I would look at there logos and see how you can do yours in comparason.
In 1996 the typeface of the logo was changed to the current version with stripe reflections underneath, whilst the corporate font used for store signage was changed from the familiar "typewriter" font that had been used since the 1970s
http://en.wikipedia.org/wiki/File:ASDA_logo.svg
Look at the history of these and see if you can brainstorm some simalarities?
I would say You could do with the type and but make the logo custom slightly?
A basic type only Wont be that great in my opinion in todays age.
Maybe search for images like :
http://www.google.co.uk/images?q=grocery&hl=en&client=firefox-a&hs=Aed&rls=org.mozilla:en-GB:official&prmd=ivnscm&source=lnms&tbs=isch:1&ei=doMcTbCoAaaAhAfgpZC3Dg&sa=X&oi=mode_link&ct=mode&ved=0CBsQ_AU&biw=1152&bih=759