Honey comes from a transformation of the nectar by adding enzymes
The nectar arrives in the melaria bag, a dilation of the esophagus where it is accumulated, after which the foragers on returning to the hive regurgitate the content to the bees of the house that proceed to add other enzymes (through the phenomenon of trophylaxis). After several steps they place it in the cells where it undergoes a concentration, when the honey is mature that is sufficiently concentrated they protect it with a wax operculum.
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Glucose is one of the main constituents of flower honey, however it is less soluble in water than fructose and therefore more subject to crystallization. Crystallization is a natural process and there are no nutritional differences between solid honey and liquid honey, it is the same substance only in a different form. As soon as the honey is extracted, it is only a supersaturated substance of water and sugars and, given its instability, it tends to reach a balance over time, releasing an excess solute in the form of crystals. However, the influence of temperature on this process must not be overlooked, in fact, crystallization can take place between 5 ° and 25 ° C, with a peak of 14 ° C. Crystallization is hindered by decreasing temperature, because by increasing the viscosity of honey, the movements that take place inside the mass are more difficult, which entails a slowing down of the chemical processes of growth of the crystals. Too high temperatures, on the other hand, slow down the process where the crystals are destroyed. Some honeys have a greater tendency to crystallize than others, this depends on the different botanical characteristics, however, there are people who prefer liquid honeys, others, crystallized honeys.
Liquid honey (photo www.organicsoul.com)
Honey is classified based on its origin, how it is collected and processed or thanks to the use for which it is intended.
It is distinguished on the basis of origin in:
- flower honey: obtained from the nectar of flowers,
- honeydew honey: produced by bees following the transformation of the honeydew - sugary substance emitted by the homoptera, in particular psyllids, whiteflies, mealybugs (except the jasper), the aphids (except the adelgids and the phylloxera) and the buzzers.
It consists of liquid excrements produced by the phytomyces filtering chamber, a physiological adaptation due to the exclusive lymph nutrition. However, the lymph-based diet is unbalanced due to the high sugar content and the low amino acid content; therefore the filtering chamber, present in the mesentery, acts by filtering the water and sugars by diverting them to the proctodeo to prevent dilution of the food substrate, which is only thus concentrated and satisfies the nitrogen requirement that the phytomizide needs.
Honeydew honey has an absence or almost of crystallization and this is due to a high percentage of fructose compared to glucose. In addition, honeydew honey has high acidity and significant levels of hydroxymethylfurfural enzyme (HMF). Honeydew honey has higher values, compared to flower honey, in: mineral salts, amino acids, sugars with higher molecular weight (oligosaccharides). This honey also has a higher electrical conductivity, a greater ash content and a more intense flavor, some research indicates that it also has antibacterial properties on average higher than the other honeys thanks to high levels of glucose oxidase which leads to the formation of peroxide of hydrogen,
- monoflora honey: it is obtained when bees are mainly foraging a botanical species,
- multiflora honey: characterized by different botanical species.
Crystallized sunflower honey (website photo)
Classification based on processing:
- honey comb: it is obtained when the beekeeper does not separate the honey from the frames (without brood) therefore it also contains the wax, it represents the easiest type of honey to collect,
- honey with honeycomb pieces or honeycomb sections: honey that contains one or more pieces of honey in the comb
- filtered honey: the honey is separated from the wax by filtration,
- centrifuged honey: obtained by centrifugation of uncapped frames not containing brood (most common type),
- pressed honey: extracted thanks to the pressing of the frames (not containing brood) without heating or with moderate heating to a maximum of 45 ° C,
- crystallized honey: honey that has undergone the crystallization process,
- liquid honey: has a uniform fluid consistency.
Classification based on use:
- table honey: intended for the consumer to be eaten directly as a natural sweetener for drinks or for cooking,
- industrial honey: it can naturally contain more than 40 mg / kg of HMF or this depends on having been subjected to excessive heat.
HMF is used as an index of the freshness of honey and its state of conservation. A specific regulation regulated by law n. 753 of 12 October 1982 (and subsequent amendments), governs the production, packaging and labeling of honey; the de facto regulations place for the HMF a maximum limit of 40mg / kg (ppm), an excessively high value since a quality honey should not exceed, at production, a value higher than 10 mg / kg. Most manufacturers, and distributors, perform periodic checks both on the product just packaged, and on the stock present in the warehouse, to make sure that during the time in which the product is on the shelves of the sales shop, or warehouse, there has been no degradation of sugars. To prevent this problem it is necessary to pay attention to the phases of honey extraction, potting, heat treatments, working in conditions of hygiene to avoid contamination by bacterial agents or of various foreign particles and storage at room temperature, which can lead to a greater formation of HMF compared to a temperature of 4 ° C, such as that of the refrigerator. But in addition to temperature, as responsible for the formation of HMF, acidity also plays a fundamental role. All honeys have an acid component, numerous organic acids are in fact contained in nectar or honeydew and partly from bees, always showing PH values lower than 7, mostly between 3.5 and 4.5. The acidity increases with aging, with fermentation, or if honey is extracted from highly propolisated honeycombs. In an acidic environment, fructose undergoes a degradation process that leads to the formation of HMF.
The reason why the HMF content should be checked, in addition to the need to provide a fresh product that maintains the organoleptic characteristics intact, lies in its potential toxicity to bees.
Beekeepers often feed their bee farms using old honey, often subjecting it to sterilization processes (to eliminate possible pathogens) and high temperatures for a long time. HMF exerts its gastrointestinal toxicity to bees, even causing death in high concentrations. There was no evidence of toxicity in humans at concentrations found within honey.