In Situ Spectroscopic Study on the Effect of UV Radiation on Stabilized Collagen Fibre: Role of Plant Tannin

摘要

Ultraviolet-Visible Diffuse Reflection (UV-Vis DR) spectroscopy and Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) spectroscopy were employed to investigate the influence of deleterious UV radiation on the pure collagen fibre and plant tannin crosslinked collagen fibre. After exposure to UV radiation, the UV-Vis absorption intensity of the pure collagen fibre is found to be dramatically increased at the peak of 280nm, which should be attributed to the increase of photo-products of free tyrosine and phenylalanine formed by UV radiation damage. However, the damage effect on collagen fibre is significantly hindered in the presence of barberry tannin. On the other hand, the study of ATR FT-IR spectroscopy also showed that the intensities of amide bands (amide A, B, I and II) of pure collagen fibre decreased with the increase of UV radiation time, while the intensity changes of amide bands in bayberry tannin stabilized collagen fibre are less than those in the case of pure collagen fibre. In addition, the weakness of C-O-H in-plane deformation vibration and the stretching vibration of phenolic hydroxyls suggested that the UV protection effect of barberry tannin on collagen fibre should be closely related to the photoxidation of phenolic hydroxyls in bayberry tannin molecule.