NMR Profiling of North Macedonian and Bulgarian Honeys for Detection of Botanical and Geographical Origin

Abstract

Bulgaria and North Macedonia have a long history of the production and use of honey; however, there is an obvious lack of systematic and in-depth research on honey from both countries. The oak honeydew honey is of particular interest, as it is highly valued by consumers because of its health benefits. The aim of this study was to characterize honeydew and floral honeys from Bulgaria and North Macedonia based on their NMR profiles. The 1D and 2D 1H and 13C-NMR spectra were measured of 16 North Macedonian and 22 Bulgarian honey samples. A total of 25 individual substances were identified, including quinovose, which was found for the first time in honey. Chemometric methods (PCA—principal component analysis, PLS-DA—partial least squares discriminant analysis, ANOVA—analysis of variance) were used to detect similarities and differences between samples, as well as to determine their botanical and geographical origin. Semiquantitative data on individual sugars and some other constituents were obtained, which allowed for the reliable classification of honey samples by botanical and geographical origin, based on chemometric approaches. The results enabled us to distinguish oak honeydew honey from other honey types, and to determine the country of origin. NMR was a rapid and convenient method, avoiding the need for other more time-consuming analytical techniques.

A Preliminary Study of Chemical Profiles of Honey, Cerumen, and Propolis of the African Stingless Bee Meliponula ferruginea

“…However, our findings, being among the first concerning African stingless bees, demonstrated the importance of studies of the products of African Meliponini. The honey chemical composition was studied by 1 H and 13 C NMR, which had been successfully applied in research of honey samples, including stingless bee honey [ 11 , 12 ]. Multivariate analysis (PCA—principal component analysis and HCA—hierarchical clustering) and Nightingale’s diagram were performed based on the 13C-NMR data applying Excel and Simca15 [ 12 , 13 , 14 ].…”

“… m x = N TSP /N x ∗ Int x /Int TSP ∗ MW x /MW TSP ∗ m TSP or m x = 9.77 ∗ 10 −4 ∗ Int x /Int TSP ∗ MW x /N x where N TSP is the number of TSP protons (9); N x –number of chemically equivalent protons of the studied compound X, used for quantitation (3 for CH 3 , 2 for CH 2 , 1 for CH, etc. ); Int TSP –integral area under the peak of TSP; Int X –integral area under the peak of compound X used for quantitation; MW TSP –molar weight of TSP (172.27 g/mol); MW X –molar weight of the studied compound X; m TSP –quantity of TSP in the sample measured (0.0187 g/100 g) The quantities of the various mono-, di-, and trisaccharides were determined from the intensities of the anomeric protons in the 13 C NMR spectra according to [ 12 ].…”

“…The quantities of the various mono-, di-, and trisaccharides were determined from the intensities of the anomeric protons in the 13 C NMR spectra according to [ 12 ].…”

The Use of UV Spectroscopy and SIMCA for the Authentication of Indonesian Honeys According to Botanical, Entomological and Geographical Origins

“…While these two classical methods are accurate, they are time consuming, tedious to implement, and require highly trained personnel to perform them. Included among the modern methods available for honey authentication are chromatographic, mass spectrometry, spectroscopy (UVvisible, near infrared (NIR), mid infrared (MIR) and terahertz (THz)), nuclear magnetic resonance/NMR ( 1 H NMR, 13 C NMR), and molecular (real-time PCR) techniques [20]. Both chromatographic and mass spectrometry methods are time consuming and involve expensive devices and laborious sample preparation.…”

“…To ensure fair trading of such high valued products as honey, an authentication system needs to be established to detect fraud in the honey supply chain. Most reported works on honey authentication mainly focus on the floral type (botanical origin) and geographical origins, and less frequently on entomological origins [ 10 , 11 , 12 , 13 , 14 ]. Few reported works have been reported on the honey authentication based on entomological origins [ 15 , 16 ].…”