Authors : T. Kim and J.L. Silva
Abstract: Ultrasound has been reported as a possible alternative to disinfect water. However, few studies have been conducted to establish application of high-frequency ultrasound on liquid foods. Processing of orange juice for 30 min using continuous high-frequency ultrasound (CHFU) increased temperature up to 53 C. Ultrasonic power was determined by calorimetry method. The increased temperature could be a critical parameter to decide whether some effects to orange juice of CHFU are due to heat generated during CHFU processing. Changes in pH, titratable acidity, and browning index were not significant while ‘L`, ‘a`, ‘b`, ‘SI`, and Hue values increased. Ascorbic acid degradation and some inactivation of pectin methylesterase (PME) were observed over time. An approximate 5 log reduction in yeast counts was obtained by application of CHFU for 30 min.
T. Kim and J.L. Silva , 2004. Effects of Continuous High-frequency Ultrasound on Selected Characteristics of Orange Juice . Journal of Food Technology, 2: 120-124.