Oligomers: Hidden sources of bisphenol A from reusable food contact materials.

A recent European Regulation further restricted the use of bisphenol A in food-contact materials, reducing its limit of migration. However, all analytical systems of control are aimed at identifying and quantifying the molecules of this monomer without taking in consideration the possible presence of its oligomers, species originating from material degradation and able to follow an in-vivo hydrolysis providing bisphenol A generation. Thus, the presence of oligomers of polycarbonate deriving by unreacted species or polymer degradation can be considered a hidden source of several bisphenol A units, that remains outside the control of legislation and should be considered of high concern. This work was focused on the identification and the description of kinetics of release of different molecules migrating from polycarbonate food contact materials to simulants and to a model food sample such as melted chocolate. Analyses were performed by UHPLC system coupled to a Q-Exactive mass spectrometer. Targeted and untargeted analysis through data dependent acquisition mode allowed to detect the occurrence of several species deriving from polycarbonate, and permitted to investigate the polymer degradation pattern and explore the correlation of the recorded amounts of each product with age, hours of usage, and washing cycles of the plastic items.

Optimization of mass spectrometry acquisition parameters for determination of polycarbonate additives, degradation products, and colorants migrating from food contact materials to chocolate.

The interest towards "substances of emerging concerns" referred to objects intended to come into contact with food is recently growing. Such substances can be found in traces in simulants and in food products put in contact with plastic materials. In this context, it is important to set up analytical systems characterized by high sensitivity and to improve detection parameters to enhance signals. This work was aimed at optimizing a method based on UHPLC coupled to high resolution mass spectrometry to quantify the most common plastic additives, and able to detect the presence of polymers degradation products and coloring agents migrating from plastic re-usable containers. The optimization of mass spectrometric parameter settings for quantitative analysis of additives has been achieved by a chemometric approach, using a full factorial and d-optimal experimental designs, allowing to evaluate possible interactions between the investigated parameters. Results showed that the optimized method was characterized by improved features in terms of sensitivity respect to existing methods and was successfully applied to the analysis of a complex model food system such as chocolate put in contact with 14 polycarbonate tableware samples. A new procedure for sample pre-treatment was carried out and validated, showing high reliability. Results reported, for the first time, the presence of several molecules migrating to chocolate, in particular belonging to plastic additives, such Cyasorb UV5411, Tinuvin 234, Uvitex OB, and oligomers, whose amount was found to be correlated to age and degree of damage of the containers.

Correlation between different markers for the assessment of red chilli pepper powders stability during shelf-life.

Pungency and red colour of Capsicum powders deteriorate during processing and storage, resulting in a decrease in market value. Two varieties of pepper with different pungencies were monitored for capsaicinoids, colour and furosine. Aliquots were stored at room and at low temperature during one year. At low temperature all indicators were stable in both varieties, while at room temperature, redness and capsacinoids decreased significantly, while furosine increased. High correlation was found between those markers. The more pungent variety exhibited higher stability in terms of all parameters. Differences observed suggest a potential protective effect exerted by capsaicinoids on powder stability. The decrease in capsaicinoids and redness accompanied by furosine increase showed a linkage between those markers never reported before. Considering that capsaicinoids and furosine occurrence have strong impact on the nutritional profile, the findings of this work show relevant changes in the nutritional value of chilli pepper powder after storage.

UHPLC-high-resolution mass spectrometry determination of bisphenol A and plastic additives released by polycarbonate tableware: influence of ageing and surface damage.

A new UHPLC-ESI-Orbitrap method for the identification and the quantitative determination of bisphenol A and some common additives employed in plastic manufacturing has been developed and validated. The method has been applied to evaluate the migration from 14 samples of tableware of different age and degree of surface damage, in both ethanol and isooctane (used as food simulants according to EU plastic regulation). Bisphenol A, three UV light absorbers, and one whitening agent were detected and quantified. Data were analyzed with the aim of exploring a possible correlation between bisphenol A and additives release, ageing, and surface integrity. A high correlation between age of samples, surface damage, and bisphenol A migration has been evaluated, while the release of additives was not correlated with other parameters. Obtained data showed for the first time that the release of bisphenol A seems to be more connected to ageing than to scratches and cracks occurrence. Graphical Abstract Bisphenol A and additives released by polycarbonate tableware: influence of ageing and surface damage.

Targeted and untargeted data-dependent experiments for characterization of polycarbonate food-contact plastics by ultra high performance chromatography coupled to quadrupole orbitrap tandem mass spectrometry.

Materials that come in contact with foods are potential sources of chemical food contamination. Consequently, characterization of their composition is of paramount importance considering the possible occurrence of several unknown molecules such as non-intentionally added substance (NIAS), residual monomers, degradation products, plastic additives and organic colorants. Previous studies concerning the characterization in terms of composition are focalized in the recognition of additives. To the best author's knowledge there are no scientific data about the composition of a plastic material in terms of colorants. In this work, an analytical method employing capillary ultra high-performance liquid chromatography and electrospray ionization quadrupole orbitrap high-resolution mass spectrometry (UHPLC-ESI Q-orbitrap) was exploited for characterization of polycarbonate for food contact material. Data-dependent experiments for targeted and untargeted analysis were employed after a total dissolution of polycarbonate samples and extraction of its components. The presence of common additives such as antioxidants and UV absorbers was confirmed by targeted analysis, while, the untargeted approach combined with the high mass accuracy of orbitrap technology allowed to identify for the first time some polycarbonate degradation products and the organic dyes effectively used for the coloration of plastic objects intended to come in contact with food. The present study shows the high potential of this technique in the field of material characterization aimed at food safety evaluation.

Evaluation of thermal treatment markers in wheat flour-derived products cooked in conventional and in low-emissivity ovens.

Different markers for the assessment of thermal treatment entity of food products were investigated on a model bread prepared from wheat flour. Samples were submitted to different cooking procedures by combining three different times and temperatures, and employing two different ovens: a low-emissivity oven and a conventional one. The cook value index was calculated for each sample to evaluate the entity of the thermal treatment. Furosine, maltose:maltulose ratio, colour indexes (L, a, b) have been evaluated in all samples. Furosine has been quantified by capillary electrophoresis-mass spectrometry, maltose:maltulose ratio was determined by HPAEC-PAD, colour indexes were measured by spectrophotometer method. Values for weight loss during cooking and surface temperature have also been monitored. A statistical analysis showed good correlation between the cook value index and all the parameters evaluated. Low emissivity oven shown higher performances and lower energy consumption than conventional oven.

Characterization of 12 Capsicum varieties by evaluation of their carotenoid profile and pungency determination.

In this research 12 different varieties of Capsicum cultivars belonging to three species (Capsicum chinense, Capsicum annuum, Capsicum frutescens) and of various colour, shape, and dimension have been characterised by their carotenoids and capsaicinoids content. The berries were cultivated in the region Emilia-Romagna, in Northern Italy. The native carotenoid composition was directly investigated by an HPLC-DAD-APCI-MS methodology, for the first time. In total, 52 carotenoids have been identified and considerable variation in carotenoid composition was observed among the various cultivars investigated. Among the cultivars with red colour, some Habanero, Naga morich and Sinpezon showed an high ß-carotene content, whereas Serrano, Tabasco and Jalapeno showed an high capsanthin content and the absence of ß-carotene. Habanero golden and Scotch Bonnet showed a high lutein, α-carotene and ß-carotene amounts, and Habanero orange was rich in antheraxanthin, capsanthin and zeaxanthin. Cis-cryptocapsin was present in high amount in Habanero chocolate. The qualitative and quantitative determination of the capsaicinoids, alkaloids responsible for the pungency level, has also been estimated by a validated chromatographic procedure (HPLC-DAD) after a preliminary drying step and an opportune extraction procedure. Results have also been expressed in Scoville units. Dry matter and water activity have also been established on the fresh berries. The dried peppers of each variety were then submitted to the evaluation of the total nitrogen content, measured by a Dumas system, permitting to provide information on the protein content that was found to be in the range between 7 and 16%.

Determination of furosine in food products by capillary zone electrophoresis-tandem mass spectrometry.

A new method for qualitative and quantitative analysis of furosine in food products by capillary electrophoresis coupled to tandem mass spectrometry (CE-MS(2) ) has been optimized and validated. In analytical conditions, the pH value of the run buffer was similar to that of the hydrolyzed samples, which helps in avoiding interactions of the analyte with silanol groups of the inner wall of the fused silica capillary. In all previous CE methods proposed in literature, no SPE treatment has been used. The method has been applied to the analysis of food products, such as flour, having low amounts of furosine. Flour samples of different origin (wheat, chestnut, lupin, einkorn, chickpeas) have been investigated. Different food products such as pasta, milk, and tigelle bread (a typical Italian unleavened bread) were also analyzed. Some of the samples have also been analyzed by reversed-phase HPLC, and when compared to CE-MS, data obtained showed good agreement. CE-MS, in comparison to HPLC, showed advantages in terms of time of analysis and cost. The validation procedure provided good values for LOD and LOQ (respectively 0.07 and 0.25 mg L(-1) ), recovery (77 and 97%), and precision investigated in terms of intraday repeatability (RSD%: 4-6% for peak areas; 1-2% for migration times) and intermediate precision (below 16% for peak areas, and below 7% for migration times). Therefore, the technique reported can be proposed as a powerful analytical method and a valid alternative to common traditional analytical techniques.

Rapid shotgun proteomic liquid chromatography-electrospray ionization-tandem mass spectrometry-based method for the lupin ( Lupinus albus L.) multi-allergen determination in foods.

Allergy to lupin is a growing food safety problem because this legume, increasingly exploited in the food industry, is one of the allergens that, according to law, must be declared on the labels of food products in the European Union. In this context, a rapid targeted proteomic approach based on liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) analysis was proposed and aimed to unequivocal confirmation and reliable determination of the major lupin allergens, i.e., conglutins, in pasta and biscuits. Detected concentrations were around 1 mg of lupin/kg of pasta and biscuits, proving the capabilities of the MS-based method in terms of the sensitive allergen screening method. Good precision was observed in terms of both intra- and interday repeatability, with relative standard deviation (RSD) lower than 23%. Recoveries from 95 ± 10 to 118 ± 12% and from 103 ± 1 to 110 ± 12% ranges were calculated for biscuits and pasta, respectively. Finally, the applicability of the devised method was investigated by analyzing market samples containing lupin and samples that may possibly contain traces of lupin deriving from cross-contamination between products and production lines.

Copper binding agents acting as copper ionophores lead to caspase inhibition and paraptotic cell death in human cancer cells.

We report a quantitative structure-activity relationship study of a new class of pyrazole-pyridine copper complexes that establishes a clear correlation between the ability to promote copper accumulation and cytotoxicity. Intracellular metal accumulation is maximized when ligand lipophilicity allows the complex to rapidly cross the membrane. Copper and ligand follow different uptake kinetics and reach different intracellular equilibrium concentrations. These results support a model in which the ligand acts as an ionophore for the metal ion, cycling between intra- and extracellular compartments as dissociated or complexed entities. When treating cancer cells with structurally unrelated disulfiram and pyrazole-pyridine copper complexes, as well as with inorganic copper, the same morphological and molecular changes were reproduced, indicating that copper overload is responsible for the cytotoxic effects. Copper-based treatments drive sensitive cancer cells toward paraptotic cell death, a process hallmarked by endoplasmic reticulum stress and massive vacuolization in the absence of apoptotic features. A lack of caspase activation, as observed in copper-treated dying cells, is a consequence of metal-mediated inhibition of caspase-3. Thus, copper acts simultaneously as an endoplasmic reticulum (ER) stress inducer and a caspase-3 inhibitor, forcing the cell into caspase-independent paraptotic death. The establishment of a mechanism of action common to different copper binding agents provides a rationale for the exploitation of copper toxicity as an anticancer tool.

Particle-packed column versus silica-based monolithic column for liquid chromatography-electrospray-linear ion trap-tandem mass spectrometry multiallergen trace analysis in foods.

A bicarbonate buffer-based extraction method for the simultaneous analysis of five nut allergens (Ana o 2, cashew-nut; Cor a 9, hazelnut; Pru 1, almond; Ara h3/4, peanut; Jug r 4, walnut) in cereals and biscuits using liquid chromatography-electrospray-linear ion trap-tandem mass spectrometry (LC-ESI-LIT-MS(2)) was developed and validated. The method was based on our earlier published LC-MS(2)-based method in a research frame aimed at the identification and determination of hidden allergens in foods by using selective biomarker peptides. A C18 particle-packed column and a silica-based C18 monolithic column were compared in terms of chromatographic performances, such as peak shape, resolution, analysis time and selectivity. The C18 particle-packed column exhibited better performances and was further used for method development and validation. By operating under MS(2) selected reaction monitoring (SRM) acquisition mode, linearity, limits of detection (LOD) and quantitation, trueness and precision were evaluated on breakfast samples enriched with a mix of the five nuts. Good linearity of the matrix matched-calibration curves was obtained and detection limit values generally varied from 14 to 55 mg nut/kg matrix. Recoveries were in the 76±4% to 94±3% range with RSD <15%. The capabilities of LIT to perform MS(n) fragmentation was exploited to improve selectivity of the analysis, and the LC-(SRM) MS(2) method was compared in terms of LOD, linearity, precision and accuracy with a LC-(SRM) MS(3) method. Finally, both the LC-MS(2) and LC-MS(3) methods were successfully applied to the analysis of nut traces in commercially available breakfast cereals and biscuits.