Thank you very much for the information Charles. This will help me support my HACCP plan and give me pointers on areas where we need to improve.
There are a few points where we do things differently. For example, we have roller mills right after the maize is dehulled and degermed. Also, there is virtually no conditioning period, since the time from which water is added to the maize, to the point where it is degermed is only about 10 minutes. This minimizes the risk of mould growth. Our maize grits are not fortified, since they are used mostly for extruded products, such as snacks or cereals, that would be fortified after extrusion. It's probably quite difficult, as the document says, to have homogenous distribution of the vitamin premix, since maize grits have a wide range of particle sizes. I would imagine that because vitamin premixes are in powdered form, they would tend to separate from larger particles.
There's a thread about fat acidity in corn grits, which I asked about because I needed to extend the shelf life of our product from 4 months to 6 months. From the info on this document, we can extend it to 10 months. In that thread you mentioned that rancidity begins to be detectable to the palate when the fat acidity value is around 0.8 to 1.5%. Do you happen to have a bibliographical reference for this data?