Fig. 2A shows the raw spectrum [log (1/R)], averaged over warm
and cold subcutaneous fat samples. Although the overall absorbance
represented by these spectra was different for warm and cold samples
as a consequence of the temperature, they followed the same pattern.
In both samples the spectral information showed a series of
characteristic absorption bands at 1130–1250, 1350–1450, 1720–
1760 and 2200–2400 nm, which are known wavelengths where the
C–H bond (fundamental constituent of fatty acid molecules) causes
different forms of vibration In addition, there was a peak at 1940 nm which
corresponds to the absorption of the O–H bond that is related to water
content.