Foam and conformational changes of egg white as affected by ultrasonic pretreatment and phenolic binding at neutral pH
Foam and conformational changes of egg white as affected by ultrasonic pretreatment and phenolic binding at neutral pH
复制标题
中性 pH 值下超声波预处理和酚类结合对蛋清泡沫和构象变化的影响
DOI：
10.1016/j.foodhyd.2019.105568
复制
发表时间：
2020-05-01
影响因子：
10.7
通讯作者：
Ma, Meihu
中科院分区：
文献类型：
--
作者：
Chen, Yinxia;Ma, Meihu
研究了超声波预处理和酚类结合对鸡蛋白色（EW）结构特征和发泡性能的影响。将未经超声波处理的EW（NEW）和经超声波处理的EW（UEW）（功率为28%，时间为25分钟：接通时间为3秒，断开时间为2秒）分别与pH 7.0的没食子酸（GA）和表没食子儿茶素没食子酸酯（EGCG）在25 ℃下孵育2小时。酚处理引起巯基含量的显着损失，在UEW中观察到更显着的效果，特别是在120 μ mol/g浓度。两种酚类物质均显著降低了蛋白质的表面疏水性，并略微增加了蛋白质二级结构的无序性。此外，蛋白质分子的微环境的极性增加，由UV吸收蓝移证实酚处理，特别是对于240 μ mol/g GA-UEW。超声波预处理后，低浓度的EGCG（20 μ mol/g）显着增加发泡能力。240 μ mol/g的EGCG处理显著地增加了通过超声的降低的发泡稳定性，从81.00%增加到95.10%（p < 0.05），这是由于高的绝对xi-电位值。本研究揭示了超声波处理对酚结合的去折叠结构的影响的机制。
This study investigated the impact of ultrasound pretreatment and phenolic binding on the structure characteristic and foaming properties of egg white (EW). EW treated without ultrasound (NEW) and with ultrasound (UEW) (power for 28% and time for 25 min: on-time 3 s and off-time 2 s) were incubated separately at 25 degrees C for 2 h with gallic acid (GA) and epigallocatechin gallate (EGCG) at pH 7.0. Phenolic treatment caused a significant loss of sulfhydryl content, with a more remarkable effect observed in UEW, especially at 120 mu mol/g concentration. Both phenolics significantly decreased the surface hydrophobicity and slightly increased the disordered secondary structure of protein. Additionally, the microenvironment polarity of protein molecules was increased by phenolic treatment corroborated by UV absorption blue shift, especially for 240 mu mol/g GA-UEW. After ultrasound pretreatment, low EGCG concentration (20 mu mol/g) significantly increased the foaming ability. The 240 mu mol/g EGCG treatment notably increased the reduced foaming stability by ultrasound from 81.00 to 95.10% (p < 0.05), which was due to high absolute xi-potential value. This study has shed light on the mechanisms underlying the influence of unfolding structure by ultrasound treatment on phenolic binding.