Mulberry leaf protein (MLP) is a nutrient-rich protein, but its applicability is limited because of its poor solubility. To address this issue, this study combines MLP with whey protein isolates (WPI), known for the high nutritional value, and subsequently forms composite protein nanoparticles using the ultrasound-assisted pH shifting method. Microscopic observation and SDS-PAGE confirmed the binding between these two proteins. Fluorescence spectra and Fourier Transform infrared spectroscopy (FTIR) analysis supported the involvement of electrostatic interactions, hydrophobic attractions, and hydrogen bonding in the formation of stable complex nanoparticles. The interactions between the proteins became stronger after ultrasound-assisted pH-shifting treatment. Solubility, emulsification capacity, foaming, and antioxidant activity, among other indicators, demonstrate that the prepared composite nanoparticles exhibit favorable functional properties. The study successfully illustrates the creation of protein-based complex nanoparticles through the ultrasound-assisted pH shifting method, with potential applications in the delivery of bioactive compounds.

中文翻译：

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研究超声波辅助处理对桑叶蛋白和乳清分离物复合物制作的影响：结构和功能的综合分析


桑叶蛋白（MLP）是一种营养丰富的蛋白质，但由于其溶解性差，其适用性受到限制。为了解决这个问题，本研究将 MLP 与以高营养价值而闻名的乳清分离蛋白 (WPI) 相结合，随后使用超声辅助 pH 值变换方法形成复合蛋白纳米颗粒。显微镜观察和 SDS-PAGE 证实了这两种蛋白质之间的结合。荧光光谱和傅里叶变换红外光谱 (FTIR) 分析支持静电相互作用、疏水吸引力和氢键参与稳定复合纳米粒子的形成。经过超声波辅助 pH 值变换处理后，蛋白质之间的相互作用变得更强。溶解度、乳化能力、发泡性和抗氧化活性等指标表明所制备的复合纳米颗粒具有良好的功能特性。该研究成功地说明了通过超声辅助 pH 变化方法创建基于蛋白质的复合纳米粒子，在生物活性化合物的输送方面具有潜在的应用。