Collagen from Bovine Omentum: Extraction and Characterization

Bovine omentum, a by-product of beef processing, offers potential for collagen recovery within the circular bioeconomy. It consists mainly of lipids (42.14%) and proteins (18.79%), such as collagen. In this study, collagen was isolated using acid-based and enzymatic methods. Acid-soluble collagen (ASC) was successfully extracted, yielding 3.98%. Additionally, enzymatic extraction of collagen from the residue obtained after ASC extraction using Protana^® Prime (1-10%, <i>w</i>/<i>w</i>) resulted in variable yields (4.98% to 11.15%) (<i>p</i> < 0.05). The maximum solubility of all collagen samples was observed at pH 3, while NaCl concentrations above 4% (<i>w</i>/<i>v</i>) significantly reduced solubility (<i>p</i> < 0.05). ASC demonstrated the highest emulsifying activity index and emulsion stability index (213.73 m²/g and 172.09 min, respectively) (<i>p</i> < 0.05), whereas enzyme-extracted collagens exhibited comparatively lower emulsifying capacities, particularly at higher enzyme concentrations (7.5% and 10%). FTIR spectra revealed characteristic bands for collagen, indicating that the triple helical structure was maintained, irrespective of treatment. All collagen samples contained glycine as the major amino acid (approximately 1/3rd of the total amino acid) with proline and hydroxyproline. SDS-PAGE identified type I collagen, which consisted of αI and αII chains. Therefore, bovine omentum would be an alternative source of collagen for various applications in the food industry.