Plant extractive ideas

[Brian Doyle]

My major professor has asked me to coordinate a laboratory exercise for
a Plants and Society course (non-majors/non-laboratory based course). 
Several folks have mentioned this type of course before and I was
wondering if anyone has any ideas or protocols for a lab which explores
the concept of extractives.  I am considering the extraction of
caffeine from coffee beans, but am eagerly seeking alternate ideas. 
Thanks for your help.

Brian Doyle
University of Maine
Dept. of Plant Biology and Pathology
Orono, ME 04469-5722

brian_doyle at voyager.umeres.maine.edu