I. Overview of potato
The potato tubers are cobblestone-like, and the number and thickness of tubers vary greatly among different varieties. Potato tubers contain high amounts of starch, but contain less protein and fat, and the starch content is 15 to 25%. Some of the unique properties of potato starch are not replaceable by other starches, so they are widely used in the food industry. Here is the introduction about the method of preparation of potato starch.

2. Process flow for method of preparation of potato starch
Potato - stone removal lifting - cleaning - rotary washing - crushing- separation - sand removal - concentration and purification - vacuum dehydration - air drying - finished product packaging

Potato & potato starch

3. Main steps for method of preparation of potato starch are introduced briefly

Potato cleaning: The fresh potatoes stacked on the yard are first sent by forklift to the receiving hopper and then by conveying machine to the cleaning machine.  The main purpose of cleaning in method of preparation of potato starch is to remove sediment from the outer layer of potato and remove the epidermis of potato.  Cleaning raw material stage is the basis guarantee of starch quality.  The cleaner the starch, the better the starch quality.

Raw material crushing: Crushing serves to destroy the structure of the potato cell, so that the tiny starch granules can be smoothly separated from potato. The requirements for crushing in method of preparation of potato starch are:

a. As much as possible to break the cells of the material and release more free starch granules in;

b. Easy to separate. It is not desirable that the skin residue is too fine for potato starch production. For the fineness of the skin residue is not conducive to the separation of the starch from other components, and increases the difficulty of separating the fine residue.

Besides, the fineness is required uniform so as to ensure quality of final potato starch. Rasper crushing is the ideal crushing used in method of preparation of potato starch whose crushing degree is controllable and can be adjusted according to the nature of the material.

Potato crushing machine

Screening process: Starch extraction, also known as pulp separation, is a key link in method of preparation of potato starch, directly affecting starch extraction rate and starch quality in potato starch processing plant. The crushed material is fine fiber whose volume is larger than the starch granule, and the expansion coefficient is also larger than the starch granule, while the specific gravity is lighter than the starch granule. The crushed material is separated from the starch by using water as a medium. Doing Company uses screening and washing in a multi-stage cycle in method of preparation of potato starch. Fully panning to free the starch from the fiber; pressureless percolation allows the slurry water to pass through the mesh hole and the fine residue remains on the net; squeezed to further filter out the starch slurry water contained in the fiber, which can be used with less power and quick process completes the extraction of starch.

Potato starch drying machine

Dehydration and drying: The starch after screening enters refining hydrocyclone to remove separate insoluble protein and residual soluble protein and other impurities, then goes through desander for sand removal. From here it comes to dehydration stage in method of preparation of potato starch. Dehydration of wet starch is a very important step. For the water content will directly determine the efficiency and effect of subsequent drying equipment, so the water content must be controlled below 38-40% after dehydration. And the drying step follows dehydration operation to further reduce water content in starch so as to meet the commercial standard for method of preparation of potato starch.  The principle of drying is that the wet starch is suspended in the high speed hot air flow, and the starch is dried in the flow process.

The above is the introduction of main steps of method of preparation of potato starch.  As is a professional potato starch processing machine manufacturer, Doing Company has the professional starch processing technology and equipment R & D engineering technical talents in starch industry. Your question about method of preparation of potato starch is welcomed by DOING engineer.