National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, PR China.
Analysis and Test Center, Dalian Polytechnic University, Dalian 116034, PR China.
Food Res Int. 2017 Oct;100(Pt 1):850-857. doi: 10.1016/j.foodres.2017.08.004. Epub 2017 Aug 10.
The effects of electron beam irradiation (EBI) on structure characteristics and thermal properties of walnut protein flour (WPF) were evaluated. The WPF was irradiated by 0-15.0kGy of the EBI. Scanning electron microscopy and X-ray diffraction analysis revealed that the EBI irradiation could not change the amorphous structure of WPF but resulted in puncture pores and fragmentation on microcosmic surface of WPF. Besides, low-field nuclear magnetic resonance results showed the EBI irradiation had effects on increasing denaturation temperature of WPF to 70°C, and the particle size of WPF hydrolysates (WPFHs) irradiated by EBI at dose of 5.0kGy significantly (P<0.05) increased to 753.8±21.0nm. The molecular weight of WPFHs at dose of 5.0kGy increased compared with that of non-irradiated sample. These revealed that EBI irradiation led to aggregation or cross-linking of the walnut protein. In addition, thermogravimetric analysis and zeta potential values indicated that the EBI enhanced thermal stability of WPF and didn't affect the physical stability of the WPFHs. Therefore, these results provided a theoretical foundation that the EBI applies on improving the properties of protein in the future.
研究了电子束辐照（EBI）对核桃蛋白粉（WPF）结构特性和热性能的影响。用 0-15.0kGy 的 EBI 辐照 WPF。扫描电子显微镜和 X 射线衍射分析表明，EBI 辐照不能改变 WPF 的非晶结构，但会导致 WPF 微观表面出现穿孔和破碎。此外，低场核磁共振结果表明，EBI 辐照对提高 WPF 的变性温度至 70°C 有影响，辐照剂量为 5.0kGy 的 WPF 水解产物（WPFHs）的粒径显著（P<0.05）增加到 753.8±21.0nm。与未辐照样品相比，辐照剂量为 5.0kGy 的 WPFHs 的分子量增加。这些结果表明，EBI 辐照导致了核桃蛋白的聚集或交联。此外，热重分析和 Zeta 电位值表明，EBI 提高了 WPF 的热稳定性，而不影响 WPFHs 的物理稳定性。因此，这些结果为将来应用 EBI 来改善蛋白质性能提供了理论基础。
