In the past, starch was extracted from wheat by fermentation, that is, wheat was soaked in water to soften and ground, and then fermented with acid, so that the cells around starch particles were dissolved and starch was easily separated. However, this method has lost a lot of gluten, and protein in starch is not easy to be removed, which affects the quality of starch. At present, it has been replaced by Martin method.

Matinfa

It uses wheat flour as raw material, adds 50-80% water in a blender, and kneades the flour into dough at the speed of 40 rpm. The mixing time is about 30 minutes, and it is left for 30 minutes to make the gluten swell and bond with each other, so that the starch is easy to separate. If proper amount of salt is added, the quality of gluten can be improved and its bonding can be promoted. If there is too much free acid in flour, appropriate amount of calcium hydroxide can be added to adjust its pH value. After the dough is allowed to stand for a while, add 5-8 times of water to knead and wash it for 3-4 times. The washed emulsion is starch milk, which needs to be refined and purified. The residue is gluten, with a water content of 65-70%. After drying, the protein content is about 75-85%, which can be eaten or used as raw material for making oil gluten.

The above extraction method of wheat starch belongs to subsection treatment and cannot be operated continuously. It has been reported abroad that the continuous process is basically the same, but it needs to be combined with continuous equipment for production.

Aektine method

In recent years, there is also the method of producing starch with wheat as raw material. The production principle of this method is the same as that of corn starch.

Production method

Soft wheat with water content of 14% and coarse protein content of about 10% was soaked in soaking water containing 0.2% sulfur dioxide at 39℃ for 12 hours, and the water absorption increased to 55%. Other operation methods are the same as corn processing. The content of crude protein in the finished starch is below 0.4%, and the highest recovery rate is 83%.