Liquid by-products from fish canning industry as sustainable sources of ω3 lipids

Fish canning industry generates large amounts of liquid wastes, which are discarded, after proper treatment to remove the organic load. However, alternative treatment processes may also be designed in order to target the recovery of valuable compounds; with this procedure, these wastewaters are converted into liquid by-products, becoming an additional source of revenue for the company. This study evaluated green and economically sustainable methodologies for the extraction of ω3 lipids from fish canning liquid by-products. Lipids were extracted by processes combining physical and chemical parameters (conventional and pressurized extraction processes), as well as chemical and biological parameters. Furthermore, LCA was applied to evaluate the environmental performance and costs indicators for each process. Results indicated that extraction with high hydrostatic pressure provides the highest amounts of ω3 polyunsaturated fatty acids (3331,5 mg L-1 effluent), apart from presenting the lowest environmental impact and costs. The studied procedures allow to obtain alternative, sustainable and traceable sources of ω3 lipids for further applications in food, pharmaceutical and cosmetic industries. Additionally, such approach contributes towards the organic depuration of canning liquid effluents, therefore reducing the overall waste treatment costs.REQUIMTE received financial support from FEDER (NORTE-07-0124-FEDER-000069 and Norte-01-0145-FEDER-000011-RL1–QUALIFOOD), PEst-C/EQB/LA0006/2013, and from FCT (UID/QUI/50006/2013). Authors acknowledge La Gondola for supplying the raw material used. QOPNA acknowledges FCT/MEC (FCT UID/QUI/00062/2013), and FEDER (PT2020 Partnership Agreement).