Bees produce and store honey as a food source. The final product is made of roughly 80% sugar, 17% water, and a hodgepodge of trace compounds that are critical to the honey’s varied flavors and colors. The most abundant sugars in honey are fructose and glucose. Among the myriad minor complex sugars in the goo are maltose, sucrose, and other disaccharides, as well as trisaccharides such as erlose.
To make this delicious treat, foraging bees start out by guzzling nectar, a dilute solution of sugars in flowers. Then, they mix the nectar with enzymes in their stomachlike honey sacs. Back at the hive, the foragers pass the digested material to house bees who reduce the moisture content of the mixture by ingesting and regurgitating it. They then deposit concentrated drops into honeycomb cells. Over the next few days, bees fan the fluid with their wings to further concentrate it, and finally, they cap the cells with wax. At the same time, enzyme-mediated changes produce a range of sugars and acids in the honey.
Bee enzymes also show up in the finished product. Invertase is the most critical. It splits the sucrose in the nectar into fructose and glucose and also produces some erlose. Another enzyme, glucose oxidase, converts glucose to gluconolactone, which is then hydrolyzed to give gluconic acid, the principal acid in honey. Formic, acetic, butyric, and lactic acids are also found in honey, which explains why its pH typically measures 3.8-4.0 and bacteria have a hard time growing in it.
Honey also contains small amounts of minerals and proteins. About 0.2% of honey is ash, probably originating in the flower nectar. Potassium accounts for about one-third of the ash. Other trace elements in honey include iron, manganese, copper, and silicon. The sweetener also contains up to 1% nitrogen, which comes principally from proteins. These proteins can cause honey to foam and form tiny air bubbles.
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Excerpted with permission, Chemical & Engineering News
Copyright © 2007 American Chemical Society