To address the delamination phenomenon during storage and flavor characteristics of Oyster protein hydrolysates (OPH). In this study, xylo-oligosaccharides (XOS) were selected to covalently graft with OPH through ultrasound-assisted Maillard reaction, and the effect of ultrasound-assisted Maillard reaction on the structure, functional properties, and flavor characteristics of OPH were investigated. The results revealed that the ultrasound treatment led to a 1.46-fold increase in the degree of grafting compared with the conventional wet-heat Maillard reaction methods. Structural analyses at various levels indicated substantial alterations in the OPH structure following the ultrasound-assisted Maillard reaction. More ordered α-helical secondary structures were shifting to random coiling, the tertiary structure showed more stretching changes, and the surface structure was characterized by loose and porous features. Compared with OPH, the solubility of the ultrasound-assisted Maillard reaction products (OPH-U-M) increased from 54.67% to 70.14%, leading to a notable enhancement in storage stability. Flavor profile analysis demonstrated a decrease in unsaturated aldehydes and ketones presenting fishy and bitter aromas, while an increase in presenting meat aroma compounds was observed in OPH-U-M. Furthermore, OPH-U-M exhibited superior antioxidant properties with DPPH and ABTS radical scavenging abilities enhancing 46.05% and 42.09% in comparison with OPH, respectively. The results demonstrated that covalently binding with XOS under ultrasonication pretreatment endowed OPH with superior functional properties (including solubility, storage stability, and antioxidant activity), and the improvement of flavor profile. This study can provide theoretical guidance and practical implications for promoting the processing applications of oyster protein.

中文翻译：

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超声辅助美拉德反应对牡蛎蛋白酶解物功能特性和风味特性的影响


解决牡蛎蛋白水解物 （OPH） 储存过程中的分层现象和风味特性。本研究通过超声辅助美拉德反应选择低聚木糖 （XOS） 与 OPH 共价接枝，并研究了超声辅助美拉德反应对 OPH 结构、功能特性和风味特性的影响。结果表明，与传统的湿热美拉德反应方法相比，超声处理导致嫁接程度增加了 1.46 倍。不同级别的结构分析表明，超声辅助美拉德反应后 OPH 结构发生了重大变化。更有序的α螺旋二级结构向无规卷绕转变，三级结构表现出更多的拉伸变化，表面结构以疏松和多孔特征为特征。与 OPH 相比，超声辅助美拉德反应产物 （OPH-U-M） 的溶解度从 54.67% 提高到 70.14%，导致贮藏稳定性显著提高。风味特征分析表明，在 OPH-UM 中观察到呈现鱼腥和苦涩香气的不饱和醛和酮减少，而呈现肉香气的化合物增加。此外，OPH-UM 表现出优异的抗氧化特性，与 OPH 相比，DPPH 和 ABTS 自由基清除能力分别提高了 46.05% 和 42.09%。结果表明，在超声预处理下与 XOS 共价结合赋予 OPH 优异的功能特性 （包括溶解度、储存稳定性和抗氧化活性），并改善了风味特征。 本研究可为促进牡蛎蛋白的加工应用提供理论指导和实际意义。