The olive tree is an evergreen tree cultivated for thousands of years throughout the Mediterranean basin, which represents the largest international olive growing area. The European Union holds the record in terms of olives and olive oils production, consumption, and exportation. Extra virgin olive oils are particularly important for the national agroindustrial sector, for the aspects related to the production territory (authenticity), and for the link with the Mediterranean Diet. However, at the same time, because of economical purposes, it is also one of the products most subjected to adulteration. The determination of the multi-elemental profile of extra-virgin olive oils has aroused increasing interest in the scientific community due to its possible application in geographical traceability studies. The determination of the multi-elemental profile in extra-virgin olive oil is, however, one of the most difficult analytical challenges, due to the high viscosity of the matrix, high organic load increasing the matrix effect and the possibility of interferences. Furthermore, the extremely low concentration of elements makes it extremely susceptible to contamination during pre-treatment of the sample. Analysis of existing literature has revealed that microwave digestion (with HNO3 and sometimes with the addition of H2O2) and ultrasound-assisted extraction are the sample pre-treatment procedures most widely used. However, some authors highlighted that the elemental content variability in different samples, even with the same geographical origin, can also be influenced by the different pre-treatment techniques. To overcome these difficulties, a method for the analysis of the multielemental profile of extra virgin olive oils was developed using HR ICP-AES PlasmaQuant 9100 equipped with an organic kit sample introduction system. This new method allows to directly analyse the extra virgin olive oil without the need for mineralization or extraction. Extra virgin olive oils, in fact, are only diluted in solvents with low viscosity before direct aspiration. This "dilute and shoot" approach offers the advantage of less sample preparation and handling, significantly reducing the risk of sample handling errors.

The quality of coffee is affected by the amount of oxygen present in the packaging. A maximum oxygen content is authorized to avoid oxidation of coffee during the shelf life, which would lead to off-taste in coffee cup. Oxygen content in the packaging can be measured by Fluorescent Decay, as described in ASTM F2714-08 (2021). However, this is only possible for transparent packaging. If it is not the case, direct sampling in the packaging is necessary. This requires a minimum amount of headspace in the pack. This minimum amount is defined by the oxygen sensor technology. In the case of limited headspace, gas chromatography is one of the promising options because of the limited amount of gas sample required but also because of the high accuracy and good precision of the tool. Development of any alternative packaging goes along with oxygen barrier measurement. At the production level, oxygen barrier properties might also need to be monitored for quality purposes. In this contribution, we propose to discuss a novel method for the determination of oxygen content in new coffee packaging by considering the challenges of new materials and measurements in production environment (at-line tool) i.e robustness of the material, time of the analysis and cost, repeatability of the measurement... Our contribution proposes a new way of sampling from the packaging when direct sampling gives unsatisfying results especially when low amount of oxygen needs to be measured in classical ambient environment. Together with a micro-GC, a sampling station connected to vacuum and a home-made hermetic chamber to isolate the sample from the environment. The sampling process is in two steps. Gas sampling being destructive, special care has been given to improve trueness and robustness of the measurement. Moreover, the proposed solution is a plug and play on actual set-up and does not require modification of existing set-ups. Finally, the measurement uncertainty has been evaluated based on the different components of the measurement chain. The results demonstrated that the proposed method was reliable and accurate with a detection limit of 0.1% oxygen. Furthermore, the method was found to be highly reproducible and showed excellent stability over time.

Food colorants are applied in commercial products and domestic cooking to enhance the appearance of food. To obtain specific hues, inorganic food additives containing (nano)particles are mixed in varying concentrations, and pearlescent pigments consisting of mica platelets coated with a layer of titanium dioxide and/or iron oxide particles, are applied to provide glitter effects1 . For assessing potential risks of multi-constituent substances and mixtures, characterisation of the fraction of small particles, including the particle size distribution, is needed for each single constituent or each component in the mixture2 . This is challenging for control laboratories and only limited guidance is currently available3 . This study developed electron microscopy-based methods to identify and characterize the particles of individual components in eight commercially available food-decoration sprays of different colours, containing mixtures of food additives and pearlescent pigments. No dispersion protocols or purifications steps were applied so as to faithfully reproduce the properties of the particles consumers are exposed to. Samples were prepared by spraying 5 mL in a glass vial and coated on EM-grids using the grid-on-drop method. Scanning transmission electron microscopy (STEM) combined with energy dispersive X-ray spectroscopy (EDX) allowed identifying individual components, including potassium aluminium silicate-based pearlescent pigments, vegetable carbon, rutile titanium dioxide, iron oxide and aluminium containing (nano)particles by their elemental composition. Their presence and relative concentration varied among the different spray colours. Often the layer of titanium dioxide particles detached from the mica substrate, and titanium dioxide particles were also observed forming nearspherical aggregates. STEM-EDX tomography allowed identifying particles of overlapping components and examining the structure of the pearlescent pigments in 3D. The presence of a fraction of nanoparticles in each component was demonstrated based on their number-based particle size distributions. The methods and findings support regulatory bodies in assessing potential health risks of mixtures of (nano)particles used in food-related applications.

A simple, fast and a robust method for routine speciation analysis of inorganic (Hg2+) and methylmercury (MeHg) by reverse phase (RP) high-performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC-ICP-MS) was optimized and validated. This novel method is to be applied for the analysis of a large panel of foodstuffs samples within the framework of the 3rd (French) total Diet Study (3rd TDS). TDSs are endorsed by the World Health Organisation (WHO) and Food and Agriculture Organization of the United Nations (FAO) and they are one of the most efficient tools for national assessment of chemical contamination of food prepared as consumed. This allows estimating human dietary exposure after matching contamination data (occurrence) with the consumption patterns based on samples representativeness. TDSs provide valuable scientific information to national authorities in order to address the risk for the general population in terms of food chemical hazards and permitting to protect the public health on a long-term basis. An effective separation of Hg2+ and MeHg species was achieved in less than 7 min using a peptide mapping RP column. The development was carried out using an experimental design for the HPLC separation and the sample extraction. In the latter case, two extraction approaches, employing a closed microwave system and the use of a heating block, respectively, were compared. The method was validated based on the accuracy profile approach according to the NF V03-110 French standard, which takes into account the simultaneous assessment of the accuracy and precision of the method. The accuracy profile is an expression of the combination of the systematic (trueness) and the random error (repeatability and/or intermediate precision) for a series of analyst's levels in various matrices in range of concentrations called validity domain. For this purpose, five measurement series were repeated in duplicate on (5) different days, over a timespan of two months for constructing the accuracy profile. The method was applied to the speciation analysis of MeHg and Hg2+ in a variety of foodstuffs of the 3rd(French) Total Diet Study

Trace elements can occur in food because of their presence in the environment, due to human activities or contamination during storage and food processing, including cooking.
There are various ways of cooking (boiling, grilling, frying, etc.) and each of them can affect differently the elements' content. This may lead to a decrease or an increase in element concentration, or even to a transformation of the species. Therefore, to better assess people's exposure to these contaminants and avoid or reduce harmful human effects, it is important to know the fate of the elements and their species in food during cooking.
For this work, we conducted various studies and implemented different approaches to evaluate the impact of cooking on (i) arsenic (As), lead (Pb) and cadmium (Cd) in whelks (ii), total arsenic and inorganic arsenic (iAs) in rice and (iii) total chromium (Cr), Cr(III) and Cr(VI) in milk and meat. For the total elements' determination, analyses were carried out by inductively coupled plasma-mass spectrometry (ICP-MS). For the speciation analyses, high performance liquid chromatography (HPLC) coupled to ICP-MS alone or in combination with species-specific isotope dilution (ID) was implemented. This latter technique allows also to assess possible interconversions of Cr species due to foodstuffs cooking. Results obtained show that boiling was the cooking method with the highest impact on the elements' content, especially for As and iAs with a significant concentration decrease in cooked samples (rice and whelks). On the other hand, the culinary treatments employed for meat and milk samples (heating and frying) did not induce significant differences on total Cr and Cr species levels between raw and cooked samples. Thanks to the IDICP-MS approach used, we demonstrated that a total reduction of Cr(VI) to Cr(III) occurred in the samples but that this was due to the sample preparation (extraction) and not to the cooking process.