Preparation and Physicochemical Properties of Collagen from Bone of Yunnan Bream

Acid-soluble collagen (ASC) was extracted from the bone of Yunnan bream using cold acetic acid, and its amino acid composition, subunit composition, Fourier transform infrared (FTIR) and UV absorption characteristics, thermal stability and X-ray diffraction (XRD) characteristics, microstructure, peptide fragments and solubility were analyzed. Amino acid analysis showed that ASC mainly consisted of Gly, Pro and Ala, as well as lesser amounts of Tyr, Met, and Cys. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis confirmed ASC to be typical I collagen. The maximum absorption peak of ASC appeared at 230 nm. The FTIR and XRD spectra proved that the helical structure of ASC remained intact. Differential scanning calorimetry showed that ASC had two denaturation temperatures of 86.5 and 226.2 ℃indicating high thermal stability. Scanning electron microscopy showed that the microstructure of ASC was homogenous with a smooth surface. Peptide analysis showed that amino acid sequence of ASC was Gly-X-Y, which was in agreement with the primary structure characteristics of collagen. The solubility of ASC was relatively high under acidic conditions(pH © 2018, China Food Publishing Company. All right reserved.