The technology for fortifying wheat flour is simple and cost effective.
Micronutrients in the form of a premix are added through a volumetric feeder located towards the end of the milling process.
The screw rotates inside a chamber containing the premix and pushes the premix through an outlet spout. The amount of premix
added to the flour can be modified by changing the motor speed. The premix can be either fed directly into the flour by gravity
or by air convection using a pneumatic system. In a gravity driven system, best site for adding micronutrients is before the
midpoint along the screw conveyor that collects flour from all the mill passages, just before bulk storage or sacking.
If the feeder is placed towards the beginning of the screw conveyor, the amount of flour in the conveyor will be too little.
If, on the other hand, the feeder is located toward the end of the screw conveyor, the required homogenisation will not be achieved.
In a pneumatic system feeders can be placed in a remote centralised location.