Trace elements and rare earth elements in honeys from the Balkans, Kazakhstan, Italy, South America, and Tanzania

Levels of Rare Earth Elements in Food and Human Dietary Exposure: A Review

Rare earth elements (REEs) are a group consisting of the following 17 metals: Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Pm, Sc, Sm, Tb, Tm, Y and Yb. In the current century, the number of applications of REEs has significantly increased. They are being used as components in high technology devices of great importance industrial/economic. However, information on the risk of human exposure to REEs, as well as the potential toxic effects of these elements is still limited. In general terms, dietary intake is the main route of exposure to metals for non-occupationally exposed individuals, which should be also expected for REEs. The current paper aimed at reviewing the studies -conducted over the world- that focused on determining the levels of REEs in foods, as well as the dietary intake of these elements. Most studies do not suggest potential health risk for consumers of freshwater and marine species of higher consumption, or derived from the intake of a number of vegetables, fruits, mushrooms, as well as other various foodstuffs (honey, tea, rice, etc.). The current estimated daily intake (EDI) of REEs does not seem to be of concern. However, considering the expected wide use of these elements in the next years, it seems to be clearly recommendable to assess periodically the potential health risk of the dietary exposure to REEs. This is already being done with well-known toxic elements such as As, Cd, Pb and Hg, among other potentially toxic metals.

Assessing Mineral Content and Heavy Metal Exposure in Abruzzo Honey and Bee Pollen from Different Anthropic Areas

Honey and bee pollen offer potential health benefits due to their nutrient and bioactive molecules, but they may also harbor contaminants such as heavy metals. This study aimed to assess the content of different metals, including Mg, Al, K, Ca, V, Cr, Mn, Fe, Co, Ni, Zn, Cu, As, Rb, Sr, Cd, Cs, Tl, Pb and U, in honey and bee pollen collected from different Abruzzo region (Italy) areas (A1, A2, A3, A4), characterized by different anthropic influences described by Corine Land Cover maps. Differences were observed in the mineral and heavy metal content associated with the influence of biotic and abiotic factors. Honeys were found to be safe in regard to non-carcinogenic risk in all the consumer categories (THQm < 1). A particular carcinogenic risk concern was identified for toddlers associated with Cr (LCTR > 1 × 10-4) in A1, A2 and A3 apiaries. Pb and Ni represent potential non-carcinogenic and carcinogenic health risks in children and adults due to bee pollen consumption, showing high values of THQm and LCTR. The results suggest the advantages of utilizing bee products to screen mineral and heavy metal content, providing valuable insights into environmental quality and potential health risks.

Botanical origin and elemental content of Turkish honey: Implications for health risks from essential and non-essential elements

Honey, which is popular for its taste and health benefits, can pose health risks due to excessive levels of essential and non-essential elements. Turkey's unique geographical location and biodiversity have made it a major player in the global honey industry. This study analysed Turkish honey samples to determine their botanical origin and elemental content, and to assess non-carcinogenic risks associated with their consumption. Twelve samples were classified as monofloral, while the rest were considered multifloral. The results showed that the levels of elements in the honey samples varied significantly depending on the plant source and geographical location (p < 0.05). However, the health risk assessment for both adults and children indicated that the levels of these elements do not pose a health risk. Principal component -analysis has revealed a correlation among the elements present in honey samples. Overall, the risk of exposure to toxic elements in honey is low unless consumed excessively.

Geographical Origin Authentication-A Mandatory Step in the Efficient Involvement of Honey in Medical Treatment

Nowadays, in people's perceptions, the return to roots in all aspects of life is an increasing temptation. This tendency has also been observed in the medical field, despite the availability of high-level medical services with many years of research, expertise, and trials. Equilibrium is found in the combination of the two tendencies through the inclusion of the scientific experience with the advantages and benefits provided by nature. It is well accepted that the nutritional and medicinal properties of honey are closely related to the botanical origin of the plants at the base of honey production. Despite this, people perceive honey as a natural and subsequently a simple product from a chemical point of view. In reality, honey is a very complex matrix containing more than 200 compounds having a high degree of compositional variability as function of its origin. Therefore, when discussing the nutritional and medicinal properties of honey, the importance of the geographical origin and its link to the honey's composition, due to potential emerging contaminants such as Rare Earth Elements (REEs), should also be considered. This work offers a critical view on the use of honey as a natural superfood, in a direct relationship with its botanical and geographical origin.

Elemental Fingerprinting Combined with Machine Learning Techniques as a Powerful Tool for Geographical Discrimination of Honeys from Nearby Regions

Discrimination of honey based on geographical origin is a common fraudulent practice and is one of the most investigated topics in honey authentication. This research aims to discriminate honeys according to their geographical origin by combining elemental fingerprinting with machine-learning techniques. In particular, the main objective of this study is to distinguish the origin of unifloral and multifloral honeys produced in neighboring regions, such as Sardinia (Italy) and Spain. The elemental compositions of 247 honeys were determined using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The origins of honey were differentiated using Principal Component Analysis (PCA), Linear Discriminant Analysis (LDA), and Random Forest (RF). Compared to LDA, RF demonstrated greater stability and better classification performance. The best classification was based on geographical origin, achieving 90% accuracy using Na, Mg, Mn, Sr, Zn, Ce, Nd, Eu, and Tb as predictors.

A probabilistic approach to compare the risk associated with heavy metals and bromine in honey from Dominican Republic, Mexico, Mozambique and Spain

This study aims to analyse the risk to consumers given the presence of heavy metals and bromine in honey from different countries. A probabilistic approach was applied to assess carcinogenic risk. Concerning exposure, Al in Spain (3.3E-04 mg/kgBw/day), B in Dominican Republic and Mexico (2E-04 mg/kgBw/day in both cases) and Fe in Mexico and Mozambique had the highest values (5E-05 and 4.8E-05 mg/kgBw/day). In risk characterisation, the values were less than 1 for hazard index (HI), meaning that the consumption of honey represents a low level of concern for non-genotoxic effects. A combination of margin of exposure and probability of exceedance results that exposure to Pb pose no threat. The probability of suffering cancer for Br, Cd, Ni and Pb was lower than 1.0E-06 and, therefore, considered safe. However, the risk at the 95th percentile of Br in Dominican Republic was 1.18E-04 in adults and 2.45E-04 in children, exceeding 1.0E-04, and therefore, considered intolerable. Finally, the sensitivity analysis indicated that the most influential factor in the HI was the consumption in adults and the concentration of Ni in children, whereas for cancer risk, were the concentrations of Ni, Cd, Br and Pb, in both cases.

Multi-Element Assessment of Potentially Toxic and Essential Elements in New and Traditional Food Varieties in Sweden

With the global movement toward the consumption of a more sustainable diet that includes a higher proportion of plant-based foods, it is important to determine how such a change could alter the intake of cadmium and other elements, both essential and toxic. In this study, we report on the levels of a wide range of elements in foodstuffs that are both traditional and "new" to the Swedish market. The data were obtained using analytical methods providing very low detection limits and include market basket data for different food groups to provide the general levels in foods consumed in Sweden and to facilitate comparisons among traditional and "new" food items. This dataset could be used to estimate changes in nutritional intake as well as exposure associated with a change in diet. The concentrations of known toxic and essential elements are provided for all the food matrices studied. Moreover, the concentrations of less routinely analyzed elements are available in some matrices. Depending on the food variety, the dataset includes the concentrations of inorganic arsenic and up to 74 elements (Ag, Al, As, Au, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cs, Cu, Fe, Ga, Ge, Hf, Hg, K, Li, Mg, Mn, Mo, Na, Nb, Ni, P, Pb, Rb, S, Sb, Sc, Se, Si, Sn, Sr, Ta, Te, Th, Ti, Tl, U, W, V, Y, Zn, Zr, rare Earth elements (REEs) (Ce, Dy, Er, Eu, Gd, Ho, La, Lu, Nd, Pr, Sm, Tb, Tm, and Yb), platinum group elements (PGEs) (Ir, Os, Pd, Pr, Pt, Re, Rh, Ru, and Pr), and halogens (Br, Cl, and I)). The main focus (and thus the most detailed information on variation within a given food group) is on foods that are currently the largest contributors to dietary cadmium exposure in Sweden, such as pasta, rice, potato products, and different sorts of bread. Additionally, elemental concentrations in selected food varieties regarded as relatively new or "novel" to the Swedish market are provided, including teff flour, chia seeds, algae products, and gluten-free products.

Trace Elements and Heavy Metal Contents in West Algerian Natural Honey

Analysis of trace elements and heavy metals in honey is essential for honey quality and safety and also monitoring environmental pollution. This study aimed to evaluate the composition of thirty-seven honey samples of different botanical origins (14 multifloral and 23 unifloral) obtained from beekeepers located in the west region of Algeria. Inductively coupled plasma-mass spectrometry (ICP-MS) and atomic absorption spectroscopy (AAS) methods were used to determine the levels of 19 elements in honey (K, Na, Ca, Mg, Mn, Cu, Fe, Zn, V, Cr, Co, As, Ru, Rh, Cd, W, Pt, Au, and Pb). Ru, Rh, Pt and, Au were not detected in any of the tested honey samples. The most abundant minerals were K, Ca, Na, and Mg ranging within 153.00-989.00 mg/kg, 33.10-502.00 mg/kg, 13.30-281.00 mg/kg, and 20.80-162.00 mg/kg, respectively. Fe, Mn, Zn, and Cu were the most abundant heavy metals while Pb, V, Cr, W, Co, and Cd were the lowest ones (<1 mg/kg) in the honey samples surveyed. Several honey types, lavender, rosemary, mild white mustard, thyme, milk thistle, carob tree, orange tree, Euphorbia, Eucalyptus, camphor, jujube tree, sage, and harmal, were studied, and the statistical analysis was carried out using principal component analysis (PCA) and hierarchical cluster analysis (HCA) techniques to evaluate the data. The results showed that the analyses of mineral content were sufficient to determine the floral origin and their variability may be related to geochemical and geographical differences. On other hand, all elements detected were at levels below safe thresholds.

Multi-element Analysis of Honey from Amhara Region-Ethiopia for Quality, Bioindicator of Environmental Pollution, and Geographical Origin Discrimination

Honey is a widely utilized sweetener containing mainly sugars with many other minor ingredients such as metallic elements. The analysis aimed to develop a chemometric model for tracing the geographical origin, evaluating nutritional quality, assessing pollution effect, and searching for marker metals for the region's honey. Forty-seven honey samples were collected directly from the apiarists at seven administrative zones. The contents of 14 metals were analyzed using inductively coupled plasma optical emission spectrometry after standard sample digestion. The findings showed us the major elements ranged from 24.8 to 1996 mg/kg of the honey sample with K > Ca > Na > Mg. The minimum and maximum values for the trace metals were 2.35 mg/kg and 163 mg/kg, respectively, in the order of Fe > Cr > Zn > Ni > Mn > Cu > Co. From this data, the region's honey has its own contribution as a source of major and trace elements. Furthermore, mean values for the toxic heavy metals were 0.57 to 1.85 for Pb, 1.03 to 1.21 for Cd, and 2.85 to 6.21 for As in mg/kg. Thus, the pollution level in the environment seems to be at an alarming rate. Using principal components analysis (PCA), the first four principal components explained 80.16% of the total variation. The region's honey was best classified into five major clusters using linear discriminant analysis (LDA) with an average discrimination power of 89.91%. The LDA sorting model was verified by the cross-validation method. The verification revealed that the model has 92.11% recognition power and 93.33% prediction ability.

Heavy metal in honey bees, honey, and pollen produced in rural and urban areas of Konya province in Turkey

We investigated the levels of heavy metals in honey bee, honey, and pollen samples obtained from different locations in Konya City in Turkey. Five honey bee colonies were placed in eight different locations, four of them around urban areas and four in rural areas, in the province of Konya City in Turkey. Heavy metal (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) levels were determined in honey bee, honey, and pollen samples taken from these colonies, with a comparison between samples from urban and rural areas. The values of Cd in honey samples and those of Cd in pollen samples did not differ significantly among the locations. All heavy metal values of honey bee samples were lower in rural areas than in urban areas. Significant statistical differences were determined for Cr, Cu, Fe, Mn, Ni, Pb, and Zn values of honey and pollen samples among the locations. Heavy metal values of honey and pollen samples obtained from different locations were in agreement with the International Food Standard values.

Differentiating Wild and Apiary Honey by Elemental Profiling: a Case Study from Mangroves of Indian Sundarban

Honey is a natural substance produced by honeybees from the nectar or secretion of flowering plants. Along with the botanical and geographical origin, several environmental factors also play a major role in determining the characteristics of honey. The aim of this study is to determine and compare the elemental concentration of various macro and trace elements in apiary and wild honeys collected from different parts of Indian Sundarbans. The elemental analysis was performed in inductively coupled plasma optical emission spectroscopy preceded by microwave digestion method. The concentrations of 19 elements (Ag, Al, As, B, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Se and Zn) were investigated from thirteen locations of Indian Sundarbans. This comparative study shows in wild honey samples, the concentration of K was highest followed by Ca, Mg and Na and Zn was lowest among all. In contrast, in apiary honey samples, Ca had maximum concentration followed by K, Mg and Na and Ag had minimum among all. The elemental concentration in honey from apiary was either equal or higher than their wild counterpart. The results of the factor analysis of PCA algorithm for wild and apiary honey samples were highly variable which implies that the elements are not coming from the same origin. The concentration of element was found to be highly variable across sites and across sources of honey samples.

Levels of trace elements and rare earth elements in honey from Jordan

Honey is a common sweetener in the Jordanian diet with an annual consumption of approximately one thousand tons, two-thirds of which are imported. It is believed that the elemental profile of honey is an indicator of safety and botanical and geographic origin. In the literature, there are a lack of studies concerning the levels of major and trace elements in honey in Jordan. A total of 46 elements, including 15 rare earth elements (REEs), were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) in 18 monofloral and multifloral imported honey samples and 12 multifloral local samples. Regarding monofloral samples, Black Forest samples had the highest total metal content, while acacia samples had the lowest total metal content. Local multifloral honey had the largest Sr and total REE levels, while it had the lowest Mn levels. Very low levels of toxic elements were found in all samples, indicating the safety of honey in Jordan for human consumption. The results of this study showed that a large number of samples (> 100) and the application of advanced statistical models are required to discriminate between multifloral imported and local honey.

Combination of zinc and selenium alleviates ochratoxin A-induced fibrosis via blocking ROS-dependent autophagy in HK-2 cells

BACKGROUND

Ochratoxin A (OTA) is a mycotoxin produced by Aspergillus and Penicillium. The key target organ of OTA toxicity is the kidney, which has a significant impact on human health. Recently, nutrition regulation is suggested to be an effective protection against mycotoxins contamination. The current study investigated the combined protective effects of zinc and selenomethionine (SeMet) (a major component of organic selenium) on OTA-induced renal fibrosis and their potential mechanisms in human renal proximal tubule epithelial cells (HK-2 cells).

METHODS

Cytotoxicity of different concentrations of OTA, zinc and SeMet on HK-2 cells was detected by cell viability, lactate dehydrogenase (LDH) and apoptotic nuclei assays. The expression of fibrosis biomarkers was detected by Real-Time PCR, western blotting and indirect immunofluorescence assays. The production of reactive oxygen species (ROS) was detected by ROS assay kit. The protein expression of autophagy biomarkers was detected by western blotting assay.

RESULTS

Cytotoxicity was induced by OTA treatment in a dose-dependent manner, and it was attenuated by zinc or SeMet application in HK-2 cells. Zinc or SeMet application also down-regulated the expression of fibrosis biomarkers, and the combination of them displayed better effects. In addition, OTA increased intracellular ROS level and activated autophagy in a dose-dependent manner, and it was reversed by zinc and SeMet combined application. With the treatment of hydrogen peroxide (H₂O₂) or rapamycin (the specific activator of autophagy), the combined protective effects of zinc and SeMet were abolished.

CONCLUSIONS

Zinc and SeMet application alleviated OTA-induced cytotoxicity and fibrosis in HK-2 cells. Combination of them was more effective than its individual application. The present study manifest novel insight about the alleviation of OTA-induced nephrotoxicity by nutrition regulation, and had a guiding effect on the clinical supplementation of nutritional elements.

Assessment of environmental impact on essential and toxic elements composition in natural honeys by using inductively coupled plasma mass spectrometry

The quality of natural honey depends upon many factors with significant contribution of environmental factors. In this study, environmental impact on the quality of honey was assessed by determining concentrations of 11 essential and 17 toxic elements in 24 different honey samples of northern and southern regions of Pakistan and Turkey using inductively coupled plasma mass spectrometry. Statistical analysis showed higher variance in the concentrations of Cu, P, and Mo (essential), and Ga, Rb, Cs, Ba, and Pb (toxic) among all the honey samples (coefficient of variance > 100). Multivariate comparison based on botanical flora, honey bee species, and geographic regions revealed that the honeys of different botanical flora exhibited statistically nonsignificant difference in elemental composition, whereas, species wise, honeys of Apis dorsata contained significantly higher concentration of P than honeys of Apis mellifera and Apis flora (p < 0.01). Geographical regions wise, the honeys showed statistically significant difference in concentrations of six essential elements (K (p < 0.01), Mn (p < 0.001), Fe (p < 0.001), Cu (p < 0.05), P (p < 0.001), and Mo (p < 0.01)), and two toxic elements (V (p < 0.01) and As (p < 0.05)). Principal component analysis (PCA) using the essential elements contents clustered uni-floral honeys together separating out 3 multi-floral honeys including the artificial one, whereas PCA using concentrations of toxic elements showed mixed clustering of all honey samples, representing their independence of floral type. Taken together, our analyses show that the environmental factors of the geographical regions, apart from the honeybee species and the botanical flora, have profound impact on the elemental composition in the natural honeys affecting their quality. Although the concentrations of the toxic elements in the honey samples were not exceeding the permissible limit of FAO/WHO, yet we suggest regular surveillance on toxic elements in the honeys to avoid their harmful effects on human health.

Antioxidant activity and enzyme inhibitory potential of Euphorbia resinifera and E. officinarum honeys from Morocco and plant aqueous extracts

Natural products may be applied in a wide range of domains, from agriculture to food and pharmaceutical industries. In this study, the antioxidant properties and the capacity to inhibit some enzymatic activities of Euphorbia resinifera and Euphorbia officinarum aqueous extracts and honeys were assessed. The physicochemical characteristics were also evaluated. Higher amounts of iron, copper and aluminium were detected in E. officinarum honey, which may indicate environmental pollution around the beehives or inadequate storage of honey samples. This honey sample showed higher amounts of total phenols and better capacity for scavenging superoxide anion free radicals and DPPH free radicals as compared with E. resinifera honey, but poorer capacity for inhibiting lipoxygenase, acetylcholinesterase, tyrosinase and xanthine oxidase. The ratio plant mass:solvent volume (1:100) and extraction time (1 - 2 h) were associated with higher total phenols and better antioxidant activities and lipoxygenase, acetylcholinesterase and tyrosinase inhibitory activities, regardless of the plant species. The aqueous extracts had systematically higher in vitro activities than the respective honey samples.

Mineral and Trace Element Analysis of Australian/Queensland Apis mellifera Honey

Honey is an extensively utilized sweetener containing sugars and water, together with small quantities of vitamins, minerals, fatty acids, amino acids and proteins. Naturally produced by honeybees (Apis mellifera) from floral nectar, honey is increasingly sold as a health food product due to its nutritious features. Certain honeys are retailed as premium, trendy products. Honeybees are regarded as environmental monitors, but few reports examine the impact of environment on Australian honey trace elements and minerals. In higher density urban and industrial environments, heavy metals can be common, while minerals and trace elements can have ubiquitous presence in both agricultural and urban areas. Honey hives are traditionally placed in rural and forested areas, but increasingly the trend is to keep hives in more urban areas. This study aimed to determine the levels of 26 minerals and trace elements and assess elemental differences between honeys from various regional Queensland and Australian sources. Honey samples (n = 212) were acquired from markets, shops and supermarkets in Queensland while urban honeys were purchased online. The honey samples were classified into four groups according to their regional sources: urban, rural, peri-urban and blend honey. Elemental analyses of honey were performed using ICP-MS and ICP-OES after microwave and hot block digestion. Considerable variations of essential trace elements (Co, Cu, Cr, Fe, Mn, Mo and Zn) and mineral levels (Ca, K, Mg, Na and P) were found in honeys surveyed. There were significant differences (p < 0.05) between urban and rural honey samples for B, Na, P, Mn, K, Ca and Cu. Significant differences (p < 0.05) were also found between blend and urban honey samples for K, Cu, P, Mn, Sr, Ni, B and Na. Peri-urban versus urban honeys showed significant differences in P, K and Mn. For rural and peri-urban honeys, the only significant difference (p < 0.05) was for Na. Toxic heavy metals were detected at relatively low levels in honey products. The study revealed that the Queensland/Australian honey studied is a good source of K and Zn and would constitute a good nutritional source of these elements.

Applications of emerging stable isotopes and elemental markers for geographical and varietal recognition of Romanian and French honeys

The research towards the identification of new authenticity markers is crucial to fight against fraudulent activities on honey, one of the top ten most falsified food commodities. This work proposes an association of stable isotopes and elemental content as markers for honey authentication, with respect to its floral and geographical origin. Emerging markers like isotopic signature of honey water alongside with carbon and hydrogen isotopic ratios of ethanol obtained from honey fermentation and Rare Earth Elements, were used to develop new recognition models. Thus, the efficiency of the discrimination potential of these emerging markers was discussed individually and in association. This approach proved its effectiveness for geographical differentiation (>98%) and the role of the emerging markers in these classifications was an essential one, especially of: (D/H)_I, δ²H, δ¹⁸O, La, Ce and Pr. Floral recognition was realized in a lower percentage revealing the suitability of these markers mainly for geographical classification.