The objective of this study was to investigate the effect of pork oxidation through modified atmosphere packaging (MAP) on gel characteristics of myofibrillar proteins (MP) during the heat-induced gelation process. The pork longissimus thoracis (LT) was treated by MAP at varying oxygen concentrations (0, 20, 40, 60, and 80% O₂) with a 5-day storage at 4 °C for the detection of MP oxidation and gel properties. The findings showed the rise of O₂ concentration resulted in a significant increase of carbonyl content, disulfide bond, and particle size, and a decrease of sulfhydryl content and MP solubility (p < 0.05). The gel textural properties and water retention ability were significantly improved in MAP treatments of 0–60% O₂ (p < 0.05), but deteriorated at 80% O₂ level. As the concentration of O₂ increased, there was a marked decrease in the α-helix content within the gel, accompanied by a simultaneous increase in β-sheet content (p < 0.05). Additionally, a judicious oxidation treatment (60% O₂ in MAP) proved beneficial for crafting dense and uniform gel networks. Our data suggest that the oxidation treatment of pork mediated by O₂ concentration in MAP is capable of reinforcing protein hydrophobic interaction and disulfide bond formation, thus contributing to the construction of superior gel structures and properties.

The effects of octenyl succinic anhydride-modified hydrophobic starch (OSA starch) on the properties of myofibrillar protein (MP) emulsions were investigated. The results show that the stability of protein emulsions was significantly enhanced with the addition of OSA starch (0.25–1.0%), with the most pronounced effect observed at a 1% concentration. Concomitantly, increasing OSA starch concentrations led to a reduction in the fat globule size. Electrostatic interactions between anionic groups in the modified starch and myofibrillar proteins were observed, which effectively decreased the zeta potential of the emulsion to a minimum of −52.3 mV. However, in the composite emulsion system, a competitive relationship between OSA starch and myofibrillar proteins was evident, as reflected by the decrease in interfacial protein content from 1.16 mg/mL in the control (CK) group to 0.78 mg/mL in the OSA starch-treated group. Despite this competition, the overall emulsion stability was improved due to the synergistic effects of the modified starch and proteins. These findings suggest that OSA-modified starch holds promise as a stabilizer for enhancing the stability of myofibrillar protein emulsions.

As one of the endocrine-disrupting compounds (EDCs), diethylstilbestrol (DES) poses significant risks to ecosystems and human health. This study reports the development of a magnetic nanocomposite (Fe₃O₄@Al³⁺@laccase) via glutaraldehyde (GA) crosslinking to enhance DES degradation. The single factor experiments revealed that the optimum immobilization conditions were: temperature 40℃, pH 5, enzyme concentration 1.0 mg/mL, and immobilization time 1.0 h. Under these conditions, Fe₃O₄@Al³ ⁺@laccase achieved 91.71 %±2.95 % DES degradation within 12 h, as validated by HPLC, retaining 31.29 %±1.99 % of its initial catalytic activity after 10 reuse cycles. Notably, the immobilized laccase exhibited superior stability in organic solvents compared to free laccase. Fourier-transform infrared (FTIR) analysis confirmed that laccase was successfully conjugated onto Fe₃O₄@Al³ ⁺. Scanning electron microscopy and transmission electron microscopy revealed that the immobilization process preserved the original morphology and crystalline structure of Fe₃O₄@Al³ ⁺. Multi-spectroscopic analyses, including enzyme kinetics, fluorescence, and three-dimensional (3D) spectroscopy, elucidated the binding affinity and conformational changes between laccase and DES. Molecular docking simulations predicted a binding free energy of −6.4 kJ·mol⁻¹ , indicating that the conformation stability between laccase and surrounding free amino acids was mainly maintained via van der Waals, pi-pi T-shaped, Pi-Donor Hydrogen Bond, and Pi-Alkyl. This work provides proof-of-concept for using Fe₃O₄@Al³ ⁺ as a reusable magnetic support for laccase, offering a promising strategy for DES degradation and guiding the design of advanced nanomaterials for environmental bioremediation.