Analysis of δ13C and δ15N values in Croatian honey by EA-IRMS and possibility of their application in botanical origin verification

Abstract

The aim of this work was to give characteristic stable carbon and nitrogen isotope ratio (δ¹³C_honey, δ¹³C_protein and δ¹⁵N) ranges and examine their relation with botanical origin of honey. Despite that δ¹³C parameter has primary purpose to detect honey adulteration, stable isotopes generally have become important parameter for detection its botanical and geographical origin. The data about stable isotopes are scarce in comparison to other well-known parameters in honey, and in Croatia there is no data about stable isotopes in unifloral honey. This research includes six characteristic honey types (black locust, chestnut, lime, rape, winter savory, and sage honey) from Croatia. Large number of differences between honey types were found in the analyzed IRMS parameters. PCA analysis has successfully separated winter savory from all other honey types, except sage honey, whose samples differed from black locust samples.

Supplementary information: The online version contains supplementary material available at 10.1007/s13197-023-05888-9.

Keywords: Botanical origin; Honey; Isotope ratio mass spectrometry (IRMS); δ13C; δ15N.

Fig. 1

Display of aggregate values for δ¹³C_honey, δ¹³C_protein and δ¹⁵N_protein in honey (x average; - median; o extreme; ┴ ┬ min and max that does not include extremes, □ Q1–Q3)

Fig. 2

Classification of honey samples according to botanical origin using PC1 and PC2 as functions of IRMS variables

Fig. 3

Display of aggregate values for δ¹³C_honey, δ¹³C_protein and δ¹⁵N_protein in honey according to production year (x average; - median; o extreme; ┴ ┬ min and max that does not include extremes, □ Q1–Q3)