Effects of ultrasound on the structure and physical properties of black bean protein isolates
Effects of ultrasound on the structure and physical properties of black bean protein isolates
复制标题
超声对黑豆分离蛋白结构和物理性质的影响
DOI：
10.1016/j.foodres.2014.04.022
复制
发表时间：
2014-08-01
影响因子：
8.1
通讯作者：
Zhang, Min
中科院分区：
文献类型：
--
作者：
Jiang, Lianzhou;Wang, Jing;Zhang, Min
在这项研究中，我们的目的是比较不同功率(150、300或450W)、不同持续时间(12或24分钟)的低频(20 KHz)超声对黑豆分离蛋白(BBPI)分散体功能和结构特性的影响。在SDS-PAGE分析中，我们没有检测到蛋白质电泳谱的显著变化。然而，圆二色谱二级结构分析表明，除E样品(300W，24分钟)外，所有样品经超声处理后，BBPI中的OX-螺旋比例降低，β-折叠含量增加。此外，发射荧光光谱表明，超声处理后的黑豆蛋白的三级结构发生了变化，扫描电子显微镜显示，超声处理的BBPI样品的微观结构发生了变化，与未处理的BBPI样品相比，BBPI样品中含有更大的聚集体。当中等功率超声作用24分钟时，颗粒尺寸最小，绝对Zeta电位最大。超声增强了BBPI分散体的表面疏水性和蛋白质的溶解性，破坏了蛋白质分子内部的疏水相互作用，加速了蛋白质的分子运动，引起蛋白质的聚集。然而，中等功率的超声波处理通过空化力破坏了BBPI分散成小的可溶蛋白质聚集体，从而导致表面疏水性和溶解性的增加。高功率超声处理引起了BBPI聚集体的重组，导致了颗粒尺寸的增加，但绝对Zeta电位降低。(C)2014爱思唯尔有限公司。保留所有权利。
In this study, our aim was to compare the effects of low-frequency (20 kHz) ultrasonication applied at various powers (150, 300, or 450W) and for different durations (12 or 24 min) on the functional and structural properties of black-bean protein isolate (BBPI) dispersions. In SDS-PAGE analysis, we detected no marked changes in protein electrophoretic patterns. However, secondary-structure analysis performed using circular dichroism indicated that all samples except Sample E (300W, 24 min) showed a decrease in the ox-helix proportion and an increase in beta-sheets content in the BBPI after ultrasonic treatment. Moreover, emission-fluorescence spectra revealed that the tertiary structure of black-bean proteins changed after ultrasonic treatment, and scanning electron microscopy of ultrasonicated BBPI samples showed that BBPI microstructure had changed and it contained larger aggregates when compared with the untreated BBPI sample. When medium-power ultrasonication was applied for 24 min, the particle size was minimized and the absolute zeta potential was maximized. Surface hydrophobicity and protein solubility of the BBPI dispersions were enhanced after ultrasonication, which increased the destruction of internal hydrophobic interactions of protein molecules and accelerated the molecular motion of proteins to cause protein aggregation. However, medium-power ultrasound treatment disrupted BBPI dispersions into small soluble protein aggregates by means of cavitation forces that induced increases in surface hydrophobicity and solubility. High-power ultrasound treatment caused a restructuring of BBPI aggregates, which led to an increase of particle size but a decrease in the absolute zeta potential. (C) 2014 Elsevier Ltd. All rights reserved.