Phase change material-based antibacterial nanoparticles for short-term preservation of cooked meat during temperature abuse

To prevent the rapid microbial growth caused by unintended temperature abuse during the handling of cooked meat, such as malfunctioning hot-holding equipment or improper storage, this study developed a smart formulation that can be triggered by high temperature to release antibacterial agents on demand. A mixture of lauric acid and stearic acid was employed as the phase change material (PCM), and cinnamaldehyde (CA) was used as the active substance to fabricate this composite (CA/PCM). At 42 °C, CA/PCM can transit from a solid phase to a molten state, leading to the rapid release of embedded CA. In vitro experiments showed that, compared with the 25 °C group, the CA/PCM-42°C group reduced the colony counts of E. coli and S. aureus by 74.5% and 74.0%, respectively, and also decreased the biofilm absorbance by 92.75% and 82.08%, respectively. Compared with the samples stored at 25 °C, the inoculated meat stored at 42 °C for 24 h exhibited smaller changes in colour (∆E* < 3.5), hardness, pH, TVB-N, and MDA values. Moreover, the microbial counts remained below 5 log CFU·g-1. The results demonstrate that CA/PCM serves as an effective fail-safe strategy, providing targeted antimicrobial protection specifically under temperature-abuse conditions for the preservation of cooked meat.