Zhongguo youzhi (Apr 2023)
核桃衣多酚改性对植物蛋白溶解性和抗氧化活性的影响Effect of walnut pellicle polyphenols modification on solubility and antioxidant activity of vegetable protein
Abstract
为改善植物蛋白的溶解性并提升其抗氧化活性，选择核桃蛋白、小麦蛋白和芝麻蛋白为实验对象，在碱性条件下与核桃衣多酚相互作用，考察了核桃衣多酚改性对3种植物蛋白中性条件下的溶解度和抗氧化活性的影响。此外，通过SDS-PAGE、圆二色光谱和荧光光谱对溶出蛋白质的结构变化进行表征。结果表明：在核桃衣多酚添加量为75 mg/g时，核桃蛋白、小麦蛋白和芝麻蛋白在中性条件下的溶解度分别提升了61.54、 61.23、69.25百分点；同时，添加核桃衣多酚改性后的核桃蛋白、小麦蛋白和芝麻蛋白的DPPH自由基和ABTS自由基清除活性显著升高；3种植物蛋白在核桃衣多酚的作用下均形成了大分子聚集体，总体上蛋白质的α-螺旋和β-转角含量增加，β-折叠含量减少，同时内源性荧光强度降低。综上所述，核桃衣多酚改性可以使蛋白质结构发生改变，显著改善植物蛋白的溶解性并提升其抗氧化活性。 In order to improve the solubility and antioxidant activity of vegetable protein, walnut protein, wheat protein and sesame protein were selected as experimental objects, and the interaction of the vegetable protein with walnut pellicle polyphenols under alkaline conditions was performed to study the effects of walnut pellicle polyphenols modification on the solubility under neutral conditions and antioxidant activity of three vegetable proteins. The structural changes of dissolved proteins were characterized by SDS-PAGE, circular dichroism and fluorescence spectra. The results showed that the solubility of walnut protein, wheat protein and sesame protein increased by 61.54, 61.23 percentage points and 69.25 percentage points respectively when the dosage of walnut pellicle polyphenols was 75 mg/g. At the same time, the DPPH free radical and ABTS free radical scavenging activity of walnut protein, wheat protein and sesame protein were significantly improved. It was found that the three vegetable proteins formed macromolecular aggregates under the action of polyphenols, the contents of α-helix and β-turn contents of protein increased, while β-sheet content decreased, as well as the endogenous fluorescence intensity. In conclusion, the walnut pellicle polyphenols modification can change the structure of vegetable protein and significantly improve the solubility and antioxidant activity.
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