OBJECTIVE
The purpose of the experiment is to compare the rate of
fermentation of the given samples of Wheat Flour, Gram Flour,
Rice Flour, Potatoes, Carrot Juice and Orange Juice
I became interested in this idea when I saw some experiments
on fermentation and wanted to find out some scientific facts
about fermentation.
The primary benefit of fermentation is the conversion of sugars
and other carbohydrates e.g. converting juice into wine, grains
into beer, carbohydrates into carbon dioxide to leaven bread,
and sugars in vegetables into preservative organic acids.
INTRODUCTION
Fermentation typically is the conversion of carbohydrates to
alcohols and carbon dioxide or organic acids using yeasts,
bacteria, or a combination thereof, under anaerobic conditions.
A more restricted definition of fermentation is the chemical
conversion of sugars into ethanol. The science of fermentation
is known as zymology.
Fermentation usually implies that the action of microorganisms
is desirable, and the process is used to produce alcoholic
beverages such as wine, beer, and cider.
Fermentation is also employed in preservation techniques to
create lactic acid in sour foods such as sauerkraut, dry sausages,
kimchi and yoghurt, or vinegar for use in pickling foods.
HISTORY
Since fruits ferment naturally, fermentation precedes human
history. Since ancient times, however, humans have been
controlling the fermentation process. The earliest evidence of
winemaking dates from eight thousand Years ago in Georgia,
in the Caucasus area. Seven thousand years ago jars containing
the remains of wine have been excavated in the Zagros
Mountains in Iran, which are now on display at the University
of Pennsylvania. There is strong evidence that people were
fermenting beverages in Babylon circa 5000 BC, ancient Egypt
circa 3150 BC, pre-Hispanic Mexico circa 2000 BC and Sudan
circa 1500 BC.
There is also evidence of leavened bread in ancient Egypt
circa1500 BC and of milk fermentation in Babylon circa 3000
BC. French chemist Louis Pasteur was the first known
zymologist, when in 1854 he connected yeast to fermentation.
Pasteur originally defined fermentation as “respiration without
air”.
USES
Food fermentation has been said to serve five main purposes:
1.
2.
3.
Enrichment of the diet through development of a diversity
of flavours, aromas, and textures in food substrates.
Preservation of substantial amounts of food through lactic
acid, alcohol, acetic acid and alkaline fermentations
Biological enrichment of food substrates with protein,
essential amino acids, essential fatty acids, and vitamins
4.
Elimination of anti-nutrients.
5.
A decrease in cooking times and fuel requirements.
BENEFITS OF FERMENTED FOOD
1.
2.
Enhanced Digestion: Fermented foods are easier to digest
because the fermentation process breaks down complex
compounds, making it simpler for the body to absorb
nutrients.
Rich in Probiotics: They are a natural source of beneficial
bacteria that help maintain a healthy gut microbiome,
improving digestive health and reducing gut-related
issues.
3.
4.
5.
6.
7.
8.
Boosts Immunity: Regular consumption of fermented
foods can strengthen the immune system by enhancing the
gut’s ability to fight off harmful pathogens and
inflammation.
Improved Nutrient Content: Fermentation enhances the
availability of essential nutrients, such as B vitamins,
vitamin K, and iron, making them more accessible for the
body to absorb.
Better Food Preservation: Fermentation naturally
preserves foods, extending their shelf life without the need
for artificial preservatives or additives.
Reduces Inflammation: Fermented foods contain antiinflammatory properties through probiotics and bioactive
compounds, which can help reduce chronic inflammation
in the body.
Aids in Weight Management: By improving gut health and
metabolism, fermented foods can regulate appetite,
support weight loss efforts, and help maintain a healthy
weight.
Detoxifies the Body: Certain fermented foods can help
detoxify harmful compounds in the body, such as phytic
acid, and improve the body’s ability to eliminate toxins.
EXPERIMENT – 1
AIM - To compare the rate of fermentation of given sample of wheat
flour, gram flour, rice flour and potato using yeast
MATERIAL REQUIRED:
1.
Conical flask
2.
Test tube
3.
Funnel
4.
Filter paper
5.
Water bath
6.
1 % Iodine solution
7.
Yeast
8.
Wheat flour
9.
Gram flour
10.
Rice flour
11.
Potatoes
12.
Aqueous NaCl solution
THEORY
i. Take 5 gm of wheat flour in 100 ml conical flask and add
30 ml of distilled water.
ii. Boil the contents of the flask for about 5 minutes.
iii. Filter the above contents after cooling, the filtrate obtained
is wheat flour extract.
iv. To the wheat flour extract. taken in a conical flask.
v. Add 5 ml of 1% aq. NaCl solution.
vi. Keep this flask in a water bath maintained at a temperature
of
50-60-degree Celsius. Add 2 ml of malt extract.
vii. After 2 minutes take 2 drops of the reaction mixture and
add to diluted iodine solution.
viii.
Repeat step 6 after every 2 minutes. When no bluish
colour is produced the fermentation is complete.
ix.
Record the total time taken for completion of
fermentation.
x. 10.Repeat the experiment with gram flour extract, rice
flour extract, potato extract and record the observations.
OBSERVATION
SAMPLE
FERMENTATION
WHEAT FLOUR
10 HOUR
GRAM FLOUR
12.5 HOUR
RICE FLOUR
15 HOUR
POTATO
13 HOUR
Result :- Rice flour takes maximum time for fermentation and
wheat flour takes the minimum time for fermentation.
EXPERIMENT - 2
AIM - To compare the rates of fermentation of the following fruit or
vegetable juices:
i.
Orange juice
ii.
Carrot juice
MATERIAL REQUIRED:
i.
Conical flasks (250ml)
ii.
Test tubes and water bath
iii.
Orange juice
iv.
Carrot juice
v.
Fehling solution A
vi.
Fehling solution B
vii.
Solution of Pasteur salts and distilled water
THEORY
i. Take 5 ml of orange juice in a clean 250 ml conical flask
and dilute it with 50 ml of distilled water.
ii. Add 2.0 g of Baker’s yeast and 5 ml of Pasteur’s salts to
the above conical flask.
iii. Shake well the contents of the flask and maintain the
temperature of the reaction mixture between 35-40°C.
iv. After 10 minutes take 5 drops of the reaction mixture from
the flask and add to a test tube containing 2 ml of Fehling
reagent.
v. Place the test tube in boiling water bath for about 2min
and note the colour of the solution or precipitate.
vi. Repeat the step 4 after every 10 min. When the reaction
mixture stops giving red colour or precipitate with Fehling
reagent, the completion of fermentation is indicated.
vii. Note the time taken for completion of fermentation.
viii.
Repeat the above experiment by taking 5 ml of carrot
juice.
OBSERVATION
i.
Volume of fruit juice taken = 5 ml
ii.
Volume of distilled water added = 50 ml
iii.
Weight of Baker’s yeast added = 2g
iv.
Volume of solution of Pasteur’s salts = 5 ml
Result :- The rate of fermentation of orange juice is more than
the rate of fermentation of carrot juice.
PRECAUTION
i. Ensure all glassware and apparatus are clean and sterilized
to avoid contamination.
ii. Accurately measure all reagents, yeast, and solutions to
maintain consistency.
iii. Maintain the water bath temperature strictly within the
specified range (50-60°C for Experiment 1, 35-40°C for
Experiment 2).
iv. Use freshly prepared fruit and vegetable extracts for
reliable results.
v. Add yeast and other solutions immediately after
preparation to avoid delays in fermentation.
vi. Perform the iodine and Fehling tests at precise intervals
for accurate observations.
vii. Filter extracts carefully to remove solids and impurities
that may interfere with fermentation.
viii.
Cover the flasks properly to prevent external
microorganisms from contaminating the samples.
ix. Conduct the experiment in a well-ventilated area to avoid
inhaling any fumes