This document describes an experiment to test the relative amount of vitamin C in various fruit and vegetable juices. Students tested 10 different juices by adding iodine solution drops until the juice changed color, indicating the presence of vitamin C. Lemon juice and grapefruit juice required the fewest drops, while tomato juice needed the most. The results were recorded and showed that lemon juice and red grapefruit juice contained the highest amounts of vitamin C, while parsley, carrot, and tomato contained the least. The experiment aimed to demonstrate that different juices contain varying levels of the important vitamin C.

2. EXPERIMENTS
Important source of knowledge at education of scientific subjects

3. ESTIMATION OF VITAMIN C IN
FRUIT AND VEGETABLE JUICES
• The aim of
experiment is
checking the relative
amount of vitamin C
in different juices.

4. WHAT IS VITAMIN C?
Vitamin C, ascorbic acid, a water soluble vitamin, which plays
a major role in the cellular oxidation, especially in the
tyrosine oxidation and reduction processes.
Vitamin C increases body resistance, what is essential to
maintain correct condition of the connective tissue.
It facilitates the absorption of iron.
Its deficiency causes scurvy.

5. MATERIALS

6. MATERIALS

7. MATERIALS
• A beaker is a simple
container for stirring, mixing
and heating liquids.
• Pasteur pipettes, also
known as droppers,are
used to transfer small
quantities of liquids

8. TESTING JUICES
1) Orange
2) Pomagranate
3) Lemon
4) Carrot
5) Celery
6) Tomato
7) Parsley
8) Cherry
9) Grapefruit
10) Apple

9. PROCEDURE
Preparing the solution of starch including iodine
Pour starch to the bowl or beaker . Next, pour hot water
from kettle to the bowl. Then, put the bowl into cold water
and blend the solution quickly. When the solution looks
like a jelly you must add drops of iodine and blend it. The
solution is ready when it stained blue.

10. START OF THE EXPERIMENT

11. PROCESS OF THE
EXPERIMENT
Note the number
of iodine
solution drops
which are
being put into
each juice
Add the iodine
solution to the
test tube drop by
drop until it
changes the
colour into violet-blue
Add the iodine
solution drops
to the test tube

12. RESULTS
Extract Number of drops
of iodine solution
orange 6
pomagranate 5
lemon 2
carrot 8
celery 7
tomato 9
parsley 6
cherry 3
grapefruit 2
apple 3
• Lemon and grapefruit
juice were the ones
that changed colour
in the shortest time.
• Tomato juice
required the biggest
amount of iodine
solution to change
its colour.

13. THE RELATIVE LEVEL OF
VITAMIN C IN DIFFERENT
JUICES
juices
10
9
8
7
6
5
4
3
2
1
0
orange
pomegranate
lemon
carrot
celery
tomato
parsley
cherry
grapefruit
apple

14. CONCLUSIONS
• All of the examined juices contain vitamin C,
however its content is different.
• The biggest amount of vitamin C in examined
extracts was found in the fresh lemon juice
prepared in the lab as well as in the juice of red
grapefruit which was bought in the shop.
• The least content of vitamin C was reported in
the essence of vegetables such as parsley,
carrot and tomato.
• Vitamin C was also detected in apple and
grapefruit juices containing preservatives.

15. EXPERIMENT CONDUCTED BY
• Marika Karasek
student
• PhD Anna
Gruszczyńska
biology teacher