Honey Phenolic Compound Profiling and Authenticity Assessment Using HRMS Targeted and Untargeted Metabolomics.

Honey consumption is attributed to potentially advantageous effects on human health due to its antioxidant capacity as well as anti-inflammatory and antimicrobial activity, which are mainly related to phenolic compound content. Phenolic compounds are secondary metabolites of plants, and their content in honey is primarily affected by the botanical and geographical origin. In this study, a high-resolution mass spectrometry (HRMS) method was applied to determine the phenolic profile of various honey matrices and investigate authenticity markers. A fruitful sample set was collected, including honey from 10 different botanical sources (n = 51) originating from Greece and Poland. Generic liquid-liquid extraction using ethyl acetate as the extractant was used to apply targeted and non-targeted workflows simultaneously. The method was fully validated according to the Eurachem guidelines, and it demonstrated high accuracy, precision, and sensitivity resulting in the detection of 11 target analytes in the samples. Suspect screening identified 16 bioactive compounds in at least one sample, with abscisic acid isomers being the most abundant in arbutus honey. Importantly, 10 markers related to honey geographical origin were revealed through non-targeted screening and the application of advanced chemometric tools. In conclusion, authenticity markers and discrimination patterns were emerged using targeted and non-targeted workflows, indicating the impact of this study on food authenticity and metabolomic fields.

Determination of isoascorbic acid in fish tissue by hydrophilic interaction liquid chromatography-ultraviolet detection.

A new hydrophilic interaction liquid chromatographic (HILIC) method for the simultaneous determination of isoascorbic (IAA) and ascorbic acid (AA) was developed. The separation of IAA and AA was studied in various HILIC stationary phases and the influence of the composition of the mobile phase, the ionic strength and the column temperature to the chromatographic characteristics is presented. The final method used an aminopropyl column under isocratic elution with acetonitrile-100 mM ammonium acetate solution (90:10, v/v) at a flow rate of 0.4 mL/min and a detection wavelength of 240 nm. This method was validated and the calibration curves were found to be linear in the range of 1.0-65 microg/mL for both IAA and AA. The method limit of detection for IAA determination in fish tissue was 2.3 microg/g. Inter-day precision (as %RSD(R)) was ranged between 0.56% and 8.3% at three concentration levels, whereas the respected recoveries ranged between 82% and 98%. This method was applied to the determination of IAA (as additive E315) in frozen redfish samples. The hyphenation of the HILIC separation with a tandem mass spectrometer was also studied and the problems encountered with negative electrospray ionization under HILIC separation conditions are discussed.