Extraction and characterization of collagen from sheep slaughter by-products

•The sheep slaughter by-products proved to be a viable source for obtaining collagen.•The yield of collagen was adequate, with values of 18.0 and 12.5% on a dry basis.•The collagens presented bands (α1, α2, and β), characteristic of collagen type I.•Obtaining collagen added value and gave the waste a sustainable destination.•Collagens obtained can be used to replace other collagens or synthetic agents. There is a growing search for alternative raw materials to obtain collagen and hydrolysates and processes that do not threaten the environment or human health. Thus, sheep slaughter residue, which doesn’t yet have an adequate and sustainable destination, is an excellent source of study. The objective of this study was to investigate the technological properties of collagen extracted from sheep slaughter by-products. It was possible to produce and characterize collagens extracted from sheep slaughter by-products. The yield of collagen was 18.0% and 12.5% for lamb and sheep by-products, respectively, on a dry basis. Lamb and sheep collagens showed similar FTIR and digestibility spectra and increased solubility at acidic pH-value. Higher foaming capacity was found for lamb collagen, while the sheep collagen presented higher viscosity. The emulsifying power of the collagens was 59.1 and 69.6 m2/g for lamb and sheep by-products, respectively. The collagens presented bands corresponding to α1, α2, and β chains, characteristic of collagen type I and a molecular weight (SDS-PAGE) between 100 and 5 kDa. The collagens of this study showed potential for application in food products, both for the technological improvement and nutrient enrichment, adding value and giving a sustainable destination to sheep slaughter by-products.