Zabala Inés, Merino Santos, Eletxigerra Unai, Ramiro Jorge, Burguera Miren, Aranzabe Estibaliz
Tekniker, Basque Research Alliance (BRTA), 20600 Eibar, Spain.
Departamento de Electricidad y Electrónica, Universidad del País Vasco, UPV/EHU, 48940 Leioa, Spain.
Foods. 2024 Jun 4;13(11):1765. doi: 10.3390/foods13111765.
The electrical impedance of dilute aqueous solutions containing extracts from five brands of canned tuna is analyzed using impedance spectroscopy in order to analyze their salt content and detect the potential presence of other salts beyond the well-stated NaCl. A complex electrical impedance is modeled with an equivalent electrical circuit, demonstrating good agreement with experimental data. This circuit accounts for the contribution of ions in the bulk solution, as well as those contributing to electrode polarization. The parameters describing the equivalent circuits, obtained through fitting data to the electrical impedance, are discussed in terms of the various ion contributions to both the electrical double layer at the electrode interface and the electrical conductivity of each solution. The ionic contribution to the electrical impedance is compared with that of a pure NaCl solution at the same concentration range. This comparison, when extended to real samples, allows for the development of a model to estimate the electrical conductivity of canned tuna samples, thereby determining the salt concentration in tuna. The model enables differentiation among the various samples of tuna studied. Subsequently, the potential presence of other ions besides Na and Cl and their contribution to the electrical properties of each canned tuna extract is considered, especially for samples with a higher ratio of the sum of K and phosphates to Na concentration. This analysis shows the potential of impedance spectroscopy for on-site and rapid analysis of salt content and/or detection of additives in canned tuna fish.
使用阻抗谱分析了含有五个品牌罐装金枪鱼提取物的稀水溶液的电阻抗，以分析其盐含量，并检测除明确列出的氯化钠之外其他盐的潜在存在情况。用等效电路对复电阻抗进行建模，结果表明与实验数据吻合良好。该电路考虑了本体溶液中离子的贡献以及对电极极化有贡献的离子。通过将数据拟合到电阻抗来获得描述等效电路的参数，并根据各种离子对电极界面双电层和每种溶液电导率的贡献进行了讨论。将离子对电阻抗的贡献与相同浓度范围内的纯氯化钠溶液进行了比较。这种比较扩展到实际样品时，有助于建立一个模型来估算罐装金枪鱼样品的电导率，从而确定金枪鱼中的盐浓度。该模型能够区分所研究的各种金枪鱼样品。随后，考虑了除钠和氯之外其他离子的潜在存在及其对每种罐装金枪鱼提取物电学性质的贡献，特别是对于钾和磷酸盐总和与钠浓度之比更高的样品。该分析表明了阻抗谱在现场快速分析罐装金枪鱼盐含量和/或检测添加剂方面的潜力。
