*3.4. Absorbance UV Maxima and FTIR Spectra*

The maximum UV absorbance of collagen was done using a UV-spectrophotometer, scanning at a different wavelength from 210 to 318 nm. For the FTIR spectra, the collagen samples were mixed with kBr to produce a disk and scanned at different wavelengths using a Fourier transform infrared spectrometer (Nicolet 6700, Thermofisher Scientific Inc., Waltham, MA, USA) equipped with a DLaTGS detector. The absorption intensity of each peak was calculated as mentioned in our previous method [1].
