Yeah, you will miss the supermarkets, even the one in Portal Marina on the 332 at Ondara closes at 10. One (expensive) option might be to go upstairs at Alicante airport into the departures area, you can find some basics there just for overnight maybe.
Other than that you could dive into Alicante city on the way through and find something. Follow N332 Alicante from airport for that.
Otherwise go out for a big breakfast!