This study evaluated the effect of FI (Fraction I, molecular weight < 1 kDa), which is separated from natural whey protein, on the antioxidant activity, sensory quality, color, texture characteristics, and microbial growth of pork balls during repeated freeze–thaw cycles (F-T cycles). The results indicated that pork balls mixed with FI significantly improved in quality after repeating the F-T cycle, especially with the addition of 10% FI. The quality was improved significantly after repeated F-T cycles by adding 10% FI, and the antioxidant activity after seven F-T cycles decreased by 40.78%, a similar result to that obtained with the addition of 0.02% BHA. In addition, FI effectively reduced the sensory damage of pork balls caused by repeated freezing–thawing and also significantly inhibited the growth of microorganisms. In summary, FI not only has excellent antioxidant capacity under repeated freeze–thaw conditions but also has significant antibacterial and quality preservation effects and is expected to be quantified as a kind of natural food additive with antibacterial and antioxidant properties. This paper not only explores the effect of FI on the quality characteristics of frozen and thawed pork balls in prepared dishes but also provides a theoretical basis for the application of whey polypeptides in prepared meat.

The global rise in metabolic disorders demands novel interventions targeting starch digestion. This study investigated two dietary phenolic acids (caffeic acid (CA) and p-hydroxycinnamic acid (p-HA)) as inhibitors of α-amylase and α-glucosidase through integrated experimental and computational approaches. Molecular docking showed distinct binding modes, and CA formed stable hydrogen bonds with catalytic residues of α-glucosidase, while p-HA interacted mainly with α-amylase via hydrophobic contacts. Enzyme kinetics revealed concentration-dependent mixed-type inhibition, with CA being more potent against α-glucosidase and p-HA against α-amylase. Spectroscopic analysis indicated both acids induced structural changes in the enzymes, with CA causing greater α-helix reduction (Δ7.03% vs. Δ2.10%) by altering the tryptophan microenvironment. Moreover, both compounds significantly suppress glucose absorption in the proximal small intestine in an ex vivo everted gut sac model, with p-HA exhibiting exceptional efficacy in the duodenum. These findings clarify structure–activity relationships and support the potential use of CA and p-HA as local intestinal agents for modulating carbohydrate absorption.

Background/Objectives: The widespread adoption of high-fat diets has contributed to a rising incidence of metabolic disorders and associated cardiovascular diseases. This trend exacerbates myocardial ischemia–reperfusion (I/R) injury following interventional or thrombolytic therapy for acute myocardial infarction, leading to higher mortality and heart failure in affected individuals with metabolic dysregulation, for whom effective interventions are limited. Nuciferine, which possesses anti-inflammatory, antioxidant, and metabolic regulatory properties, has shown potential in improving post-I/R cardiac function, yet its mechanism remains unclear. Methods: This study utilized an ex vivo mouse heart model perfused with high-glucose/high-fatty acid solutions to establish a metabolic stress condition mimicking key aspects of the diabetic milieu and to evaluate the underlying mechanisms of nuciferine. Complementarily, a model of lipotoxicity combined with hypoxia/reoxygenation (H/R) injury was established in human cardiomyocyte cells (AC16). Results: Nuciferine significantly improved post-I/R functional recovery and attenuated succinate accumulation, an effect comparable to the succinate dehydrogenase (SDH) inhibitor dimethyl malonate (DMM). Mechanistically, nuciferine bound to an SDH subunit, inhibiting its activity and subsequent reactive oxygen species (ROS) production via mitochondrial reverse electron transport (RET). It also activated Sirt1-dependent pathways, mitigating apoptosis and mitochondrial dysfunction in AC16 cardiomyocytes. The Sirtuin 1 (Sirt1) inhibitor selisistat (EX527) abolished nuciferine’s protection, while DMM mirrored its efficacy, underscoring nuciferine’s dual role in inhibiting SDH-mediated RET and activating Sirt1 in alleviating I/R injury under metabolic stress conditions. Conclusions: These findings suggest that nuciferine confers cardioprotection by simultaneously attenuating RET-related oxidative stress and activating Sirt1.