Abstract:
To enhance the stability of double-loaded clove essential oil liposomes (DLCL), chitosan was used for surface modification, and the modified liposomes were comprehensively evaluated for their physicochemical properties and storage stability. The average particle size of chitosan-modified DLCL (CS-DLCL) was 330.43 nm, the PDI was 0.24, the Zeta potential was 17.78 mV, and the encapsulation rate was as high as 70.75%. These were obtained via optimization experiments with an optimal chitosan modification concentration of 3.5 mg/mL. FTIR analysis confirmed the electrostatic interaction between chitosan and DLCL. After 30 days of storage, the essential oil retention rate reached 87.08%. In terms of beef meatball freshness preservation, the ice temperature+CS-DLCL treatment group showed the best results, with the pH value of all meatballs increasing gradually over the storage period, and with the ice temperature + CS-DLCL group maintaining the lowest pH value after 12 days. Moreover, the total number of bacterial colonies grew the slowest, reaching 6.08 lg CFU/g (critical value of 6.0 lg CFU/g) only on the 12th day, significantly extending the shelf-life in the refrigerated group from 2~4 days to 10~12 days. Protein oxidation analysis showed that the ice temperature+CS-DLCL group had the lowest carbonyl content and the highest sulfhydryl content at the end of storage. This was further confirmed by the Thiobarbituric Acid Reactive Substances(TBARS) value analysis, which indicated the lowest lipid oxidation in this group, suggesting a synergistic effect of ice temperature and CS-DLCL in preserving beef meatballs. In addition, the meatballs in the ice temperature+CS-DLCL group maintained the best quality and sensory evaluation scores throughout storage. Collectively, the present study offers valuable insights for applying chitosan-modified double-loaded clove essential oil liposomes in beef meatball preservation.