Application and Mechanism of Nanofluid in Liquid Food Sterilization

Nanofluid is an emerging fluid that can replace the traditional medium in heat exchanger. The heat exchanger using nanofluid as the heat transfer medium has the characteristics of high heat transfer efficiency, short sterilization time and can better maintain the sensory and nutritional characteristics of food based on the characteristic of nanofluid such as good stability, reusability, and energy saving. The fluid has been successfully applied to the sterilization of liquid foods (milk and juice). The application of different types of nanofluids, such as multi-wall carbon nanotubes (MWCNT)/water, TiO₂/water and Al₂O₃/water nanofluids in liquid foods sterilization are outlined. Meanwhile, the methods for preparing nanofluids and improving the stability of nanofluids are also reviewed. At last, the thermal conductivity enhancement mechanism according to its Brownian motion, liquid film layer and nanoparticle chain structure of nanofluid as well as the sterilization mechanism of nanofluids based on the reactive oxygen effect and the interaction between nanoparticle and cell wall, cell membrane and cell contents are importantly summarized. It is expected to provide theoretical guidance for the application of nanofluids in food and improve food safety.