The production process of corn starch is as follows, and the specific steps are as follows:
Corn warehouse -> Weighing and purifying sulfur dioxide -> Soaking and concentrating corn steep liquor -> Coarse grinding -> Germ separation, washing of embryo stem, embryo oil extraction -> Fine grinding, fiber separation, sieving, water feed -> Sand removal -> Screening -> Protein separation and bran separation Concentrated gluten dry protein powder->cyclone separation->dehydration->drying->packaging->starch finished product
1. Corn starch production process:
(1) Purification of corn
The purpose is to remove dust, sand, nails, wood chips and other impurities from the corn kernels, using methods such as screening, winnowing, specific gravity stone removal, and magnets to purify them.
(2) Soaking of corn
Soak corn in an aqueous solution containing 0.2% sulfur dioxide for 48 to 72 hours under 5 rays to soften the corn kernels and increase the moisture content of the corn kernels to more than 40%.
(3) Coarse grinding
Break the soaked corn into more than 10 small pieces for germ separation.
(4) Germ separation
The old method in the past was to take advantage of the small oil content of the germ and use the trough method to separate the germ. Modern new starch plants use germ hydrocyclones, which have high separation efficiency and can reach more than 95%.
(5) Corn grinding
Since after the germ is separated, the thin starch slurry, starch granules and endoderm proteins are connected together and cannot be separated on the sieve, so they must be finely ground to separate the starch from fiber and gluten.
(6) Starch screening
The corn syrup obtained by fine grinding can be separated from the starch, coarse residue and fine residue using a hexagonal sieve, flat sieve or curved sieve.
(7) Protein separation
Protein separation used to use launders, but they occupied a large area and the separation efficiency was low. Nowadays, centrifuges are gradually used, which have high separation efficiency. After the centrifuge separates the protein, the starch milk still needs to be separated in a hydrocyclone separator (a total of 9 series connected ) to further separate the protein. Generally, the protein content in starch is 2.5% after separation by a centrifuge. After separation by a hydrocyclone, the protein content is reduced to 0.3%.
(8) Centrifugal dehydration
The starch milk contains 78% water. Use a centrifuge to dehydrate the milk to reduce the water content to 45% to obtain wet starch.
(9) Dry wet starch
In the past, drum vacuum drying was used, but now air flow drying is mostly used. After drying, the moisture of the starch is 12%, which is the finished product. Sometimes it also needs to be screened to ensure the fineness for packaging.
2. Ways to improve starch extraction rate
(1) It is a constant temperature soaking method to extend the soaking time.
The soaking temperature is maintained at 40°C ~ 60°C and the soaking time is 72 hours, which can increase the acidity of the slurry, making the old slurry reach 3.5 degrees, and the slurry extraction reaches about 4 degrees, thereby increasing the flour extraction rate.
(2) First coarse and then fine, crushing twice
During processing, the corn is ground once with a small steel grinder, which will grind the skin fibers. Not only is the flour extraction rate low, but the flour quality is not good. If the corn is ground twice, the corn will be broken into 6 pieces for the first time~ 8 petals, grind again for the second time, the result is that the powder extraction rate is increased by 0.76% compared with the first grinding.
3. Deep processing of corn starch
Processing corn into starch is only the first step in processing. If further value is added, starch can also be used as raw material for further processing. Starch can be used to produce starch sugars such as glucose, fructose, maltose, etc. In addition, starch can also be used to produce sorbitol ( Used in the manufacture of vitamin C, etc.), the manufacture of starch chemical processing products such as starch plastics, super absorbent resins, modified starch and aldehyde-containing oxides for the pharmaceutical industry, etc.

Henan Huatai is your best choice, if you want to set up corn starch plant, any need please email to [email protected]