Purcea Lopes Pompilia Mioara, Moldovan Dumitriţa, Moldovan Marioara, Carpa Rahela, Saroşi Codruţa, Păşcuţă Petru, Mazilu Moldovan Amalia, Fechete Radu, Popescu Violeta
Physics and Chemistry Department, Technical University of Cluj-Napoca, 28 Memorandumului Str., 400114 Cluj-Napoca, Romania.
Polymeric Composite Laboratory, Institute of Chemistry Raluca Ripan, Babeş-Bolyai University, 30 Fȃntȃnele Str., 400294 Cluj-Napoca, Romania.
Materials (Basel). 2022 Apr 1;15(7):2611. doi: 10.3390/ma15072611.
By-products from the meat and dairy industries are important sources of high biological value proteins. This paper explores possibilities for improving the swelling and integrity of a cross-linked whey and gelatin hydrogel with different amounts of CuSO × 5HO. Overall, swelling tests demonstrate that cross-linked samples show a better hydration capacity and stability in the hydration medium, but different copper concentrations lead to different swelling behavior. At concentrations smaller than 0.39%, the sample lasts for 75 h in a water environment before beginning to disintegrate. At a concentration of copper sulphate higher than 0.55%, the stability of the sample increased substantially. The swelling kinetics has been investigated. The diffusion constant values increased with the increase in copper concentration, but, at the highest concentration of copper (0.86%), its value has decreased. Spectroscopy analyses such as Fourier transform infrared (FT-IR), X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-VIS), and nuclear magnetic resonance (NMR) relaxometry analyses revealed changes in the secondary and tertiary structure of proteins as a result of the interaction of Cu ions with functional groups of protein chains. In addition to its cross-linking ability, CuSO × 5HO has also shown excellent antibacterial properties over common bacterial strains responsible for food spoilage. The result of this research demonstrates the potential of this hydrogel system as a unique material for food packaging.
肉类和乳制品行业的副产品是高生物价值蛋白质的重要来源。本文探讨了用不同量的CuSO₄·5H₂O改善交联乳清和明胶水凝胶的溶胀和完整性的可能性。总体而言，溶胀试验表明，交联样品在水化介质中表现出更好的水化能力和稳定性，但不同的铜浓度导致不同的溶胀行为。在浓度小于0.39%时，样品在水环境中持续75小时后才开始分解。在硫酸铜浓度高于0.55%时，样品的稳定性大幅提高。对溶胀动力学进行了研究。扩散常数的值随着铜浓度的增加而增加，但在最高铜浓度（0.86%）时，其值有所下降。傅里叶变换红外光谱（FT-IR）、X射线衍射（XRD）、紫外可见光谱（UV-VIS）和核磁共振（NMR）弛豫分析等光谱分析揭示了由于铜离子与蛋白质链官能团的相互作用，蛋白质二级和三级结构发生了变化。除了其交联能力外，CuSO₄·5H₂O对导致食物变质的常见细菌菌株也表现出优异的抗菌性能。本研究结果证明了这种水凝胶体系作为食品包装独特材料的潜力。
