Cold atmospheric plasma–antioxidant synergy improves the gel structure of squid surimi

Cold atmospheric plasma (CAP) inactivates proteases in squid surimi but induces protein oxidation. This study evaluated three antioxidants—tea polyphenols (TP), butylated hydroxyanisole (BHA), and octyl gallate (OG)—for mitigating CAP-induced oxidation. CAP treatment significantly enhanced the radical-scavenging capacity of the antioxidants, particularly TP (38.6% increase of ABTS assay results) and OG (8.41% increase of DPPH assay results), likely by activating phenolic hydroxyl groups. While CAP alone improved whiteness and gel strength, it reduced sulfhydryl content and Ca 2+ -ATPase activity, indicating protein oxidation. However, combining CAP with TP or OG effectively preserved protein integrity, promoted the formation of disulfide bonds and hydrophobic interactions, and enhanced storage modulus, water-holding capacity, and texture. These findings demonstrate that natural polyphenols constructively moderate CAP-induced oxidation, offering a promising strategy for improving the gel quality and techno-functionality of squid surimi. • FTIR confirms CAP boosts antioxidant activity of TP ,BHA and OG. • CAP improves gel strength and whiteness of squid surimi. • TP and OG mitigate CAP-induced protein oxidation effectively. • CAP–antioxidant synergy promotes ordered protein cross-linking. • Natural polyphenols improve surimi gel structure and functionality.