing years affect
vintages
Coffee

1.
2.
Coffee beans fermented
by bacteria and
enzymes (2 methods):
Wet Method: soaked for
12-24 hours and dried
Dry Method: washed
then dried for 2-3 weeks
Tea




3000 AD (at the latest)Cultivated in China
Rolled leaves begin to
ferment
Lets stand at 27 degree
C for 2-3 hrs
Types: Green, Oolong,
Black
Chocolate




1.5 million tons cocoa
produced each year
Supply: W. Africa
Produced: S. America
Enzyme fermentation in
the sun via proteolytic
bacteria
Bitter beans become
sweeter and brown
Fermentation around the world

Food, drink, sauces,
et cetera