Maize starch production process flow chart

Maize is cleaned and transported in to steeping vats. The steeping water has a temperature of maximum 52⁰C which is maintained by circulation via a heat–exchanger. To facilitate the gluten separation about 0.2 to 0.3% sulfurous acid is added. This additive also bleaches the starch. The steeped maize is discharged by screw conveyors to the de-germinating mill. It breaks up the maize kernels and sets the germs free without damaging them. 

 Flow sheet of maize starch manufacturing process

The maize slurry drops into the germ separator where the fat-containing germs are separated from the slurry and flow into a container. They are pumped into a washing machine and a dewatering press. The germs are then dried and ready for storage. Having high value edible oil content of about 45%, the germs can be used for oil extraction. The maize slurry flows into the container and is pumped to the refiner mill. For coarse fiber washing, the slurry is delivered to an extraction section. The starch milk is collected in raw milk vessels equipped with stirrers. The crude starch milk is pumped to the extraction section for fine fiber washing. From the extractors the starch milk flows to the container. This is followed by a series of filtering and refining processes which results in high quality maize starch. By-products of the process include high quality animal feed. 

By using an alternative technology, maize starch can be made using a larger scale and capital intensive technology. As compared to the technology used to produce maize starch at a smaller scale, this technology is expensive but requires less labor per unit of output.