I've looked through the documentation, and can't find any clear indication of which noble house might be the one that controls food production and distribution, if one does at all.
You can't have a city without plenty of food being grown or produced outside it, and in a society like Zalanthas's it seems pretty unlikely that such an important industry would be left untouched by the greedy, greedy fingers of our betters.
So, who is it?
Rennik runs the farming villages located around 'nak, Oash has their vineyards.
Also remember that Allanak imports an amazing amount of grain from Red Storm East which is controlled by the Sand Lord.
I believe in the north, food distribution is left in the fat hands of House Uaptal.