[angiosperm]

Prehistorically, fructose without intermixed fiber was found mainly in honeycombs, i.e. rarely. Beverages are the way most people get the most concentrated blasts of fructose nowadays. With enough fiber, intestinal bacteria get first crack at it. (Keep your intestinal bacteria well-fed; hungry bacteria will eat you instead.)

Your body has processes to produce fructose, which is then processed by the liver to fat for storage, when preparing for lean times seems indicated.

It is hard to research, but it seems like mangoes have the highest proportion of fructose. Honey has more fructose than glucose, and agave syrup is mostly fructose.