Fig. 4
From: Colorimetric detection of edible oil oxidation using PAN–Congo red nanofiber mats
FTIR spectra of (A) fresh and oxidized SBO and EVOO, spectral changes due to the development of secondary oxidation products (aldehydes, and ketones) at (B) 1160 cm− 1, and (C) 1743 cm− 1; a reduction in unsaturated fatty acid amounts at (D) 722 cm− 1, (E) 3008 cm− 1; and formation of hydroperoxides (F) 3400–3600 cm− 1.
