Impact of KCl and ultrasound on the structural properties of myofibrillar proteins in low sodium semi-dried large yellow croaker (Pseudosciaena crocea)

Abstract

The effect of ultrasound treatment combined with KCl instead of NaCl on the structure of myofibrillar proteins of semi-dried large yellow croaker was investigated by measuring protein oxidation indicators and observing structural changes. Compared with the fillets treated with NaCl combined with ultrasound, the fillets treated with KCl combined with ultrasound had high carbonyl content, low sulfhydryl content, small particle size, and strong surface hydrophobicity. In contrast, when KCl replaced 50% of NaCl, it was found that the oxidation was effectively alleviated, and intermolecular force was enhanced. According to structural changes, the irregular curvature of myofibrillar proteins accounted for a large number of smaller and more stable structures in KCl substitution with 50% NaCl. In conclusion, partial substitution of KCl for NaCl combined with ultrasound in the preparation of semi-dried rhubarb can protect myofibrillar protein structure and reduce oxidation to some extent.