Stability of low-fat oil in water emulsions obtained by ultra turrax, rotor-stator and ultrasound homogenization methods

The stabilities of 20 formulations of low-fat oil in water emulsions were evaluated with Ultra Turrax, rotor-stator and ultrasound applied as homogenization methods. Emulsions were formulated with extra virgin olive oil (15-20% w/w), egg yolk (0-5% w/w), mustard (0-5% w/w) and vinegar (10-25% w/w). The stability was determined at 7 days of storage through the parameters: ζ potential (mV), droplet size (nm), phase separation (cm), and viscosity (µ). The most stable emulsions were found with less phase separation distance in order ultrasound, rotor-stator and Ultra Turrax. Emulsions with smaller droplet sizes were obtained with ultrasound. The highest viscosity was found in emulsions obtained with the rotor-stator homogenizer. Regarding sensory preference, 43% acceptance was obtained with the rotor-stator method versus 21% for ultrasound. To cooks and chefs the use of rotor stator as homogenization technology could be an opportunity to prepare low fat emulsions with lower separation phases without effects on overall taste perception.