Fig. 1. (A) Middle infrared spectrum of edible oil recorded on the surface of an attenuated total reflectance (ATR) accessory; (B) raw spectra of edible oil with varying
concentration of trans fatty acids; (C) second derivative of middle infrared spectra of edible oil with varying concentration of trans fatty acids; (D) second derivative of middle
infrared spectra from 1.65% to 0.20% of TFAs content.