Now that you've got the 411 on the history of sugar, I thought I'd introduce you to the history of salt. In addition to being a vehicle for how salt is harvested through the ages, Mark Kurlansky's Salt: A World History, is also a history of how salt is linked to culture, food prep and government. Most of us take salt for granted, but in the past it was certainly crucial to survival. It allowed people to preserve food for consumption during the long winter months, and was so valuable it actually acted as currency.
Overall it is a well researched book, sprinkled with amusing anecdotes and fascinating tidbits. If you're interested in food, it's definitely worth the read.