Abstract

Biophysical properties and aggregation of natural actomyosin (NAM) from threadfin bream (Nemipterus bleekeri) subjected to atmospheric pressure cold plasma (APCP) treatment with different contact times were determined. Protein solubility, turbidity, Ca²⁺-ATPase activity, total sulfhydryl (SH) group content, protein carbonyl content, and SDS-PAGE were monitored. With increasing APCP contact times (from 0 to 30 min), total SH group content (5.74–3.77 mol/10⁵ g protein), Ca²⁺-ATPase activity (0.32–0.23 μmol Pi/mg protein/min), and solubility (100–92%) of NAM decreased, while protein carbonyl content (1.43–36.47 μmol/g protein) increased to a higher extent. During APCP treatment, cross-linking via disulfide bond as visualized by SDS-PAGE along with increased turbidity of NAM was observed. Therefore, APCP treatment markedly induced biophysical changes and aggregation of NAM which can be used as a possible approach to strengthen the gel formation of threadfin bream surimi.