¹National Research and Development Institute for Cryogenics and Isotopic Technologies - ICSI Rm. Valcea, Uzinei Street no. 4, P.O. Box Râureni 7,

240050, Râmnicu Vâlcea, Romania, e-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it ;

²Politehnica University of Bucharest, Faculty of Applied Chemistry and Materials Science, 1-7 Polizu Str., 011061, Bucharest, Romania

ABSTRACT

The specific compounds that provide specific particularities to each honey type give its value and unicity, reason for selecting the most appropriate and highly sensitive techniques when an authenticity study is considered. The main aim of the work is to demonstrate that the combination of isotopic ratios (¹³C/¹²C of honey and¹³C/¹²C and ¹⁵N/¹⁴N from protein fraction extracted from honey) with multivariate analysis, can be a reliable tool to differentiate the botanical origin of honey. A set of 35 honey samples of different floral varieties, from different parts of Romania, during year 2013, were included in the study. Processed by cluster analysis, principal component analysis and discriminant analysis, the data obtained by isotope ratio mass spectrometry (IRMS) technique for δ¹³C_honey, δ ¹³C_protein and δ ¹⁵N_protein allowed a good separation of the honey samples across different botanical varieties, enabling 97% correct classification for the generated model. Significant differences were observed among the honey samples, especially for δ¹⁵N ranging from -2.40‰ (multiflower honey) to +4.90‰ (acacia honey), that is strongly correlated with the area’s soil composition (different types of soil which fix the soluble nitrogen compounds better than other soil types), amount of precipitation, water stress and botanical origin (plants with the ability of fixing nitrogen from air). The degree of discrimination for the botanical origin of honey is explained by the strong correlation between the stable isotopes and the specific fingerprint of the plant-soil system provenance.

Keywords: Authentication of botanical origin; Honey; Isotopic tracers/markers; Multivariate statistical analysis.