Inventive step

At a conference I was stuck with a man named Eric from a known organization for patents. I feigned interest in patents until he mentioned that what separates inventions from modifications is the 'inventive step'. He also mentioned that Gatorade is from the University of Florida, and that a university in Cebu has just patented their mango starch. Interesting guy, although he sounds a bit bored when I push him to explain things further, as I'm sure he gets these questions all the time.