Can the value of Afrcia agricultural product be integrated into civilian factory? Which means adding more civil factory to the various states of Africa, increasing it's importance.
I don't think that's a good idea. The real impact of food shortages in Europe sound like in game terms they would be unrest (eg in conquered Greece), lower national unity, lower available manpower.
The effect of having extra civilian factories in Africa would be a faster expansion of military activity. Did African foods really let the British build more fighters, ships or tanks?