Multi-element screening in milk and feed by SF-ICP-MS

Toxic metal levels in raw camel milk sold in the northern Algerian Sahara

The consumption of camel milk is gaining popularity in Algeria. This study aimed to determine the concentrations of Lead (Pb), Cadmium (Cd), Nickel (Ni) and Mercury (Hg) in camel milk sold in Southeast Algeria and assess the potential health risks associated with its consumption. 120 samples of camel milk were collected from 10 farms located near the roads in the south of Algeria. Metals were measured using an atomic absorption spectrophotometer with a graphite furnace and Target Hazard Quotients (THQs) were calculated. The mean concentrations were 0.026 ± 0.013 mg/kg, 0.001 ± 0.0002 mg/kg, 0.017 ± 0.002 mg/kg and 0.0005 ± 0.0002 mg/kg for Pb, Cd, Ni and Hg. The THQ was higher for children, suggesting health risks associated with consumption of camel milk for this age group (p < .001). The primary contribution of this study is the establishment of a database on toxic metal levels in camel milk, which can be valuable to manage possible risk associated with metals in milk.

Halogenated aliphatic and phenolic disinfection byproducts in chlorinated and chloraminated dairy wastewater: Occurrence and ecological risk evaluation

The increasing demand for dairy products has led to the production of a large amount of wastewater in dairy plants, and disinfection is an essential treatment process before wastewater discharge. Disinfection byproducts (DBPs) in disinfected dairy wastewater may negatively influence the aquatic organisms in receiving water. During chlorine and chloramine disinfection of dairy wastewater, the concentrations of aliphatic DBPs increased from below the detection limits to 485.1 μg/L and 26.6 μg/L, respectively. Brominated and iodinated phenolic DBPs produced during chlor(am)ination could further react with chlorine/chloramine to be transformed. High level of bromide in dairy wastewater (12.9 mg/L) could be oxidized to active bromine species by chlorine/chloramine, promoting the formation of highly toxic brominated DBPs (Br-DBPs), and they accounted for 80.3% and 71.1% of the total content of DBPs in chlorinated and chloraminated dairy wastewater, respectively. Moreover, Br-DBPs contributed 49.9-75.9% and 34.2-96.4% to the cumulative risk quotient of DBPs in chlorinated and chloraminated wastewater, respectively. The cumulative risk quotient of DBPs on green algae, daphnid, and fish in chlorinated wastewater was 2.8-11.4 times higher than that in chloraminated wastewater. Shortening disinfection time or adopting chloramine disinfection can reduce the ecological risks of DBPs.

Elemental characterization of freeze dried domestic animals' milk using ion beam analysis techniques

Particle induced X-ray emission (PIXE) and particle induced γ-ray emission (PIGE) techniques were employed to perform elemental analysis in four milk samples of local domestic animals, namely sheep, caw, camel and goat. Additionally, Rutherford backscattering (RBS) spectra were acquired simultaneously with PIXE and PIGE to determine matrix elements. Milk samples were prepared in a simple dried base following freeze drying process. Optimization of PIXE/PIGE/RBS experimental conditions as well as data acquisition and analysis procedures were carefully addressed. Verification study was performed relying on the analysis of both IAEA-11 and IAEA-153 reference materials. Accuracies of ±5-10% together with relative standard deviations of less than 15% were mostly reported. Chemical element concentrations of 11 elements were determined, namely Na, Mg, P, S, Cl, K, Ca, Zn, Br, Rb and Sr. Obtained element concentration values were mostly in the range 1000-10000 μg/g for major elements and 5-100 μg/g for trace elements. No significant changes in elemental concentration differences for both trace and major elements were noticed in the four different milk samples. The contribution of the elements in these milk samples to the dietary recommended intakes (DRI) has been evaluated. Advantages of applying multiple ion beam analysis techniques have been discussed.

Heavy metal levels in milk and dairy products and health risk assessment: A systematic review of studies in China

Previous studies have indicated that heavy metal levels in milk vary partly depending on environmental metal concentrations. Given the increasing consumption of milk in China, it is essential to pay attention to milk safety. We performed a systematic review of relevant published studies to evaluate the heavy metal levels in milk and dairy products and the associated health risks, discuss environmental sources of heavy metals, and propose future research directions. A literature search was implemented in the Web of Science Core Collection and PubMed using multiple keywords such as "metal," "milk," "dairy products," and "China". A total of 16 published studies that analyzed metal levels in milk and dairy products in 20 provincial administrative regions were included. Most studies detected toxic heavy metals in milk and dairy products samples, including mercury, lead, cadmium, chromium, and arsenic. The lead concentration in milk from these studies did not exceed the Chinese standard for milk. However, three studies detected relatively high lead levels in both commercial and raw milk, exceeding the European Commission standard. The polluted environment surrounding the farm, feed, and packaging materials are likely sources of metals in milk and dairy products. The hazard index for the 11 analyzed metal elements in milk and dairy products was lower than 1, indicating negligible non-carcinogenic health risks from exposure to these metals. Children are at a higher risk than adults. This review illustrates that research in this field is limited to China. More research should be conducted in the future, such as evaluating the contribution of each environmental source of metal in milk and dairy products.

Calcium: A comprehensive review on quantification, interaction with milk proteins and implications for processing of dairy products

Calcium (Ca) is a key micronutrient of high relevance for human nutrition that also influences the texture and taste of dairy products and their processability. In bovine milk, Ca is presented in several speciation forms, such as complexed with other milk components or free as ionic calcium while being distributed between colloidal and serum phases of milk. Partitioning of Ca between these phases is highly dynamic and influenced by factors, such as temperature, ionic strength, pH, and milk composition. Processing steps used during the manufacture of dairy products, such as preconditioning, concentration, acidification, salting, cooling, and heating, all contribute to modify Ca speciation and partition, thereby influencing product functionality, product yield, and fouling of equipment. This review aims to provide a comprehensive understanding of the influence of Ca partition on dairy products properties to support the development of kinetics models to reduce product losses and develop added-value products with improved functionality. To achieve this objective, approaches to separate milk phases, analytical approaches to determine Ca partition and speciation, the role of Ca on protein-protein interactions, and their influence on processing of dairy products are discussed.

Determining the geographical origin of milk by multivariate analysis based on stable isotope ratios, elements and fatty acids

To construct a reliable discrimination model for determining milk geographical origin, stable isotope ratios including δ¹³C, δ¹⁵N and δ¹⁸O, 51 elements and 35 fatty acids (FAs) in milk samples from Australia, New Zealand and Austria were detected and analyzed. It is found that all of the stable isotope ratios in the milk samples of Australia are the highest, followed by those of the samples from New Zealand and Austria. In addition, 14 elements and 8 FAs show different contents in the samples of different countries at the significance level of P < 0.05. Based on these results, a multivariate model with good robustness and predictive ability for authenticating milk origin (R²X = 0.693, Q² = 0.854) was successfully constructed. Element contents and stable isotope ratios are more reliable variables for milk origin discrimination and Rb, δ¹⁸O, Tl, Ba, Mo, Sr, δ¹⁵N, Cs, As, Eu, C20:4n6, Sc, C13:0, K, Ca and C16:1n7 are the critical markers in the multivariate model for verifying milk origin.

Analytical Methodologies for Agrometallomics: A Critical Review

Agrometallomics, as an independent interdiscipline, is first defined and described in this review. Metallic elements widely exist in agricultural plants, animals and edible fungi, seed, fertilizer, pesticide, feedstuff, as well as the agricultural environment and ecology, and even functional and pathogenic microorganisms. So, the agrometallome plays a vital role in molecular and organismic mechanisms like environmetallomics, metabolomics, proteomics, lipidomics, glycomics, immunomics, genomics, etc. To further reveal the inner and mutual mechanism of the agrometallome, comprehensive and systematic methodologies for the analysis of beneficial and toxic metals are indispensable to investigate elemental existence, concentration, distribution, speciation, and forms in agricultural lives and media. Based on agrometallomics, this review summarizes and discusses the advanced technical progress and future perspectives of metallic analytical approaches, which are categorized into ultrasensitive and high-throughput analysis, elemental speciation and state analysis, and spatial- and microanalysis. Furthermore, the progress of agrometallomic innovativeness greatly depends on the innovative development of modern metallic analysis approaches including, but not limited to, high sensitivity, elemental coverage, and anti-interference; high-resolution isotopic analysis; solid sampling and nondestructive analysis; metal chemical species and metal forms, associated molecular clusters, and macromolecular complexes analysis; and metal-related particles or metal within the microsize and even single cell or subcellular analysis.

Preliminary Study on Tracing the Origin and Exploring the Relations between Growing Conditions and Isotopic and Elemental Fingerprints of Organic and Conventional Cavendish Bananas (Musa spp.)

The stable isotopic ratios and elemental compositions of 120 banana samples, Musa spp. (AAA Group, Cavendish Subgroup) cultivar Williams, collected from six countries (Colombia, Costa Rica, Dominica Republic, Ecuador, Panama, Peru), were determined by isotope ratio mass spectrometry and inductively coupled plasma mass spectrometry. Growing conditions like altitude, temperature, rainfall and production system (organic or conventional cultivation) were obtained from the sampling farms. Principal component analysis (PCA) revealed separation of the farms based on geographical origin and production system. The results showed a significant difference in the stable isotopic ratios (δ¹³C, δ¹⁵N, δ¹⁸O) and elemental compositions (Al, Ba, Cu, Fe, Mn, Mo, Ni, Rb) of the pulp and peel samples. Furthermore, δ¹⁵N was found to be a good marker for organically produced bananas. A correlation analysis was conducted to show the linkage of growing conditions and compositional attributes. The δ¹³C of pulp and peel were mainly negatively correlated with the rainfall, while δ¹⁸O was moderately positively (R values ~0.5) correlated with altitude and temperature. A moderate correlation was also found between temperature and elements such as Ba, Fe, Mn, Ni and Sr in the pulp and peel samples. The PCA results and correlation analysis suggested that the differences of banana compositions were combined effects of geographical factors and production systems. Ultimately, the findings contribute towards understanding the compositional differences of bananas due to different growing conditions and production systems linked to a defined origin; thereby offering a tool to support the traceability of commercial fruits.

The occurrence of eleven elements in dairy cow´s milk, feed, and soil from three different regions of Slovakia

The objective of this study was to measure the concentrations of eleven essential, potentially toxic and toxic elements (arsenic – As, calcium – Ca, cadmium – Cd, copper – Cu, iron – Fe, mercury – Hg, magnesium – Mg, nickel – Ni, lead – Pb, selenium – Se, zinc- Zn) in raw cow’s milk (spring, summer, and autumn season), feed (spring and autumn season) and soil (spring season) from three different environments by routine methods in the certified testing laboratory. The samples were collected in the undisturbed region around Novoť, the moderately disturbed region around Tulčík, and the strongly disturbed region around Čečejovce. The concentrations of all toxic elements (As, Cd, Hg, Ni, Pb) and two essential elements (Cu, Se) in milk were under the limits of quantification (LOQ) from all investigated areas and during all seasons. Concentrations of other elements in milk from the undisturbed and disturbed areas were significantly different, generally with the highest levels in summer. In soil samples, the significantly highest concentrations of Ca, Cu, Ni were found in a strongly disturbed area, Mg and As in moderately disturbed area, and Fe, Se, Zn, Hg, and Pb in an undisturbed area. Cadmium was under the LOQ. In feed, the concentrations of essential elements, except of Se, were higher in the autumn. The significantly highest concentration of As, Ni were recorded in a moderately disturbed area and Pb in the undisturbed area in both seasons. Cadmium and Hg were under the LOQ. Despite the higher level of some elements in soil (Fe, Mg, Ca) from all regions, there were not elevated concentrations of any element in feed or milk. The concentrations of all toxic elements in milk were under the permitted limits. Thus, the milk from all investigated areas was not contaminated with the elements posing a health risk for consumers and it is considered safe for human consumption.

Concentrations of toxic metals and essential elements in raw cow milk from areas with potentially undisturbed and highly disturbed environment in Slovakia

Dietary composition and husbandry practices largely determine the essential trace element status and the toxic metal exposure of livestock and consequently their concentrations in animal products. The main objective of this study was to determine the real contamination of selected areas of Slovakia compared with existing Environmental regionalization of the Slovak Republic (SR) created by the Ministry of the Environment SR. Another aim of this study was to determine the content of essential and toxic metals in feed and milk of dairy cows on selected farms in Slovakia referred to the suitability of the use of milk from these areas to other food processing. This article deals with the analysis of the content of selected elements in feed and milk of dairy cows in the area of Novoť (Northern Slovakia; area with undisturbed environment) and Čečejovce (Eastern Slovakia; highly disturbed environment). Eleven elements have been analyzed (essential elements: calcium, zinc, magnesium, selenium, iron, copper; toxic elements: arsenic, cadmium, mercury, lead, nickel). Samples of feed and milk were collected five times during the spring season and five times during the autumn season in 2016. Analysis of samples was performed in Eurofins Bel/Novamann (Nové Zámky, Slovak Republic). Analyses were performed by atomic absorption spectroscopy and atomic emission spectrometry. The obtained values of the individual elements in the feed and milk were evaluated by Student's t test. Significantly higher contents of essential elements Ca, Zn, Fe, Mg, and Cu were found in the feed of dairy cows in Čečejovce (P < 0.001). Significantly higher (P < 0.001) As and Ni content in feed in Čečejovce in autumn season was also recorded. However, the content of these elements in feed did not affect their milk content. The content of Ca, Zn, and Mg in milk was significantly (P < 0.001) higher in Novoť in both investigated seasons. Some essential elements and toxic elements in feed and milk were below the LOQ (limit of quantification). Reduced content of Ca and Zn in milk in both farms compared with optimal limits, decreased Ca and Mg content in feed in Novoť, and a significant increase of Ca and Mg in feed in Čečejovce in autumn season were found. It can be concluded, due to the low content of toxic elements on these farms, that the use of milk of dairy cows from these areas for direct use or for dairy product processing is appropriate and poses no health risk to the consumers.

Analysis of 17 elements in cow, goat, buffalo, yak, and camel milk by inductively coupled plasma mass spectrometry (ICP-MS)

We analyzed the concentrations of 17 elements including arsenic (As), lead (Pb), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), zinc (Zn), strontium (Sr), tin (Sn), aluminum (Al), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), sodium (Na), and selenium (Se) in cow, goat, buffalo, yak, and camel milk in China using inductively coupled plasma mass spectrometry. The concentrations of the elements varied and depended on the milk type. K, Ca, Na, and Mg were the most abundant elements. Fe and Zn concentrations ranged from 1 to 6 μg g⁻¹, while Cu, Al, and Mn concentrations ranged from 0.1 to 1 μg g⁻¹. Trace elements, especially toxic trace elements, were present at very low concentrations; however, Pb concentrations in cow milk reached the MRLs established by the Codex Alimentarius Commission. Data were analyzed by chemometrics to evaluate the correlations between elements in the milk samples. PCA and factor analysis highlighted the relationship between element distribution and milk type. The LDA model correctly identified most milk types. Element analysis combined with chemometrics can be used to distinguish milk types.

17 elements in cow, goat, buffalo, yak, and camel milk were determined by ICP-MS; element analysis combined with chemometrics can be used to distinguish milk types.

Mineral Elements in the Raw Milk of Several Dairy Farms in the Province of Alberta

The objective of this study was to determine the concentrations of 20 minerals in the whole raw milk from Holstein dairy cows in the province of Alberta, Canada. A total of 156 milk samples were collected from 26 dairy farms (n = 6 per farm) and analyzed with inductively coupled plasma mass spectrometry (ICP-MS) for five macrominerals (Ca, Mg, P, K, and Na), ten microminerals (Bo, Co, Cu, Fe, Mn, Mo, Ru, Se, St, and Zn), and five heavy metals (Al, As, Cd, Cr, and Pb). Calculated means were compared with their recommended daily intakes (RDIs) or minimal risk levels (MRLs) obtained from several food safety agencies and with data obtained from a world meta-analytical study we conducted previously. Results of the present study showed differences in the concentrations of multiple minerals between the Alberta farms involved and world averages (WA) and within Alberta farms. Concentrations of macrominerals, including Ca, Mg, P, K, and Na, in the raw milk were greater in Alberta dairy farms than the WA (p < 00.5; except Ca). Of note, concentrations of Ca showed the highest variability among Alberta farms, with 11 farms having lower milk Ca than WA. The other macrominerals were higher than WA in more than 88% of Alberta farms. Data demonstrated that concentrations of microminerals, including Co, Cu, Fe, Mn, and Mo, in Alberta raw milk were lower compared with WA (p < 0.05). Selenium was the only element in raw milk that was found to have higher concentrations in all farms in Alberta vs. WA. High variability was observed for B, Sr, and Zn, which were lower in multiple locations around the province. Concentrations of heavy metals in the Alberta raw milk, including Al, As, Cd, and Pb, were lower than WA, whereas concentrations of Cr were higher. Most importantly, all heavy metals were below their respective MRLs in all analyzed samples. Overall, data from this study showed that raw milk from Holstein dairy cows in Alberta has concentrations of most mineral elements below their MRLs and some of them different from WA. Of note, although concentrations of Se and Zn in the raw milk were higher in Alberta compared with WA, their concentrations were still below their respective MRLs.

Levels of Essential and Xenobiotic Elements and Their Relationships in Milk Available on the Slovak Market with the Estimation of Consumer Exposure

The monitoring of various elements in the cow milk is important in the agricultural sector. The goal of this study was to determine the concentrations of calcium (Ca), cadmium (Cd), copper (Cu), iron (Fe), mercury (Hg), potassium (K), magnesium (Mg), sodium (Na), nickel (Ni), lead (Pb), and zinc (Zn) in the milk samples coming from different origins (local region in Nitra, nationwide sample represents the common Slovak brands of milk and common brands of milk from Czech Republic widely available in Slovakia). The samples were analyzed using atomic absorption spectrometry. A high level of variability in the Cu, Fe, Na, Ni, and Zn contents was observed. Magnesium was comparatively high in the milk sample from Slovakia (273.23 ± 16.32 μg/mL) against sample from Nitra (230.91 ± 9.48 μg/mL) and Czech Republic (202.70 ± 10.83 μg/mL). Potassium was significantly higher in milk from Nitra region (3301.98 ± 95.66) against SK sample (2925.16 ± 75.74 μg/mL). There were no significant differences in other elements among the three regions. The provisional tolerable weekly intake (PTWI) contribution suggested low dietary exposure to observed toxic metals (Cd, Hg, and Pb) in milk samples. Margin of exposure (MOE) evaluation denoted that even higher consumption of milk poses no high cardiovascular and nephrotoxicity threat. However, Cd and Pb are known for their cumulative effect and the monitoring of these elements in milk is strongly required.

How elevated CO2 affects our nutrition in rice, and how we can deal with it

Increased concentrations of atmospheric CO2 are predicted to reduce the content of essential elements such as protein, zinc, and iron in C3 grains and legumes, threatening the nutrition of billions of people in the next 50 years. However, this prediction has mostly been limited to grain crops, and moreover, we have little information about either the underlying mechanism or an effective intervention to mitigate these reductions. Here, we present a broader picture of the reductions in elemental content among crops grown under elevated CO2 concentration. By using a new approach, flow analysis of elements, we show that lower absorption and/or translocation to grains is a key factor underlying such elemental changes. On the basis of these findings, we propose two effective interventions-namely, growing C4 instead of C3 crops, and genetic improvements-to minimize the elemental changes in crops, and thereby avoid an impairment of human nutrition under conditions of elevated CO2.

Colloidal properties of protein complexes formed in β-casein concentrate solutions as influenced by heating and cooling in the presence of different solutes

Monomeric bovine β-casein self-associates into micelles under appropriate conditions of protein concentration, serum composition and temperature. The present study investigated self-association characteristics of a β-casein concentrate (BCC) prepared from milk at pilot-scale using membrane filtration. The BCC had a casein:whey protein ratio of 77:23, with ∼95% of casein consisting of β-casein, and the remainder being mostly κ-CN. BCC was reconstituted to 1.2% protein (a typical level in infant formula) in various liquid media at pH 6.8 and incubated at different temperatures from 4 to 63 °C for 30 min. Self-association of β-casein on heating was thermo-reversible in deionised water, lactose (4, 6 or 8%) or calcium (9 mM) solutions. In most serum phases, BCC became highly opaque after incubation at 63 °C, but clarified rapidly during cooling to 25 °C. However, in simulated milk ultrafiltrate (SMUF), which has a high ionic strength and is supersaturated in calcium phosphate (CaP), BCC remained opaque during cooling to 25 °C, and retained residual turbidity after 15 h of holding at 4 °C; if SMUF was prepared without phosphate then turbidity development in BCC solutions was markedly reduced. The complexes responsible for this turbidity development were successfully dissociated with 50 mM trisodium citrate. Analysis of pH during heating and holding at 60 °C indicated that SMUF acidified continuously under the period of study, while acidification in BCC/SMUF mixtures terminated after a short period, indicating that the type of CaP formed on heating is altered in the presence of BCC. This study demonstrates that BCC ingredients exhibit pronounced temperature-dependant changes in colloidal properties that are strongly affected by the presence of minerals commonly found in nutritional product formulations.

Quantification of 71 detected elements from Li to U for aqueous samples by simultaneous-inductively coupled plasma-mass spectrometry

Quantitative analysis of multi-element concentrations in aqueous solutions, such as water, beverages and biofluids, has long been performed by sequential inductively coupled plasma-mass spectrometry. Recently, a fully simultaneous mass spectrum monitoring ICP-MS instrument that fits a compact Mattauch–Herzog geometry (MH-ICP-MS) with a permanent magnet and a large, spatially resolving semiconductor ion detector has been introduced. This technology allows coverage of the complete inorganic relevant mass range from ⁶Li to ²³⁸U in a single measurement, which helps to mitigate the restriction on the number of inorganic elements whose concentrations may be routinely measured from one sample, thus reducing operational assay times and aqueous sample volumes for evaluations across the breadth of the periodic table. We report here on a detailed method for utilizing MH-ICP-MS to detect all elements of the relevant inorganic spectrum in aqueous samples; 7 types of water, 4 types of beverage, and 4 biofluid biological samples. With this method 71 elements can be routinely detected simultaneously in seconds and in as little as 1–4 mL sample, when using a specific set of calibration and internal standards. Quantitative results reveal distinct element patterns between each sample and within types of samples, suggesting that different types of aqueous solutions can be recognized and distinguished by their elemental patterns. The method has implications for understanding elemental distribution and concentration for many fields, including nutrition, studies of the biosphere, ecological stoichiometry, and environmental health fields, among others, where broad elemental information is actually required.

Quantitative analyses of multi-element concentrations in aqueous solutions, such as water, beverages and biofluids, are performed by simultaneous MH-ICP-MS.

Minerals and Heavy Metals in the Whole Raw Milk of Dairy Cows from Different Management Systems and Countries of Origin: A Meta-Analytical Study

The objective of this meta-analytical study was to investigate selected macrominerals, microminerals, and toxic heavy metals in the bovine whole-raw-milk (WRM) samples of published data. An analytical data set was constructed from 72 different studies from 37 countries with two types of production systems: a conventional production system (CPS) and an organic production system (OPS) compared with commercially available or retail-store-available milk (COM). Results of the meta-analytical study showed differences in the concentrations of macrominerals. Concentrations of Ca, Mg, K, and P were greater in the CPS samples, whereas Na was greater in the COM samples ( P < 0.05). Data also demonstrated that concentrations of microminerals like Cu, I, Fe, Mn, Se, and Zn in the organic WRM were lower ( P < 0.05) compared with the milk from CPS. The highest concentration of Ni was reported for COM ( P < 0.05); however, this value was below the minimum-risk level (MRL). Concentrations of heavy metals like As and Ni were greater in CPS milk than those in organic milk ( P < 0.05). In addition, there were greater concentrations of Cd and Pb in the WRM from CPS versus that from the organic farms. Concentration of Al was lowest in the OPS milk versus Al in the CPS which was 6.5-fold greater than in organic milk. The amount of Hg was below the MRL of 0.01 μmol/L for all production systems. A high variability was observed in the published data regarding the country of origin. Raw milk originating from Europe and North America was characterized by concentrations of macro- and microminerals below the MRLs as compared with that from specific countries, which had some minerals above the MRLs. For example, concentrations of Pb were above the MRL in the milk samples from Brazil, Croatia, Egypt, Mexico, Nigeria, Palestine, Romania, Serbia, and Turkey. Moreover, data from this study indicate that organic dairy farms are characterized by lower concentrations of toxic heavy metals in the WRM compared with those from CPS dairy farms.

Analysis and Risk Assessment of Seven Toxic Element Residues in Raw Bovine Milk in China

The object of this study is to analyze the levels of seven toxic elements residues in raw bovine milk in China and assess the potential health risk of those residues. The 178 raw bovine milk samples were collected from eight main milk-producing provinces and from three types of milk stations in China, and were analyzed for arsenic (As), lead (Pb), cadmium (Cd), chromium (Cr), mercury (Hg), aluminum (Al), and nickel (Ni) using inductively coupled plasma-mass spectrometry (ICP-MS). Al, Pb, Hg, Ni, Cr, and As were detected in 47.8, 29.2, 28.1, 23.6, 12.4, and 9.0% of total milk samples, respectively, and Cd were not detected in all samples. The raw bovine milk samples with high levels of toxic elements were found in industrial areas, such as Heilongjiang and Shanxi. Nemerow pollution index analysis showed that the levels were lower in the samples from the processing plants than that from the large-scale farms and small farm cooperatives. The margin of exposure (MOE) values suggest that the levels of As, Pb, Hg, Cr, Al, and Ni in the raw milk samples are not causing a health risk for Chinese consumers, including adults and children. Nevertheless, the risk of Pb for infant and young children was more serious than adult.

Occurrence of selected metals in feed and sheep´s milk from areas with different environmental burden

The content of selected essential elements and toxic metals in feed and sheep's milk from areas with different parts of Slovak Republic was analyzed. Region of Novoť (undisturbed environment; North Slovakia) and region of Klátova Nová Ves (widely disturbed environment; Western Slovakia) were under investigation. Eleven metals have been analyzed (essential elements - calcium, zinc, selenium, iron, magnesium, copper; toxic elements - arsenic, mercury, lead, cadmium, nickel). Samples of feeds and milk were collected five-times during the year (spring and autumn season). Analyses of samples were performed by certified testing laboratory Eurofins Bel/Novamann (Nové Zámky, Slovak Republic). Analyses were performed by routine methods, according to the valid methodologies. The results showed significantly higher content of selected essential elements in feed in spring season from area with widely disturbed environment (Klátova Nová Ves). Significantly higher content of essential elements in milk was on farm of Novoť (undisturbed environment). Occurrence of toxic metals in feed from area with widely disturbed environment in spring season did not affect their content in milk. It can be concluded, that the use of milk of sheep from these areas for direct use or for dairy products processing is appropriate, safe and poses no health risk for the consumers.

Characterization and application of in-vacuum PIXE/EBS system for the direct elemental analysis of thick solid biological samples

Utilization of combined particle-induced X-ray emission (PIXE) and elastic backscattering (EBS) spectrometry for the direct elemental analysis of thick solid biological samples was thoroughly discussed. Powdered samples pressed as pellets were directly analyzed. Combination of applying low ion beam currents, random scanning of the sample across the beam during data acquisition, and using special sample holder enabled effective minimization of local ion beam heating. This subsequently inhibited potential element loss during ion beam irradiation. Matrix elements were determined from multiple EBS spectra, which were acquired using three different ion beam energies. Subsequently, averaging of the elemental concentrations obtained was achieved using novel MultiSIMNRA software. Moreover, combined EBS spectrometry, nuclear reaction analysis (NRA), and elastic recoil detection analysis (ERDA) measurements were used to overcome the limitations of using EBS separately and subsequently obtain accurate matrix element concentrations. The validity of the PIXE/EBS system for the direct elemental analysis of thick biological samples was comprehensively evaluated. The obtained concentration values demonstrated reliable results for most investigated elements (5-15%), starting from sodium onwards. The non-satisfying results were evaluated and justified.

Analysis of 22 Elements in Milk, Feed, and Water of Dairy Cow, Goat, and Buffalo from Different Regions of China

The objectives of this study were to measure the concentrations of elements in raw milk by inductively coupled plasma-mass spectrometry (ICP-MS) and evaluate differences in element concentrations among animal species and regions of China. Furthermore, drinking water and feed samples were analyzed to investigate whether the element concentrations in raw milk are correlated with those in water and feed. All samples were analyzed by ICP-MS following microwave-assisted acid digestion. The mean recovery of the elements was 98.7 % from milk, 103.7 % from water, and 93.3 % from a certified reference material (cabbage). Principal component analysis results revealed that element concentrations differed among animal species and regions. Correlation analysis showed that trace elements Mn, Fe, Ni, Ga, Se, Sr, Cs, U in water and Co, Ni, Cu, Se, U in feed were significantly correlated with those in milk (p < 0.05). Toxic and potential toxic elements Cr, As, Cd, Tl, Pb in water and Al, Cr, As, Hg, Tl in feed were significantly correlated with those in milk (p < 0.05). Results of correlation analysis revealed that elements in water and feed might contribute to the elements in milk.

Characterisation of heat-induced protein aggregation in whey protein isolate and the influence of aggregation on the availability of amino groups as measured by the ortho-phthaldialdehyde (OPA) and trinitrobenzenesulfonic acid (TNBS) methods

Whey protein isolate (WPI) solutions, with different levels of aggregated protein, were prepared by heating (5% protein, pH 7, 90°C for 30min) WPI solutions with either 20mM added NaCl (WPI+NaCl), 5mM N-ethylmaleimide (WPI+NEM) or 20mM added NaCl and 5mM NEM (WPI+NaCl+NEM). Gel electrophoresis demonstrated that the heated WPI and WPI+NaCl solutions had higher levels of aggregated protein, due to more covalent interactions between proteins, than the heated WPI+NEM and WPI+NaCl+NEM solutions. There were marked differences in the levels of amino groups between all heated WPI solutions when measured by the OPA and TNBS methods, with lower levels being measured by the TNBS method than by the OPA method. These results demonstrate that the measurement of available amino groups by the OPA method is less impacted than by the TNBS method after heat-induced structural changes, arising from disulfide or sulfhydryl-disulfide bond-mediated aggregation of whey protein molecules.

Improving the quantity, quality and transparency of data used to derive radionuclide transfer parameters for animal products. 2. Cow milk

Under the International Atomic Energy Agency (IAEA) MODARIA (Modelling and Data for Radiological Impact Assessments) Programme, there has been an initiative to improve the derivation, provenance and transparency of transfer parameter values for radionuclides from feed to animal products that are for human consumption. A description of the revised MODARIA 2016 cow milk dataset is described in this paper. As previously reported for the MODARIA goat milk dataset, quality control has led to the discounting of some references used in IAEA's Technical Report Series (TRS) report 472 (IAEA, 2010). The number of Concentration Ratio (CR) values has been considerably increased by (i) the inclusion of more literature from agricultural studies which particularly enhanced the stable isotope data of both CR and F_m and (ii) by estimating dry matter intake from assumed liveweight. In TRS 472, the data for cow milk were 714 transfer coefficient (F_m) values and 254 CR values describing 31 elements and 26 elements respectively. In the MODARIA 2016 cow milk dataset, F_m and CR values are now reported for 43 elements based upon 825 data values for F_m and 824 for CR. The MODARIA 2016 cow milk dataset F_m values are within an order of magnitude of those reported in TRS 472. Slightly bigger changes are seen in the CR values, but the increase in size of the dataset creates greater confidence in them. Data gaps that still remain are identified for elements with isotopes relevant to radiation protection.

How knowledge of the gastrointestinal absorption of elements could be used to predict transfer to milk

The quality and quantity of data used to derive transfer parameter values for milk are variable and there are many data gaps for elements/radionuclides which may need to be considered for risk assessment of the agricultural foodchain. There has been a recent focus on critically evaluating current methods to fill data gaps and on identifying extrapolation methods to derive suitable values for the elements, and particularly radioisotopes, with no or sparse data. The relationship between fractional absorption of elements in the ruminant gastrointestinal tract and transfer to milk has been explored to determine whether knowledge of the former can be used to predict the latter. A relationship has been derived between fractional absorption of elements and two empirical ratios commonly used to quantify transfer to milk; transfer coefficients (element concentration in milk divided by element daily intake) and concentrations ratios (concentration in milk divided by concentration in feed). We propose that fractional absorption may be used to predict the order of magnitude of the transfer to milk of elements/radionuclides for which no relevant data have yet been identified or collated.

Determination of heavy metals in milk and fermented milk products by potentiometric stripping analysis with constant inverse current in the analytical step

A simple and rapid method for the direct determination of cadmium, lead and copper in milk and fermented milk products by potentiometric stripping analysis (PSA) with oxygen as an oxidant and with inverse current imposed through the stripping step is described. For the more selective metals determination a samples pretreatment by the microwave acid extraction was applied. Due to the significant increase of the modified technique sensitivity, the detection limits of 0.30, 1.7 and 3.8 μg/l were obtained, for cadmium, lead and copper, respectively. The method accuracy was confirmed by analysing the standard reference material (SRM 1577 b). The contents of cadmium, lead and copper in milk samples were in the range of 2.13-4.82, 54.3-95.2 and 112.2-124.7 μg/kg, respectively, whereas in the samples of fermented milk products in the range of 6.30-24.1, 210.1-463.6 and 260.0-320.7 μg/kg, respectively.

Research into the functional components and antioxidant activities of North China rice wine (Ji Mo Lao Jiu)

Over the last decade, considerable experimental evidence has supported the view that grape wine and South China rice wine are rich in diverse nutrients and have powerful antioxidant activity. However, little research has been carried out for North China rice wine, of which Ji Mo Lao Jiu (JMLJ) is the outstanding representative. In this study, the functional components and antioxidant activity of JMLJ were investigated. Twenty-eight free amino acids were found in JMLJ, much more than that previously reported in other Chinese rice wines (16-21). Functional oligosaccharides (5290.222 mg/L), total phenols (722.431 ± 10.970 mg/L), and mineral elements (9) were rich in JMLJ. When compared with synthetic antioxidants, such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), JMLJ showed effective 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging and reducing capacity. The results of this study lay the foundation for promoting the utilization of JMLJ and the development of North China rice wine in the food industry.