Exploring Age-Related Changes in Bioimpedance across Diverse Biological Samples

Technology based on bioimpedance has proven itself very useful in a wide range of applications, particularly within the realm of tissue characterization. Notably, it has found significant utility in categorizing various food types, such as meats, fruits, and beverages. As biological samples, such as chicken, fruits, and vegetables, lose freshness after preservation, their internal structures transform due to distinct biological reactions, resulting in alterations to their internal properties and bonds. Consequently, the electrical properties of the tissues change. In this study, the effect of aging on different biological samples after preservation in a refrigerator was investigated over a wide range of frequencies. Freshly excised animal tissue (chicken) and vegetables (gourd, papaya, brinjal) were considered biological samples. The transfer impedance values were measured over the frequency range of 100 Hz to 100 kHz using an impedance spectrometer placing four electrodes on the samples. The findings revealed a consistent decrease in the electrical impedance of biological samples over time across all measured frequencies. The observed impedance changes exhibited a Gaussian decay curve, offering a reliable means to monitor the freshness of the samples. This technique demonstrates significant potential for enhancing the quality control of perishable foods.