Reducing sodium in meat products is nutritionally desirable, but salt reduction often weakens myofibrillar protein gelation and reduces texture quality and water retention. This study investigated the effects of L-lysine (Lys) and konjac glucomannan (KGM) on the physicochemical properties, gel characteristics, and structural changes of beef myofibrillar protein (MP) gels under low-salt conditions. The results indicated that reducing NaCl from 0.6 to 0.2 M decreased water-holding capacity (WHC), increased cooking loss, and produced a loose gel network. Compared with the 0.2 M NaCl group, the combined Lys-KGM treatment increased WHC from 28.53% to 56.70% and reduced cooking loss to 22.19% (p < 0.05). Texture analysis showed that Lys-KGM increased hardness and springiness by 69.40% and 80.43%, respectively (p < 0.05). LF-NMR indicated a higher proportion of immobilized water and reduced water mobility in the combined treatment. Lys increased reactive sulfhydryl content and surface hydrophobicity, whereas KGM reduced surface hydrophobicity and enhanced water immobilization. Lys-KGM slightly but significantly decreased α-helix and increased β-sheet contents (p < 0.05), accompanied by changes in the relative contributions of intermolecular forces and a more continuous gel network. Molecular docking and molecular dynamics simulations provided supporting evidence for different interaction patterns between myosin and Lys/KGM. These results suggested that Lys and KGM might help maintain the quality of low-salt meat protein gels and provide a formulation basis for reduced-sodium meat products.
Xiuyun Guo, Jinsheng Yang, Chao Fu et al.· Gels· 0 citations
Pre-velveting foods suffer from significant flavor loss and limited shelf life during storage, motivating a demand for multifunctional starch-based carriers. To address this, corn starch (CS)-soy protein isolate (SPI) coacervates with varying CS ratios were fabricated to encapsulate fennel essential oil (FEO), yielding a pre-velveting material with antimicrobial and flavor-enhancing properties. Results indicated that higher CS/SPI ratios (4,1 and 5,1) enhanced viscoelasticity and reduced particle size by forming a dense polysaccharide-protein network that inhibited FEO aggregation compared with the lower ratios. The resulting microcapsules (CSSP4 and CSSP5) similarly demonstrated improved DPPH radical scavenging capacity (59.49% and 56.15%, respectively) and enhanced thermal stability. SEM and XRD confirmed increased cross-linking of CS upon coacervation with SPI, which provided the basis for the improved encapsulation efficiency of FEO via the dense structure, while FTIR and molecular dynamics simulations indicated that this structure was primarily driven by hydrogen bonding and electrostatic interactions between CS and SPI, and the starch-protein interface was visualized. Electronic nose combined with GC-MS analyses identified anethole as the primary flavor compound of FEO microcapsules and showed that the stable structure delayed its release, with CSSP4 exhibiting the slowest release due to its higher density. Furthermore, among all formulations, CSSP4 showed the lowest TBARS values and pH increase, as well as the most favorable volatile profile and improved textural properties in cooked chicken cubes. This study presents a novel starch-based carrier designed to improve flavor retention and extend the shelf life of pre-velveting foods.
Hengpeng Wang, Yang Meng, Yiwei Jin et al.· Food Research International· 0 citations
Proteins are effective carriers for polyphenols, yet whether structural differences between plant- and animal-derived proteins influence the delivery and functionality of polyphenols in their nanocomplexes remains unclear. In this study, soy protein isolate-curcumin (SPI-CUR) and myofibrillar protein-curcumin (MP-CUR) nanocomplexes were fabricated via a pH-driven method, and their physicochemical properties, interaction mechanisms, and cryoprotective effects on surimi were investigated. Both nanocomplexes achieved high encapsulation efficiencies (90.63% for SPI-CUR and 83.29% for MP-CUR) and thus exhibited enhanced antioxidant activity. CUR loading induced conformational changes in the protein carriers, as evidenced by increased α-helix content and decreased β-sheet content, suggesting the formation of a more compact structure. Meanwhile, this conformational change was accompanied by a marked reduction in particle size, with SPI-CUR reaching 66.13 nm. Molecular docking further revealed that hydrophobic interactions and hydrogen bonding were the primary forces stabilizing both nanocomplexes. During freeze-thaw cycles of surimi, both SC and MC nanocomplexes were superior to commercial cryoprotectants in preserving product quality, evidenced by improved water-holding capacity, enhanced gel properties, and inhibited protein oxidation. Notably, the two nanocomplexes exhibited distinct protective profiles depending on the protein source. MP-CUR demonstrated superior preservation of gel texture by minimizing thawing loss to 0.53% and maintaining high hardness (425.50 ± 34.85 g) and springiness (0.81 ± 0.03), which facilitated the formation of a denser gel network. In contrast, SPI-CUR demonstrated superior viscoelasticity and yielded the highest storage modulus (G'). This study establishes a foundation for the rational design of natural and efficient surimi cryoprotectants derived from protein-polyphenol complexes.
Xiaoyun Liu, Yang Meng, Zhikun Yang et al.· Journal of Food Science· 0 citations