College of Biological Engineering , Henan University of Technology , Zhengzhou 450001 , China.
J Agric Food Chem. 2018 Jun 20;66(24):6151-6161. doi: 10.1021/acs.jafc.8b00910. Epub 2018 Jun 8.
During the freezing process, ice crystal formation leads to the deterioration in physicochemical properties and networks of gluten proteins. The cryoprotective effects of recombinant carrot ( Daucus carota) antifreeze protein (rCaAFP), type II antifreeze protein from Epinephelus coioides (rFiAFP), and Tenebrio molitor antifreeze protein (rTmAFP) produced from Pichia pastoris GS115 on hydrated gluten, glutenin, and gliadin during freezing were investigated. The thermal hysteresis (TH) activity and ice crystals' morphology modification ability of recombinant antifreeze proteins (rAFPs) were analyzed by differential scanning calorimetry (DSC) and cryomicroscope, respectively. The freezing and melting properties, water state, rheological properties, and microstructure of hydrated gluten proteins were studied by DSC, low field nuclear magnetic resonance, rheometer, and scanning electron microscopy, respectively. The rTmAFP exhibited strongest TH activity and ice crystals' morphology modification ability, followed by rFiAFP and rCaAFP. The addition of the three rAFPs caused freezing hysteresis and weakened the damage of freezing to the networks of hydrated gluten, glutenin, and gliadin. During freezing, the cryoprotective effects of the three rAFPs on the freezable water content, water mobility and distribution, and rheological properties of hydrated gluten were achieved by protecting these corresponding properties of hydrated glutenin. Among the three rAFPs, rTmAFP was most effective in the cryoprotective activities on hydrated gluten proteins during freezing. The results demonstrate the potential of these rAFPs, especially rTmAFP, to preserve the above properties of hydrated gluten proteins during the freezing process.
在冷冻过程中，冰晶的形成会导致面筋蛋白的物理化学性质和网络结构恶化。本研究考察了来自胡萝卜（Daucus carota）的重组抗冻蛋白（rCaAFP）、来自斜带石斑鱼（Epinephelus coioides）的 II 型抗冻蛋白（rFiAFP）和来自黄粉虫（Tenebrio molitor）的抗冻蛋白（rTmAFP）对水合面筋、谷蛋白和麦醇溶蛋白在冷冻过程中的保护作用。通过差示扫描量热法（DSC）和低温显微镜分别分析了重组抗冻蛋白（rAFP）的热滞（TH）活性和冰晶形态修饰能力。通过差示扫描量热法、低场核磁共振、流变仪和扫描电子显微镜分别研究了水合面筋蛋白的冷冻和融化特性、水状态、流变特性和微观结构。rTmAFP 表现出最强的 TH 活性和冰晶形态修饰能力，其次是 rFiAFP 和 rCaAFP。三种 rAFP 的添加均导致了冷冻滞后，并减弱了冷冻对水合面筋、谷蛋白和麦醇溶蛋白网络的破坏。在冷冻过程中，三种 rAFP 通过保护水合谷蛋白的相应性质，对水合谷蛋白的可冻结水含量、水分流动性和分布以及流变性质产生了保护作用。在这三种 rAFP 中，rTmAFP 在冷冻过程中对水合面筋蛋白的保护效果最为显著。研究结果表明，这些 rAFP 具有在冷冻过程中保持水合面筋蛋白上述性质的潜力，尤其是 rTmAFP。
