As one of nature’s wonders, honey is renowned for its sweet taste and medicinal properties. Whether you add it to your breakfast or pair it with lemon to soothe a sore throat, you’ve probably experienced the benefits of honey at one point or another. But have you ever stopped to think about its chemical composition?
As we explore below, honey is actually one of the most complex chemical mixtures produced by nature. It consists of several organic compounds including vitamins, minerals, sugars, and acids.
Continue reading to learn more about the chemistry of honey and the science behind nature’s liquid gold.
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Honey: nature’s liquid gold
The practice of harvesting honey as food is thought to date back at least 15,000 years when humans collected honey from wild hives. Honey was considered a luxury item in ancient times and was typically reserved for royalty and the wealthy. The ancient Egyptians even believed honey had magical properties. They used it in various religious ceremonies and also as a natural remedy for a wide range of illnesses. Even today, honey is often used as a naturopathic remedy thanks to its anti-inflammatory, antioxidant, and antibacterial properties.
Honey is made when bees biologically process the nectar they harvest from flowers. Nectar is primarily composed of water with dissolved fructose, glucose, and sucrose. It also contains trace amounts of other substances such as proteins, salts, acids, and essential oils. The sugars in nectar are then converted into simpler forms by enzymes in the bees’ guts. As the bees flap their wings, the water evaporates and the honey becomes syrupy in viscosity.
Unsurprisingly, honey is primarily composed of the sugars glucose and fructose (more on this below). However, it also contains various types of organic acids including acetic acid, butanoic acid, pyroglutamic acid, lactic acid, malic acid, and citric acid. Gluconic acid, which is a product of the breakdown of glucose by the enzyme glucose oxidase, is the main acid in honey.
Simple sugars: honey’s primary components
The viscous, syrupy texture of honey is primarily due to the presence of concentrated sugars. While the exact quantities can vary, honey typically contains around 40% fructose, 30% glucose, and 17% water (the remainder is made up of other minor sugars and nutrients). Honey’s natural sweetness makes it a popular alternative to processed sucrose or white sugar.
Fructose in honey
Fructose is the most dominant simple sugar in honey, accounting for around 40% of its composition. Its IUPAC name is D-arabino-Hex-2-ulose and it has the chemical formula C6H12O6. Fructose is a monosaccharide, which means that every molecule is composed of a single unit of carbohydrate.
Glucose in honey
In addition to fructose, honey comprises approximately 30% glucose. The IUPAC name for glucose is ᴅ-gluco-Hexose. Glucose and fructose both have the same molecular formula. Although they’re chemically identical, they’re classed as isomers because they have different structures.
Minor sugars
The minor sugars in honey are present in small or trace amounts. These include complex sugars like maltose, sucrose, and other disaccharides. Honey also contains small quantities of trisaccharides such as erlose.
Acids and pH in honey
Honey contains several organic acids, many of which are already present in the nectar the bees collect from flowers. Others, such as gluconic acid, are byproducts of the enzymatic breakdowns of simple sugars. Some of the acids present in honey include acetic acid, butanoic acid, gluconic acids, pyroglutamic acid, lactic acid, malic acid, and citric acid.
Although honey is sweet, its acidic nature means it also has a characteristic sourness. Honey usually has a pH of between 3.2 and 4.5, which means it’s classed as an acid on the pH scale (the exact pH depends on the specific type of honey). This acidity is one of the reasons why honey is a good antibacterial agent.
Vitamins, minerals, and antioxidants in honey
Aside from sugars and acids, honey also contains other nutrients such as minerals, antioxidants, and vitamins. Many of these are already in the nectar before the bees process the nectar into honey. For example, the vitamins in honey originate from pollen.
- Minerals – the minerals in honey come from the nutrients in the soil that are absorbed by plants. These include calcium, copper, iron, magnesium, manganese, phosphorus, potassium, and zinc.
- Antioxidants – honey has several antioxidants, which include vitamin C (ascorbic acid) and vitamin E. The latter can be found in several forms but alpha-tocopherol is the one primarily used by the human body. Other antioxidants in honey are phenolic acids, flavonoids, catalase, and peroxidase.
- Vitamins – the vitamins in honey primarily come from the pollen in the flowers. Some of the important vitamins found in honey are vitamin C, vitamin E, pantothenic acid, niacin, and riboflavin.
Enzymes in nectar & honey
Bees produce enzymes in their salivary glands, which then process the nectar into honey. The two main hydrolytic enzymes made by bees are called diastase (α- and β-amylases) and invertase (α-glucosidase). Diastase breaks down complex carbohydrates and invertase hydrolyses sucrose into glucose and fructose.
Meanwhile, the glucose oxidase in honey catalyses glucose into gluconolactone. In turn, this decomposes into gluconic acid and hydrogen peroxide. Both of these chemicals have antimicrobial properties and are the main reasons why honey can sometimes be used to combat microbial infections.
Trace elements: pollen and propolis
In addition to the components outlined above, honey may also contain trace amounts of pollen and propolis.
While bees don’t intentionally use pollen to make honey, pollen particles inevitably stick to their bodies when they harvest nectar from flowers. Although some people are allergic to pollen, it’s normally harmless when mixed with honey in trace amounts. In fact, some hay fever sufferers believe eating local honey can help them develop a resistance to pollen grains. However, there’s currently no definitive scientific evidence to support this theory.
Derived from the buds of poplar and cone-bearing trees, propolis is a resin-like substance that bees use to build their hives. Unsurprisingly, trace amounts of this substance find their way into the honey. The chemicals in propolis have antimicrobial properties and can therefore inhibit the growth of bacteria, viruses, and fungi. Propolis also has anti-inflammatory effects, which may help to alleviate certain ailments like joint pain caused by arthritis.
Summary
Honey is a complex chemical mixture composed of sugar (primarily glucose and fructose) and various acids, along with different types of vitamins and minerals. It may also contain trace amounts of pollen and propolis. As well as being a natural sweetener, honey has various antibacterial and medicinal properties. Despite its sweet taste, honey is classed as an acid because it has a pH of below 7.
