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Soy Protein Production

Soy protein is made from dehulled, defatted soybean meal. The concentration of protein is achieved by removing most of the soluble non-protein compounds. These compounds are mainly soluble carbohydrates and some nitrogenous substances and minerals. Due to this process much the undesirable beany flavour and oligocharides (raffinose and stachyose) are removed. Soy protein concentrates also have a bland taste.

Production processes

There are three methods to produce soy protein concentrate.
  • Aqueous alcohol wash process
  • Acid wash process
  • Water wash process with heat denaturation
These methods will yield soy protein concentrate with similar composition: 70 percent protein, 20 percent carbohydrates, 6 percent ash and about 1 percent oil. The solubility of the protein can differ between the different extraction processes. One ton of defatted soybean flakes will give about 750 kg (75 percent yield) of soybean protein concentrate.

Aqueous alcohol wash process

With this process the sugars are dissolved with alcohols (methanol, ethanol or isopropyl alcohol) in a batch or a continuous process. These alcohols do not dissolve the soy proteins. Defatted soy flakes are used as raw material. After the extraction of the sugars, the alcohol is recovered and re-used. This recovery is accomplished by evaporation and rectification in a distillation column. The final flakes are dried with hot air and milled.

Acid-wash process

The soybean protein becomes insoluble in water when the pH is adjusted to 4.2. With this low pH, it is possible to dissolve the sugars without the use of special solvents. This process is a lot safer due to the absence of flammable solvents. On the other hand, it is more difficult to remove the water from the soy protein. Most of the water is removed with rotary vacuum filters or centrifuges. The obtained solids wet milled and spray dried.

Water extraction process with heat denaturation

With this process, the soy proteins of defatted soy meal are first rendered insoluble by thermal denaturation. The meal is heat treated and then extracted with hot water to remove the sugars. The process is similar to the acid-wash process.


extraction of peptone from soya

hello, what is extraction of peptone from soya?
maasoud - 18/08/2014

Soy Protein Production

hello you can help me
please pdf or text file about the Soy Protein Production send me book or any text
aref - 21/04/2015

soy protein production

please tell me how to make carbohydrate free soyprotein.
Anil Rasekar - 18/06/2016

difference between soybean meal and soy flour

Can you tell me that difference between soybean meal and soy flour? Is the protein content the same for both?
Huai Cheng - 21/11/2016


Please send to me the clear and simple process of obtaining SOY PROTEIN ISOLATE (SPI 90%) from raw soy...step by step A to Z all process.
Allen Watson - 28/04/2018

Please send to me the clear and simple process of obtaining SOY PROTEIN ISOLATE (SPI 90%) from raw soy...step by step A to Z all process
Anmol - 06/10/2019


I am pleased to read about the 3 methods to produce soya Protein. Kindly provide me with more information about the production cost for the 3 methods as well as the
Investment required.
Magued Marzouk - 22/10/2019

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