In this study, research was based on influence of high intensity ultrasound treatment on degree of homogenization of soybean milk. Inhomogeneous milk was treated using ultrasonic equipment (maximal nominal power - 100 W) with the constant frequency of 24 kHz, set to different nominal power (P = 20, 60, 100W), with the time of treatment ( t = 2, 6, 10 and 15 minutes). Changes on size of fat globules were monitored with the optical microscopy (1000 × magnification). All samples were captured with high resolution digital camera, and images were analyzed in “ Image J” software. Obtained data were statistically analyzed in “ Statistica 6” software, and dimensions of fat globules were represented with “ Log – Normal distribution” graph. Physical properties of ultrasonically treated homogenized milk, which include measuring of density, viscosity, and pH – value before and after treatment were also conducted. Influence of process parameters (nominal power and time) on physical properties and degree of homogenization (variance) were represented with “ Pareto chart of standardized effects” Increase of the power (nominal power up to 100 W) leads to increase of degree of homogenization, and decrease in size of fat globules in samples. Maximum nominal power (100 W) used during maximum times (10, 15 minutes), shows highest degree of homogenization, while size of fat globules rapidly drops with the increase of amplitude and time. Longer time of treatment with ultrasound showed significant changes on all physical properties.

Food processing technology