超声预处理对米渣蛋白酶解特性的影响

Effect of Ultrasonic Pretreatment on the Enzymatic Hydrolysis Characteristics of Rice Residue Protein

摘要:

以米渣粉为原料，以常规酶解作对照，考察不同超声功率（100 W和300 W）、超声时间（15 min和30 min）和超声模式（连续超声和工作间歇比2:2 s）预处理米渣原料后对酶解改性米渣蛋白回收率、水解度、可溶性氮含量、表面疏水性和粒径的影响。研究表明，不同超声处理条件对米渣蛋白的回收率、可溶性氮含量和水解度影响不显著，但同对照组相比，蛋白质回收率和水解度均有所提升。表面疏水性随着超声功率和超声时间的的增大而增大，间歇超声处理米渣蛋白的表面疏水性小于连续超声处理的。超声功率从100 W增加到300 W时，蛋白质粒径由236 nm增加至256 nm，但都小于未超声组；超声时间15 min时米渣蛋白粒径小于未超声组，当超声延长至30 min时粒径增大；间歇超声处理的蛋白质粒径大于连续超声组且都小于未超声组。超声预处理可改善米渣蛋白的酶解敏感性，提高其水解度和蛋白质回收率。与单一酶解改性相比较，超声预处理后酶解得到的改性米渣蛋白可溶性氮含量提高，表面疏水性降低，粒径减小。

Abstract:

Rice residue was chose as raw material. The conventional enzymatic hydrolysis was selected as a control. Effects of different ultrasonic power (100 W and 300 W), ultrasonic time (15 min and 30 min) and ultrasonic mode (continuous ultrasonic and working intermittent ratio 2:2 s) on the recovery rate, hydrolysis degree, soluble nitrogen content, surface hydrophobicity and particle size of the enzymatically modified rice residue were investigated. Results showed that different ultrasonic treatment conditions had no significant effect on the recovery rate, soluble nitrogen content and hydrolysis degree of rice residue protein. The protein recovery rate and hydrolysis degree were improved compared with the control group. The surface hydrophobicity increased with the increase of ultrasonic power and ultrasonic time. The surface hydrophobicity of rice residue protein with intermittent ultrasonic treatment was less than that with continuous sonication. When the ultrasonic power increased from 100 W to 300 W, the protein particle size increased from 236 nm to 256 nm, but both were smaller than the non-ultrasound group. Under 15 min ultrasonic treatment, the particle size of the rice residue protein was less than that of the non-ultrasound group, and the particle size increased when time is extended to 30 min. The protein size of rice residue protein with the intermittent ultrasound was larger than that of the continuous ultrasound group, and both were smaller than the non-ultrasound group. Ultrasonic pretreatment can improve the enzymatic sensitization of rice residue protein and increased its hydrolysis degree and protein recovery rate. Compared with the single enzymatic modification, enzymatic hydrolysis combined with ultrasonic pretreament can induce an increase in the soluble nitrogen content of the modified rice residue protein, increasand the decrease in the surface hydrophobicity and the particle size.