Herbs and spices are known to be prone to food fraud and accurate analytical tools are needed to detect adulterants. Amongst the potential adulteration, dilution with bulking agents has regularly been reported, especially with inorganic materials such as talc or brick powder. Energy Dispersive X-Ray Fluorescence (ED-XRF) spectrometry is a well-established non-destructive analytical technique for qualitative and quantitative elemental analysis of a wide variety of samples. ED-XRF was here evaluated for the detection of inorganic adulterants in turmeric, paprika and oregano, which were selected as representative for the herbs & spices food category. Magnesium, silicon, and calcium were identified as elements to detect talc, soapstone, brick/clay powder, and chalk inorganic adulterants. ED-XRF successfully detected adulterated samples when spiked down to 5% (w/w) in the selected herbs and spices. With its ease-of-use and speed, ED-XRF is well adapted for the monitoring of inorganic adulteration of herbs and spices along the supply chain.

In this contribution, the analytical potential of total reflection X-ray fluorescence (TXRF) instrumentation has been evaluated for the determination of major and trace elements in milk powder. TXRF allows the possibility of direct analysis of solid suspensions without the need for a digestion process and therefore it can be a potential analytical candidate for simple and cost-effective analysis. A detailed study to select sample preparation and measurements conditions was carried out. Different quantification approaches (including internal standardization and empirical calibration) were also tested. Finally, the developed TXRF methods (W anode) were validated by a strict comparison with the data from the reference methods on a set of twenty-three samples using robust statistics. Results showed that acceptable results can be obtained for K, Ca, Fe and Zn determination if using adequate calibration approaches. Otherwise, only screening results can be obtained for light elements (P and Cl) in milk powder samples.

Microplastics (MPs) have gained a high degree of public interest since they are associated with the global release of plastics into the environment. Various studies have confirmed the presence of MPs throughout the food chain. However, information on the ingestion of MPs via the consumption of many commonly consumed foods like dairy products are scarce due to the lack of studies investigating the “contamination” of this food group by MPs. This lack of occurrence data is mainly due to the absence of robust analytical methods capable of reliably quantifying MPs with size < 20 µm in foods. In this work, a new methodology was developed to accurately determine and characterize MPs in milk-based products using micro-Raman (μRaman) technology, entailing combined enzymatic and chemical digestion steps. This is the first time that the presence of relatively low amounts of small-sized MP (≥ 5 µm) have been reported in raw milk collected at farm just after the milking machine and in some processed commercial liquid and powdered cow’s milk products.

Abstract Microplastics (MPs) have gained a high degree of public interest since they are associated with the global release of plastics into the environment. As a result, MPs have also been detected along the food chain. However, information on the ingestion of MPs via the consumption of many commonly consumed foods like dairy products are scarce due to the lack of studies investigating the “contamination” of this food group by MPs. This lack of occurrence data is mainly due to the absence of robust analytical methods capable of reliably quantifying MPs with size < 20 µm in foods. In this work, we have developed a new methodology to accurately determine and characterize MPs in milk-based products using μRaman technology, entailing combined enzymatic and chemical digestion steps. We demonstrate for the first time the presence of relatively low amounts of small-sized MP (≥ 4 µm) in raw milk collected at farm just after the milking machine and in some processed commercial liquid and powdered cow’s milk products.

An adequate mineral supply to preterm infants is essential for normal growth and development. This study aimed to compare the mineral contents of human milk (HM) from healthy mothers of preterm (28-32 weeks) and full term (>37 weeks) infants. Samples were collected weekly for eight weeks for the term group (n = 34) and, biweekly up to 16 weeks for the preterm group (n = 27). Iron, zinc, selenium, copper, iodine, calcium, magnesium, phosphorus, potassium, and sodium were quantitatively analyzed by Inductively Coupled Plasma-Mass Spectrometry. The mineral contents of both HM showed parallel compositional changes over the period of lactation, with occasional significant differences when compared at the same postpartum age. However, when the comparisons were performed at an equivalent postmenstrual age, preterm HM contained less zinc and copper from week 39 to 48 (p < 0.002) and less selenium from week 39 to 44 (p < 0.002) than term HM. This translates into ranges of differences (min-max) of 53% to 78%, 30% to 72%, and 11% to 33% lower for zinc, copper, and selenium, respectively. These data provide comprehensive information on the temporal changes of ten minerals in preterm HM and may help to increase the accuracy of the mineral fortification of milk for preterm consumption.

Nutritional information about human milk is essential as early human growth and development have been closely linked to the status and requirements of several macro- and micro-elements. However, methods addressing whole mineral profiling in human milk have been scarce due in part to their technical complexities to accurately and simultaneously measure the concentration of micro- and macro-trace elements in low volume of human milk. In the present study, a single laboratory validation has been performed using a "dilute and shoot" approach for the quantification of sodium (Na), magnesium (Mg), phosphorus (P), potassium (K), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), selenium (Se), molybdenum (Mo) and iodine (I), in both human milk and milk preparations. Performances in terms of limits of detection and quantification, of repeatability, reproducibility and trueness have been assessed and verified using various reference or certified materials. For certified human milk sample (NIST 1953), recoveries obtained for reference or spiked values are ranged from 93% to 108% (except for Mn at 151%). This robust method using new technology ICP-MS/MS without high pressure digestion is adapted to both routinely and rapidly analyze human milk micro-sample (i.e. less than 250 mu L) in the frame of clinical trials but also to be extended to the mineral profiling of milk preparations like infant formula and adult nutritionals.

This work describes a quick and easy method for the quantification of a series of macroelements (Na, Mg, P, Cl, K, and Ca) and trace elements (Fe and Zn) by energy-dispersive X-ray fluorescence (ED-XRF). The method was developed and validated using commercial dehydrated bouillon and sauce base products. All samples were systematically powdered and analyzed by reference methods (i.e., potentiometry for chloride and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) for other elements) and by ED-XRF. A calibration set of 15 samples was selected to cover uniformly the concentration range of each element, and their reference method values were used to calibrate the ED-XRF device. A second validation set, composed of 26 additional samples, was then analyzed as though they were unknown samples. During this validation step, the elemental concentrations obtained by ED-XRF were systematically evaluated against those obtained from the reference methods. For the eight investigated elements, the ED-XRF method was found to be comparable to the reference one; furthermore, the bias between both methods was found to be not significantly different from 0. For the macroelements, the relative uncertainties RSD(u) were found to be lower than 20%. These results have demonstrated that ED-XRF is a quick and reliable method for the quantification of the listed elements in dehydrated bouillon and sauce base products. The capability to accurately measure trace elements (below 20 mg/kg), while also being able to measure a concentration of several tens of gram per 100 g of NaCl, makes ED-XRF a perfect tool to check the correct addition of premixes and also to ensure the correct claim of macroelements, respectively.

The objective of this study was to develop and validate a quick and easy method for the quantification of iron by Energy Dispersive X-Ray Fluorescence (ED-XRF) in cocoa powder and powdered cocoa drink. Pellets of 6 g were prepared under 10 tons. Total time to analyze both sides of pelletized samples is 150 s. During this validation step, the iron concentrations obtained by ED-XRF were systematically evaluated against those obtained from inductively coupled plasma-atomic emission spectrometry. This feasibility study demonstrates the good potential of ED-XRF technique as an accurate, simple, cheap and rapid method. Indeed, ED-XRF method was found to be comparable to the reference one; furthermore, the bias between both methods was found to be not significantly different from 0. Robust relative repeatabilities and intermediate reproducibilities were found to be lower than 1.5%. The expanded uncertainties represent less than 12% of the median concentration of the validation samples.

A simple and fast method for the quantification of a series of macro elements (Na, Mg, P, Cl, K and Ca) and trace elements (Mn, Fe, Cu and Zn) by Energy Dispersive X-Ray Fluorescence (ED-XRF) was developed and validated using samples of commercial dry pet foods. All samples were systematically analyzed by reference methods (i.e. Potentiometry for chloride and Inductively coupled plasma-atomic emission spectroscopy (ICP-AES) for other elements) and by ED-XRF. A calibration set of 33 samples was selected to uniformly cover the concentration ranges of each element and their reference method values were used to calibrate the ED-XRF device. A second set (the validation set) was composed of 46 other samples, which were analyzed as unknowns. During this validation step, the elemental concentrations obtained by ED-XRF were systematically evaluated against those obtained from the reference methods. Using robust statistics, for the 10 investigated analytes, the bias between both methods was found to be not significantly different from 0 and the relative uncertainties RSD(u) were found to be lower than 15 %. This study demonstrated that ED-XRF is a fast and reliable method for minerals quantification in dry pet foods.

A single-laboratory validation (SLV) and a ring trial (RT) were undertaken to determine nine nutritional elements in food products by inductively coupled plasma-atomic emission spectroscopy in order to improve and update AOAC Official Method 984.27. The improvements involved optimized microwave digestion, selected analytical lines, internal standardization, and ion buffering. Simultaneous determination of nine elements (calcium, copper, iron, potassium, magnesium, manganese, sodium, phosphorus, and zinc) was made in food products. Sample digestion was performed through wet digestion of food samples by microwave technology with either closed or open vessel systems. Validation was performed to characterize the method for selectivity, sensitivity, linearity, accuracy, precision, recovery, ruggedness, and uncertainty. The robustness and efficiency of this method was proved through a successful internal RT using experienced food industry laboratories. Performance characteristics are reported for 13 certified and in-house reference materials, populating the AOAC triangle food sectors, which fulfilled AOAC criteria and recommendations for accuracy (trueness, recovery, and z-scores) and precision (repeatability and reproducibility RSD and HorRat values) regarding SLV and RT. This multielemental method is cost-efficient, time-saving, accurate, and fit-for-purpose according to ISO 17025 Norm and AOAC acceptability criteria, and is proposed as an improved version of AOAC Official Method 984.27 for fortified food products, including infant formula.

The performances of 2 official methods for iodine analysis based on inductively coupled plasma-mass spectrometry (ICP-MS) and the ion-selective electrode (ISE) method were compared for milk-based products. The aim of the study was to determine the performance characteristics of both methods to check the labeled concentration of iodine. Good precision was found for both methods with highest relative standard deviation of repeatability (RSD(r)) at 2.3 and 2.7% for ISE and ICP-MS, respectively. Intermediate reproducibility (RSD(iR)), single laboratory within 6 different days, was also good with the highest values at 7.3 and 8% by ISE and ICP-MS, respectively. Measurement uncertainty was estimated based on the RSD(iR) data, and it was concluded that both methods were capable of determining iodine concentrations within an uncertainty below +/- 20%. The accuracy of the methods was determined by analyzing certified reference materials, in-house proficiency test samples, and commercial products. Both methods returned similar results when applied on freshly opened samples. In samples that had been opened and kept exposed to air during storage, ISE returned lower iodine concentrations than ICP-MS. In commercial samples, the linear regression between both methods was ISE = 0.95 x ICP-MS -0.060 for freshly opened samples and ISE = 0.85 x ICP-MS + 0.069 for samples exposed to air. The tendency of ISE to return lower results than ICP-MS is explained by the fact that ISE is sensitive to iodide but does not measure iodine that may be bound organically to the matrix. This seems to be more pronounced in samples that were stored longer. Because in most countries iodine is labeled as total iodine, acceptance of an international standard based on the ICP-MS technique which takes all forms of iodine into account, is recommended. This would help to avoid any potential dispute on the accuracy of labeled iodine concentrations in finished products.

Ginseng extracts are available as ingredients for improving energy and vitality and can be used in functional foods and as flavouring ingredients. A survey was been performed to determine the content of pesticides and toxic metals in ginseng extracts. Forty-seven samples from 20 suppliers, including both Panax ginseng C. A. Meyer (Asian ginseng) and P. quinquefolius (American ginseng) species, were analysed for arsenic content and for the following metals: aluminium, molybdenum, chromium, copper, magnesium, zinc, cadmium, mercury and lead, while pesticide residues were analysed in 30 samples from 17 suppliers. The results showed that 24 samples (80%) contained pesticides above the detection limit and 13 samples (43%) did not comply with the maximum residue limits (MRL) for total quintozene, hexachlorobenzene, total hexachlorocyclohexane, lindane, total heptachlor, e-chlorpyrifos and folpet, imposed for botanical extracts. Total quintozene, hexachlorobenzene, total hexachlorocyclohexane and lindane were present in all contaminated samples and exceeded the MRL in eleven samples, with levels up to 55 and 30 times their respective MRL. Cadmium (<0.05-259 microg kg(-1)), mercury (<0.3-72 microg kg(-1)), lead (3-2710 microg kg(-1)) and arsenic (<0.3-918 microg kg(-1)) were present in most samples at concentrations lower than the MRL imposed for flavouring substances. Among the other elements, aluminium (0.3-1068 mg kg(-1)) was the most abundant.

A rapid and simple method for the determination of a series of macroelements (sodium, magnesium, phosphorus, chlorine, potassium, and calcium) and trace elements (manganese, iron, and zinc) by wavelength dispersive X-ray fluorescence has been developed and validated for infant cereal matrices. Reference values were obtained by inductively coupled plasma optical emission spectroscopy and by potentiometry. The 88 investigated samples were commercially available products. Pellets of 4 g were prepared under 10 tonnes of pressure. For each sample, 3 pellets were prepared and analyzed. Limits of quantification and repeatabilities were evaluated. Calibrations were established with 43 samples, and method validation was made using a second set of 45 samples. An evaluation of this alternative method was done by comparison with data obtained from the reference methods. The results show the good performances of the alternative method to routine infant cereals analysis.

A simple and rapid method for the determination of iron, copper and zinc in food premixes (used during human food processing) by energy dispersive X-ray fluorescence (XRF) has been established and validated using 25 samples. Reference values were obtained by inductively coupled plasma-optical emission spectroscopy after microwave acidic digestions. Studied samples presenting wide ranges of concentrations: Fe=500–35000 mg/kg, Cu=50–4000 mg/kg and Zn=700–32000 mg/kg were quantified in 200 s by XRF measurements using a rhodium tube.

The application of a dynamic reaction cell inductively coupled plasma mass spectrometer (DRC ICP-MS) for interference-free Cr determination was validated for different foods. The working conditions were optimized and the method as such validated using certified reference materials and internal food samples. For the latter, reference data obtained from graphite furnace atomic absorption spectrometry (GFAAS) were used for comparison. Samples were prepared using microwave-assisted acid hydrolysis and high-pressure ashing. Both methods yielded residual carbon that leads to an over-estimation of Cr concentrations when using the ICP-MS in standard mode. The DRC however reduced this interference efficiently making accurate and precise measurements of Cr in routine samples possible. The use of the DRC was especially justified for samples that were prepared by microwave-assisted acid hydrolysis because the interference was most pronounced in those samples.

A simple and fast method for the determination of a series of analytes (sodium, magnesium, phosphorus, sulfur, chlorine, potassium, calcium, iron, zinc) in milk-based products by wavelength-dispersive x-ray fluorescence spectrometry was developed and validated. Reference values were obtained by inductively coupled plasma optical emission spectroscopy and by potentiometry for chloride. The investigated samples were commercial products obtained from various parts of the world. Pellets of 4 g were prepared under 2 t pressure. For each sample, three pellets were prepared and analysed. Limits of quantification and repeatabilities were evaluated for the described analytes. Calibrations were established with 29 samples and validation of the method was made using a second set of 29 samples. An evaluation of this alternative method was done by comparison with data from the reference methods, using robust statistics. Copyright (C) 2004 John Wiley Sons, Ltd.

Concentrations and bioavailability of cadmium (Cd) and lead (Pb) were determined in cocoa powders and related products (beans, liquor, butter) of different geographical origins. Particular attention was paid to the fractionation of these metals, which was investigated by determining the metal fraction soluble in extractant solutions acting selectively with regard to the different classes of ligands. The targeted classes of Cd and Pb species included: water-soluble compounds, polypeptide and polysaccharide complexes, and compounds soluble in simulated gastrointestinal conditions. The bioavailability of Cd and Pb from cocoa powder, liquor and butter was evaluated using a sequential enzymolysis approach. The data obtained as a function of the geographical origin of the samples indicated strong differences not only in terms of the total Cd and Pb concentrations, but also with regard to the bioavailability of these metals. The Cd concentrations in the cocoa powders varied from 94 to 1833 microg kg(-1), of which 10-50% was potentially bioavailable. The bioavailability of Pb was generally below 10% and the concentrations measured in the cocoa powders were in the 11-769 microg kg(-1) range. Virtually all the Cd and most of Pb were found in the cocoa powder after the pressing of the liquor.

An ED-XRF method for the rapid determination of a series of analytes (phosphorus, sulfur, chlorine, potassium, calcium, iron, zinc) in milk-based products has been developed and validated. The investigated samples were commercial products obtained from various parts of the world. Reference values measured by inductively-coupled plasma-optical emission spectroscopy and by potentiometry for chloride were used to calibrate the ED-XRF. Calibrations were established with 30 samples, and validation was made using a second set of 30 samples. An evaluation of this alternative method was done by comparison with data from the reference methods. Pellets of 4 g were prepared under 2 tons of pressure. For each sample, 3 pellets were prepared and analyzed. Limits of quantification and repeatabilities were evaluated for the described analytes.

Fifteen extraction methods were investigated for the recovery of different classes of Cd and Pb species in 8 different cocoa powder samples. The procedures targeted water-soluble compounds, polypeptide and polysaccharide complexes and compounds soluble in simulated gastrointestinal conditions. The extracts were analysed by size-exclusion fast-flow liquid chromatography with ICP-MS detection. The detection limit was 0.5 mug l(-1) and the RSD was less than 7.5%. Cd and Pb were very firmly bound to the insoluble matrix components, of which the binding capacity exceeded about 1000 times the naturally present metal levels. Cocoa powder may show possible detoxifying properties for Pb and Cd by binding them into stable complexes, which are resistant in gastrointestinal conditions. The maximum average recovery for Cd and Pb was, respectively, 15% and 5% of the total metal present.

An in vitro model simulating enzymatic activity in the gastrointestinal tract was developed for the assessment of the potential bioaccessibility of Cd and Pb in cocoa powder and liquor. The model was based on the sequential extraction with simulated gastric and intestinal juices; the residue after the latter extraction was further investigated by using, in parallel, solutions of phytase and cellulase. The solubility of Cd and Pb in the corresponding enzymatic extracts was measured by ICP MS. The bioaccessibility of Cd in cocoa varied from 10 to 50% in gastrointestinal conditions. An additional 20 or 30% of Cd could be recovered by phytase and cellulase, respectively. The bioaccessibility of Pb in gastrointestinal conditions did not exceed 5-10%. Only a few percent more of this metal could be recovered by extraction with phytase and cellulase.