Missouri, to the best of my knowledge, doesn't allow alcohol or tobacco to be purchased with 'food stamps' but that doesn't mean people on the program don't buy these things.
Here, there are lots of states that tax food or tax it at a lower rate than other goods: http://www.cbpp.org/cms/index.cfm?fa=view&id=1230
(note this site states that Arkansas food tax is listed as 2%--not what the poster that lives in AR reported. This may be because of COUNTY AND/OR CITY TAXES! Missouri Counties and Cities still levy sales tax on food so that is added to the state rate--we generally pay anywhere from 2% to 4% on food dependent upon where it's purchased)