Saturday, October 18, 2008

HONEY IS GOOD FOR OUR HEALTH

Honey is a sweet and viscous fluid produced by honey bees (and some other species), and derived from the nectar of flowers. According to the United States National Honey Board and various international food regulations, "honey stipulates a pure product that does not allow for the addition of any other substance...this includes, but is not limited to, water or other sweeteners". This article refers exclusively to the honey produced by honey bees (the genus Apis); honey produced by other bees or other insects has very different properties.

Honey is significantly sweeter than table sugar and has attractive chemical properties for baking. Honey has a distinctive flavor which leads some people to prefer it over sugar and other sweeteners.

Most microorganisms do not grow in honey because of its low water activity of 0.6. However, it is important to note that honey frequently contains dormant endospores of the bacteria Clostridium botulinum, which can be dangerous to infants as the endospores can transform into toxin-producing bacteria in the infant's immature intestinal tract, leading to illness and even death.

The study of pollens and spores in raw honey (melissopalynology) can determine floral sources of honey. Because bees carry an electrostatic charge, and can attract other particles, the same techniques of melissopalynology can be used in area environmental studies of radioactive particles, dust, or particulate pollution.

A main effect of bees collecting nectar to make honey is pollination, which is crucial for flowering plants.

The beekeeper encourages overproduction of honey within the hive so that the excess can be taken without endangering the bees. When sources of foods for the bees are short the beekeeper may have to give the bees supplementary nutrition.

Honey is laid down by bees as a food source. In cold weather or when food sources are scarce, bees use their stored honey as their source of energy. By contriving for the bee swarm to make its home in a hive, people have been able to semi-domesticate the insects. In the hive there are three types of bee: the single queen bee, a seasonally variable number of drone bees to fertilize new queens, and some 20,000 to 40,000 worker bees. The worker bees raise larvae and collect the nectar that will become honey in the hive. They go out, collect the sugar-rich flower nectar and return to the hive. As they leave the flower, bees release Nasonov pheromones. These enable other bees to find their way to the site by smell. Honeybees also release Nasonov pheromones at the entrance to the hive, which enables returning bees to return to the proper hive. In the hive the bees use their "honey stomachs" to ingest and regurgitate the nectar a number of times until it is partially digested. It is then stored in the honeycomb. Nectar is high in both water content and natural yeasts which, unchecked, would cause the sugars in the nectar to ferment. After the final regurgitation, the honeycomb is left unsealed. Bees inside the hive fan their wings, creating a strong draft across the honeycomb which enhances evaporation of much of the water from the nectar. The reduction in water content, which raises the sugar concentration, prevents fermentation. Ripe honey, as removed from the hive by the beekeeper, has a long shelf life and will not ferment.

Honey is a mixture of sugars and other compounds. With respect to carbohydrates, honey is mainly fructose (about 38.5%) and glucose (about 31.0%), making it similar to the synthetically produced inverted sugar syrup which is approximately 47% fructose, 47% glucose and 5% sucrose. Honey's remaining carbohydrates include maltose, sucrose, and other complex carbohydrates.

Honey contains trace amounts of several vitamins and minerals. As with all nutritive sweeteners, honey is mostly sugars and is not a significant source of vitamins or minerals.

Honey also contains tiny amounts of several compounds thought to function as antioxidants, including chrysin, pinobanksin, vitamin C, catalase, and pinocembrin.

The specific composition of any batch of honey will depend largely on the mix of flowers available to the bees that produced the honey.

Honey has a density of about 1.36 kg/liter (40% denser than water).

Typical honey analysis

* Fructose: 38.0%
* Glucose: 31.0%
* Sucrose: 1.0%
* Water: 17.0%
* Other sugars: 9.0% (maltose, melezitose)
* Ash: 0.17%
* Other: 3.38%

The analysis of the sugar content of honey is used for detecting adulteration.

* Comb honey Honey sold still in the original bees' wax comb. Comb honey was once packaged by installing a wooden framework in special honey supers, but this labor intensive method is being replaced by plastic rings or cartridges. With the new approach, a clear cover is usually fitted onto the cartridge after removal from the hive so customers can see the product.
* Certified Organic Honey, according to the USDA, organic honey is quite rare to find because most beekeepers "routinely use sulfa compounds and antibiotics to control bee diseases, carbolic acid to remove honey from the hive and calcium cyanide to kill colonies before extracting the honey, not to mention that conventional honeybees gather nectar from plants that have been sprayed with pesticides."
* Raw honey Honey as it exists in the beehive or as obtained by extraction, settling or straining without adding heat above 120 degrees fahrenheit. Raw honey contains some pollen and may contain small particles of wax. Local raw honey is sought after by allergy sufferers as the pollen impurities are thought to lessen the sensitivity to hay fever.
* Chunk honey Honey packed in widemouth containers consisting of one or more pieces of comb honey surrounded by extracted liquid honey.
* Strained honey or Honey which has been passed through a mesh material to remove particulate material (pieces of wax, propolis, other defects) without removing pollen, minerals or valuable enzymes. Preferred by the health food trade - it may have a cloudy appearance due to the included pollen, and it also tends to crystallize more quickly than ultrafiltered honey.
* Ultrafiltered honey Honey processed by very fine filtration under high pressure to remove all extraneous solids and pollen grains. The process typically heats honey to 150-170 degrees to more easily pass through the fine filter. Ultrafiltered honey is very clear and has a longer shelf life, because it crystallizes more slowly due to the high temperatures breaking down any sugar seed crystals, making it preferred by the supermarket trade. Ultrafiltration eliminates nutritionally valuable enzymes, such as diastase and invertase.
* Heat-Treated honey Heat-treatment after extraction reduces the moisture level and destroys yeast cells. Heating liquefies crystals in the honey, too. Heat-exposure does also result in product deterioration, as it increases the level of hydroxymethylfurfural (HMF) and reduces enzyme (e.g. diastase) activity. The heat does also affect sensory qualities and reduces the freshness. Heat processing can darken the natural honey color (browning), too.
* Ultrasonicated honey Ultrasonication is a non-thermal processing alternative for honey. When honey is exposed to ultrasonication, most of the yeast cells are destroyed. Yeast cells that survive sonication generally lose their ability to grow. This reduces the rate of honey fermentation substantially. Ultrasonication does also eliminate existing crystals and inhibit further crystallization in honey. Ultrasonically aided liquefaction can work at substantially lower temperatures of approx. 35 °C and can reduce liquefaction time to less than 30 seconds.


Due to its unique composition and the complex processing of nectar by the bees which changes its chemical properties, honey is suitable for long term preservation and is easily assimilated even after long conservation. History knows examples of honey preservation for decades, and even centuries. "...small residues of edible honey have even been found in the pharaoh's tombs..."

A number of special prerequisites is, however, necessary to achieve the conservation periods of this order. These might include sealing the product in vessels of chosen material, kept in a favorable environment of specific humidity, temperature etc. An example of natural sealing of the honey with wax by the bees in little separated honey comb cells could be taken for reference.

When conventional preservation methods are applied, it is not recommended to preserve the honey for longer than 2 (maximum 3) years. As the honey has a strong tendency to absorb outside smells, it is advisable to keep it in clean, hermetically sealed vessels. It is also advisable to keep it in darkened (not lucid) vessels, or in dark store-places. When the honey remains in direct sunlight for about one day its lysozyme (antibacterial albuminous enzyme) is being destroyed. Honey should also be protected from oxygen inflow – the accelerated crystallization is brought about by it. Optimal preservation temperature is +4-10°C. The store-place should be dark and dry, preventing the honey from absorbing the moisture. When excessive moisture is soaked up by the honey, it might start fermenting. "Bee honey can absorb the moisture from the air, therefore it might ferment in a damp place"

"Exposure to fresh air brings about the soaking up of external smells, oxygen and moisture, which cause fundamental chemical change of the product - decay of valuable amino acids, vitamins, enzymes and "antibiotics". The light has a similar influence."

The acacia honey is known to be more resistant against crystallization. "The acacia honey would not crystallize (as quick as other types)..."

Due to the above reasons (high tendency to absorb outside smells and moisture) it is not advisable to preserve the honey in a fridge, especially together with other foods and products.

Honey is considered to gradually become toxic when preserved in metal containers. "Honey must not be preserved in metal containers, because the acids contained in its structure may cause oxidation. This leads to increased content of heavy metals in honey and decreases the amount of valuable healthy ingredients. Such a honey may cause obnoxious sensations in the stomach and even bring about a poisoning..." It used to be preserved in ceramic and wooden containers in ancient times. Glass bottles are recommended nowadays. "The wooden vessels of coniferous wood are not suitable for honey preservation (honey soaks up the coniferous smell in such vessels). In the oak wood vessels honey grows black."

Traditionally honey was preserved in deep cellars, but not together with wine or other products. It is considered even more sensitive to the store-place conditions than the best wines.

Honey should not be heated above 40°С (104°F).

"The best honey is in the uncut honey combs. After being pumped out from there it is very vulnerable, and the main losses of quality take place during preservation and distribution. Heating up to 37°С causes loss of nearly 200 components, part of which are antibacterial. Heating up to 40°С destroys the invertase - the main bee enzyme, thanks to which the nectar becomes honey; heating up to 50°С turns the honey into caramel (the most valuable honey sugars become analogous to synthetic sugar). Generally any larger temperature fluctuation (10°С is ideal for preservation of ripe honey) causes decay."

The high quality natural honey can be distinguished by its fragrance and taste. The best period to stock up on honey is in summer, when it is being collected in large quantities. The ripe, freshly collected, high quality honey at 20°C (68°F) flows from the knife in a straight squirt, without breaking into separate drops. After falling down the honey should form a clear hillock. A saying goes: “the honey rustles and glues like viscose”. The ripe honey is being collected from the sealed honey combs, therefore it should always be of high quality.

The honey should not lay down in layers. If this is a case, it indicates the excessive humidity (over 20%) of the product, and such a honey would not be suitable for long term preservation.

A fluffy thin layer on the surface of the honey (like a white foam), or marble-coloured and white spots in crystallized honey at the wallsides of the bottle are caused by filling of liquid honey with subsequent sealing – the air bubbles are surfacing and part of them is concentrated at the wallsides. This is an indication of a high quality honey, which was filled without pasteurization (heating).

If the honey is transparent, burning with amber-like colours, then (unless it is very fresh) it has most likely been heated and is of little value. Transparent and reluctant to thicken honey can also indicate its being a result of feeding the bees with sugar syrup or even sugar itself, which is bad both for the bees and for the honey they produce, as naturally they are supposed to feed on flower nectar.

A true honey that is at least one month old is usually of demure (not trans-lucid) colours.

Due to the natural presence of botulinum endospores in honey, children under one year of age should not be given honey. The more developed digestive systems of older children and adults generally destroy the spores. Infants, however, can contract botulism from honey.

Honey produced from the flowers of rhododendrons, mountain laurels, sheep laurel and azaleas may cause honey intoxication. Symptoms include dizziness, weakness, excessive perspiration, nausea and vomiting. Less commonly, low blood pressure, shock, heart rhythm irregularities and convulsions may occur, with rare cases resulting in death. Honey intoxication is more likely when using "natural" unprocessed honey and honey from farmers who may have a small number of hives. Commercial processing, with pooling of honey from numerous sources generally dilutes any toxins.

Toxic honey may also result when bees are in close proximity to tutu bushes (Coriaria arborea) and the vine hopper insect (Scolypopa australis). Both are found throughout New Zealand. Bees gather honeydew produced by the vine hopper insects feeding on the tutu plant. This introduces the poison tutin into honey. Only a few areas in New Zealand (Coromandel Peninsula, Eastern Bay of Plenty and the Marlborough Sound) frequently produce toxic honey. Symptoms of tutin poisoning include vomiting, delirium, giddiness, increased excitability, stupor, coma and violent convulsions. As little as one teaspoon of toxic honey may produce severe effects in humans. In order to reduce the risk of tutin poisoning, humans should not eat honey taken from feral hives in the risk areas of New Zealand. Since December 2001, New Zealand beekeepers have been required to reduce the risk of producing toxic honey by closely monitoring tutu, vine hopper, and foraging conditions within 3 km of their apiary.