Collagen extracted from the residual skin of tilapia filleting (Oreochromis spp.) obtained from fish farmers: yield, microbiological characterization and FTIR analysis

Tilapia (Oreochromis spp.) is the most produced fish species in Brazilian aquaculture. Fish processing generates a significant volume of waste, which corresponds to 30% to 70% of the total weight of the animal. However, these wastes have great economic and industrial potential, as they are raw materials rich in biomolecules with high added value, such as enzymes and collagen. Thus, this study aimed to evaluate the technical and economic feasibility of using tilapia skins as a sustainable raw material for collagen extraction. To carry out the research, the skin was collected, discarded by fish farmers from the Fish Market of Teresina, PI, and then collagen extraction was carried out with different skin treatments and extraction time in acid solution, later microbiological analyses of the extracted collagen and analysis by FTIR were carried out. Thus, it is concluded that the grinding of tilapia skin in the extraction process increased the extraction yield from 10.25% to 19.16%, in one of the treatments tested. The extraction process was efficient in reducing the microbial count and eliminating Salmonella spp. and Vibrio spp. present in the skin in natura. The extraction using ultrasonic vat maintained the characteristics of type I collagen as shown in the FTIR analyses.