In this study, the extraction efficiency of natural deep eutectic solvents (NADES) based on choline chloride as a hydrogen bond acceptor (HBA) and five different hydrogen bond donors (HBD; lactic acid, 1,4-butanediol, 1,2-propanediol, fructose and urea) was evaluated for the first time for the isolation of valuable bioactive compounds from Achillea millefolium L. The phytochemical profiles of NADES extracts obtained after ultrasound-assisted extraction were evaluated both spectrophotometrically (total phenolic content (TPC) and antioxidant assays) and chromatographically (UHPLC-MS and HPLC-UV). The results were compared with those obtained with 80% ethanol, 80% methanol, and water. The highest TPC value was found in the lactic acid-based NADES (ChCl-LA), which correlated with the highest antioxidant activity determined by the FRAP analysis. On the other hand, the highest antiradical potential against ABTS^+• was determined for urea-based NADES. Phenolic acids (chlorogenic acid and dicaffeoylquinic acid isomers), flavones (luteolin and apigenin), and their corresponding glucosides were determined as the dominant individual phenolic compounds in all extracts. The antibacterial and antifungal properties of the extracts obtained against four bacterial cultures and two yeasts were evaluated using two methods: the agar dilution method to obtain the minimum inhibitory concentration (MIC) and the minimum bactericidal or fungicidal concentration (MBC or MFC), and the disc diffusion method. ChCl-LA had the lowest MIC and MBC/MFC with respect to all microorganisms, with an MIC ranging from 0.05 mg mL⁻¹ to 0.8 mg mL⁻¹, while the water extract had the weakest inhibitory activity with MIC and MBC/MFC higher than 3.2 mg mL⁻¹.

In the present study, the potential of elemental analysis combined with statistical tools to identify honey origin was evaluated by mineral characterization of 173 honeys of 13 floral types (acacia, fir, spruce, linden, chestnut, lavender, coriander, thistle, honeydew, rosemary, sage, euphorbia and ziziphus plant species) collected from five geographical regions (Slovenia, Croatia, Bulgaria, Turkey, and Morocco). The objective of the study was to accurately and reliably differentiate the mineral composition among honey varieties. The aim was to establish traceability, to ensure product authenticity and to improve quality control measures within the honey industry. For this purpose, 18 major, minor and trace elements were quantified using microwave digestion, followed by ICP-MS measurement. Statistical evaluation of elemental concentration was undertaken using principal component analysis (PCA) to distinguish honey floral types. The research give light on the specific elements that can serve as indicators for determining the geographical and botanical source of honey. Our findings indicate that certain elements, such as Mn, K, and Ca, are primarily influenced by the type of pollen present in the honey, making them indicative of the floral source. On the other hand, levels of Na, Mg, and Fe were found to be more strongly influenced by environmental factors and can be considered as markers of geographical origin. One novel aspect of this research is the exploration of the relationship between honey minerals and honey botanical source. This was achieved through the analysis of chestnut tree samples and a subsequent comparison with the composition of chestnut honey.

A new method for determination of underivatized biogenic amines in cheese based on ion exchange chromatography coupled with tandem mass spectrometric detection was proposed. The method was applied to the analysis of 10 biogenic amines (trimethylamine, putrescine, cadaverine, histamine, 2-phenylethylamine, spermine, spermidine, tryptamine, agmatine, and tyramine) in different types of cheese. The amines were extracted only with water without any additional derivatization step or sample cleanup. This is a great advantage in terms of simplicity of sample pretreatment procedure compared with other currently existing methods in the literature. Biogenic amines were separated using cation exchange column, under gradient elution conditions by mixing formic acid (1.00 M) and deionized water. Detection was achieved using tandem MS/MS, with the instrument set into multiple reaction monitoring mode to ensure high specificity. The detection and quantification limits were in the ranges of 12–46 μg/L and 40–153 μg/L, respectively. The exceptions were spermidine and spermine, with detection limits of 0.8 and 5.4 mg/L, respectively. The linearity for most of the biogenic amines was from 10 μg/L up to 10 mg/L. The best recoveries were observed for trimethylamine, tyramine, and cadaverine, and were 89, 94, and 102%, respectively. The results showed that this method can be used for routine determination of biogenic amines in different types of cheeses as well other food matrices. It must be stressed that the proposed method is capable of determining 10 biogenic amines, including tyramine, which is reported to cause food intoxication commonly associated with cheeses.

A new method was proposed for the determination of underivatized biogenic amines based on ion-exchange chromatography coupled with mass spectrometry detection. The method was applied to the analysis of 10 biogenic amines in fresh and processed fish products. The amines were extracted from muscle tissue with water without any additional derivative step or sample clean-up. Separation of biogenic amines was done by the IonPac (4 × 50 mm) column, applying a gradient eluent by mixing formic acid (2 mol L⁻¹) and Milli-Q water (formic acid concentration from 400 mM to 2 M). The results demonstrated a linear response in the range of 0.01 to 10 mg L⁻¹. The detection limits for the fish products ranged from 20 ng/g up to around 400 ng/g for histamine and putrescine, respectively. Spermidine and spermine showed significantly higher detection limits. This current method can be used for the determination of biogenic amines in both fresh and processed fish products for regulatory purposes and monitoring food-safety issues relating to these amines, particularly histamine. It is also a useful method for evaluation of other commercial analytical test kits and commonly used methods that are possibly affected by the food matrix due to processing or other drawbacks arising from the derivatization process.

In this study, comparative analyses were carried out with ion chromatography mass-spectrometry (IC-MS/MS) which has no derivatization step, high-performance liquid chromatography (HPLC) technique, as well as two quantitative and two semi-quantitative immunoassays. The results demonstrated that HPLC and quantitative immunoassay methods were well-correlated with IC-MS/MS in determining histamine in various types of fish products. The best correlation was observed with the HistaSure ELISA Fast Track kit (R² = 0.9903). More than half of the values (68%) obtained by two methods were also statistically similar. The results of semi-quantitative test kits also supported histamine values estimated by quantitative methods, with some exceptions. The best results were found for HistaSure Lateral Flow in supporting the quantitative techniques. Therefore, these methods are found suitable for monitoring histamine in fish products in terms of food safety. Good correlations were also observed HPLC and IC-MS/MS in determining cadaverine, putrescine, and tyramine with the highest value observed for tyramine as R² = 0.9785. However, no correlation was observed for other biogenic amines, and the majority of the results were significantly different from each other for these amines (p < 0.05). The differences may be caused by the drawbacks reported previously for HPLC. However, further studies are required to confirm the possible effects. This study provides a comparative evaluation of several methods in terms of their suitability in determining biogenic amines in fish products for both monitoring and regulatory purposes.