Sardine canning byproducts as sources of functional ingredients

Sardine byproducts generated during the canning process entail a potential opportunity to drive them into a chain of high-added-value compounds while simultaneously decreasing the environmental impact of their discharge. This paper describes and discusses the biochemical variation of solid and liquid byproducts generated during the sardine canning process during one complete year. Additionally, byproducts were also evaluated in terms of their degradation over time as monitored through microbiological and chemical analysis. Finally, their valorization was ascertained through the recovery of lipid fractions rich in ω3 polyunsaturated fatty acids (PUFAs) as well as protein fractions with antihypertensive activity (ACE). The variability of the biochemical composition of byproducts during the year was significant, especially in terms of lipid content, and their degradation was strongly dependent on the conditions under which they were collected and stored. Both liquid and solid byproducts present ω6/ω3 ratios between 0.05 and 0.18 and thrombogenic indexes between 0.27 and 0.57, whereas low-molecular-weight fractions of protein extracts (<3 kDa) exhibited the strongest ACE activity (IC₅₀ = 51 μg/mL). The potential viability of using liquid byproducts as sources of functional ingredients is an interesting alternative to the management of these effluents in the fish canning industry.