Government Engineering College, Valsad
A OPENENDED PROJECTREPORT ON
FERMENTATION IN BIOCHEMISTRY
HIHORIA PRIYA (160190113018)
PATEL DHRUTI (160190113027)
PATEL ZENITH (160190113042)
BHADANI ASHISH (160190113003)
DEPARTMENT OF ENVIRONMENTAL ENGINEERING
WHAT IS FERMENTATION IN BIOCHEMISTRY?
Fermentation is a metabolic process that converts sugar to acids, gases, or alcohol.
It occurs in yeast and bacteria, and also in oxygen-starved muscle cells, as in the
case of lactic acid fermentation. Fermentation is also used more broadly to refer to
the bulk growth of microorganisms on a growth medium, often with the goal of
producing a specific chemical product.
Fermentation is a process that is important in anaerobic conditions when there is no
oxidative PROCESS to maintain the production of ATP (Adenosine triphosphate) by
glycolysis. During fermentation pyruvate is metabolised to various different
Typical examples of fermentation products are ethanol, lactic acid, and hydrogen
HISTORY OF FERMENTATION
The French chemist Louis Pasteur founded zymology, when in 1856 he connected
yeast to fermentation. When studying the fermentation of sugar to alcohol by yeast,
Pasteur concluded that the fermentation was catalyzed by a vital force, called
"ferments", within the yeast cells. The "ferments" were thought to function only within
living organisms. "Alcoholic fermentation is an act correlated with the life and
organization of the yeast cells, not with the death or putrefaction of the cells",
WHAT IS FERMENTED FOOD?
Fermented things can be the kinds of food that people refer to as “acquired tastes.”
But some of the most common things we eat and drink are fermented. The
words aged and cured should be your first clue.
Fermentation is a process in which food is exposed to bacteria and yeasts, either via
inoculation or naturally through the air. Beneficial microorganisms beat out the kind
that can kill you, and eat up the carbohydrates in the food. The results are interesting
flavours, textures, and smells. Before refrigeration, curing meats, pickling
vegetables, and clabbering milk was the only way to extend the life of perishables.
And if fermented foods haven’t been cooked, they are really good for you (cooking
kills off the beneficial bacteria).
Some of the food examples of our daily life are as follows:-
Wild yeasts and bacteria from the air eat the slimy layer, called mucilage, still
covering the beans after picking.
The fermentation deepens the flavour and body of the beans
Not all cheese is fermented (paneer, for example). For those that are, bacteria are
added to give cream or milk a sour flavor. After the curds and whey are separated
and the cheese is formed into a solid shape, it’s inoculated with specific kinds of
mold to make specific kinds of cheese (like blue cheese) and fermented (aged)
03 YOGURT, SOUR CREAM, BUTTERMILK
Milk or cream is exposed to souring bacteria, either by inoculation or through the air.
After cocoa beans are picked, the pulp surrounding them ferments, darkening the
beans beneath and mellowing their flavor.
Yeast is added to crushed grapes, or naturally occurring yeasts already on the grape
skins are allowed to thrive, and they convert the juice’s sugar to alcohol.
Yeast is added to grains that have been heated, soaked, and strained (leaving a
sweet, grainy liquid called wort), which converts the sugars to alcohol. Some beers,
like Belgian lambics, use naturally occurring bacteria and yeasts from the air.
Young beans are soaked, dried, and exposed to the air for several months to cure,
whereby their rich flavor develops.
A starter bacterial culture called a mother is introduced to alcohol (beer and wine are
most common), which converts it to acetic acid.
Yeast is introduced to flour and ferments the carbohydrates, leaving behind carbon
dioxide, which leavens the bread. Sourdough bread also contains a souring
bacterium present in the starter.
A stringy, slimy soybean product from Japan often eaten over rice. Cooked beans
are fermented with the bacterium Bacillus subtilis natto for a day, then aged under
refrigeration for a few days more.
To determine the rate of fermentation of various fruit juices.
Fermentation is a slow decomposition of complex organic compound into simpler
compounds by the action of enzymes.
Fruit juices contain various sugars like glucose, fructose etc. When juices are treated
with yeast and it converts sugar into glucose and fructose. These monosaccharides
are further converted into ethyl alcohol by another enzyme known as zymose. The
relative rates of fermentation can be established with fillings solution A and B. Since
glucose in an aldose gives red precipitate with felling solution. When all the quantity
of glucose is converted to ethanol, the mixture will not give
The word ‘Fermentation’ had been derived from Latin (Ferver means to ‘boil’). As
during fermentation there is lot of frothing of liquid due to the evolution of carbon
dioxide, it gives the appearance as if it is boiling. Sugars like glucose, sucrose when
fermented in presence of yeast cells are converted to ethyl alcohol. During
fermentation of, starch is first hydrolyzed to maltose by action of enzyme diastase.
IMPORTANCE OF FERMENTATION:
Enrichment of the diet through development of a diversity of flavours, aromas’
and textures in food substances.
Preservation of substantial amounts of food through lactic acid alcohol, acetic
acids and alkaline fermentation.
Biological enrichment of food substances with proteins, essential amino
acids, fatly acids and vitamins.
Elimination of anti nutrients.
A decrease in cooking times and fuel requirements.
Fruits such as pineapple, apple, orange, grape, lemon, yeast powder, ammonium
sulphate , Fehling’s solutions, beaker round bottom flask, thermometer, test tubes,
dropper, stand, hot water both, conical flask, distilled water etc.
Step 1 : Take approximately I g of yeast powder in beaker, add 20ml distilled water
and 3 -4ml of saturated solution of ammonium sulphate^tir the solution by a glass
Step 2: Pour 2ml of fruit juice a clean round bottom flask and add 20ml of distilled
Step 3: Now transfer the content of the beaker into a round bottom flask and shake
Step 4: Place the round bottomed flask into a hot water bath containing water at 35 -
45°C and shake the solution after each minute.
Step 5: After keeping the round bottomed flask for 10 min, take out 10 drops of the
mixture in a test tube and add 1 ml of "Fehling's solution -B". Heat the test tube in a
hot water both for few minutes observe. The change in colour and the fermentation
of red precipitate. Perform this test after internal of five minutes until the mixture
gives red precipitate with Fehling's reagent.
Step 6: Repeat the procedure in the same way taking other samples of fruit juices.
All fruit juices do not undergo fermentation at the same rate. The increasing order of
the rate of fermentation is:
Apple <Pine apple juice = orange juice <Grape juice < Lemon Juice.