Distinctive characteristics of collagen and gelatin extracted from Dosidicus gigas skin

Abstract

Squid skin, often discarded as processing by-product, is a good resource of collagen/gelatin. In this study, acid soluble collagen (ASC), pepsin soluble collagen (PSC) and water soluble gelatin (WSG) were extracted from squid (Dosidicus gigas) skin and physicochemically examined. The lowest yield of 33.5% was obtained for ASC extracted at 4°C, and the addition of pepsin increased the collagen yield by around 35.0% (PSC). The highest yield of 81.9% (WSG) was achieved by thermal extraction at 60°C. A low temperature can largely retain the native helix structures of ASC and PSC, contrariwise, thermal treatment converted collagen into gelatin with unordered and renatured structures. The proline and hydroxyproline contents of ASC, PSC and WSG were 183/1000 residues, 194/1000 residues and 175/1000 residues, respectively. In addition, WSG showed a denaturation temperature at 80.7°C which was much higher than that of ASC (24.2°C) and PSC (26.2°C), while a significant lower resistance towards enzymatic digestion.

Preparation and Characterization of Thermally Stable Collagens from the Scales of Lizardfish (Synodus macrops)

“…The morphology of collagen is vital for assessing its potential application in biomedicine [31]. The collagen solution obtained from lizardfish scales was lyophilized, and the morphology of collagen sponges was observed by scanning electron microscopy (SEM) (Figure 3).…”

Recent advances in gelatine and chitosan complex material for practical food preservation application

“…Gelatine is a denatured form of collagen but differs from collagen in its chemical composition (Sun et al ., 2021), with origins from bone and skin collagen of bovine, porcine, rabbit, camel, fish, etc. (Ghaderi, Hosseini, Keyvani, & Gómez‐Guillén, 2019; Benbettaieb, Mahfoudh, Moundanga, Brachais, Chambin, & Debeaufort, 2020; Dai et al ., 2020; Huang, Tu, Sha, Wang, Hu, & Hu, 2020; Sezer, Okur, Oztop, & Alpas, 2020; Hosseini et al ., 2021).…”

Comparative assessment of bone collagen recovered from different livestock and poultry species: microstructure, physicochemical characteristics and functional properties

“…Bone could not be completely solubilised by 0.5 M acetic acid due to high stiffness and toughness, and bone collagen also showed low solubility due to the intermolecular cross-linkages caused by hydrogen bonding through a lysine aldehyde of one chain and a hydroxylysine of an adjacent chain in the endoverlap region, resulting in the low yields of bone collagen (Li et al, 2013). Therefore, acid-solubilised and pepsinolysis-aided method was used in this study to increase the yields of LBCs and remove allergens by cleaving covalent intra-and inter-molecular crosslinkages formed by the residues of lysine and hydroxylysine, ester bonds and other bonds with saccharides at telopeptides region without affecting the tvriple helix structure (Sun et al, 2021c). Amino acid compositions (Table 1) showed that glycine (310.8-337.3 residues/1000 residues) constituted approximately 1/3 of total amino acids due to the Gly-X-Y repetitions except for the first 14 amino acid residues from the N-terminus and the first 10 amino acid residues from the C-terminus in collagen.…”