Starch is a high calorie food that converts to sugar during the
digestion process. This creates a concern for people who are observing
a low calorie diet. Because of this, you may want to test different
foods and fruits to determine if they contain starch and estimate
their relative starch contents.
State the Problem:
What foods or vegetables contain starch?
Before we start, we need to know more about starch. Studies show that starch
is white, odorless, tasteless carbohydrate powder soluble in cold water.
This information will help us extract starch from our samples for more
accurate tests. If we have any colorful fruit or vegetables for test, we can
eliminate the chance of mixed colors and inaccurate tests. Starch also plays
a vital role in the biochemistry of both plants and animals. It is made in
green plants by photosynthesis, and is one of the main forms in which plants
store food. Animals obtain starch from plants and store it as glycogen. Both
plants and animals convert starch to glucose when energy is needed.
Commercially, starch is made chiefly from corn and potatoes.
Starch is a substance in most fruits and vegetables, which means that it is
most likely in the vegetable and fruit samples. Since starch is an
inexpensive and widely available food product, it is being used as a food
additive in many food products.
In order to perform this project, we must
use Iodine solution as a reagent for starch. One drop of this solution on
any sample can detect starch by changing the color of the tested area to
We will be using the following samples:
| Fruits and
|| Food Products
|| Ice Cream
Procedure: We crush the wet samples,
add cold or room temperature water and filter the solution to get a clear
liquid. Next, test the samples of the clear liquid for starch and record the
We used iodine solution, transfer pipettes,
test tubes, petri-dishes, filter paper (coffee filter) and known starch
Report which of the foods or fruits you
tested contain starch. Can you also say which one has more starch?
in a kit:
|Starch test science kit
has everything you need in order to detect and identify starch in
different fruits, vegetables, objects around you and more.
This kit includes:
- Iodine solution
- 5 test tubes
- 3 plastic transfer pipettes
- one Petri dish
- Starch paper
- Non-starch paper
- Starch peanuts
project guide with different project ideas and step by step
instructions on most of them.
You may also use this kit to see and
demonstrate the effect of enzymes in breaking the starch molecules
down to sugar.