Download what is starch?

EXPERIMENTAL
BIOLOGY
WHAT IS STARCH?
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Starch is a white, amorphous substance,
tasteless, insoluble in cold water and ethanol.
Starch is a reserve material of the plant, is
mainly in the seeds.
Starch as a reserve material is also stored in the
fruit and storage organs.
Starch is used in the textile, cosmetic,
pharmaceutical, spirits.
DETECTION OF STARCH
DIFFERENT PRODUCTS
Starch can be detected by means of iodine or
Lugol's solution, which contains iodine.
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Under the influence of iodine starch adopt
a blue-violet color.
THE FIRST EXPERIMENT
RESULTS
In boiled rice, noodles, white cheese,
bread, potato flour Lugol's solution color
changed from orange to dark blue.
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In washing powder, white soap and
white material lugol's solution didn’t
change color.
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CONCLUSIONS
There is starch in boiled rice, noodles,
white cheese, bread, flour. .
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There is no starch in washing powder,
white soap and white material.
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WHAT IS PROTEIN?
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Proteins are macromolecules are composed of amino
acids.
Proteins are the basic building blocks of all tissues of the
human body, and many compounds such as
enzymes, hormones, antibodies.
Proteins regulate metabolism and many body functions,
ensuring correct the condition and functioning of our
body.
DETECTION OF PROTEIN
1) biuret reaction – a food product is treated
by mixture VI cupric sulfate and potassium
hydroxide in the presence of proteins which
are stained purple; reakcja ta służy do
wykrywania wiązań peptydowych
2) The xanthoproteic reaction - it is working
on the product with concentrated nitric acid
(V); this reaction finds application at the
detection of proteins having aromatic nuclei
THE SECOND EXPERIMENT
RESULTS
In biuret reaction tested product changed its
colour from blue on purple.
CONCLUSIONS
There are some proteins in eggs.
Xanthoproteic Reaction
Milk
Joghurt
Fruits:
Kiwi
Banana
Apple
RESULTS
In the reaction with the nitric acid (V):
- the milk and the yoghurt assumed the yellow
colour
- the kiwi fruit, the banana and the apple
didn't change the colour
CONCLUSIONS
1. Proteins with the aromatic structure were
identified in dairy products
2. Fruit don't contain proteins or detecting
them with this method is impossible, e.g. on
account of the low sensitivity of the method or
deficiency of proteins containing aromatic
nuclei.
DETECTION OF FAT IN FOOD
METHOD
1. Grind the tested product in the paper
napkin.
2. Check the napkin, holding it against
the light. If there are grease stains, it
means that food contains fat.
MATERIAL
Almonds
Walnut
Sunflower
Apple
RESULTS
sunflower
walnuts
RESULTS
almonds
apple
RESULTS AND CONCLUSIONS
The biggest grease stain appeared on the
napkin after grinding seeds of sunflower.
This fact suggests containing a lot of fat in
this product.
 The apple did the wet stain on the
napkin rather than fat what provides, that
with this technique it is impossible to
detect presence of fat.
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