Minetto Taiz Alana, França Beatriz Denardi, da Silva Dariz Gabriel, Veiga Emiliano Amarante, Galvão Alessandro Cazonatto, da Silva Robazza Weber
Laboratory ApTher - Applied Thermophysics, Department of Food and Chemical Engineering, Santa Catarina State University (UDESC), Pinhalzinho, SC, Brazil.
Bionexus Technology LLC, Chapecó, SC, Brazil.
Food Chem. 2022 Aug 15;385:132678. doi: 10.1016/j.foodchem.2022.132678. Epub 2022 Mar 10.
This study aimed to evaluate the applicability of electrochemical impedance spectroscopy to identify raw bovine milk adulteration with urea. Three batches of raw milk adulterated with urea were studied. Hierarchical clustering indicated that the samples could be split in three groups corresponding to low adulteration (less than 7 wt%), medium adulteration (between 8 and 16 wt%) and high adulteration (over than 16 wt%). A linear discriminant analysis was performed resulting in 90% of accuracy in classifying between groups. Besides, a partial least squares model containing three directions provided good accuracy in quantitatively predicting the urea mass fraction added to raw bovine milk. Finally, calculations using an approximated electric circuit model suggested the formation of urea aggregates that hinder charge transportation within the milk thus diminishing the solution conductivity. Results indicate that electrochemical impedance spectroscopy can be a useful, low cost and rapid tool to identify milk adulteration with urea.
本研究旨在评估电化学阻抗谱在识别生牛乳中尿素掺假方面的适用性。研究了三批掺有尿素的生牛乳。层次聚类表明，样品可分为三组，分别对应低掺假（低于7 wt%）、中等掺假（8至16 wt%之间）和高掺假（高于16 wt%）。进行了线性判别分析，在组间分类时准确率达到90%。此外，包含三个方向的偏最小二乘模型在定量预测添加到生牛乳中的尿素质量分数方面具有良好的准确性。最后，使用近似电路模型进行的计算表明，尿素聚集体的形成阻碍了牛奶中的电荷传输，从而降低了溶液的电导率。结果表明，电化学阻抗谱可以成为一种有用、低成本且快速的工具，用于识别牛奶中尿素掺假情况。
