*3.6. Spectrophotometric Characterization*

Spectra of UV, FTIR, and CD of the purified *T. flavidus* collagen were determined using a method described by Wang et al. [49] with slight modification. UV spectrum (226–300 nm) of the *T. flavidus* collagen extract (1 mg/mL) was determined by a UV-1780 spectrophotometer against 0.5 M acetic acid (blank). FTIR (500–4000 cm−1) of the same extract was measured by a horizontal ATR trough plate crystal cell (PIKE technology Inc., Fitchburg, WI, USA) coupled with a Bruker Model VERTEX 70 FTIR spectrometer (Bruker Co., Karlsruhe, Germany). FTIR spectra in the rage of 500–4000 cm−<sup>1</sup> with automatic signal gain were collected in 16 scans at a resolution of 4 cm−<sup>1</sup> prior to analysis by OPUS 6.5 data collection software program (Bruker Co., Karlsruhe, Germany). In addition, CD spectrum (190–260 nm) of the collagen extract (0.25 mg/mL) was produced by accumulating 100 scans at a speed of 100 nm/min with 1 nm interval on a Chirascan spectrometer (Applied Photophysics Limited Inc., Leatherhead, UK).
