Carbon isotope ratios in honey and proteins: A novel method for regional differentiation

This study examines honey samples to determine their regional differences using carbon isotope values and to investigate the correlation between honey and the protein isolated from the honey utilizing regression analysis. For the analyses, 196 honey samples were collected from 56 cities in Türkiye in collaboration with the Turkish Honey Producers Association. One-way analysis of variance, followed by Tukey-Kramer post-hoc and independent t-tests, revealed statistically significant differences in δ¹ ³C isotope ratios among regions (p < 0.05). Based on these results, seven geographical regions in Türkiye were categorized into three distinct groups: Group A (Southeastern Anatolia Region, Eastern Anatolia Region, Central Anatolia Region), Group B (Black Sea Region, Marmara Region, Aegean Region), and Group C (Mediterranean Region). Characterized by the lowest mean δ¹ ³C values, the Mediterranean Region was significantly differentiated from others and classified independently as Group C. On the other hand, Group A was found to have the highest mean δ¹ ³C values. A regression analysis was conducted to examine the relationship between the carbon isotope values of honey and its protein content, yielding a high regression coefficient. The regression analysis suggested a strong positive correlation between the carbon isotope ratios of honey and protein content across different regions. The analysis results indicate that the combination of carbon isotope ratio analysis and statistical methods may be a highly effective approach for determining the geographical origin of honey. • Honey samples from 56 Turkish cities analyzed for carbon isotope values. • Statistical methods classified samples into three distinct regional groups. • Strong correlation found between carbon isotope ratios of honey and its proteins. • Isotope analysis and statistics enable accurate geographical origin determination.