Ultrasound as an effective technique to reduce higher alcohols of wines and its influencing mechanism investigation by employing a model wine.

In this paper, in order to investigate the effects of ultrasound irradiation on the higher alcohols of wines, the parameters including ultrasound time, temperature and power were optimized by the response surface methodology, and the model wine solution was employed to explore the mechanism of ultrasonically decreasing the higher alcohols. The results indicate that the maximum decreasing of higher alcohols could be obtained under the ultrasound conditions of 30 min, 30 °C and 150 W, and the final content was 306.75 mg/L with the reduction rate of 40.44%, suggesting a modification of wine quality due to the negative effects of excessive contents on wine. Regarding the results of model wine, it indicates that the decrease could be definitely affected by factors, such as tartaric acid and ions in wine, which might be attributed to the free radicals generated from ultrasound cavitation and its subsequent reactions. In summary, all the results may help to understand the effects of ultrasound irradiation on improving the sensory properties of wine by decreasing the higher alcohols.

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 °C, power 225 W and frequency 28 kHz, and the activity of beta-GC achieved 3.64 × 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.

[Drying Process and Model of Banqiao Codonopsis Radix Slice in Air-impingement Jet Dryer].

Objective: To determine the drying process and to built model of Banqiao Codonopsis Radix slices dried in air-impingement jet dryer. Methods: With taking the content of polysaccharides( CPPS),rehydration ratio( RR) and drying time as the evaluation indexes,the effects of drying temperature( 40,50,60 and 70 ℃),slices thickness( 1,2,3 and 4 mm) and air velocity( 8,10,12,and 14 m / s) on the content of CPPS,RR and drying time were studied. With taking the R2,χ2and RMSE as the evaluation indexes,the optimum model was screened by fitting the drying curves data with four selected models. Results: The variety of all studied factors lead to change of the content of CPPS,RR and drying time,and the influence of air-temperature was most significant. Under the test conditions,the content of CPPS,RR and drying time were range from 20. 33% ~ 28. 26%,2. 65 ~ 3. 25 and 180 ~ 510 min, respectively. Among the four selected drying models, Modified Page model was the most suitable model to fit the drying curves data with the maximum average of R2( 0. 9993),the smallest average of χ2( 0. 00022) and the smaller average RMSE( 0. 01066). Conclusion: By comparison the content of CPPS,RR and drying time, the optimal drying process of Banqiao Codonopsis Radix slices dried in the air-impingement jet dryer was air temperature of 60 ℃,slice thickness of 2 mm and air velocity of 12 m / s. Under the drying conditions of air temperature 40 ~ 70 ℃,slice thickness 1 ~ 4 mm and air velocity 8 ~ 14 m / s, Modified Page model can effectively predict the moisture change of Banqiao Codonopsis Radix slice dried in air-impingement jet dryer.