Impact of Carbon Dioxide Nanobubbles on Crystallising Properties of Palm Oil

The influences of CO₂ incorporated in gas nanobubbles (NBs) on palm oil crystallisation and physical characteristics were investigated. Initially, CO₂ NB-treated palm oil had a significantly (p ≤ 0.05) larger amount of dissolved CO₂ (~ 1200–1700 ppm). The crystal morphology evaluation showed smaller size and higher number of palm oil crystals by the presence of CO₂ NBs. Additionally, the attendance of NBs caused a slight increment in crystallising enthalpy magnitude and a significant reduction in final end-set melting temperatures (by 4.5–6 °C) of palm oil stored at 4 °C. There was also a significant (p ≤ 0.05) increase in melting enthalpies by 1.3–3.5 J/g and 6.5–9 J/g of the NB-treated samples under 48-h storage conditions at 23 °C and 4 °C, respectively. Furthermore, the CO₂ NB-treated palm oil was characterised by both lighter colour and lower hardness. Research findings demonstrate that the introduction of food-grade gas NBs can be a sustainable and eco-friendly method to tailor thermal behaviour and physical properties of palm oil.