Army Public School Gwalior
CHEMISTRY
Investigatory Project
NAME- Vivek Singh
CLASS- XII A
Roll No.- 12134
Submitted To- Mrs. Mithilesh Chauhan
ARMY PUBLIC SCHOOL
GWALIOR
Department of Chemistry
CERTIFICATE
This is to certify that Vivek Singh of class 12 has
successfully completed the investigatory project
work on chemistry under the guidance of Mithlesh
mam for class XII practical examination of the
Central Board of Secondary Education in the year
2021-22. It is further certified that this project is the
individual work of the candidate
ACKNOWLEDGEMENT
I would like to express my special
thanks of gratitude to my teacher
Mithlesh mam as well as our principal
Arvind sir who gave me the golden
opportunity to do this wonderful project
on the topic Study of effect of
potassium bisulphite as food
preservative under various
conditions , which also helped me in
doing a lot of Research and i came to
know about so many new things I am
really thankful to them.
Secondly i would also like to thank my
parents and friends who helped me a lot
in finalizing this project within the limited
time frame.
Outline……
Introduction
Aim
Theory
Material required
Procedure
Observation
Calculations
bibliography
Introduction
Growth of microorganisms in a food material can be
inhibited by adding certain chemical substances.
However the chemical substances should not be
harmful to the human beings. Such chemical
substances which are added to food materials to
prevent their spoilage are known as chemical
preservatives.
Potassium bisulphate
Potassium bisulphite is used for the preservation of
colourless food materials such as fruit juices,
squashes, apples and raw mango chutney. This is
not used for preserving coloured food materials
because Sulphur dioxide produced from this
chemical is a bleaching powder. Potassium
bisulphite on reaction with acid of the juice liberates
Sulphur dioxide which is very effective in killing the
harmful micro-organisms present in food and thus
prevents it from getting spoiled.
HSO3–(aq) + H+(aq) H2O(l) + SO2(g)
The advantage of this method is that no harmful
chemical is left in the food.
Aim
The aim of this project is to study the effect of
potassium bisulphite as food preservative.
i. At different temperatures.
ii. At different concentrations and
iii. For different intervals of time.
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.
Material Required
Beaker, pestle and mortar, glass bottles,
balance and peeler.
Fresh fruits, potassium bisulphite and sugar.
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 labeled as I II III.
2. Put 100 gms of fruit jam in each bottle.
3. Add 5.0 gms, 10.0 gms and 15.0 gms 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.
RESULT
The increase in concentration of sugar causes deterioration of fruit jam due
to growth of fungus.
(B) EFFECT OF CONCENTRATION OF
KHSO3:–
1. Take bottles labeled as I, II, III.
2. Put 100 gm of Jam in each bottle.
3. Add 5.0 gm of sugar to each bottle.
4. Add 1.0 gm, 2.0 gm and 3.0 gm of KHSO3 to bottle No. I, II and III
respectively.
5. Mix the contents thoroughly with a glass rod.
6. Keep all the bottles at room temperature for about 10 days and observe
the changes everyday
RESULT:
The increase in concentration of KHSO3 increase more time of
preservation
(C) EFFECT OF TEMPERATURE: –
1. Take 100 gm of Jam in three bottles labelled as I, II and III.
2. Add 10.0 gm of sugar and 1.0 gm of KHSO3 to each bottle.
3. Mix the contents thoroughly with a stirring rod.
4. Keep bottle No. I in the refrigerator at 0˚C, bottle No. II at room
temperature (25˚C) and bottle No. III in a thermostat at 50˚C.
Observe the changes taking place in the jam for 10 days.
RESULT:
The increase in Temperature causes fast fermentation of jam
(D) EFFECT OF TIME: –
1. Take three bottles and label them as I, II and III.
2. To each bottle add 25 g of Jam and 1 g of potassium bisulphite.
3. Keep bottle I for 7 days, bottle II for 14 days and bottle III for 21 days at
room temperature.
4. Note the changes taking place in each bottle and record the
observations.
RESULT:
With increase of days, the quality of the jam deteriorates
CONCLUSION
food containing more amount of sugar is not
favorable to keep for a long time Potassium
bisulphite is a good preservative.
There are a number of uses for potassium bisulfite
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 bisulfate is found in some cold drinks and
fruit juice concentrates. Sulfites are common
preservatives in smoked or processed meats and
dried fruits. In spray form, it may help prevent foods
from discoloring or browning.
Potassium bisulfite is primarily a commercial
product. You might find this chemical compound at
meat processing plants. Manufacturers of juice
drinks and concentrate will use potassium bisulfite to
increase the shelf life of their products. The
preservative is also available for home use.
Sulphites such as potassium bisulfite can trigger an
attack for those with asthma. potassium bisulfite
may cause lung irritation.
Bibliography
Modern abc practical
chemistry 12
Comprehensive practical
chemistry 12
www.wikipedia.org
NCERT chemistry 12
