Organic-inorganic composite phase change gels for cold chain preservation of fruits and vegetables

In recent years, phase change materials have attracted increasing attention for cold chain logistics. However, many conventional organic or inorganic phase change materials suffer from critical limitations in low-temperature applications, including severe supercooling, poor cycling stability, leakage, and phase separation, which significantly restrict their practical use in cold chain systems. To address these challenges, a composite phase change material gel (CPCMG) was developed for cold chain applications. The material exhibits a suitable phase transition temperature, high latent heat, excellent cycling stability, and favorable scalability for large-scale production. The CPCMG is composed of 3 wt% mannitol, 5 wt% sodium carbonate, and 1 wt% xanthan gum. The material exhibits a phase transition temperature of −5.5 °C, a latent heat of 297.5 J/g, and a thermal conductivity of 0.6144 W/(m·K). After 100 thermal cycles, its thermal performance remains stable, demonstrating excellent durability. To evaluate its practical application, the CPCMG was integrated into an insulated box for a cherry preservation experiment. The results showed that the pre-cooling time for cherries in the box was 1.17 h, with an average temperature of 2.21 °C, and that the temperature could be maintained within the optimal refrigeration range of 0-4 °C for 28.41 h, effectively extending their shelf life. These findings demonstrate that CPCMG functions as an efficient cold energy storage material, offering stable temperature regulation performance and substantial potential for practical implementation in the cold chain logistics of fruits and vegetables.