Soy Protein Isolate Reinforced Yak Skin Collagen Edible Films for Ultraviolet Barring Function

In this study, collagen extraction from yakskin was conducted through an acid-pepsin hydrolysis process. The molecular weight (M-w) of yakskin collagen was 51825 Da. An amino acid analysis showed that yakskin collagen is rich in nutrients and contains essential amino acids. The effects of SPI on the mechanical properties (tensile strength (TS) and elongation at break (EAB)), light transmittance, water vapour permeability (WVP) levels, FTIR, X-ray diffraction (XRD) patterns, thermal properties, water contact angles and yakskin collagen-based films' cross section morphologies were studied. The results showed that excellent ultraviolet barring functions were achieved from edible films with the incorporation of SPI. The edible films produced by SPI present better properties than films composed of only yakskin collagen. Yakskin collagen/SPI composite film could be more widely used in edible food packaging film. As plasticiser, sorbitol can effectively replace glycerol. It opens up a new direction for the effective utilisation of yakskin resources in Qinghai province. The paper provides information specific to yakskin in contrast to other sources of collagen.