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GÖKHAN ÇANKAYA
EXPERT CHEMIST, UGM TEST AND ANALYSIS LABORATORY
Honey is an easy product to imitate and degrade, but it is difficult to detect these frauds. The quality of honey is determined primarily by its herbal source and chemical content. The compositions of honey produced in different regions and obtained from different herbal sources also vary. It is impossible to determine whether honey is imitated or adulterated by its taste, smell, or appearance alone. The most accurate method is to analyze the composition of honey. One of the most reliable methods for determining honey's origin and origin is honey profiling based on Nuclear Magnetic Resonance Spectroscopy (NMR).
Honey produced by bees is one of nature's most special desserts. This healing product is a storehouse of energy. The natural sugars it contains provide instant energy to the body. It has been indispensable for humanity for centuries. With its unique aroma and nutritional qualities, honey is a frequently consumed food item around the world.
Honey, a natural wonder, is not just a sweet treat. It's a powerful natural medicine, Boasting antiseptic and antibacterial properties. It's a soothing remedy for respiratory issues like sore throat and cough, A booster for the immune system, and a regulator for the digestive system. Some types of honey, with their low sugar content, are even ideal for those on a diet. With such impressive health benefits, it's no wonder that honey has been a staple in human diets for centuries.
Honey production worldwide is quite common. It is produced in various geographical regions of Turkey. Türkiye ranks second after China in honey production. It is among the countries that produce various types of quality honey. Honey production not only meets food needs but is also an economically important sector.
6 (23%) of the 27 honey bee subspecies worldwide are found in our country. The Muğla bee, which produces honey from the secretion of the Pine Cotton Horse, especially in September and October, is one of the fastest-growing bees in the world.
Our country is the only producer in the world of pine honey, and approximately 15,000 tons are produced annually. 85% of the pine honey obtained is exported to European Union (EU) countries. In terms of the number of colonies, the Aegean, Black Sea, and Mediterranean regions are our country's richest beekeeping regions.
WHAT IS HONEY AND HOW IS IT FORMED?
Nectar from the flowers of plants or secondary substances secreted by some winged insects using the living parts of plants are collected by honey bees. Bees change these substances in their bodies and store them in the honeycomb cells. At the end of the maturation process in the honeycombs, honey, a sweet product, is formed. The sugar concentration in the nectar of plants generally varies between 5% and 74%. Bees prefer plants with high sugar concentrations. They typically do not visit plants where density remains below 18%.
The nectar concentration of plants belonging to the Lamiaceae, Fabaceae, Boragniaceae, and Rosaceae families is generally between 15% and 55%. Bees worldwide and in Turkey produce honey mostly from plants belonging to these families.
Depending on its source, honey is generally divided into two main categories: flower honey and secretion honey. Secretion honey is the honey that honeybees collect by collecting the secretions of some insects living on plants, mixing them with their secretions, and storing them in the honeycomb cells.
Flower honeys can be divided into two subcategories according to their botanical source: polyflora honey and monoflora honey. The term poly flora honey comes from the Latin words "poly," meaning "many," and "flora," meaning "plant." Honey obtained from the nectar of different flower species is called polyflora honey. Monofloral honey types are obtained from a single flower or plant species. Chestnut honey, oak honey, lavender honey, and acacia honey are examples of monofloral honey.
HONEY IN NUMBERS
Nectar, one of the primary food sources of honey bees, is honey and pollen obtained from nectar processing. Most of the honey's content is sugar, and its rate varies between 95% and 99%. Nectar is an energy source for bees and a food source that can be converted into fat and glycogen. This feature allows a bee to travel 100 km with 50 mg of honey. The annual honey requirement of a bee colony varies between 70 and 80 kg, depending on the colony's population and the type of nectar. Honey contains various sugars and generally contains glucose, fructose, and sucrose. The quality of honey depends on the structure of the nectar, and bees reduce the water rate in the nectar to below 20% while ripening the honey. Additionally, the sugar content in the nectar of plants can vary between 5% and 74%.
To produce 1 kilogram of honey, bees must go out to collect nectar 80,000 times. Assuming that a bee travels an average distance of 3 kilometers in each flight (round trip), bees fly 240,000 kilometers to produce 1 kilogram of honey. This distance is equivalent to circling the Earth 6 times.
For 1 kg of honey, bees collect approximately 2 kg of nectar. A strong bee colony (80-90 thousand worker bees) consumes approximately 1/2 kilograms of honey daily during peak brood-rearing periods. This amount decreases to 100-150 grams in winter. The honey a colony consumes in a year is around 70 kg.
The chemical content of honey is approximately 80% sugar, 17% water, 3% enzymes and minerals, vitamins, organic acids, amino acids, aroma substances, etc. It consists of compounds such as.
CHEMICAL COMPONENTS OF HONEY…
Honey mainly contains enzymes such as invertase, diastase, catalase, phosphatase, and glucose oxidase. These enzymes are effective on sugar, starch, and proteins. Invertase is the most critical enzyme in honey and breaks down sucrose into fructose and glucose. The activity of invertase decreases with increasing temperature of honey. In heated honey, invertase activity may disappear altogether. Diastase is an enzyme found in the stomach of bees and plants and converts starch into maltose. Diastase is very sensitive to heat, and diastase activity decreases in heated honey and over time. Diastase activity is checked to check the honey's quality and determine the effect of heating.
Glucose Oxidase is secreted from the pharyngeal and mandibular glands of bees. It acts on glucose and carries out gluconic acid and hydrogen peroxide (H2O2) reactions. When honey is heated for any reason, enzymes break down, and hydroxymethyl furfural (HMF) is formed. HMF is formed due to the interaction of reduced sugars with amino acids or acid-catalyzed dehydration of hexoses during heat treatments applied to foods. It is stated that the HMF compound carries potential health risks to humans. Therefore, honey is a food that should not be exposed to high temperatures for any reason.
Although there is no parameter regarding the total activity value of honey in the Turkish Food Codex Honey Communiqué, it is considered an essential criterion for consumers. The antimicrobial quality of honey is measured by the term "Total Activity (TA)"; The higher the TA score, the greater its antimicrobial power.
Most unpasteurized and coarsely unfiltered (raw) honey have a range of activity levels, usually from 1 to 20. Honeys with a Total Activity greater than 10+ are considered to have significant antimicrobial properties.
Although combed honey is a rich source of vitamins, filtered honey does not have this feature. The amount of vitamins in honey varies depending on the nectar source, the freshness of the honey, the amount of pollen it contains, and production, processing, and storage conditions. Heating and straining honey are the leading causes of vitamin loss. Strained honey may contain small amounts of vitamins A, C, D, E, and B complex types. However, it is known that filtered honey is not rich enough to meet daily vitamin needs.
Although honey is the first thing that comes to mind, nowadays, in addition to honey, bee products such as pollen, royal jelly, beeswax, propolis, bee venom, queen bee, larva, swarm, and pack bee have also gained popularity.
HONEY FRAUD CAN CAUSE SERIOUS DAMAGE
The origin and authenticity of food products are becoming more critical daily; Consumers want to learn the source of honey in more detail. Although honey is an essential product used in food, medicine, and cosmetics, it is highly vulnerable to fraud. Honey fraud can cause severe economic harm to beekeepers who produce natural honey because this may cause raw honey prices to decrease worldwide and production costs to increase significantly. Honey can be adulterated with cheap sugar syrups or subjected to deliberately misleading labeling, claiming a more valuable geographical origin or floral source, making a considerable profit. The decline in the honey industry poses a significant threat to global food security, as bees are essential pollinators.
Honey is economically valuable and essential in the nutrition and treatment of some diseases. However, due to its high demand, it has taken a leading position among imitation and contaminated foods.
WHAT IS ADDRESSED HONEY?
Adulteration refers to the production of foodstuffs in violation of legislation or permitted specifications. In this case, unfair profits are made by adding an unnatural or cheap substance to a product, replacing some valuable ingredients.
Honey's general composition properties have been changed by "feeding bees with various sugar syrups during the production phase of honey, adding syrups after production, mixing honey with different properties, and adding water to honey with low moisture content," which is considered adulterated honey.
In the production of adulterated honey, the honey volume is increased by adding different sugar syrups in specific proportions. With this method, sucrose, glucose, and fructose in the natural structure of honey can be imitated, and its detection becomes difficult. Nowadays, high fructose corn syrup is often used for this purpose. Additionally, the botanical or geographical origin of honey obtained by mixing different types of honey needs to be clarified. Honey from other regions can be mixed and sold under the name of famous honey from a single area.
HONEY WITHOUT BEES IN THE PRODUCTION PROCESS!
Imitation honey contains honey produced from different sugar syrups, completely chemically, without any contribution from bees. That is, an artificial process is followed in honey production without the role of bees. Sucrose, glucose, and fructose structures are contained in honey; Colour, taste, aroma, and composition properties are imitated by using substances that are added externally and do not originate from bees. Artificial honey is obtained by adding substances that give a honey-like taste and appearance, such as pollen, coloring agents, and honey aroma, to high fructose corn syrup, glucose syrup, sucrose syrup, or inverted sugar syrup obtained by inverting sucrose. Honey produced this way often lacks flavor, is pale in color, differs in composition, and is not considered natural. Recently, honey-like glucose syrups can be made through an enzyme called 'beta fructofuranosa.'
DETECTING IMITATION AND ADVERTISEMENT IN HONEY
Honey is an easy product to imitate and degrade, but it is difficult to detect these frauds. The quality of honey is determined primarily by its herbal source and chemical content. The compositions of honey produced in different regions and obtained from different herbal sources also vary. It is impossible to determine whether honey is imitated or adulterated by its taste, smell, or appearance alone. The most accurate method is to analyze the composition of honey. If a product has all the features specified in the Turkish Food Codex Honey Communiqué, it is considered honey that has not been imitated or adulterated.
"Melissopalynological, sensory analysis, sugar profile, amino acid profile, enzyme activities, hydroxy methyl furfural, and proline values measurements" are used to detect honey adulteration. However, it is known that these tests are time-consuming in detecting adulteration and may only be sufficient to detect simple frauds.
Isotope analyses of honey samples gain importance in this context.
A honey sample that complies with the Honey Communiqué may be imitated or adulterated. Still, precisely determining imitation or adulteration with analytical devices may not be possible.
Experts should carry out analyses to detect imitation and adulteration in honey. These analyses are generally carried out by the Ministry of Food, Agriculture and Livestock, large honey producers and packaging companies, and exporting companies. In detecting imitation and adulteration, there are "two determining features, such as the amount of proline and the ratio of C4 sugars."
PURITY, QUALITY AND MATURITY INDICATOR: PROLINE
Although the amount of protein in honey is relatively low, many amino acids exist. Proline constitutes 50-85% of the total amount of amino acids. However, the amount of proline varies depending on the origin of the honey. Although it is found in nectar and pollen, the honey bee is the primary source of proline in honey. The honey bee adds proline in the process of converting nectar into honey. Therefore, the amount of proline is an essential indicator of honey's quality, purity, and maturation and is one of the most important features used in detecting fake honey. However, the proline content of honey obtained due to intensive feeding with sugar syrup may be low. The amount of proline alone may not be sufficient to detect adulteration due to many reasons, such as the honey bee adding some proline while converting sugar syrup into honey, the amount of sugar syrup given, the bees bringing nectar from the flora outside the hive, and the mixing of natural honey with honey produced with sugar syrup.
CARBON ISOTOPE ANALYSIS AND DETERMINATION OF C4 SUGAR RATIO
While the practice of producing honey by intensively feeding honey bees with sugar syrup was carried out using beet sugar (tea sugar, granulated sugar) consisting entirely of sucrose in the past years, inverted syrup and fructose and glucose syrups obtained from corn starch have also been preferred in recent years. In "under-the-counter" production, known as fake and imitation honey production, and in the process of adding syrup to increase the amount of natural honey and reduce the cost, corn syrups, which are generally produced on an industrial scale, have a sugar profile, sweetness level, and fluidity that are very similar to natural honey and have a low tendency to crystallize, are frequently used. Carbon isotope (C13) analysis in honey and determining the C4 sugar ratio is a common and reliable method for detecting these frauds.
Isotope analyses are based on determining the isotope ratios of carbon, hydrogen, and oxygen atoms. The most critical factor in determining the isotope atom distribution in plants is the photosynthesis system in which the plant is included.
According to the photosynthesis system classification, plants are grouped as C3, C4, and CAM plants. δ 13C (13C/12C) value is accepted as the standard in determining plant carbon metabolism. δ 13C values vary between C3, C4, and CAM plants, and based on this difference, the realness or authenticity of a food, or whether a food or ingredient from another group has been added to a food, can be determined.
Bees generally use extracts of plants included in the C3 photosynthesis system in honey production. However, plants that use the C4 photosynthesis system, such as sugar cane and corn, are used in fraudulent honey production. In identifying fake honey, protein is extracted from honey, and the δ 13C value is determined, and this value is compared with the δ 13C value of genuine honey. According to the internationally accepted limit, the difference between the δ 13C values of the compared honey should not be different than 1‰.
In C3 plants, the C13/C12 value generally varies between -22 and -33, while in plants using the C4 cycle, such as corn, it varies between -10 and -20. Since the plants from which bees get nectar generally use the C3 cycle, the C13/C12 value of real honey should generally be around -25.
IF CORN SYRUP IS ADDED TO HONEY…
If corn syrup is added to the honey, this value may increase to -10. The carbon isotope value of honey changes when corn syrup is added, but the carbon isotope value of the protein in honey does not change. Therefore, the carbon isotope value of the honey sample is determined, and this value is compared with the carbon isotope value of the protein obtained from the honey sample. If the difference is more damaging than -1, syrup may have been added to the honey. With the calculations made, it can also be determined what percentage of C4 sugars are added to honey.
Methods such as proline amount and carbon isotope analysis can be used to determine the difference between fake or imitation honey and natural honey. However, when syrups made from beet sugar are used to feed bees, this situation may be more challenging to detect because sugar beet is also a C3 plant; more than carbon isotope analysis is required. Therefore, more comprehensive analysis methods and experience may be required to detect such frauds.
THE MOST DEFINITIVE SOLUTION: NMR-BASED HONEY PROFILING…
The most accurate solution for detecting counterfeiting and adulteration through analytical devices may be Nuclear Magnetic Resonance Spectroscopy (NMR)--b Honey-Profiling. The benefit of this method is that it not only identifies artificial additives but also all the components present in Honey. NMR-based Honey-Profiling can detect the addition of any substance in Honey or the lack of any substance that should be in Honey incomparably better than other methods.
Proton NMR result of Honey using Nuclear Magnetic Resonance Spectroscopy.
The nuclear magnetic resonance spectroscopy (NMR) based Honey-publishing method creates a data bank by extracting the NMR profiles of Honey of known origin and origin. In this way, more precise results are obtained by comparing the origin and origin of the Honey with this database. This method is more reliable than others, especially for checking the origin of Honey (monofloral) with more valuable geographical origins. The most beneficial element for NMR-based Honey-Profiling is to have a data bank.
Since Honey's chemical structure varies significantly from region to region, it is the most critical factor in determining imitation and adulteration. More than one method is required to decide on Honey's naturalness. The most accurate solution to determining Honey's origin is to choose based on many parameters.
IN CONCLUSION…
As a result, when the various analysis methods used to determine the naturalness and quality of Honey are examined, the difficulty of detecting imitation and adulteration emerges. One of the most reliable methods for determining Honey's origin is Honey Profiling based on Nuclear Magnetic Resonance Spectroscopy (NMR).
However, Honey's chemical structure varies from region to region, showing that more than one method is required. Various parameters must be evaluated to determine Honey's purity and different analysis methods must be used. In particular, the data bank created with the NMR profiles of Honey of known origin makes an essential contribution to the preservation of naturalness and quality in honey production.
Analytical methods and strict control mechanisms must be developed to preserve Honey's naturalness and prevent imitation or adulteration. This will allow consumers to access healthy and reliable honey products and reward beekeepers for their efforts in a fair, competitive environment.
When buying Honey as a consumer, buying it from reliable producers and brands is essential. Considering problems such as imitation and adulteration of Honey, it is necessary to have reports showing accredited laboratories conduct honey analyses. We need to avoid products that are below the market value of Honey. To consume Honey safely, consumers must pay attention to these factors.
