Optimization of ultrasound parameters and its effect on the properties of the activity of beta-glucosidase in apricot kernels

In this paper, ultrasound was used as an auxiliary tool to activate the activity of beta-glucosidase (beta-GC) in apricot kernels, and its parameters were optimized to evaluate the effects on the beta-GC activity with the response surface methodology (RSM), variables including ultrasonic time, temperature, power and frequency. The results indicate that the obtained quadratic regression model could simulate the actual conditions, and the optimum conditions were as follows: exposure time of 31 min, temperature 50 degrees C, power 225 W and frequency 28 kHz, and the activity of beta-GC achieved 3.64 x 105 U/g.apricot kernel (dry weight), having an increase of 34.67% compared to the untreated beta-GC. In addition, the changes of the beta-GC properties demonstrated that ultrasound did improve the activity of beta-GC by influencing the beta-GC's properties of fluorescence, circular dichroism, thermal property, etc. All these results would contribute to understand the mechanism of the rapid debitterizing of apricot kernels accelerated by ultrasound.