Maize is cleaned and transported into steeping vats. The steeping water has a temperature of maximum 52 0C
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. 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 that result 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