CAMBRIDGE COURT HIGH SCHOOL
AISSCE
SESSION:2021-22
CHEMISTRY PROJECT
FOOD PRESERVATIVES
CLASS: XII-A
BOARD ROLL NO:
SUBMITTED BY: ISHITA JINDAL
SUBMITTED TO:MRS PRATIBHA MA’AM
ACKNOWLEDGEMENT
I would like to express my gratitude to my teacher
who gave me the opportunity to do project on
FOOD PRESERVATIVES, which also helped me in
lot of research and I come to know about so many
things. I am really thankful to them. I would also
like to thank my parents who gave me guidance
and suggestions regarding this project. I would
like to thank my friends for their support. Finally, I
would like to thank everyone who helped me in
completing this project.
CERTIFICATE OF AUTHENTICITY
This is to certify that ISHITA JINDAL, student of
class XII has completed research project on FOOD
PRESERVATIVES under the guidance of
MRS.PRATHIBHA MA’AM.
This project is absolutely genuine and does not
indulge in plagiarism of any kind. The references
taken in making project have been declared at the
end of this project.
SIGNATURE (SUBJECT TEACHER)
INDEX
Contents
❖Introduction
❖Experiment
❖Food Spoilage
❖Harmful food preservative
❖Traditional ways of
Preserving food
❖Pros & Cons
❖Uses
❖References
Page no.
1
2-4
5
6-7
8
9
10
11
INTRODUCTION
• In the present scene, food preserve had become
the life of man. Food preservation is important
due to more reasons. Some foods as fruit and
vegetable are in specific seasons and not
others, while other foods are more abundantly
available in some season than in others. In
certain areas there is more food products,
whereas in other places there is an inadequate
supply.
• Food
preservation methods
of preparing food so
that it can be stored
for future use.
Because most foods
remain edible for only a brief period of time,
people since the earliest ages have
experimented with methods for successful food
preservation. Among the products of early food
conservation were cheese and butter, raisins,
pemmican, sausage, bacon, and grain.
Experiment
OBJECTIVE:
The purpose of this experiment is to determine
what preservatives keep fruit from turning brown
the longest.
REQUIREMENTS:
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Container
Stirrer
Fruits (Pureed apple, banana and avocado)
Salt
Sugar
Lemon juice
Vegetable oil
Avocado pit
PROCEDURE:
1.
Pureed apple, banana, & avocado (480 mL
each) were measured into 6 separate
containers (3 trials each).
2. Then 2.5 mL of each preservative (salt,
sugar, lemon juice, avocado pit, & vegetable
oil) were measured separately into the fruit
& stirred.
3. As the control, one container of each fruit
did not contain any preservative.
4. The colour of the fruit was measured at
similar time periods over the next 2 days
using a colour scale.
RESULT:
• Salt was the best preservative for apples by
far. Even 2 weeks after the start of the
experiment, the apples did not turn brown.
• Lemon juice & salt in bananas slowed the
browning a little more than the other
preservatives.
• For avocados, none of the preservatives
slowed the browning. Adding salt to avocados
increased the browning even more than with
no preservative.
• The avocado pit, sugar, oil, & control all gave
about the same results for all 3 fruits.
CONCLUSION:
• When fruit is peeled or cut open, oxidation
occurs. Oxygen reacts with the ironcontaining phenols in the fruit. The oxidation
forms sort of a rust on the surface of the fruit
to cause browning.
• Enzymes act as catalysts for the oxidation
reaction or speed up the ripening or browning
of the fruit. Both physical and chemical
methods inhibit oxidation typically by
denaturing the enzyme.
• My hypothesis that lemon juice is the best
preservative was not proven. Because each
fruit has different enzymes that act as
catalysts to speed up the browning, no one
preservative will denature (break down) all
the enzymes in all fruits the same.
• For example, salt denatures the enzyme in the
apple the most probably by removing water
from the cells. Without water the enzyme
denatures& the apple doesn’t brown. But salt
browns the avocado the fastest. So, salt
somehow helps the enzyme brown the
longest.
FOOD SPOILAGE
We often see that the food that has been kept out
for too long smells foul and looks rotten. It is all
because of growing of microorganisms on food.
Once the food is spoiled, it cannot be eaten and
has to be thrown away.
Spoilage is a process in which food items
deteriorate to the point in which it is not edible to
human. Food spoilage is
the process where a
food product becomes
unsuitable to ingest by
the consumer. The cause
of such a process is due
to many outside factors
as a side effect of the type of product it is, as well
as how the product is packaged and stored.
Bacteria and various fungi are the responsible for
spoilage and can create serious consequences for
the consumers. But this food spoilage can be
stopped by taking suitable preservation steps.
Moreover, issues of food spoilage do not
necessarily have to do with the quality of the food,
but more so with the safety of consuming food.
Harmful Food Preservatives
Although preservatives food additives are used to keep
the food fresh and to stop the bacterial growth. But still
there are certain preservatives in food that are harmful
if taken in more than the prescribed limits.
Certain harmful food preservatives:
Butylates
❖ This chemical food preservative is expected to
cause
❖ high blood pressure and cholesterol level.
❖ This can affect the kidney and live function. It is
found in butter, vegetable oils and margarine.
BHA (butylated hydroxyanisole)
❖ BHA is expected to cause the live diseases and
cancer.
❖ This food preservative is used to preserve the
fresh pork and pork sausages, potato chips,
instant chips etc.
Caramel
❖It is the colouring agent that causes the
vitamin B6 deficiencies, genetic effects and
cancer.
❖It is found in candies, bread, brown coloured
food and frozen pizza.
Traditional And Indigenous
Ways of Preserving Food
• Kiviak is a traditional wintertime food
from Greenland that is made of seabirds
preserved in the hollowed-out body of
a seal and which are served at feasts or
weddings.
• North American tribes were the first ones to
eat, a mixture of dried meat and tallow. It was
adopted as a high energy food by explorers as
it is fatandprotein.
• Bedouins and other desert populations
produce ghee that has a shelf-life and no
refrigeration, prepared by boiling butter and
removing residue.
• Earthen pots served as preservation of boiled
food which could remain fresh for several
days. The food could be kept in a well aerated
store called "Ikumbi".
In Andhra Pradesh, India, lemon juice is used
as preservative for chutneys, pickles for long
journeys.
PROS AND CONS
✓ Increase the life of food.
✓ Make food safer to eat by removing toxins.
✓ Enrich food by adding daily nutrition
requirements.
 Preservatives cause allergic reactions in
people with asthma.
 Some preservatives are harmful to children.
 Some preservatives like sodium nitrates are
carcinogenic.
USES OF FOOD PRESERVATIVES
• Increasing the self-life of foods thus increasing
the supply.
• Many perishable foods can be preserved for a
long time.
• Making the seasonal available throughout the
year.
• Adding variety to the diet.
• Stabilizing prices of the food thus reducing
food demand.
• Improving the nutrition of the population.
• Preventing decay or spoilage of food.
REFERENCES
• WIKIPEDIA
• VEDANTU
• NCERT BOOK