Table 2.
Ratio assignment obtained from Fourier-transform infrared microspectroscopy (FTIRM).
| Ratio name | Chemical description | Spectral assignment |
|---|---|---|
| Protein/lipid | Amide II bending N-H and stretching vibration C-N (δNH-vC-N)/CH3 asymmetric stretching vibration (vasCH3) | 1543 cm−1/2960 cm−1 |
| Olefinic/total lipid | =CH cis stretching vibration (cisvC=C-H)/[=CH cis stretching vibration (cisvC=C-H)+CH2 asymmetric stretching vibration (vasCH2)+CH2 symmetric stretching vibration (vsCH2)+C=O stretching (vC=O)+CH2 bending (δCH2)] | 3013 cm−1/(3013 + 2921 + 2854 + 1746 + 1457 cm−1) |
| Olefinic/total CH2 | =CH cis stretching vibration (cisvC=C-H)/[CH2 asymmetric stretching vibration (vasCH2)+CH2 symmetric stretching vibration (vsCH2)+CH2 bending (δCH2)] | 3013 cm−1/(2921 + 2854 + 1457 cm−1) |
| CH2/CH3 | CH2 asymmetric stretching vibration (vasCH2)/CH3 stretching vibration (vasCH3) | 2921 cm−1/2960 cm−1 |
| Lipid peroxidation | C=O stretching (vC=O)/CH2 bending (δCH2) | 1746 cm−1/1457 cm−1 |