Effects of orthogonal dual-frequency ultrasound-assisted treatment combined with bioactive coating containing L. essential oil on changes in quality, lipid, and protein of large yellow croaker () during cold storage.

How to reduce the quality loss of aquatic products during storage is a topic worth exploring. This study proposed a method combining orthogonal dual-frequency ultrasound-assisted treatment (20 kHz vertically, 40 kHz horizontally, 400 W) with bioactive coating ( L. essential oil-carboxymethyl chitosan-locust bean gum) and discussed the effects of this combined treatment on the quality, lipid, and protein of large yellow croaker during cold storage (4 °C). The results showed that both ultrasound-assisted treatment (US) and bioactive coating (CMCS) significantly inhibited microbial growth and quality deterioration in the fish, with the combined treatment group (US+CMCS) showing the best effect. The shelf life of large yellow croaker in the control group (CK) was 6 d, while the shelf life for US, CMCS, and US+CMCS treatments was 12 d, 12 d, and 18 d, respectively. Additionally, the combined treatment inhibited lipid oxidation and effectively delayed the oxidative degradation of protein in the large yellow croaker during cold storage. Therefore, the method of orthogonal dual-frequency ultrasound-assisted treatment (20 kHz vertically, 40 kHz horizontally, 400 W) combined with bioactive coating ( L. essential oil-carboxymethyl chitosan-locust bean gum) proposed in this study was a promising approach for the preservation of aquatic products during storage.