Chemistry Project
Chemistry Project
Chemistry Project
RAIGANJ
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Internal Examiner External Examiner
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Principle
Acknowledgement
I would like to sincerely and profusely thank
my chemistry teacher Miss Rituparna
Chakraborty (PGT Chemistry) and our lab
attendant for their able guidance and support
in completing my project on the study od
effect of potassium bisulphite as a food
preservative.
I would also like to extend my gratitude to
principle Mr. Avijit Chakraborty for providing
me with all the facility that was required.
Soumyadip Debnath
XII Science
S. Contents Page
No. NO.
1) Purpose of the project
2) Introduction
3) apparatus used in this project
4) Food preservation
5) Need for food preservation
6) Principles of food preservation
7) Role of food preservation
8) Procedure of food processing
9) Procedure
10) Study of effect of concentration
of potassium bisulphite and the
effect of time
C. BIOPRESERVATION :
Biopreservation is the use of natural or controlled micro biota
or antimicrobials as a way of preserving food and extending
its shelf life. Beneficial bacteria or the fermentation products
produced by these bacteria are used in biopreservation to
control spoilage and render pathogens inactive in food. Lactic
acid bacteria have antagonistic properties that make them
useful as bio- preservatives.
THEORY
Food materials undergo natural changes due to
temperature, time and enzymatic action and become
unfit for consumption. These changes may be checked
by adding small amounts of potassium bisulphite. The
effectiveness of KHSO3 as preservative depends upon
its concentration under different conditions which may
be determined experimentally.
Procedure :
1. Take fresh fruits, wash them thoroughly with water and
peel off their outer cover.
2. Grind it to a paste in the mortar with a pestle.
3. Mix with sugar and colouring matter.
4. The material so obtained is fruit jam. It may be used to
study the effect of concentration of sugar and KHSO3,
temperature and time.
(A) Effect of concentration of Sugar:-
1. Take three wide mouthed reagent bottles labelled as I,II,III
2. Put 100 gm of fruit jam in each bottle.
3. Add 5.0 gm, 10.0 gm and 15.0 gm of sugar to bottle No.
I, II and III respectively.
4. Add 0.5 gm of KHSO3 to each bottle.
5. Mix contents thoroughly with a stirring rod.
6. Close the bottle and allow them to stand for one week or 10
days at room temperature.
7. Observe the changes taking place in Jam every day.
RECORD:
Bottle number A B C
Weight of jam taken 100 gm 100 gm 100 gm
Weight of sugar 5 gm 10 gm 15 gm
added
Weight of KHSO3 0.5 gm 0.5 gm 0.5 gm
Observation (Days)
Colour Dark orange Dark orange Dark orange
Odour Pleasant smell Pleasant smell Pleasant smell
Day1
Fungus Fungus not formed Fungus not Fungus not
formed formed
Colour Dark orange Orange Light orange
Odour Pleasant smell Pleasant smell Pleasant smell
Day 2
Fungus Fungus not formed Fungus not Fungus not
formed formed
Colour Dark orange Orange Light orange
Odour Pleasant smell Pungent smell Pungent smell
RECORD:
Bottle no. Wt. of jam Wt. of Wt. of Observations(Days)
taken sugar KHSO3 1 2 3 4 5
added
I 100 gm 5.00 gm 1.0 gm no no n few som
o e
RECORD:
Bottle Wt. of jam Wt. of Wt. of Observations(Days)
no. taken sugar KHSO3 1 2 3 4 5
added
I 100 gm 10.00 1.0 gm n n no no no
gm o o
RECORD:
Bottle no. Observations(Days)
7 14 21
I No ******** ********
II No Taste ********
changes
III No No Unpleasant
smell
Result: With increase of days, the quality of the jam
deteriorates.
CONCLUSION
Food containing more amount of sugar is not favourable to
keep for a long time Potassium bisulphite is a good
preservative.
Uses
There are a number of uses for potassium bisulphite as a food
preservative. The Manitoba Agriculture, Food and Rural
Initiatives reports this product works to prevent the growth of
mold, yeast and bacteria in foods. It is also an additive for
homemade wine. Potassium bisulphate is found in some cold
drinks and fruit juice concentrates. Sulphites are common
preservatives in smoked or processed meats and dried fruits.
In spray form, it may help prevent foods from discolouring or
browning.
AVAILABILITY
Potassium bisulphite is primarily a commercial product. You
might find this chemical compound at meat processing plants.
Manufacturers of juice drinks and concentrate will use
potassium bisulphite to increase the shelf life of their
products. The preservative is also available for home use.
ALLERGIES
Sulphites such as potassium bisulphite can trigger an attack
for those with asthma. Potassium bisulphite may cause lung
irritation.
BIBLIOGRAPHY
The necessary information for the project is collected from
The references stated below:
http://en.wikipedia.org/wiki/Potassium
bisulfate/
http://www.thetrustedtrolley.com.au
http://www.livestrong.com/article/308673-
potassium bisulphate-as-a-food-preservative/