Electrodialysis Extraction of Pufferfish Skin (Takifugu flavidus): A Promising Source of Collagen

Collagen is widely used in drugs, biomaterials, foods, and cosmetics. By-products of the fishing industry are rich sources of collagen, which can be used as an alternative to collagen traditionally harvested from land mammals. However, commercial applications of fish-based collagen are limited by the low efficiency, low productivity, and low sustainability of the extraction process. This study applied a new technique (electrodialysis) for the extraction of Takifugu flavidus skin collagen. We found electrodialysis to have better economic and environmental outcomes than traditional dialysis as it significantly reduced the purification time and wastewater (95%) while maintaining high extraction yield (67.3 +/- 1.3 g/100 g dry weight, p < 0.05). SDS-PAGE, amino acid composition analysis, and spectrophotometric characterization indicated that electrodialysis treatment retained the physicochemical properties of T. flavidus collagen. Heavy metals and tetrodotoxin analyses indicated the safety of T. flavidus collagen. Notably, the collagen had similar thermal stability to calf skin collagen, with the maximum transition temperature and denaturation temperature of 41.8 +/- 0.35 and 28.4 +/- 2.5 degrees C, respectively. All evidence suggests that electrodialysis is a promising technique for extracting collagen in the fishing industry and that T. flavidus skin collagen could serve as an alternative source of collagen to meet the increasing demand from consumers.