聚能式逆流脉冲超声预处理对玉米蛋白酶解的影响

为了研究聚能式逆流脉冲超声预处理对玉米蛋白酶解性能的改善，在单因素试验基础上，以水解度和酶解产物血管紧张素转换酶（angiotensin-I converting enzyme，ACE）抑制率为评价指标，进行正交设计优化试验，得到最优的超声预处理条件：超声工作频率40 kHz、液料初始温度30℃、超声处理时间15 min、单 位体积超声功率200 W/L、超声脉冲工作时间6 s和脉冲间歇时间3 s。玉米蛋白经最优超声工作条件预处理，其水解度和酶解产物的ACE抑制率分别达到24.22% 和70.97%，与未经超声预处理的玉米蛋白常规酶解相比较，分别提高了9.39%和11.08%。结果表明：超声预处理玉米蛋白，不仅促进其酶解，而且对其酶解产物 ACE抑制活性同样有显著提高的作用。

Effect of Energy-gathered Pulsed Ultrasonic Pretreatment on Enzymatic Hydrolysis of Corn Gluten Meal

In order to research the improvement of enzymatic hydrolysis of corn gluten meal by energy-gathered pulsed ultrasonic pretreatment, on the basis of single factor experiment, this paper took the degree of hydrolysis (DH) and angiotensin-I converting enzyme (ACE) inhibition rate as evaluation indexes, and carried out orthogonal optimization test and gains the optimal ultrasonic pretreatment conditions: ultrasonic working frequency 40 kHz, initial temperature of liquid material 30℃, ultrasonic treatment time 15 min, per unit ultrasonic power 200 W/L, ultrasonic pulse work time 6 s and interpulse time 3 s. Under the optimal ultrasonic pretreatment conditions, hydrolysis degree and enzymatic hydrolysis product of ACE inhibition rate of corn gluten meal were 24.22% and 70.97%, respectively. Compared with those without pretreatment, the hydrolysis degree and ACE-inhibitory rate raised 9.39% and 11.08%, respectively. The results showed that ultrasonic pretreatment of corn gluten meal could not only promote its enzymatic hydrolysis, but also have a significant promotion on its enzymatic hydrolysis product of ACE inhibition activity.