The shop and pub issues are matters of trademark infringement/passing off, but fortunately that has little, if anything, to do with works mentioning them -- there are plenty of books in which companies such as Harrods and Fortnums are specifically named without causing any problems, so as long as the companies aren't defamed in any way, it's fine.
Defamation is likely to be an issue if the named ice cream/soup causes widespread food poisoning, or is said to contain illicit ingredients, or aspersions are cast on the manufacturers' probity or ethics -- it's largely a question of using common sense in talking about them.