Honey is composed primarily of the sugars glucose and fructose; its third greatest component is water. Honey also contains numerous other types of sugars, as well as acids, proteins and minerals.1,2 Sugars are also called sweet carbohydrates. Carbohydrates are described by the number of sub-units they contain. Fructose and glucose are monosaccharides, that is, simple sugars. Sucrose, which is composed of fructose and glucose linked together, is a disaccharide; it comprises a little over 1% of the composition of honey. Honey contains other disaccharides which make up over 7% of its composition. Some of the disaccharides in honey are maltose, sucrose, kojibiose, turanose, isomaltose, and maltulose.
In addition, honey also contains carbohydrates known as oligosaccharides. These are medium-sized carbohydrates, containing more than three simple sugar sub-units, often made of mono- and disaccharides. Oligosaccharides are sometimes referred to as “higher sugars.”
Fructose is slightly sweeter than sucrose, glucose is less sweet, and maltose even less sweet. In most honeys, fructose predominates and tends to make honey taste slightly sweeter than sugar. Some honeys which are very rich in fructose tend to taste very sweet, but there are a few types of honeys which contain more glucose than fructose.
On the average honey is 1 to 1.5 times sweeter (on a dry weight basis) than sugar. Liquid honey is approximately as sweet as sugar, yet it contains only 82.4 g carbohydrates/100 g (vs. 100 g for sucrose) and provides only 304 Kcal/100 g (vs. 400 Kcal for sucrose).
Because honey contains such a variety of carbohydrates and other nutrients, it is much more than just a sweetener. The carbohydrates, major monosaccharides and minor oligosaccharides of honey, are responsible for some of its key functional properties. The ability of honey to hold moisture and extend shelf-life, its microwave reactivity and its ability to promote color and flavors development are all related to its carbohydrate composition.
Another important aspect of honey carbohydrate composition is crystallization. The fructose/glucose and glucose/water ratios are parameters which are used to help predict the tendency of honey to crystallize. Honeys with a low glucose/water ratio generally do not crystallize easily.
About 3 to 4% of the composition of honey is made up of oligosaccharides. Examples of oligosaccharides found in honey include erlose, theanderose, and panose. These sugars are formed when nectar and honeydew are converted to honey.
One tablespoon of honey weighs 21 grams, approximately 17 grams of that are carbohydrates. The total sugar content is the sum of all mono-, di- and oligosaccharides.
Using the usual value of 4 calories per gram, one tablespoon of honey contains 17 grams of carbohydrates and 64 calories (kcal). FDA guidelines suggest that, alternately, one may use the Atwater factor of 3.68 calories per gram of carbohydrate for calorie calculations.
Various methods exist to measure total sugars, individual sugars (glucose, fructose, sucrose, and maltose), and higher sugars. The Association of Official Analytical Chemists International publishes official testing methods (AOAC 1995, 16th edition, section 44.4). Most laboratories can do these tests or have developed alternate techniques. The technique of choice will depend upon the particular situation. A list of laboratories is available from the National Honey Board.
Approximately 95% of the carbohydrates found in honey are fermentable. This characteristic is important for the manufacture of honey beers3 and wines, and in bakery applications. However, pure honey with a carbohydrate content = 83% or a moisture content =17.1% will not ferment when stored properly.
Honey does contain small amounts of oligosaccharides but no “ complex” carbohydrates such as fiber.
Although monofloral (from a single type of flower) honeys may have very different flavors and aromas, their sweetening “ power” is similar (see table below). However, a few floral types of honeys which are very rich in fructose may taste somewhat sweeter. Manufacturers commonly use blends of honey which have been mixed to provide a consistent sweetness and flavor.
Honey is a potent sweetness enhancer, especially when added to products with low levels of sweetness. The sweetness intensity of honey increases with increased honey concentration, to a point. Research has shown that the addition of 25% honey to a 5% sucrose solution doubles the intensity of sweetness.4 The sweetness enhancement effect is somewhat less pronounced when honey is added to sweeter products. The addition of 25% honey to a 10% sucrose solution increases the sweetness intensity by 16%.
Because it is a highly concentrated “sugar” solution rich in fructose, honey can absorb water readily under certain conditions. In some bakery products, honey is added to extend shelf-life and “lock” moisture in the product.5 Bakers often substitute 10-15% or more of a bakery product’s total sugar with a corresponding amount of honey. Research has also shown that honey can be successfully incorporated at levels as high as 12- 15% in dry products such as breakfast cereals,6 potato chips7 and extruded snacks.8 It has been suggested that direct incorporation of liquid honey by extrusion processing may impart a protective effect against moisture absorption by the hygroscopic honey components.
A 68% honey solution freezes at 21.6 °F (-12.01 ° C), and a 15% solution at 29.44 °F to 29.25 °F (-1.42 ° C to -1.53 °C). However, the freezing point depression effect is not very pronounced in product applications. Research on honey ice cream and frozen desserts and honey has shown the following:
Research has shown that honey is more microwave reactive than high fructose corn syrup.10 Honey can be used as a browning agent or surface coating in a wide range of microwaveable products. These include snacks such as potato, corn or cerealbased chips as well as muffins, cookies, brownies and other baked goods.
Manufacturers need to consider that honey contains an average of 17.1% water. A simplified practical substitution formula on a sweetness/ moisture basis is: subtract 1.8 lbs of water from the original formula for every 10 lbs of honey added. Other substitutions are found in the Table 3.11
©2007 National Honey Board
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