Ultrasonic processing of butter oil (ghee) into oil-in-water emulsions

Butter oil (ghee) derived from cow or buffalo milk is in semi-solid form at room temperature and contains >99% of lipids. Apparent high viscosity and water immiscibility - owing to the hydrophobic nature of lipid components hinder the applicability of butter oil for formulations. Here, we have employed ultrasonic processing technique to create oil-in-water emulsions of butter oil. We show that the butter oil is capable of self-stabilizing an emulsion at low concentration while higher concentrations could be kinetically stabilized using pluronic stabilizer. We were able to modulate water contents of emulsions in the range of 80%-95% and maintain the particle size in submicron range. Reported butter oil emulsions retain hydrophobic properties of the original butter oil within cores of dispersed particles, overcome a problem of butter oil-water immissibility, display fluid consistency, and are stable for several months. These properties are highly suitable for developing food, pharmaceutical, and cosmetic formulations. Practical applicationsUltrasonic processing of butter oil improves its miscibility with water and increases its fluidity thereby enhancing its capability to be used as or to derive formulations for various applications. Further advantage of the reported butter oil emulsions is that they can be loaded with polar' in addition to non-polar' active molecules, which was hardly possible with formulations merely based on butter oil. This is because an aqueous phase of the butter oil emulsion contains 80%-95% water where polar molecules can easily be solvated. These emulsions, prepared from quite an abundant and economical source, can potentially act as alternatives to the emulsions that usually involve highly expensive lipid components whose extraction or synthesis are rather tough tasks. The ultrasonic processing of butter oil, presented here, could be easily scaled-up using continuous processing modes.