Electrical impedance spectroscopy: potential non-destructive method for aflatoxin B1 in peanut

Achieving non-destructive detection of aflatoxin in peanuts can prevent the processing of aflatoxin-contaminated peanuts into food products. A potential non-destructive electrical impedance spectroscopy method for aflatoxin B1 (AFB₁) in peanuts is proposed. To research the relationship between electrical parameters and aflatoxins, this study analyzed the effects of improper storage duration on the content of aflatoxins and conducted experiments using impedance spectroscopy and NMR with different content of AFB₁. Results showed that the aflatoxin content was proportional to the number of days of improper storage. The impedance Z could as an indicator for characterizing AFB₁. The parameters of electrical impedance spectrum under multi-frequency (1000 Hz and 4 MHz) were better than those under the single frequency (1000 Hz or 4 MHz), and the combination of Z and θ showed the best correlation (R² = 0.998). The detection mechanism was accurate under improper storage conditions, and aflatoxin production was accompanied by moldy kernel, leading to changes in endosperm structure and impedance. Our study informs the development of non-destructive detection devices for aflatoxins in peanuts.