(Received November 20, 2001; revised manuscript revised December 25, 2001; accepted for publication January 25, 2002)
In recent years, applications of ultrasound to food processing have been of interest. Fermentation is a typical example of food processing which has been used, since ancient times, on milk and is utilized for processing various dairy products, e.g., yoghurt. In this study, ultrasonic irradiation to shorten the time of fermentation in yoghurt production is attempted. It is proven that shortening the fermentation time is possible by employing ultrasonic irradiation.