EXPERIMENTS Important source of knowledge at education of scientific subjects.

EXPERIMENTSImportant source of knowledge at education of scientific subjects

ESTIMATION OF VITAMIN C IN FRUIT AND VEGETABLE JUICES• The aim of

experiment is checking the relative amount of vitamin C in different juices.

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.

MATERIALS

MATERIALS

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

TESTING JUICES1) Orange

2) Pomagranate

3) Lemon

4) Carrot

5) Celery

6) Tomato

7) Parsley

8) Cherry

9) Grapefruit

10) Apple

PROCEDUREPreparing 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.

START OF THE EXPERIMENT

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

RESULTS

Extract Number of dropsof 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.

THE RELATIVE LEVEL OF VITAMIN C IN DIFFERENT JUICES

juices0

1

2

3

4

5

6

7

8

9

10

orangepomegranatelemoncarrotcelerytomatoparsleycherrygrapefruitapple

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.

EXPERIMENT CONDUCTED BY

• Marika Karasek

student

• PhD Anna Gruszczyńska

biology teacher