Spectrometric determination of the collagen crosslinking degree through pyridinoline identification and evaluation of the viscosity properties of Octopus vulgaris and Dosidicus gigas arm muscles

• 1 H NMR and amino acid profile can be used to determine Pyr content. • Collagen crosslinking degree is higher in D. gigas compared to O. vulgaris arms. • The collagen viscoelastic properties are not affected by the crosslinking degree. Field application of collagen obtained from marine organisms is in wide practice. Moreover, its use could be conditioned depending on the desired purpose and structural characteristics. Therefore, further studies on collagen crosslinking are needed to determine how this may affect the properties of collagen. A spectrophotometric characterization of the collagen found in Octopus vulgaris and Dosidicus gigas arms was carried out. The 1 H NMR and fluorometric spectra confirmed the presence of pyridinoline as the main molecule responsible for collagen crosslinking. Using the amino acid profile and 1 H NMR spectra, it was determined that the jumbo squid has a relatively high pyridinoline content. The viscosity properties of this collagen were found to exhibit the behaviour of a pseudoplastic fluid. Finally, under the conditions proposed in this study, the degree of crosslinking of the collagen of the octopus and the jumbo squid did not affect the viscosity properties of the protein.