I can see my house from here!
In the rules of the game there is a note saying:
"In this game, Food can ALWAYS be replaced 1:1 with Francs".
Does this mean that in the end of the game you can replace you leftover food with francs and count them as victory points?
No. That rule means that if you need to pay food, you can pay with money. The reverse is not true, if you need to pay money you can NOT pay with food.
You can think of it as you are "spending" your money at the end of the game for points - you can't use food in place of money.