Abstract
The influences of low intensity ultrasound and ohmic heating on Sake yeast were investigated. The results showed that low intensity ultrasound promoted the growth of Sake yeast K-7 and increased the rate of glucose consumption and ethanol production. After ultrasonic irradiation, a significant increase of intracellular uptake was observed. The promotion effect on growth was frequency dependent. In addition, the ultrasonic irradiation during the exponential phase showed the strongest influence and during the stationary phase the influences were not obvious. During ohmic heating treatment, the rate of glucose consumption and ethanol production was increased and the promotion effect on cell growth was slightly higher at 3 kHz than that of 60 Hz. However, the influence of electricity consumption on cell growth was not obvious. Meanwhile, the combined effect of ultrasound and ohmic heating on the growth of Sake yeast was slightly higher than those of separate treatments.