Collagen extracts from blue cannonball jellyfish (<i>Stomolophus meleagris</i>): Antioxidant properties, chemical structure, and proteomic identification

The demand for jellyfish is increasing mainly because of its health benefits. This study focuses on extracting and characterizing pepsin-soluble collagen extracts from blue cannonball jellyfish (Stomolophus meleagris) mesoglea. Jellyfish mesoglea’s amino acids were analyzed, and collagen extracts were obtained using pepsin (24 h, 4°C) and then characterized. Collagen extracts contain high amounts of glycine and hydroxyproline. The extracts obtained in this study exhibited electrophoretic bands corresponding to collagen “a” and “b” chains, and experienced denaturation at 23.9ºC and an enthalpy change of 0.078 J/g. The Fourier transform infrared spectra exhibited peaks associated with specific collagen tripeptides, and the proton nuclear magnetic resonance spectra showed the characteristic resonance of collagen-like triple helices. Proteomic studies identified the presence of actin, myosin, and collagen type IV. The collagen extracts exhibited higher in vitro ability to trap free radicals, reduce ferric power, and inhibit erythrocyte homolysis than commercial marine fish collagen. The results presented in this paper show the properties of collagen extracts, highlighting their potential application as an antioxidant or a supplement in the food industry.