Underused Marine Resources: Sudden Properties of Cod Skin Gelatin Gel.

The main object of this work was to characterize the structure and properties of laboratory-made fish gelatin from cod skin in comparison with known commercial gelatins of fish and mammalian origin. This is one way we can contribute to the World Food Program and characterize foodstuff resources from alternative natural sources. Our research was based on the combination of an expanded set of complementary physical-chemical methods to study the similarities and distinctions of hydrogels from traditional and novel gelatin sources from underused marine resources. In this work, we have compared the morphology, supramolecular structure and colloid properties of two commercial (mammalian and fish) gelatins with gelatin we extracted from cold-water cod skin in laboratory conditions. The obtained results are novel, showing that our laboratory-produced fish gelatin is much closer to the mammalian one in terms of such parameters as thermal stability and strength of structural network under temperature alterations. Especially interesting are our experimental observations comparing both fish gelatins: it was shown that the laboratory-extracted cod gelatin is essentially more thermally stable compared to its commercial analogue, being even closer in its rheological properties to the mammalian one.

Intermolecular Interactions in the Formation of Polysaccharide-Gelatin Complexes: A Spectroscopic Study.

Gelatin, due to its gelling and stabilizing properties, is one of the widely used biopolymers in biotechnology, medicine, pharmaceuticals, and the food industry. One way to modify the characteristics of gelatin is molecular modification by forming non-covalent polyelectrolyte complexes with polysaccharides based on the self-organization of supramolecular structures. This review summarizes recent advances in the study of various types and the role of intermolecular interactions in the formation of polysaccharide-gelatin complexes, and conformational changes in gelatin, with the main focus on data obtained by spectroscopic methods: UV, FT-IR, and 1H NMR spectroscopy. In the discussion, the main focus is on the complexing polysaccharides of marine origin-sodium alginate, κ-carrageenan, and chitosan. The prospects for creating polysaccharide-gelatin complexes with desired physicochemical properties are outlined.