To enhance the frozen storage stability of surimi gels cross-linked with transglutaminase (TG), the synergistic effect of silver carp scale-derived antifreeze peptides (ScAFPs) combined with TG cross-linking on the texture properties, gel characteristics, whiteness, drip loss, morphology, and microstructure of surimi gels was investigated during frozen storage. The results demonstrated that TG promoted the formation of a compact gel network through cross-linking myofibrillar proteins, while ScAFPs effectively inhibited structural deterioration caused by ice crystal growth during frozen storage. Texture profile analysis revealed that the combination of 2.0% ScAFPs and 0.05% TG resulted in smaller variations in gel hardness, elasticity, and strength after 28 days of frozen storage compared with 0.05% TG alone and a commercial antifreeze formulation (4.0% sucrose + 4.0% sorbitol). The synergistic treatment reduced whiteness loss by 37.50% and decreased thawing drip loss by 63.25% compared with the control group. Microstructural analysis indicated that the combination of ScAFPs and TG effectively suppressed ice crystal growth, reducing the increase in ice crystal porosity by 48.50% compared with the control group, while mitigating gel shrinkage and surface collapse. This study helps to understand the mechanism by which ScAFPs synergize with TG to stabilize surimi gel quality during frozen storage, providing both a theoretical foundation and technical pathway for developing novel frozen surimi products.

With the improvement of living conditions, people’s eating habits gradually trend to “healthy” development. However, it is difficult to strike a balance between “healthy” and “delicious”. Seasoning is a crucial step during cooking. Saltiness is one of the five basic tastes, and it is produced mainly by adding salt in daily life. Salt plays an important role in human life, but excessive sodium intake can lead to many cardiovascular diseases. Today many health authorities around the world advocate a low-sodium diet. In this context, reducing the amount of salt in foods without affecting their flavor or quality has become a popular research topic. This paper reviews the mechanism of salty taste perception and the current status of salt reduction in foods, with special focuse on salty peptides. The sources, preparation and identification methods, synergistic effect and application prospects of salty peptides are outlined in this paper, so as to provide a basis for the development and application of salty peptides, which will help in advancing the salt reduction campaign.

The purpose of this study was to investigate the effect of crimson snapper scale peptides (CSSPs) on H₂O₂-induced oxidative damage in Caco-2 cells. The levels of lactate dehydrogenase (LDH) and interleukin-8 (IL-8) in the cell supernatant, the activity of intracellular antioxidant enzymes, the release of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA), and the expression of apoptosis-related genes (Caspase-3, Caspase-9, Bax and Bcl-2) were measured. The antioxidant effects of CSSPs in intestinal cells were elucidated from the aspects of cellular redox state and apoptosis. Results showed that CSSPs mitigated H₂O₂-induced oxidative damage in Caco-2 cells through the antioxidant defense system. This effect involved increased activities of antioxidant enzymes and consequent inhibition of LDH release, intracellular ROS accumulation, and MDA and IL-8 production. Furthermore, CSSPs inhibited oxidative stress-induced apoptosis by regulating the mitochondrial apoptotic pathway, which significantly increased mitochondrial membrane potential, down-regulated the mRNA expression of Caspase-3, Caspase-9 and Bax, and up-regulated the mRNA expression of Bcl-2. In conclusion, CSSPs can effectively reduce the degree of cell damage by maintaining redox homeostasis and inhibiting apoptosis.

This study assessed the effects of antifreeze peptides (CsAFPs) produced by enzymatical hydrolysis of chicken skin on chicken mince stability. CsAFPs, 85.88% of which were short peptides (180–3000 Da), showed high hydrophilicity and strong thermal hysteresis activity and ice recrystallization inhibition activity, reducing the ice crystal content by (26.03 ± 0.40)% and raising the glass transition temperature by 7.3 ℃. The flavor of CsAFPs was well coordinated with that of chicken mince and the addition of 2% CsAFPs enhanced the water-holding capacity of chicken mince without color change. After four freeze-thaw cycles, mince added with 2% CsAFPs showed less reductions in water-holding capacity, elasticity, and resilience than did the control group. Ultraviolet (UV) absorption and Fourier transform infrared spectroscopy (FTIR) indicated that CsAFPs could prevent the aggregation and denaturation of proteins under freezing stress. After freezethaw cycles, the r value of myofibrillar protein in the mince with 2% added CsAFPs was higher than the control group without CsAFPs. This study contributes to a better understanding of the protective mechanisms of CsAFPs in frozen meat and highlights that CsAFPs are promising novel low-sweetness and low-calorie cryoprotectants for meat products.

Identification of natural substances with antioxidant properties is ongoing research for addressing issues related to oxidative stress especially attributed to environmental effects. Our previous study demonstrated that Lateolabrax japonicus peptides (LPH), rich in Glu, Gly, and hydrophobic amino acids, exhibited remarkable antioxidant activity in vitro, with though its action mechanism yet to be revealed. Therefore, to assess the in vivo antioxidative properties of LPH, we employed H₂O₂ to generate oxidative stress in Drosophila melanogaster model. Results indicated that LPH significantly prolonged the lifespan of Drosophila subjected to oxidative stress mostly mediated via LPH’s enhancement of the antioxidant defense system and intestinal functions. Antioxidant effects were manifested by a decrease in malondialdehyde (MDA) levels, elevated superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities, decreased levels of reactive oxygen species (ROS) in intestinal epithelial cells, and the preservation of intestinal length. LPH effectively controlled the excessive proliferation and differentiation of oxidative stress-induced Drosophila intestinal stem cells. At the gene level, LPH upregulated the expression of antioxidant-related Nrf2 genes while concurrently downregulated mTOR expression level. Furthermore, high-throughput 16S rDNA sequencing revealed that the addition of LPH significantly influenced the diversity and abundance of the intestinal microbiota in H₂O₂-induced Drosophila. These findings provide a deeper understanding of the antioxidative mechanism of LPH, suggesting its potential applications in food industry and to be assessed using other in vivo oxidative stress models.