Effect of ultrasound pretreatment with mono-frequency and simultaneous dual frequency on the mechanical properties and microstructure of whey protein emulsion gels
Effect of ultrasound pretreatment with mono-frequency and simultaneous dual frequency on the mechanical properties and microstructure of whey protein emulsion gels
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DOI：
10.1016/j.foodhyd.2018.11.007
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发表时间：
2019-04-01
影响因子：
10.7
通讯作者：
Ma, Haile
中科院分区：
文献类型：
--
作者：
Cheng, Yu;Donkor, Prince Ofori;Ma, Haile
研究了单频超声波（MFU）和双频同步超声波（SDFU）预处理对乳清蛋白乳液凝胶流变性、质构、持水力和微观结构的影响。利用圆二色谱和荧光光谱显示了蛋白质的结构。结果表明，超声波能改善乳清蛋白乳化凝胶的力学性能，改变其微观结构。超声波处理后，α-螺旋减少，无规卷曲增加，从而使更多的色氨酸残基暴露。储能模量（G '）、质地硬度和保水性与α-螺旋含量呈负相关，与无规卷曲含量呈正相关。在超声预处理中，同步双频超声处理的效果最好。结果表明，超声波预处理增强了蛋白质分子间的相互作用，从而导致了乳化凝胶微结构中油滴颗粒聚集体网络和蛋白质聚集体网络的复合。结果表明，双频超声能有效改善乳清乳化凝胶的力学性能。
The effect of ultrasound pretreatment with mono-frequency ultrasound (MFU) and simultaneous dual frequency (SDFU) on rheology, texture, water holding capacity (WHC) and microstructure of whey protein emulsion gels was investigated. Also, the protein structure was displayed using circular dichroism and fluorescence spectrum. The Results showed that ultrasound could improve mechanical properties and change the microstructure of whey protein emulsion gel compared with the control. It was also found that, ultrasound could lead to decreasing in alpha-helix and increasing in random coil thereby exposing more tryptophan residues. As storage modulus (G'), texture hardness and WHC were negatively correlated with alpha-helix content, however, they had positive correlation with random coil content. Simultaneous dual frequency ultrasound exhibited the highest effect among the ultrasound pretreatments. It was indicated that the composite of oil droplet particulate aggregate network and protein aggregate network in the microstructure of emulsion gel might have resulted from enhanced molecular interactions of protein by ultrasound pretreatment. In conclusion, the dual frequency ultrasound was effective in improving the mechanical properties of whey emulsion gel when compared with the mono-frequency ultrasound.