Right now it is not important because many big stores have 1-2 months food supply and by that time situation might change, also Russia limited import from many countries of the EU this winter already, so the sanctions are just continuation of that limit, looks like some kind of strategy. Maybe Russia wants the EU to appeal to WTO where it would also try to question Western sanctions on Russia and lift them.
Something tells me that in September Russia might bring gas "sanctions" on the table.
Russia was always telling that sanctions would hurt both sides, it looks like finally the EU realized that, it's a start.