摘要：The effect of acoustic energy on the rheological behaviour and serum separation during storage of traditional Ayran, which is a mixture of yogurt, water and salt, was investigated. Ayran samples were prepared by the addition of water at a level of 40% (w/w) and salt at a level of 1% (w/w) and stored at 4 °C. They were sonicated for two and four minutes using an ultrasonic generator at a frequency of 20 kHz. The ultrasonic amplitudes used were 40% (22.91W), 60% (33.38W) and 80% (44.54W). Viscosity was measured using a rotational viscometer at the speed of 20, 30, 50, 60, 100 and 200 rpm. The highest apparent viscosity in Ayran was obtained at 44.54 W power level for 4 minutes. In addition, it was obtained that acoustic energy had a significant effect on the serum separation of Ayran. An empirical power-law model was used to describe the rheological behaviour of Ayran samples with regression coefficients between 0.891 and 0.997. Ayran exhibited a pseudoplastic behaviour, non-Newtonian.
关键词：Acoustic energy; traditional Ayran; viscosity; serum separation
