The preservative properties of waste liquor obtained from octopus (Octopus vulgaris) cooking were investigated. Three different concentrations (high, medium, and low) of octopus cooking liquor (OCL) were included, respectively, in the aqueous packaging medium employed for mackerel (Scomber colias) canning. As a result, the canning process led to an increase (p < 0.05) of lipid content, lipid oxidation (development of fluorescent compounds and thiobarbituric acid reactive substances, TBARS), lipid hydrolysis (formation of free fatty acids, FFA) and ω3/ω6 ratio in fish muscle. In all canned samples, primary (peroxides) and secondary (TBARS) levels of lipid oxidation were low. Remarkably, the presence in the packaging medium of the high and medium OCL concentrations led to lower (p < 0.05) lipid oxidation development (fluorescent compound and TBARS detection, respectively). Furthermore, an increasing OCL presence led to an average decrease of peroxide and FFA content and to an average increase of the polyene index (PI). All OCL-packaged muscle showed lower average values of saturated fatty acids and ω3/ω6 ratio and higher average values of PI and monounsaturated fatty acid presence. This study provides a first approach to novel and beneficial use of the present marine waste to inhibit lipid damage of commercial canned fish.

The effect of the rigor stage (pre or post) and previous high-pressure processing (HPP; 450 and 550 MPa for 3 min) was checked during the storage on ice of farmed palm ruff (Seriolella violacea). Fish processed in pre-rigor conditions led to higher and lower levels (p < 0.05) of moisture and lipid contents in chilled fish, respectively, when compared to their counterpart samples processed in the post-rigor stage. Pre-rigor fish showed a higher (p < 0.05) quality level than post-rigor samples according to the assessment of the K value (59.0–92.1 and 70.3–96.3 ranges, respectively), fluorescent compounds (0.29–1.11 and 0.37–1.90 ranges, respectively), free fatty acids (FFA) (15.1–188.0 and 33.8–232.5 g·kg⁻¹ lipids ranges, respectively), and total volatile amines (216.3–387.6 and 217.7–412.2 g·kg⁻¹ muscle ranges, respectively). Pressure-treated fish showed higher (p < 0.05) quality retention than non-treated samples according to the formation of fluorescent compounds (0.29–0.86 and 0.85–1.90 ranges, respectively), FFA (15.1–50.6 and 58.9–223.5 g·kg⁻¹ lipids ranges, respectively), and total volatile amines (216.3–250.3 and 351.1–412.2 g·kg⁻¹ muscle ranges, respectively) and the evolution of the K value (59.0–77.2 and 86.9–96.3 ranges, respectively). The use of pre-rigor fish and previous HPP is recommended for the commercialisation of the current species as a fresh product.

The direct transformation of simple and abundant feedstocks into structurally complex molecules remains a central challenge in modern organic synthesis. Herein, we report a method for the oxidative cascade cyclization of N ‐aryl and N ‐benzoyl acrylamide derivatives, promoted by methane and other gaseous alkanes. This transformation is enabled by a readily available iron catalyst in combination with N ‐fluorobenzenesulfonimide (NFSI) as the oxidant, proceeding under mild conditions to afford a diverse array of N ‐heterocyclic frameworks in high yields. Late‐stage functionalization studies highlight the utility of methane in the synthesis of biologically relevant scaffolds. Moreover, the Fe/NFSI system facilitates a radical sampling regime that enables the selective functionalization of less reactive primary C─H bonds. Overall, this work establishes a sustainable and versatile platform for constructing molecular complexity directly from gaseous alkanes.

The direct transformation of simple and abundant feedstocks into structurally complex molecules remains a central challenge in modern organic synthesis. Herein, we report a method for the oxidative cascade cyclization of N ‐aryl and N ‐benzoyl acrylamide derivatives, promoted by methane and other gaseous alkanes. This transformation is enabled by a readily available iron catalyst in combination with N ‐fluorobenzenesulfonimide (NFSI) as the oxidant, proceeding under mild conditions to afford a diverse array of N ‐heterocyclic frameworks in high yields. Late‐stage functionalization studies highlight the utility of methane in the synthesis of biologically relevant scaffolds. Moreover, the Fe/NFSI system facilitates a radical sampling regime that enables the selective functionalization of less reactive primary C─H bonds. Overall, this work establishes a sustainable and versatile platform for constructing molecular complexity directly from gaseous alkanes.