This study investigates the antioxidant and anti-aging properties of Katsuwonus pelamis peptides (KPPs) using a high-fat diet (HFD) Drosophila melanogaster model. In vitro analysis revealed KPPs exhibit potent radical scavenging activity (e.g., DPPH IC₅₀ = 1.80 mg/mL). In HFD-fed flies, KPPs supplementation significantly extended median lifespan by 23.4% (P < 0.01) and improved motor function (e.g., climbing index increased by 30.0%). In the model, KPPs significantly prolonged lifespan, improved motor function, lowered peroxide, malondialdehyde (MDA) levels, and triglyceride content. Concurrently, KPPs enhanced antioxidant enzyme activity, increasing T-SOD by 20.9% and GSH-Px by 80.1%. Furthermore, KPPs attenuated aging by upregulating key antioxidant genes (Sod1, Cat) and inhibiting the insulin/IGF-like signaling (IIS) pathway. KPPs also demonstrated significant intestinal protection: reducing lipid droplet accumulation and ROS levels, decreasing apoptosis in epithelial cells by 43.2%, while suppressing intestinal stem cell proliferation. These effects collectively preserved gut integrity, maintained homeostasis, and contributed to delayed aging. This study provides compelling evidence for KPPs as a novel intervention to counteract HFD-induced damage and mitigate aging processes.

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.

The aim of this study was to investigate the effects of the composition of bigels on rheological performance, 3D printing performance and textural properties of surimi inks. The results showed that when the addition level of beeswax was 9.0%, the mass ratio of oleogel (9% beeswax) to hydrogel (4% xanthan gum) was 6:4, and the mass ratio of bigels to surimi was 3:7, the moisture content of surimi was 86%, the best rheological properties were obtained with yield stress (τ₀) of 44.44 Pa, viscosity index (K) value of 7.972 × 10⁴ Pa·sⁿ, flow index (n) value of 0.265, and recovery rate of 86.75%. The surimi inks with bigels were able to continuously print up to 40 layers of 20.00 mm × 20.00 mm × 40.00 mm rectangular structures and some types of complex structures. And the printed structures had a hardness of 204.91 g, elasticity of 0.28, cohesiveness of 0.26, adhesiveness of 52.68 g, and breaking strength of 31.65 g. This study provides ideas for the development and application of bigels in food 3D printing.