Study of Quality Factor (Q) obtained per electrical impedance to characterization and detection adulteration in honey

The quality control of honey is very important for the food industry and for the final consumer. Honey has been constantly the target of adulteration, usually with the aim of illegally increasing profit. However, the analytical methods used sometimes are very complex and beyond time- consuming. The electrical impedance spectroscopy (EIS) appears as a good alternative to the traditional methods of analysis due to its practicality and low costs. In order to show the applicability of this tool in honey quality control analysis, in the present study, honey samples were purposefully adulterated with syrup to simulate adulteration conditions. Then, they were submitted to impedance analysis with frequency scanned from 10 Hz to 2 MHz, in order to obtain different spectral electrical parameters. The phase angle, the real part of the impedance and the quality factor (Q) were collected. The results available show that the Q has great potential for use, as it presents a linear correlation between the frequencies relative to the peaks of the Q as a function of concentration and adjustment model above 0.99. Therefore, it is proposed that an analytical methodology based on electrical impedance spectroscopy can be a powerful technique for quality control and detection of adulterants.---

Study of Quality Factor (Q) and Phase Angle (θ) obtained per electrical impedance to characterization and detection adulteration in honey.

The quality control of honey is very important for the food industry and for the final consumer. Honey has constantly been the target of adulteration, usually with the aim of illegally increasing profit. However, the analytical methods used in the fraud investigation sometimes are very complex and beyond time-consuming. Electrical measurements appear as a good alternative to the traditional methods of analysis due to its practicality and low costs. In order to show the applicability of some electrical parameters derived from the impedance technique for honey quality control analysis, in the present study, samples were purposefully adulterated with syrup to simulate adulteration conditions. Then, they were submitted to electrical impedance analysis with frequency scanned from 10 Hz to 2 MHz. The impedance module (Z), the phase angle  and the quality factor (Q) data were collected and studied. The results showed that there is a linear correlation between the frequencies relative to the peaks of the Q for samples and adulterant concentration with coefficient of determination of ~0.992. The proposal to use the Q as a property to be used in methodologies of analysis is the main contribution from this study, since it is traditionally little mentioned in the literature

Electrical characterization of milk samples by Electrical Impedance Spectroscopy (EIS)

This work presents a study of electrical impedance spectroscopy (EIS) as an alternative to characterize milk, aiming to develop an analysis methodology. The behavior of the electrical impedance module, the real part and the imaginary part (reactance), and the derived quantities such as admittance, phase and diffusion coefficient (D) were also analyzed and will be discussed. Comparisons of the measured spectra with theoretical models of equivalent circuits were carried out in order to understand the electrical behavior of the samples. Understanding this electrical phenomenon will help in the development of future analysis methodologies and applications. The results indicated that milk is a solution with predominantly resistive behavior with resistance of approximately 500 Ohms, capacitance of about of 0.5 MicroFarad (μF) and admittance of the order of MiliSiemens (mS), presenting small storaged charge due to low viscosity. The best-fitting equivalent circuit was a mixed RC model consisting of a series resistor coupled with a resistor in parallel with a capacitor