Electrical impedance spectroscopy for potassium content analysis and botanical origin identification of honey

• Published in: Food chemistry Vol. 453; p. 139605
• Main Authors: Elamine, Youssef, Inácio, Pedro M.C., da Graça Miguel, Maria, Carlier, Jorge D., Costa, Maria Clara, Estevinho, Leticia M., Gomes, Henrique L.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 30.09.2024
• Subjects: Electrical-double-layer; Electrochemical impedance; Electronic tongue; Food certification; Honey; Honey adulteration; Potassium; Honey; Electronic tongue; Electrochemical impedance; Food certification; Honey adulteration; Electrical-double-layer; Potassium
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2024.139605

Minerals are reported to dominate the electrical properties of honey and indicate its botanical and geographical origins. In this study, Electrochemical Impedance Spectroscopy (EIS) was used to assess the relation between mineral elements, electrical properties and botanical origin using three honey varieties - Citrus sp., Eucalyptus sp., and Erica sp. These varieties are identified through pollen analysis and market labelling. Flame atomic absorption and emission spectroscopies were used to quantify the concentrations of eight elements (potassium, sodium, calcium, magnesium, manganese, zinc, copper, and iron). Among all the mineral elements, potassium showed a consistent correlation with impedance. The potassium estimation in honey and standard solutions (calibration curve) had similar sensitivities of 153.43 nF/mM and 132.68 nF/mM, respectively. Additionally, the analysis revealed that potassium dominates the mineral composition, with the other species present in minimal quantities. The EIS technique showed high sensitivity to potassium and other ionisable species, making it possible to classify the botanical origin of these three honey types. The EIS technique proved to be both time and cost effective, yielding a classification rate higher than that achieved by analysing mineral composition. [Display omitted] •Potassium is the predominant element influencing the electrical properties of honey.•Electrochemical impedance measurements provide a quantitative assessment of potassium concentration in honey.•An impedance-based sensor classifies honey samples according to their botanical origin.•The impedance-based sensor is time and cost-effective, when compared with mineral composition analysis.