Proteins, as core macronutrients in human nutrition, play irreplaceable roles in growth and development, tissue repair, and physiological regulation. With the acceleration of population aging and the rising demand for health-oriented products, functional food proteins have attracted increasing attention for their health benefits beyond basic nutrition, showing broad application prospects in medical foods, sports nutrition, and healthy aging. The functional properties of proteins are highly dependent on their complex hierarchical structures. However, conventional food processing often causes uncontrolled disruption to these structures, thereby limiting their application potential. Therefore, how to achieve targeted regulation of protein structure and function through precise regulation strategies has become an important research issue in food science. This review systematically summarizes the theoretical basis for the structural regulation of food proteins, including denaturation and renaturation mechanisms, intermolecular interactions, and multi-scale characterization methods for conformational changes. It highlights advances in various structural regulation techniques, such as physical field treatments (e.g., high pressure, ultrasound, and cold plasma), biological approaches (e.g., enzymatic hydrolysis, fermentation, and genetic engineering), and green chemical methods (e.g., pH-shifting and glycosylation). The synergistic effects of combined physical and biological approaches are also discussed. Furthermore, this review discusses the potential of functional food proteins in different application scenarios. In light of current challenges and industrial obstacles, it proposes that future research should focus on precise regulation mechanisms, cross-scale structure-function relationships, and the development of sustainable processing technologies. This review provides a comprehensive perspective on the structural modulation and innovative processing of food proteins, aiming to support both scientific research and industrial innovations in functional foods.

The interaction mechanism of cyanidin-3-glucoside (C3G) with β-conglycinin and glycinin was investigated by multiple spectroscopies and molecular docking. The results showed that C3G quenched the intrinsic fluorescence of β-conglycinin/glycinin strongly in both static and dynamic modes and C3G had stronger binding affinity toward glycinin than β-conglycinin. However, the major interaction force involved in C3G binding to glycinin was different from that for β-conglycinin. As judged from the number of binding sites, a stable C3G-soy protein complex with a molar ratio of 1:1 was formed. C3G induced partial unfolding of the secondary structure of soy protein and a conformational switch from α-helix to β-sheet, thus resulting in conformational unfolding of soy protein. The addition of C3G could reduce the hydrophobicity of the microenvironment around tryptophan residues in β-conglycinin, but had no significant effect on the microenvironment around amino acid residues in glycinin. In addition, the majority of the phenolic hydroxyl groups in the C3G molecule were mainly involved in hydrogen bonds and hydrophobic interaction with soy protein. Compared with β-conglycinin, glycinin showed great potential as a biological carrier for the stabilization and delivery of C3G. However, it may be unfavorable for the biological activity of C3G.

The interaction between β-conglycinin (7S)/glycinin (11S) and (–)-epigallocatechin-3-gallate (EGCG) under neutral conditions was characterized by fluorescence spectroscopy, ultraviolet-visible (UV-Vis) absorption spectroscopy, Fourier transform infrared (FTIR) spectroscopy and molecular docking. The results showed that EGCG and 7S/11S could interact with each other at pH 7.0, which induced a change in the microenvironment of amino acid residues. EGCG could quench the intrinsic fluorescence of 7S/11S in dynamic and static manners. EGCG had higher affinity to 11S than to 7S. The reaction between EGCG and 7S/11S was a spontaneous binding process, resulting in the formation of a complex at 1:1 molar ratio by hydrogen bonding and van der Waals force. EGCG could reduce the surface hydrophobicity of 7S/11S. With increasing EGCG concentration, 11S showed a greater change in surface hydrophobicity. FTIR and molecular docking studies suggested that in addition to hydrogen bonds, hydrophobic interactions were also involved in the formation of complexes. Binding to EGCG could cause different changes in the secondary structure of 7S/11S subsequently resulting in protein unfolding.

The indirect preparation of oleogels by the aerogel template method has received widespread attention due to its advantages such as simple operation and excellent performance. In this study, composite aerogels of carboxy methyl cellulose-Na (CMC-Na) and soybean protein isolate (SPI) were prepared by the electrostatic interaction between them. The effects of different protein contents on the average particle size, microstructure, Fourier transform infrared (FTIR) spectrum, oil absorption kinetics, oil absorption capacity and oil holding capacity of aerogels were investigated. The oleogels prepared based on aerogel templates were characterized for their textural properties, antibacterial properties, and storage stability. The results showed that SPI and CMC-Na formed stable complexes through electrostatic interactions, and the average particle size of the complexes increased with protein content. The composite aerogel displayed a denser porous network structure along with improved oil-holding capacity, but had unfavorable effects on oil absorption performance. Moreover, the addition of protein improved the strength and Young’s modulus, and enhanced the antibacterial effect and storage stability of the oleogel. Therefore, the aerogel template method is good for preparing oleogels and a stable oleogel system can be prepared by electrostatic adsorption between polysaccharides and proteins.