Preparation of Cinnamon Essential Oil/Succinic Acid-Modified Cyclodextrin and Their Application in Grass Carp Preservation.

The spoilage of grass carp is driven by multiple factors, predominantly microbial proliferation and lipid oxidation. Although cinnamon essential oil exhibits potent antibacterial and antioxidant properties, its industrial application is constrained by high volatility, poor water solubility, and a strong pungent odour. To address these challenges, β-cyclodextrin-succinate (SACD) was synthesized via esterification. Prior studies confirmed that SACD demonstrates significantly improved solubility and antibacterial efficacy compared to β-CD. Thereafter, SACD was employed to encapsulate cinnamon essential oil. Moreover, the succinic acid-modified cyclodextrin-encapsulated essential oil exhibits a stronger antioxidant capacity compared to the free essential oil. Through a series of characterization techniques and molecular docking analysis, the successful synthesis of SACD and its inclusion complexes was confirmed. To assess their efficacy in preserving grass carp meat, four experimental groups were established: a control group, an essential oil group (EO), an unmodified inclusion complex group (EO/CD), and a modified inclusion complex group (EO/SACD). Under refrigerated conditions at 4 °C, the pH, drip loss rate, TBARS, TVC, TVB-N, K-value, and texture of fish meat samples were determined across different treatment groups. During the later stages of storage, the total bacterial count in the inclusion complex group was lower than that in the EO group and the control group, indicating that the cyclodextrin-encapsulated essential oil effectively inhibited microbial growth (p < 0.05). The results demonstrated that the EO/SACD group delayed spoilage and prolonged the storage period of grass carp compared to both the EO and EO/CD groups.