Development and validation of an analytical methodology based on solvent microextraction and UHPLC-MS/MS for determining bisphenols in honeys from different botanical origins

A new analytical methodology was proposed to determine fourteen bisphenols in honeys from different botanical origins using ultra-high performance liquid chromatography-tandem mass spectrometry. A fast, efficient, environmentally-friendly and simple sample treatment (recoveries between 81% and 116%; matrix effect <20% for all studied compounds except for bisphenol E, F and S) was proposed, which involved a solvent microextraction with acetone and a small volume/amount of 1-hexanol. Chromatographic analysis (< 15 min) was performed in a Kinetex EVO C18 column under gradient elution mode. The method was validated in terms of selectivity, limits of detection (0.2-1.5 μg/kg) and quantification (0.5-4.7 μg/kg), linearity, matrix effect, trueness, and precision (relative standard deviation <17%). Finally, thirty honey samples were analyzed, revealing the presence of residues of nine bisphenols in some of them. However, quantification was possible only in two cases for bisphenol A, with a concentration of approximately 13 μg/kg.

Free amino acid profile in Mimosa scabrella honeydew honey from Brazil and chemometric analysis for geographical discrimination

In this study, twenty free amino acids (FAA) were investigated in samples of bracatinga (Mimosa scabrella) honeydew honey (BHH) from Santa Catarina (n = 15) and Paraná (n = 13) states (Brazil), followed by chemometric analysis for geographic discrimination. The FAA determination was performed by gas chromatography-mass spectrometry (GC-MS) after using a commercial EZ:faast™ kits for GC. Eight FAA were determined, being proline, asparagine, aspartic and glutamic acids found in all BHH, with significant differences (p < 0.05). In addition, with the exception of proline, the others FAA (asparagine, aspartic and glutamic) normally showed higher concentrations in samples from Santa Catarina state, being that in these samples it was also observed higher FAA sums (963.41 to 2034.73 mg kg-1) when compared to samples from Paraná state. The variability in the results did not show a clear profile of similarity when the heatmap and hierarchical grouping were correlated with the geographic origin and the concentration of eight determined FAA. However, principal component analysis (PCA) demonstrated that serine, asparagine, glutamic acid, and tryptophan were responsible for the geographic discrimination among samples from Santa Catarina and Paraná states, since they were the dominant variables (r > 0.72) in the PCA. Therefore, these results could be useful for the characterization and authentication of BHH based on their FAA composition and geographic origin.

MONITORING CHANGES IN THE VOLATILE FRACTION OF ROASTED NUTS AND SEEDS BY USING COMPREHENSIVE TWO-DIMENSIONAL GAS CHROMATOGRAPHY AND MATRIX TEMPLATES

Static headspace coupled with comprehensive two-dimensional gas chromatography and a flame ionization detector (HS-GC × GC-FID), has been applied to monitor changes in the volatile fraction of commercial edible nuts and seeds (peanuts, almonds, hazelnuts, and sunflower seeds). Effects of the roasting conditions (time, 5-40 min; temperature, 150-170 °C), which were employed under different combinations by using a ventilated oven, on target volatile fraction were examined to identify potential differences in relation to the roasting treatment of raw samples. In addition, reference templates were created, from the HS-GC × GC-FID method, for each of the four food matrices analyzed, and they were applied to characterize the samples according to the presence or absence of volatile compounds. Finally, these templates were successfully employed to make a quick distinction between different roasting conditions.•HS-GC × GC-FID was applied to study the volatile profile of edible nuts and seeds.•Reference templates (GC × GC-FID) were created for each of the four food matrices.•Rapid discrimination between raw and roasted samples was achieved.

Fast Chromatographic Determination of Free Amino Acids in Bee Pollen

The consumption of bee pollen has increased in the last few years due to its nutritional and health-promoting properties, which are directly related to its bioactive constituents, such as amino acids. Currently, there is great interest in understanding the role of these in bee products as it provides relevant information, e.g., regarding nutritional value or geographical and botanical origins. In the present study, two fast chromatographic methods were adapted based on commercial EZ:faast™ kits for gas chromatography-mass spectrometry and liquid chromatography−mass spectrometry for determining free amino acids in bee pollen. Both methods involved the extraction of amino acids with water, followed by a solid phase extraction to eliminate interfering compounds, and a derivatization of the amino acids prior to their chromatographic separation. The best results in terms of run time (<7 min), matrix effect, and limits of quantification (3−75 mg/kg) were obtained when gas chromatography−mass spectrometry was employed. This latter methodology was applied to analyze several bee pollen samples obtained from local markets and experimental apiaries. The findings obtained from a statistical examination based on principal component analysis showed that bee pollen samples from commercial or experimental apiaries were different in their amino acid composition.