## 2 Materials and Methods
### Measurement of Dielectric Properties  
The dielectric properties of _Cirrhinus microlepis_ tissues, specifically, scales, skin, and muscle, were measured using an open-ended coaxial probe method in conjunction with a vector network analyzer (VNA). This approach is widely recognized for its accuracy in characterizing the dielectric properties of biological tissues, as it enables precise measurements over a broad frequency range. The experimental setup consisted of a VNA (Keysight Technologies Inc., Santa Rosa, CA, USA) and an open-ended coaxial probe connected via a Keysight N1501A Dielectric Probe Kit, while data acquisition and analysis were conducted using Keysight N1500A software prior to conducting the measurements, such as the measurement of the properties of fertilizers, jasmine rice (_Oryza sativa_), soil, and fungi [38; 39; 40; 41; 42]. The system was calibrated using air, distilled water, and a standard dielectric reference block. Calibration ensured the accuracy of the measurements across the frequency range of 0.5-3 GHz, with a particular focus on 2.45 GHz, the frequency used for dielectric heating optimization. The calibration steps included verifying the reflection  
Figure 1: Sample preparation of _Cirrhinus microlepis_ (small-scale mud carp) for dielectric property measurement and dielectric heating experiments: (**a**) Specimens obtained from Siam Makro Public Company Limited. (**b**) Collection of scale tissues during dissection. (**c**) Collection of skin tissues during dissection. (**d**) Collection of muscle tissues during dissection. coefficient (S11) for each reference material to minimize systematic errors. Freshly prepared tissue samples from the scales, skin, and muscle of _Cirrhinus microlepis_, as described in the sample preparation section, were used to obtain region-specific dielectric data. Each sample was placed on a non-conductive surface to maintain structural integrity and avoid external interference [43; 44; 45]. The coaxial probe was gently positioned to ensure firm contact with the sample surface without deforming the tissue, as illustrated in Figure 2. Measurements were conducted at room temperature (\(25\pm 1\)\({}^{\circ}\)C) to simulate experimental conditions, and each sample was measured five times to ensure consistency and reproducibility of the data. The dielectric constant (\(\epsilon^{\prime}\)) and loss factor (\(e^{\prime\prime}\)) of biological tissues, such as the scales, skin, and muscle of _Cirrhinus microlepis_, are derived from the reflection coefficient (\(\mathbb{S}_{11}\)) measured using an open-ended coaxial probe connected to a vector network analyzer (VNA). The reflection coefficient, which represents the ratio of reflected to incident electromagnetic waves at the interface between the probe and the sample, is a complex value expressed as follows:  
\[\Gamma=\frac{Z_{s}-Z_{o}}{Z_{s}+Z_{o}} \tag{1}\]  
where \(Z_{s}\) is the complex impedance of the sample, and \(Z_{o}\) is the characteristic impedance of the coaxial system, typically 50 \(\Omega\). The dielectric properties of the sample are inferred from the impedance relationship and the calibration of the measurement system using standard materials such as air, distilled water, and a dielectric block. The complex permittivity (\(\epsilon\)), which describes how the material interacts with the electromagnetic field, is expressed as \(\epsilon=\epsilon^{\prime}+je^{\prime\prime}\), where \(\epsilon^{\prime}\) represents the ability of the material to store electric energy, and \(\epsilon^{\prime\prime}\) represents the energy dissipated as heat. These properties are calculated from the impedance of the sample, given by \(Z_{s}=1/j\omega\epsilon\), where \(\omega=2\pi f\) is the angular frequency of the electromagnetic wave. In the case of _Cirrhinus microlepis_, high \(\epsilon^{\prime\prime}\) values were consistently observed in the scale region, indicating enhanced dielectric loss and thereby a higher microwave energy absorption potential compared to the muscle region.