DETERMINATION OF HONEY GEOGRAPHIC ORIGIN ACCORDING TO ITS ELEMENTAL COMPOSITION BY THE METHOD OF X-RAY FLUORESCENCE

The aim of the research was to determine features of the elemental composition of polyfloral honey from the Odessa region (Ukraine) by the method of x-ray fluorescence for using these features in the geographic marking of the region of honey origin. A choice of honey from the Odessa region is explained by its relatively good ecology, optimal maritime climate and enough motley grass resources for gathering nectar by bees. At the same time the Odessa region occupies the fourth place among regions – honey producers in Ukraine with a right to export honey beyond the country with specific weight 10 % from the total export of this product. 11 samples of fresh honey and 14 samples of honey, stored during one year were studied as to the content of 22 mineral elements. The elemental analysis of honey was realized on the energy-dispersive x-ray fluorescent spectrometer ElvaX Light SDD. Each sample was studied for 5 times. The obtained results were statistically processed by the standard methodology. The determination distinctness of mass shares of metals is no worse than 0,1 %. Limits of finding admixtures of heavy metals in the light matrix are no worse than 1 ppm. The studies were realized during 2016–2017. It has been established, that lyophilization of honey doesn’t essentially influence determination parameters of the elemental composition of honey by the method of x-ray fluorescence. The analysis of energy-dispersive spectrums of mineral elements determined that marker elements for honey from the Odessa region are Cl, K, Ca, that prevail among other studied mineral elements. There has been established the typical intensity of a signal of energy-dispersive spectrums for Cl, K, Ca of honey from the Odessa region that correspond to the following values: for fresh honey Cl from 27075 to 29429; K from 47 296 to 41 546; Ca from 7572 to 6928; for honey, stored during one year: Cl from 40383 to 37044; K from 43 589 to 42 591; Ca from 15495 to 10006. These parameters Reports on research projects (2019), «EUREKA: Life Sciences» Number 2


Introduction
Bee honey is a product with unique food and healing properties, so its consumption in the world continuously grows.At the same time honey production is one of the most important branches of agriculture of the USA, some EU countries, Africa, Asia and Ukraine [1].This natural product is very popular among persons of elder age and among children because of its consumption properties.It is well-known, that due to the essential amount of mineral substances, vitamins, simple sugars, organic acids, antioxidants and enzymes, honey is considered as a good product with nutritive, healing and cosmetic properties [2].
Different types of honey contain near 300 diverse components, 100 of them are always present in each type.Main components of honey are carbohydrates, water, proteins, free amino acids, enzymes, vitamins, mineral substances.It is commonly known, that the honey composition is influenced by the region, where it was produced.That is why honey from certain regions may have better properties, comparing with other honey types, so higher demand and price [3][4][5].
The resolution of the European Parliament presents a list of products, subjected to the highest risk of fraud in the food sphere [6].Honey is included in this list.One of fraud types is declaration of the botanical or geographic origin of it.European consumers worry about a possibility of falsification, especially if talk about more expensive types of honey.At producing honey with indicating a place of its origin, there may take place its falsification by mixing it with one from different regions [7,8].
Beekeepers of many countries have patented specific markers of honey that allow to determine its origin place and to confirm its specific signs.It allows to honey protect from a certain place from such falsifications as mixing with other honey types [9].
A traditional determination of geographic and/or botanical origin of honey is a study of pollen of bee plants [10].But this method is rather laborious and insufficiently reliable, especially for polyfloral honey, because pollen of bee plants may be added in honey artificially.In this connection scientists offer different marker combinations for identifying a geographic origin of honey: content of carbohydrates, proteins, furfural hydroxyl oxymethyl, and also definitions of the complex of physical and chemical quality parameters of honey [10,11].
Most scientists think that the mineral content of honey may be a marker sign of its origin that is confirmed by the following data of scientific publications.Mineral substances of honey are presented by 37 macro-and microelements that have importance for its food value.The ratio of correspondent elements in honey depends on soil, where bee plants grow and from the environment.The content of mineral substances in honey varies from 0,006 to 3,45 %.Light floral honey types contain near 0,2-0,3 % of these elements, dark floral from 0,5 to 0,6 %.Honey includes 13 elements, most spread in the earth's crust (В, Si, Al, Fe, Сu, Na, K, Mg, H, Са, Р, S, Mn).It is universally recognized, that all honey types contain calcium, magnesium, manganese, phosphorus, silicon, cooper and nickel.Especially much K, Р, Са are in honey.At the same time Tl, Ag, As, Ва, Bi, Cd, Co, Cr, Ge, Hg, Ni, Pd, Sb, Sn, V, Zn, W were found in honey from different countries [10][11][12][13].
Chinese researchers determined using mass-spectrometry with the inductively-connected plasma (ICP-MS) that most spread minerals in honey from different regions of China are K, Ca, Na and Mg.So they state that the mineral composition of honey depends on its region of origin [10].The same method revealed that most spread macroelements in honey from the Southern and Eastern districts of Turkey were K, Na and Ca, and most spread microelements -Zn and Cu [13].Using another method (spectral x-ray fluorescent spectroscopy), it was determined, that K and Са are observed most often in honey samples from four regions of the Rio-de-Janeiro state (Brazil) [11].The study of scientists from different countries demonstrated that the quality and quantity ratio of mineral substance differs in honey of different regions that may be a reliable marker of the geographic origin of honey.
The problem of Ukraine is that honey is exported in big parties, but packed and marked in Europe, so it is written on a label not "Ukrainian honey", but "honey, produced in EU countries".Consumers are ready to pay more for specific attractive features of honey, signed on a mark, for example, indication of an origin place that is ecologically safe.At the process of marking honey, its name may be added by information about its origin place.Ukrainian honey may have indications of a place of geographic origin on a mark, for example "Ukrainian honey" or an origin region -"Odessa honey", if producers confirm its specific markers and methods of their identification.But unfortunately there is no such marking for Ukrainian honey for today.It is connected with a fact that honey is a multi-component product, and it is difficult to determine specific features of its composition, inherent to a certain location.
There are no studies in Ukraine about regional peculiarities of the content of micro-and macroelements and their ratio in honey as marker parameters for determining its geographic origin that is an important marketing factor for determining its consumption price, including one at the world market.The topicality of the research theme is determined also by the fact that together with a function of individualization of unique honey as a commodity, produced at the territory of a certain geographic object, geographic marking of an origin place plays an important role of legal protection of its unique properties and also informs a consumer about their uniqueness.
The aim of this research was to determine peculiarities in the elemental composition of natural polyfloral bee honey from the Odessa region (Ukraine) that differs from honey from other regions.The method of x-ray fluorescence was used for it.Fixed features of the elemental composition of Odessa honey may be used for identifying this region of honey origin at international trade.
Food Science and Technology ergy-dispersive x-ray fluorescent spectrometer.The elemental composition of "light" elements and "heavy" ones was determined according to the regimes, cited below.
The studies were conducted as follows: a batch of a honey sample with mass 10 g was studied using the energy-dispersive x-ray fluorescent spectrometer with an x-ray tube and rhodium anode.At studying the first group of "light" elements (from Na to Sc), the tension on the tube was 10 kW without a filter of primary x-ray radiation.For the analysis of the group of "heavy" elements (from Ti) there was used the tension of the x-ray tube as 40 kW and the aluminium filter of primary x-ray radiation with width 800 mcm.The current force was chosen automatically for achieving load level 50000 impulses/s.Each sample was studied 5 times.The obtained results were statistically processed using Satistica software (version 8) for determining parametric indicators, namely determining mean values (М) and error of mean (m) [15].The determination distinctness of mass shares of metals is no worse than 0,1 %.Limits of finding admixtures of heavy metals in the light matrix are no worse than 1 ppm.

Results
The obtained results are presented in Table 1.The data of Table 1 demonstrate that lyophilization almost didn't influence the intensity of a signal from the chemical elements of the sample.It has been also established, that the most intensity of a signal in the energy-dispersive spectrum of the elemental composition of honey was in such elements as Cl, K, Ca.The results of the study of polyfloral honey samples, stored during 1 year, are presented below (Table 2).
Table 2 presents the intensity of a signal of elements, found in the honey samples, selected in 2016 and studied after storage during 1 year.
28 elements were found in the studied samples.8 elements of 28 constantly were present in all honey samples: Al, Si, Cl, K, Ca, Cr, Fe, Ni.
At that the most signal intensity was typical for such elements as Cl, K, Ca.The rest of elements occurred in not all honey samples, but most often the following: P (13 samples); Cu (12 samples); Zn, Y (10 samples) Mn (9 samples), Br (8 samples), the other elements were present in the insufficient number of samples.The data of table 2 also testify that the elements Cl, K, Ca are constantly present in honey of the Odessa region and generate strongest signal of x-ray radiation comparing with the other elements.
Then samples of fresh polyfloral honey were studied using the energy-dispersive x-ray fluorescent spectrometer as it was described above.The research results are presented in Table 3.As it can be seen on table 3, the following 8 elements are constantly present in all 11 honey samples: Al, Si, Cl, K, Ca, Cr, Fe, Cu.The following elements are present in honey samples inconstantly: Co (in 10 samples) Mg, Zn and Ni (in 9 samples) P (in 8 samples) Mn (in 7 samples).
Thus, in honey, stored during 1 year and in fresh one there was registered the constant presence of such elements as: Si, Cl, K, Ca, Cr, Fe.Whereas Ni was present in all honey samples, stored during 1 year, and Cu was revealed in all samples of fresh honey.The obtained results were compared with literary data, where peculiarities of the elemental composition of honey from different countries

Table 1
Elemental composition of honey samples of the Odessa region before and after lyophil drying

Table 2
Elemental composition of 14 samples of polyfloral honey from the Odessa region, produced in 2016 (after storage during 1 year)

Table 3
Elemental composition of 11 sample of fresh polyfloral honey from the Odessa region, produced in 2017