Temperature-responsive microcapsule sachet enhances food preservation in cold chain through controlled ClO2 release and multimodal action

To address the accelerated spoilage of food caused by temperature fluctuations during cold chain transportation, an intelligent preservation sachet (MCs-Sachet) with temperature-responsive activation was developed. The MCs-Sachet incorporates a polyethylene glycol–citric acid (PEG-CA) matrix and sodium chlorite (NaClO 2 ) microcapsules. Upon exposure to elevated temperature, the composite undergoes a phase transition, releasing acid that triggers the controlled generation of chlorine dioxide (ClO 2 ). The MCs-sachet exhibited broad-spectrum antimicrobial activity, achieving complete inactivation of Escherichia coli , Staphylococcus aureus , and Botrytis cinerea to below the detection limit at a microcapsule loading of 0.75 g. Additionally, it suppressed respiration and reduced ethylene accumulation in blueberries by 88.13%, thereby extending shelf life by approximately 2-fold at 25 °C. In shrimp stored at 4 °C, freshness was prolonged by 48 h. These multifunctional effects demonstrate that the MCs-Sachet servers as an adaptive platform for enhancing food preservation within dynamic cold chains environments.