Effect of reduced flaxseed cyclic peptide [1–9-NαC]-linusorb B2 (CLB) and its oxidized form on the oxidative stability of flaxseed oil

This study aimed to explore the antioxidant capacity and mechanism of cyclic peptide [1–9-NαC]-linusorb B2 (CLB) and its oxidized form ([1–9-NαC],[1-MetO]-linusorb B2 (CLC),[1–9-NαC],[1-MetO2]-linusorb B2 (CLK)) in flaxseed oil (FSO). The results showed that CLB delayed the oxidation of FSO (containing Cu²⁺) in the initial stage of accelerated oxidation, whereas CLK accelerated the oxidation, leading to an increase of 25 % in AV and 33 % in POV (P < 0.05). In molecular docking, the binding ability of cyclic peptides to metal ions and intermediate oxidative products such as aldehydes tends to decrease when CLB oxidized to CLC, then CLK. CLK had the poorest binding capacity with the most serious oxidation on FSO. In conclusion, the antioxidant capacities of CLB and its oxidized form were contributed by their reducing ability as well as their binding ability to metal ions and intermediate oxidative products of fatty acids.