Bulk nanobubbles (NBs) are ultrafine gas-filled cavities at nanoscale size possessing unique properties which can provide promising benefits to food product quality and processability. This work aimed to investigate the formation and stability of CO₂ bulk NBs in water for intended applications in food processing. The NBs were generated by injecting CO₂ gas at 300, 350 and 400 kPa pressures to deionised water pumped at 100 and 200 kPa through a commercial NB generator. Size measurement via dynamic light scattering (DLS) technique indicated that CO₂ NBs generated were in the range of 200–500 nm depending on the gas pressures, gas and water flow rate used. Concentration of CO₂ in water containing the NBs (~ 2000 ppm) also increased significantly. Zeta potential of the formed NBs varied from − 8 to − 19 mV, indicating their stability in the aqueous medium. Their existence lasted for more than 7 days with a good repeatability of size distribution density, and the pH values of CO₂–NB solution were maintained below 4. These findings highlight some new fundamental understandings on the generation and physical characteristics of CO₂ NBs, which can have potential applications in food processing that need to be further explored.

散装纳米气泡（NBs）是纳米级的超细充气腔，具有独特的性能，可以为食品的质量和可加工性提供有希望的益处。这项工作旨在研究食品加工中预期用途中水中CO ₂块状NB的形成和稳定性。通过将300、350和400 kPa的压力的CO ₂气体注入通过商用NB发生器以100 kPa和200 kPa泵送的去离子水中来生成NB。通过动态光散射（DLS）技术进行的尺寸测量表明，根据所使用的气压，气体和水的流速，产生的CO ₂ NBs在200–500 nm范围内。CO ₂浓度含有NBs（〜2000 ppm）的水中的水也显着增加。形成的NB的Zeta电位在− 8至− 19 mV之间变化，表明它们在水性介质中的稳定性。它们的存在持续了超过7天，并且具有良好的尺寸分布密度可重复性，并且CO ₂ -NB溶液的pH值保持在4以下。这些发现突显了对CO ₂ NB的产生和物理特性的一些新的基本认识，在食品加工中可能具有潜在的应用，需要进一步探讨。