Protein-polysaccharide complexes from soy protein and carrageenan obtained by electrosynthesis

Protein - polysaccharide interactions play a fundamental role in the development of plant-based biomaterials. The aim of this study was to characterize the electrochemical production (12 V, on chromium‑nickel stainless steel electrodes) of polysaccharide-protein complexes from carrageenan and soy protein isolate, followed by analysis of the obtained products. The resulting complexes contained by approximately 10 % more protein than the blends from which they were prepared. Solubility tests, spectroscopic studies, thermogravimetric, and differential thermal analysis suggested that covalent bonds and strong electrostatic interactions the main role in their formation play. Electrocomplexes are characterized by their low solubility and water holding capacity, and some have a partially crystalline structure. The small amplitude oscillatory test shows that 20 % aqueous suspensions of these electrocomplexes exhibit the rheological characteristics of weak gels. As new materials, they can find applications in both the food and non-food industries, for example as edible film coatings or biodegradable packaging materials.