Extracting starch from potatoes

Starch is a fairly common source of energy in the human diet. It is found not only in potatoes, but also in many foods that we eat every day. Starch is one of the products of photosynthesis and is quite widespread among plants, where it acts as a reserve of substances. Thus, a high starch content (about 80%) is observed in representatives of cereal crops - in grains of rice, wheat, and corn. Potato tubers contain less starch - approximately 20%.
Starch itself is a white powder, soluble in hot water and insoluble in cold water. Obtaining it is not a labor-intensive process.
Let's get started!

Experiment - making starch from potatoes with your own hands

So, to conduct the experiment we will need four large potatoes that need to be peeled.

Next, we chop our potatoes using a grater.

This destroys plant cells that contain starch.
After chopping, pour warm water over the potato chips, which should barely cover them.

The starch immediately begins to stand out, and we just need to “scrape” it a little with our hand into the solution.When it seems that all the starch has been washed away from the potatoes, pour the solution into another container.

We use our hands to prevent the chips from leaking out along with the liquid, but at this stage this is not critical.
Afterwards we wash the chips a couple more times. We won’t need it anymore; we can use it to prepare something or simply throw it away.
At this stage, you need to let the solution sit for about an hour so that the starch settles to the bottom of the vessel.

The water in the solution turns brown due to the decomposition of other organic substances contained in the potatoes.
When the starch settles, drain off most of the water.

Filter the remaining solution in the vessel through a sieve and rinse with a small amount of water.


Let the solution sit again so that the starch settles.


After half an hour, you can continue the experiment. We drain the cloudy water, and rinse the starch collected at the bottom with distilled water and mix.

Let the starch settle again.

Drain the cloudy water and repeat the washing again. We do this so that we have a pure substance at the output.
After repeating the procedure, spread the sediment with a spoon on plain paper, placing a paper towel under it, and leave to dry.
After a day, the starch will dry and we will get a white crispy powder.

The yield of pure substance was 47 grams.

Conclusion

The experience turned out to be quite visual and is great for introducing a child to a large and interesting science - chemistry.
The resulting starch can later be used in food or as a reagent for some chemical experiments.
Spectacular experiments everyone!

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