Challenges and potential for detecting and quantifying titanium dioxide in food.

BACKGROUND: Titanium dioxide (TiO2) is banned in some countries but its use is still permitted in others. The global food supply chain is therefore challenged with the need to use rapid and reliable testing methods to either detect the presence of TiO2 or to quantify its concentration. The goal of this study was to determine the feasibility of using color, texture profile analysis, Raman microscopy, and X-ray fluorescence (XRF) spectroscopy to detect and quantify TiO2 in fillings used in the pastry and confectionery industry. In this study, two types of fillings were investigated: vanilla based and chocolate based. All fillings were prepared in four different variations - without TiO2 and with three concentrations as follows: 0.25 g*kg-1, 0.5 g*kg-1, or 0.75 g*kg-1 TiO2 per sample. The methods were selected for their ability to analyze the samples in a short period of time. RESULTS: All of the methods showed moderate to high potential for detecting TiO2 in the samples. The results reveal how TiO2 affects the food matrix color and texture. Use of Raman microscopy confirms its detectability, although concentrations of TiO2 do not follow a pattern. X-ray fluorescence spectroscopy showed the greatest potential as it can not only detect TiO2 but can also quantify its concentration in the samples. CONCLUSIONS: The highest potential for quantifying the concentration of this food additive was achieved with XRF. © 2024 Society of Chemical Industry.

ENVIRONMENTAL EFFECTS ON SUPEROXIDE DISMUTASE AND CATALASE ACTIVITY AND EXPRESSION IN HONEY BEE.

Understanding the cellular stress response in honey bees will significantly contribute to their conservation. The aim of this study was to analyze the response of the antioxidative enzymes superoxide dismutase and catalase in honey bees related to the presence of toxic metals in different habitats. Three locations were selected: (i) Tunovo on the mountain Golija, as control area, without industry and large human impact, (ii) Belgrade as urban area, and (iii) Zajaca, as mining and industrial zone. Our results showed that the concentrations of lead (Pb) in whole body of bees vary according to habitat, but there was very significant increase of Pb in bees from investigated industrial area. Bees from urban and industrial area had increased expression of both Sod1 and Cat genes, suggesting adaptation to increased oxidative stress. However, in spite increased gene expression, the enzyme activity of catalase was lower in bees from industrial area suggesting inhibitory effect of Pb on catalase.

Statistical analysis of the influence of major tributaries to the eco-chemical status of the Danube River.

We have assembled and assessed the statistical procedure which is capable to objectively explore influence of the Danube's major tributaries (the Rivers Tisa, Sava, and Velika Morava) to its eco-chemical status. Procedure contains several tests for measurement of central tendencies: one-way analysis of variance (ANOVA), repeated measures ANOVA, and nonparametric Kruskal-Wallis and Mann-Whitney tests. Various nuisance factors, (outliers, departures from normality, seasonality, and heteroscedasticity) which are present in large data bases, affect the objectivity of central tendency tests; therefore, it was important not only to estimate their robustness, but also to apply proper procedures for detection of the nuisance factors (Grubbs', generalized ESD-extreme Studentized deviate, Kolmogorov-Smirnov, Shapiro-Wilk, turning point, Wald-Wolfowitz runs, Kendall rank, and Levene's tests) and to mitigate their influence (outlier exclusion, Box-Cox, and logarithmic transformations). The analysis of selected eco-chemical parameters: biological oxygen demand-5, chemical oxygen demand, UV extinction at 254 nm, dissolved oxygen, oxygen saturation, total dissolved solids, electrical conductivity, suspended matter, total phosphorus, phosphates, nitrates, ammonia, pH, total alkalinity, m-2p alkalinity, CO2, and temperature, was performed for 15 years period. The Tisa was the most polluted tributary, but its pollution load was not substantial enough to exceed the Danube self-purification potential. The City of Belgrade was also identified as serious pollution source. Assessment of assembled statistical procedure, which was based on the real environmental data, indicates that proposed tests are sufficiently robust to the observed level of nuisance factors with the exception of pronounced seasonality.

Long-term seasonal changes of the Danube River eco-chemical status in the region of Serbia.

Seasonal spatial and temporal changes of selected eco-chemical parameters in section of the Danube River flowing through Serbia were analyzed. Data for electrical conductivity (EC), dry and suspended matter, residue on ignition, chemical oxygen demand (COD), biochemical oxygen demand (BOD-5), ultraviolet extinction, dissolved oxygen (DO), oxygen saturation, pH, nitrates, total phosphorus, and nitrogen were collected between 1992 and 2006. The use of monthly medians combined with linear regression and two-sided t test has been proven to be the best approach for resolving trends from natural variability of investigated parameters and for determining trend significance. Patterns of temporal changes between different months were examined. It was also determined that spatial trends of some parameters oscillate in predictable manner, increasing in one part of the year and declining in the other. Regression slope coefficients, an excellent indicator for determining when the water quality is changing the most along the course of the Danube, reach their maximum during summer for temperature (t), electric conductivity, nitrates, and total N, while in the same season suspended matter, COD, BOD-5, DO, and oxygen saturation coefficients reach their minimum. Correlations for used data sets of selected parameters were analyzed for better understanding of their behavior and mutual relations. It was observed that as Danube flows through Serbia, its general eco-chemical status either stagnates or improves, but the rate of river self-purification often depends on the season of the year.

Anthropogenic influence on seasonal and spatial variation in bioelements and non-essential elements in honeybees and their hemolymph.

Honeybee colony losses have been a focus of research in the last years, due to the importance of managed honeybee colonies for economy and ecology. Different unfavorable conditions from the outside environment have a strong impact on the hive health. The majority of losses occur mainly during winter and the exact reason is not completely understood. Only a small number of studies are dealing with content of bioelements, their function and influence on honeybee physiology. The aim of the present study was to determine seasonal and spatial variations in content of bioelements and non-essential elements, in hemolymph and whole body of honeybees originating from three regions with different degrees of urbanization and industrialization. Concentrations of 16 elements were compared: macroelements (Ca, K, Mg, Na), microelements (Cu, Fe, Mn, Zn) and non-essential elements (Al, Ba, Cd, Co, Cr, Ni, Pb, Sr) in samples collected from 3 different environments: Golija (rural region), Belgrade (urban region) and Zajaca (industrial region). Content of bioelements and non-essential elements in honeybees was under noticeable influence of the surrounding environment, season and degree of honeybee activity. Hemolymph was proven to be helpful in differentiating air pollution from other sources of honeybee exposure. The results of our study demonstrated that bees can be successfully used as biomonitors since we have observed statistically significant differences among observed locations, but unless compared locations are exposed to excessively different pollution pressures, it is essential that all bees should be collected at the same season.

Assessment of spatial and temporal variations in trace element concentrations using honeybees (Apis mellifera) as bioindicators.

With the increase in anthropogenic activities metal pollution is also increased and needs to be closely monitored. In this study honeybees were used as bioindicators to monitor metal pollution. Metal pollution in honeybees represents pollution present in air, water and soil. Concentrations of As, Cs, Hg, Mo, Sb, Se, U and V were measured. The aim of this study was to assess spatial and temporal variations of metal concentrations in honeybees. Samples of honeybees were taken at five different regions in Serbia (Belgrade - BG, Pancevo - PA, Pavlis - PV, Mesic - MS, and Kostolac - TPP) during 2014. Spatial variations were observed for Sb, which had higher concentrations in BG compared to all other regions, and for U, with higher concentrations in the TPP region. High concentrations of Sb in BG were attributed to intense traffic, while higher U concentrations in the TPP region are due to the vicinity of coal fired power plants. In order to assess temporal variations at two locations (PA and PV) samples were taken during July and September of 2014 and June, July, August and September of 2015. During 2014 observing months of sampling higher concentrations in July were detected for Sb and U in BG, which is attributed to lifecycle of plants and honeybees. During the same year higher concentrations in September were observed for As, Sb in PA and Hg in PV. This is due to high precipitation during the peak of bee activity in spring/summer of 2014. No differences between months of sampling were detected during 2015. Between 2014 and 2015 statistically significant differences were observed for Hg, Mo and V; all elements had higher concentrations in 2014. This is in accordance with the trend of reduction of metal concentrations in the bodies of honeybees throughout the years in this region.

Honeybees as sentinels of lead pollution: Spatio-temporal variations and source appointment using stable isotopes and Kohonen self-organizing maps.

In this study, honeybees were used to determine spatio-temporal variations and origin sources of Pb. Lead concentrations and isotopic composition were used in combination with selected statistical methods. The sampling was carried out at five different locations in Serbia: urban region (BG), petrochemical industry (PA), suburban region (PV), rural region (MS) and thermal power plant region (TPP) during 2014. At PA and PV locations, samples were taken during multiple years. This is the first use of Kohonen self-organizing map (SOM) in combination with honeybees as bioindicators to determine spatio-temporal variations and origin of Pb pollution. It was observed that during the years Pb concentrations were in decline. Anthropogenic sources are most dominant in BG and TPP, in PA there are mixed sources of natural and anthropogenic origin and in PV Pb is of natural origin. It can be concluded that honeybees in combination with SOM can be used to differentiate between slight changes in spatio-temporal variations of Pb, as well as for source appointment.

Use of honeybees (Apis mellifera L.) as bioindicators for assessment and source appointment of metal pollution.

The ability of honeybees to collect particulate matter (PM) on their bodies makes them outstanding bioindicators. In this study, two cities, Pancevo (PA) and Vrsac (VS), South Banat district, Vojvodina, Serbia, were covered with two sampling sites each. The aims of this study were to determine concentrations of Al, Ba, Cd, Co, Cr, Cu, Fe, Mn, Na, Ni, Sr, and Zn in the bodies of honeybees during July and September of 2013, 2014, and 2015 and to analyze their spatial and temporal variations and sources of analyzed elements, as well as to assess pollution levels in the two cities. Significant temporal differences were found for Al, Ba, Cd, Co, Cr, Cu, Fe, Mn, Na, Ni, and Zn. Trend of reduction in metal concentrations in bodies of honeybees during the years was observed. Statistically significant spatial variations were observed for Al, Ba, and Sr, with higher concentrations in VS. PCA and CA analyses were used for the first time to assess sources of metals found in honeybees. These analyses showed two sources of metals. Co, Cd, Na, Fe, Mn, Zn, and partly Cu were contributed to anthropogenic sources, while Ca, Al, Mg, Cr, Ba, Sr, and Ni were contributed to natural sources.

The Protective Effects of Probiotic Bacteria on Cadmium Toxicity in Rats.

One of the useful properties of probiotic bacteria is their capacity to bind different targets, thus eliminating them through feces. It is supposed that one of these targets could be cadmium, a widespread environmental toxicant that causes various disturbances in biological systems. This study examined the protective effects of probiotic supplementation against cadmium-induced toxicity in the rat. The experiment was conducted in the course of 5 weeks. Animals were divided into four groups: (1) controls, (2) probiotics treated, (3) cadmium treated, and (4) probiotics + cadmium treated. The cadmium concentration was measured in the blood, liver, kidney, and feces, as well as the blood alanine aminotransferase (ALT) and aspartate aminotransferase (AST) as biomarkers of the liver function. Histomorphological changes in the liver and kidney were also determined. Our results revealed that probiotics combined with cadmium increase this metal concentration in feces. As a result, blood, liver, and kidney Cd levels, as well as blood ALT and AST activities were lessened compared to the rat group treated with cadmium only. Besides, probiotics consumed simultaneously with cadmium attenuated histomorphological changes in the liver and kidney caused by cadmium. The rise in lactobacilli number in feces of rats treated simultaneously with cadmium and probiotics results in strong correlation with the increase of Cd concentration in their feces and the decrease of Cd concentration in their blood. We speculate that probiotics actively contribute to cadmium excretion through feces, probably, by its binding to their bacterial cell wall.