Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, Harbin 150030, China.
Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, Harbin 150030, China; Food Laboratory of Zhongyuan, Luohe 462300, Henan, China.
Ultrason Sonochem. 2024 Nov;110:107025. doi: 10.1016/j.ultsonch.2024.107025. Epub 2024 Aug 17.
Whey protein is an important food ingredient, but it is also considered a major food allergen. The aim of this study was to investigate the effect of ultrasound pretreatment on the structure, IgE binding capacity, functional properties and biological activity of whey protein isolate (WPI) hydrolysates (WPH), including WPI hydrolyzed by a combination of enzymes from Bromelain and ProteAXH (BA-WPI) and WPI hydrolyzed by a combination of enzymes from Papain W-40 and ProteAXH (PA-WPI). The IgE binding capacity of BA-WPI and PA-WPI was reduced to 40.28% and 30.17%, respectively, due to disruption/exposure/shielding of conformational and linear epitopes. The IgE binding capacity of sonicated WPI was increased, but ultrasound pretreatment further reduced the IgE binding capacity of the hydrolysates to 32.89% and 28.04%. This is due to the fact that ultrasound pretreatment leads to conformational changes including increased α-helix and β-sheet structure, exposure of aromatic amino acids, surface hydrophobicity, and increased sulfhydryl content, which increases the accessibility of allergenic epitopes to WPI by the enzyme. Multispectral and LC-MS/MS results further indicated that ultrasound pretreatment altered the conformational and primary structural changes of the hydrolysates. The thermograms showed that ultrasound pretreatment mainly altered the epitope spectra of β-lactoglobulin hydrolysates, while it had less effect on the epitope spectra of α-lactalbumin hydrolysates. Additionally, ultrasound pretreatment significantly improved the foaming properties, antioxidant activity, and α-glucosidase inhibition of the hydrolysates without impairing the solubility and emulsification properties of the hydrolysates. Therefore, ultrasound pretreatment is a feasible method to reduce the allergenicity of WPH and to improve their functional properties and bioactivity. Notably, ultrasonic pretreatment improved the effectiveness and efficiency of WPI hydrolysis, which is a feasible method to produce high-quality protein feedstock in a green, efficient, and economical way.
乳清蛋白是一种重要的食品成分，但也被认为是主要的食物过敏原。本研究旨在探讨超声预处理对乳清蛋白分离物（WPI）水解产物（WPH）结构、IgE 结合能力、功能特性和生物活性的影响，包括用菠萝蛋白酶和 ProteAXH（BA-WPI）组合酶水解的 WPI 和用木瓜蛋白酶 W-40 和 ProteAXH（PA-WPI）组合酶水解的 WPI。由于构象和线性表位的破坏/暴露/屏蔽，BA-WPI 和 PA-WPI 的 IgE 结合能力分别降低至 40.28%和 30.17%。超声处理后的 WPI 的 IgE 结合能力增加，但超声处理进一步将水解产物的 IgE 结合能力降低至 32.89%和 28.04%。这是因为超声预处理会导致构象变化，包括增加α-螺旋和β-折叠结构、暴露芳香族氨基酸、表面疏水性和增加巯基含量，从而增加过敏原表位与 WPI 的酶结合的可及性。多光谱和 LC-MS/MS 结果进一步表明，超声预处理改变了水解产物的构象和一级结构变化。热图谱表明，超声预处理主要改变了β-乳球蛋白水解产物的表位谱，而对α-乳白蛋白水解产物的表位谱影响较小。此外，超声预处理显著改善了水解产物的起泡性、抗氧化活性和α-葡萄糖苷酶抑制活性，而不损害水解产物的溶解性和乳化性。因此，超声预处理是降低 WPH 致敏性并改善其功能特性和生物活性的可行方法。值得注意的是，超声预处理提高了 WPI 水解的效率和效果，这是一种以绿色、高效和经济的方式生产高质量蛋白原料的可行方法。
