超声预处理对脱脂小麦胚芽酶解制备ACE抑制肽的影响

为了研究不同工作模式超声预处理对脱脂小麦胚芽水解度和ACE抑制率的影响,在相同能耗条件,利用聚能逆流单频、聚能逆流双频、脉冲扫频多频、发散三频、对振双频五种工作模式超声,对脱脂小麦胚芽进行预处理。同时进行单因素实验来寻找最佳超声预处理参数。结果表明,超声波预处理对水解度没有显著的影响,但可以显著提高酶解产物的ACE抑制活性,最佳的超声波工作模式为脉冲平板式40 k Hz/28 k Hz双频超声;在此模式下超声预处理单位体积超声功率60 W/L、超声时间70 min、超声初始温度60℃、底物浓度7%时得到的酶解产物IC₅₀值低至2.483 mg/m L,为较优结果,和未超声相比,其产物IC₅₀值降低了5.8%。 

Effect of ultrasound pretreatment on enzymatic preparation of ACE- inhibitory peptides from defatted wheat germ

In order to study the effects of different working mode of ultrasound on the degree of enzymatic hydrolysis and ACE inhibitory activity of defatted wheat germ,five kinds of working mode of ultrasound,energy aggregation counter flow single- frequency ultrasound,energy aggregation counter flow dual- frequency ultrasound,pulsed and sweeping frequency ultrasound,divergence triple- frequency ultrasound and opposite- site dual- frequency ultrasound were used to pretreat of defatted wheat germ under the same condition in this article.The one- factorial experiments were taken to search the best pretreatment parameters of ultrasound.The results illustrated that ultrasound pretreatment had no significant effect on the degree of hydrolysis but could increase the ACE inhibitory activity of enzyme products significantly.The best ultrasonic working mode was 40 k Hz /28 k Hz pulse plate dual- frequency ultrasound. With this working mode,the enzymatic hydrolysates value of IC₅₀ could drop to2.483 mg / m L under the following optimal ultrasound pretreatment conditions: ultrasonic power per unit volume of60 W/ L,ultrasound time of 70 min,ultrasonic initial temperature at 60 ℃,the substrate concentration 7%.As a better result,the value of IC₅₀ decreased by 5.8% compared with control group.