What is the procedure for isolation of starch from potato?

Potato starch is the starch extracted from potato, which can be widely used in food, chemical and other industries. In recent years, there is an increasing demand for potato starch in the international market. so more and more people are interested in potato starch processing. But do you know how is potato starch made? And what is the procedure for isolation of starch from potato?

Potato processing

Generally speaking, the procedure for isolation of starch from potato includes cleaning, washing, crushing, fiber sieving, starch refining, dewatering and drying. They can also be classified into three main steps:

First step is cleaning and washing of raw potato.

The harvested potato from the field attaches some impurities like sand, roots, weeds, stones, etc. Therefore, the first procedure for isolation of starch from potato is to remove these impurities. Dry sieve is the commonly used machine for removing attached impurities. To achieve a better cleaning effect, a rotary washing machine is installed after a dry sieve to further wash away impurities.

Potato cleaning & washing

The second procedure for isolation of starch from potato is to extract starch, which includes potato crushing, fiber sieving and starch refining.

Cleaned potato firstly enters into the rasper machine. Here the potato is crushed to the most extent so that the starch can be released as much as possible in the crushing process. Then we get mixture of starch, fiber, protein, fat, etc, which we call cassava mash.

To get purified starch, we need to separate solid fibers and liquid protein and fats from cassava mash. Firstly centrifuge sieve is used to remove fiber and tiny fibers. Then the de-sander machine is installed to eliminate sand impurities. After that, hydrocyclone is furnished to remove liquid protein, fats, etc. to get purified starch slurry at end.

Fiber sieving, starch desanding & starch refining

The last step of potato starch processing is dehydration and drying.

After the above processing section, starch is released and separated, existing in the form of liquid. In the last procedure for isolation of starch from potato, what we need to do is removing extra water and get dried starch powder with required moisture content.

Firstly using a vacuum dehydrator to reduce the moisture content of starch milk to 38-40%, then wet starch is sent to flash dryer to make moisture content reduced to 12-14%. The moisture content of output starch can be adjusted according to the client’s actual request.

Starch dewatering & drying

The procedure for isolation of starch from potato is basically the same as the process of making starch from sweet potato. Therefore, machines for potato starch processing can also be applied for sweet potato starch making. Whether your material is potato or sweet potato, you can use the same production line. If you want to learn more details, please contact us for further discussion.