GUITAR-enhanced facile discrimination of aged Chinese Baijiu using electrochemical impedance spectroscopy

Highlights: • GUITAR electrode were employed to collect EIS data of verities' aged Baijiu. • The obtained Nyquist plots were simulated with the corresponding equivalent circuit. • The curve fitting data were dimensionally reduced with principle components analysis (PCA). • PCA score image showed a well-defined clustered profile for aged Baijiu discrimination. -- Abstract: The presented research demonstrated a method to evaluate aged Chinese Baijiu by measuring their electrochemical impedance spectrums (EIS) according to the distinctive colloidal impedance phenomena of verities' aged Baijiu. Graphite from the University of Idaho Thermolyzed Asphalt Reaction (GUITAR) electrode was employed for EIS data collection to achieve enhanced resolution. The obtained EIS Nyquist plots were simulated with the corresponding equivalent circuit to extract the numerical values of parameters which characterize the physicochemical properties of aged Baijiu. The curve fitting data were dimensionally reduced with principle components analysis (PCA). PCA score image originated from GUITAR electrode EIS measurement showed a more defined clustered profile in comparison to glassy carbon electrode. These results implicate GUITAR electrode based EIS is potentially available to develop a household device for aged Baijiu classification.