Extraction and characterization of collagens from yak rumen smooth muscle

This study reports an effective method using enzymatic methods to extract collagen from yak rumen smooth muscle. The enzymatic extraction methods were optimized by response surface methodology. Additionally, the properties of the extracted collagen were analyzed by Fourier transform infrared (FT-IR) spectroscopy and mass spectrometry (MS). The results showed that the optimal conditions were as follows: the pepsin addition was 0.95%, the enzymatic hydrolysis time was 21 hr, and the solid-to-solvent ratio was 1:11. Under these conditions, the collagen extraction rate could reach 3.62/100 g. The results of FT-IR revealed that the amide A, amide B, amide I, amide II, and amide III bands of the collagen appeared at 3,293.18, 3,068.18, 1654.94, 1,540.58, and 1,236.58 cm^-1 , respectively. The MS identified seven types of collagen, which were type I, type III, type IV, type V, type VI, type VIII, and type XII. The results demonstrated that the enzymatic method can extract collagen from yak rumen smooth muscle with a considerably high yield and can preserve the intact structure of the collagen.