Trade publications --- Online, library databases
Popular --- Online newspapers, library newspaper databases
Scholarly --- Library databases, Google scholar
- topic has to interest scholars, search for categories or industries for business topics
Since you will be looking at local restaurant, farms, or markets, you best sources of information will be local newspapers and the web.
If you keep your topic broad, rise of organic foods, eat local movement, technology (apps) used by restaurants, you can find
journal articles in Discovery@MU or in the major business databases.