Large scale emulsification of turmeric oil in skimmed milk using different cavitational reactors: A comparative analysis

The present work investigates the use of different cavitational reactors for obtaining stable emulsion of turmeric oil in skimmed milk comparing the efficacy in terms of the droplet size distribution and energy requirements. The effect of different operating parameters such as ultrasonic power in the case of flow cell, inlet pressure in the case of hydrodynamic cavitation and speed of rotation in the case of high speed homogenizer (HSH) on the droplet size and stability was investigated. In the case of ultrasonic bath, the effectiveness of treatment approach was also analyzed for different combinations based on the ultrasound and stirring. An increase in power in the case of ultrasonic flow cell, inlet pressure in hydrodynamic cavitation and speed of rotation in HSH resulted in a reduction in the oil droplet size. Optimum operating conditions were established so as to get the desired size and stability of emulsion. To produce stable emulsion, the energy requirement of ultrasonic bath (98.28 J/mL) was observed to be far lower than that of ultrasonic flow cell (461.4 J/mL) and hydrodynamic cavitation with orifice plate (1008.00 J/mL), circular venturi (756.00 J/mL) and slit venturi (1008.00 J/mL). The obtained results clearly established that ultrasonic bath reactor operated in combination with stirrer produced stable emulsion with minimum droplet size (232.2 +/- 2.5 nm) and PDI value as 0.12 at lowest energy consumption.