Effects of sonication on the kinetics of orange juice quality parameters

The effects of sonication on pH, degrees Brix, titratable acidity (TA), cloud, browning index, and color parameters ( L*, a*, and b*) of freshly squeezed orange juice samples were studied. Ultrasonic intensity (UI) levels of 8.61, 9.24, 10.16, 17.17, and 22.79 W/cm2 and treatment times of 0 (control), 2, 4, 6, 8, and 10 min were investigated. No significant changes in pH, degrees Brix, and TA ( p < 0.05) were found. Cloud value, browning index, and color parameters were significantly affected by ultrasonic intensity and treatment time. Changes in cloud value followed first-order kinetics, whereas browning index, L*, a*, and b* values followed zero-order kinetics. Reaction rate constants were linearly correlated ( R2 > 0.90) to ultrasonic intensity.