Zhiwen Qi,Xingying Xue,Hao Zhou,Hua Yuan,Wenjun Li,Guliang Yang,Pujun Xie,Chengzhang Wang
To valorise olive mill wastewater phenols (OPs) potentially applied in food preservation, a novel stable and regularly spherical OPs-AgNPs ( D avg = 78 nm) were successfully assembled in aqueous solution under the optimized conditions (pH 8.0, 5 mM AgNO 3 , 35C and 30 min). The results of antimicrobial zone diameters indicated that 50 μg/mL of promising OPs-AgNPs presented excellent antimicrobial effects. Especially, the cell wall damages of E. coli ATCC 23,815 were caused when OPs-AgNPs concentration was exceeded its MIC (8.58 μg/mL). Also, a significant down-regulating of the Ca 2+ -ATPase activity in E. coli was revealed, and the intracellular Ca 2+ concentrations were thus decreased from 12.5 to 1.35 µg/mL after a treatment for 3 h. The apoptosis level of E. coli was significantly increased more than the control (55.13% of OPs-AgNPs vs 9.90% of control). In sum, OPs exerts enhanced antimicrobial function via penetrating cell membrane and targeting Ca 2+ -ATPase after chelated with AgNPs.
Guan Wang,Manman Liu,Liwei Cao,Jirawat Yongsawatdigul,Shanbai Xiong,Ru Liu
The effect of NaCl (0.1 − 3.0 M) on self-assembly of silver carp myosin at 4 °C was investigated in terms of microstructure, conformation, intermolecular interactions, and particle size distribution. During setting at 4 °C, the self-assembly of myosin showed an obvious concentration dependence. At low concentrations (<0.3 M), myosin assembled into filaments mainly through rod-rod ionic linkages, and showed significantly (P < 0.05) higher turbidity and lower solubility than at ≥0.3 M. The addition of NaCl (0.3 − 0.6 M) led to the extension and dissolution of myosin by interfering with electrostatic interactions. The myosin assemblies gradually became smaller and more uniform. The solubility and Ca 2+ -ATPase activity reached a maximum at 0.6 M NaCl. When the concentrations increased to >1.0 M, myosin further assembled into filaments dominated by hydrophobic interactions. Both rod-rod and head-head interactions contributed to the myosin filaments at high concentrations (1.0 − 3.0 M). The solubility and uniformity of the myosin assemblies decreased as the NaCl concentration increased from 1.0 to 3.0 M.
Tsekwi Gracious Rinwi,Da-Wen Sun,Ji Ma,Qi-Jun Wang
This study investigated the impact of isochoric freezing-thawing (ISF-T) cycles (C0–C5) on the quality of chicken breast. The results indicated a significant increase (P < 0.05) in pH from 5.41 to 5.96 after C1 to C4 before slightly decreasing to 5.72 (C5). Lightness (L*) varied between 50.13 and 44.55 across C1 to C4, with redness notably decreasing from −1.15 after C0 to −2.09 after C5 while yellowness (b) sharply increased from 2.65 (C0) to 4.65 (C5). Moisture content decreased from 74.01% to 68.13% after C5. WHC slightly reduced from 89.25% after C0 to 85.66% after C4, with an 83.78% reduction after C5. Cooking loss increased linearly across the ISF-T cycles from 18.08% reaching 24.14% after C5. Conversely, shear force decreased to 21.83 N after C5 from 25.21 N after C1. Protein solubility slowly increased to 88.79% after C3, then decreased to 72.84 after C5. The myofibrillar index remained stable until C3, then increased from 35.51 after C5. Lipid oxidation slowly increased to 0.27 mg MDA/kg after C3, then sharply increased to 0.44 mg MDA/kg after C5. In addition, Ca 2+ -ATPase activity showed that the samples obtained after C1 to C3 fluctuated between 23.59% and 24.71%, followed by a substantial reduction to 12.35% after C5. Furthermore, validation of the results by magnetic resonance imaging and nuclear magnetic resonance analysis confirmed the findings, suggesting that isochoric freezing could offer a viable solution to control temperature fluctuations, a challenging problem during meat storage and distribution in the cold chain food industry.
危险品化学品经营许可证（带存储）