The potential of right-angle fluorescence spectroscopy and selected chemical parameters for discrimination of botanical origin of Croatian honey types (n = 55) previously classified by physicochemical and melissopalynological analyses was evaluated. Systematic step-by-step fluorescence analysis included the measurement of complete excitation-emission matrix (EEM) in the range of excitation wavelengths from 260 to 400 nm, and emission wavelengths from 300 to 600 nm, followed by fluorescence intensity measurement at detected peaks of different excitation/emission wavelengths, and emission spectra recordings at selected specific excitation wavelengths of honey solutions in 50 mmol L−1 phosphate buffer pH 7.0 and methanol. A total of five different sets of emission spectral data for buffer and two for methanolic honey solutions were considered for chemometric analysis of original and normalized emission spectra including principal component analysis and linear discriminant analysis. Additionally, chemical analysis of buffer and methanolic honey solutions included determination of protein, total polyphenol and reactive amino group content. Results showed that right-angle fluorescence spectroscopy of honey solutions has great potential for honey botanical origin discrimination, either by visual comparison of excitation-emission spectra landscapes, or even better, by normalized emission fluorescence spectra recordings at 260 and 280 nm of excitation. Moreover, increased honey discrimination was achieved in conjunction with chemometrics of fluorescence spectras. In addition, two rapid markers/indicators of honey authentication were found. Chestnut honey could be clearly discriminated from the other honey types by simple measurement of fluorescence intensity at 390/470 nm, while sage honeys by measurement of reactive amino group content.
Characterization Chemometrics Chemical analysis Honey Right-angle fluorescence Reactive amino group content
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Conflict of Interest
Ivica Strelec declares that he has no conflict of interest. Lidija Brodar declares that she has no conflict of interest. Ivana Flanjak declares that she has no conflict of interest. Frane Čačić Kenjerić declares that he has no conflict of interest. Tihomir Kovač declares that he has no conflict of interest. Daniela Čačić Kenjerić declares that she has no conflict of interest. Ljiljana Primorac declares that she has no conflict of interest.
This article does not contain any studies with human participants or animals performed by any of the authors.
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