蛋白质水解物因其高的生物活性而备受关注,是利用谷糠副产品的关键产品形式。在这项研究中,结构的变化,功能,研究了不同超声功率(0-600W)下谷草蛋白水解物(FMBPH)的活性和肽谱。结果表明,超声促进α-螺旋和β-折叠向无规卷曲和β-转角的转变,以及FMBPH中疏水基团和巯基的暴露。样品的平均粒径减小,ζ电位的绝对值显著增加。同时,当超声功率增加到450W时,FMBPH表面出现较小的多孔颗粒和松散的碎片。450W的超声处理提高了溶解度,发泡性能,乳化性能,FMBPH的热稳定性。DPPH,ABTS和羟自由基清除能力(IC50,2.65,1.06和3.02mg/mL),Fe2+螯合活性(IC50,2.62mg/mL),样品的还原能力也增强。肽组学结果表明,超声处理增加了水解产物中活性肽的数量,450W时17种活性肽的相对丰度明显升高。肽图分析表明,超声诱导的结构修饰影响了含泛素样结构域蛋白的肽谱,含Cupin1型结构域的蛋白质,40S核糖体蛋白S19和Oleosin1,显示某些肽的丰度变化,这可能与FMBPH表征的变化有关。
Protein hydrolysates have attracted much attention for their high biological activity and are a crucial product form for the utilization of foxtail millet bran by-products. In this study, changes in the structure, functionality, activity and peptide profile of foxtail millet bran protein hydrolysates (FMBPHs) at different ultrasound powers (0 - 600 W) were investigated. The results showed that ultrasound promoted the transformation of α-helix and β-sheet to random coils and β-turn, and the exposure of hydrophobic groups and sulfhydryl groups in FMBPHs. The average particle size of the samples decreased, and the absolute value of the ζ-potential increased significantly. Simultaneously, smaller porous particles and loose fragments appeared on the surface of FMBPHs when the ultrasonic power was increased to 450 W. Additionally, 450 W ultrasound treatment improved solubility, foaming properties, emulsifying properties, thermal stability of FMBPHs. The DPPH, ABTS and hydroxyl radical scavenging ability (IC50, 2.65, 1.06 and 3.02 mg/mL), Fe2+ chelating activity (IC50, 2.62 mg/mL), and reducing power of the samples were also enhanced. The peptidomics results demonstrated that ultrasonication increased the number of active peptides in the hydrolysate, and the relative abundance of 17 active peptides was obviously elevated at 450 W. Peptide map analysis showed that ultrasound-induced structural modifications affected the peptide profiles of Ubiquitin-like domain-containing protein, Cupin type-1 domain-containing protein, 40S ribosomal protein S19, and Oleosin 1, showing changes in the abundance of certain peptides, which may be related to changes in the characterization of FMBPHs.