Original scientific paper

https://doi.org/10.24099/vet.arhiv.1619

Spectrophotometric determination of the main polyphenol groups in propolis samples from different regions of Croatia

Eleonora Perak Junaković orcid.org/0000-0003-0630-7428 ; Laboratory for VMPs, Department for Veterinary Public Health, Croatian Veterinary Institute, Zagreb, Croatia
Ksenija Šandor orcid.org/0000-0002-8730-5282 ; Laboratory for VMPs, Department for Veterinary Public Health, Croatian Veterinary Institute, Zagreb, Croatia
Anja Vujnović ; Laboratory for VMPs, Department for Veterinary Public Health, Croatian Veterinary Institute, Zagreb, Croatia
Nada Oršolić orcid.org/0000-0001-5102-3606 ; Division of Animal Physiology, Department of Biology, Faculty of Science, University of Zagreb, Zagreb, Croatia
Miroslav Andričić ; Laboratory for VMPs, Department for Veterinary Public Health, Croatian Veterinary Institute, Zagreb, Croatia
Irena Žarković orcid.org/0000-0002-3263-2024 ; Laboratory for VMPs, Department for Veterinary Public Health, Croatian Veterinary Institute, Zagreb, Croatia
Katja Vretenar Špigelski ; Laboratory for VMPs, Department for Veterinary Public Health, Croatian Veterinary Institute, Zagreb, Croatia
Dominika Fajdić ; Laboratory for VMPs, Department for Veterinary Public Health, Croatian Veterinary Institute, Zagreb, Croatia
Sonja Sinković orcid.org/0000-0001-6293-0842 ; Laboratory for VMPs, Department for Veterinary Public Health, Croatian Veterinary Institute, Zagreb, Croatia
Svjetlana Terzić ; Laboratory for VMPs, Department for Veterinary Public Health, Croatian Veterinary Institute, Zagreb, Croatia

Abstract

Spectrophotometric procedures for the rapid characterization of propolis have been performed on propolis samples from different regions of Croatia. In order to determine the major groups of bioactive compounds in propolis, the following optimised and validated spectrophotometric methods were carried out: the Folin-Ciocalteu method for the content of total phenolics (TPs) and two distinct methods for the content of total flavonoids: aluminium chloride (AlCl3 ) complexation method for total flavones/flavonols (TFFs) and the 2.4-dinitrophenylhydrazine (2.4-DNPH) method for total flavanones/dihydroflavonols (TFDs). Validation parameters, including linearity, sensitivity, range, accuracy, limit of detection, limit of quantification, precision and robustness were implemented. The following polyphenol standards were used for the validation procedure: gallic acid (GA), pinocembrin (PC), galangin (GN), quercetin (QC) and a mixture of PC and GN. Validated methods were applied to analyse six samples of raw propolis from Croatian continental and Adriatic regions. The high qualitative/quantitative variability of the TP, TFF and TFD content was observed. Although the method of extraction (ultrasonic-assisted extraction or microwave assisted extraction) showed a non-significant effect on extraction yield (P>0.05) and the polyphenolic concentrations obtained of each sample in general, ultrasonic extraction was found to be more selective. Furthermore, the calibration compound used for constructing the calibration curve highly influenced the final concentrations of TPs and TFFs. The study showed good linearity, accuracy, repeatability, intermediate precision, LOD and LOQ for all three spectrophotometric methods, considering that these analyses are the basis for further research into the individual polyphenolic compounds in the propolis samples covered by this research.

Keywords

raw propolis; polyphenols; ultrasonic-assisted extraction; microwave-assisted extraction; spectrophotometric determination; validation

Hrčak ID:

305651

URI

https://hrcak.srce.hr/305651

Publication date:

25.6.2023.

Article data in other languages: croatian

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