Evaluation of antioxidant modification on the functional and structural properties of EWP conjugates.
Evaluation of antioxidant modification on the functional and structural properties of EWP conjugates.
复制标题
抗氧化修饰对 EWP 缀合物功能和结构特性的评价
作者：
采用碱性条件下儿茶素（CT）和表没食子儿茶素没食子酸酯（EGCG）共价修饰鸡蛋白色蛋白（EWP），以提高EWP的氧化稳定性。研究了CT和EGCG结合对EWP抗氧化活性、理化性质和结构性质的影响。结果表明，CT和EGCG修饰改变了EWP的等电点，使其pH值降低，从而使EWP结合物在pH 3.8时的溶解度降低，尤其是修饰EGCG后。EWP-CT和EWP-EGCG偶联物的抗氧化活性分别是未修饰EWP的2.88和3.52倍（2-二苯基-1-苦肼基自由基清除活性）、2.60和7.91倍（铁还原力）。此外，CT或EGCG修饰后，EWP的α-螺旋增加，β-折叠减少，表明经CT或EGCG修饰后，EWP的二级结构更加紧密，Trp和Tyr残基参与了EWP与CT或EGCG的偶联反应。此外，CT和EGCG的结合明显提高了EWP的乳化稳定性，这是由于CT或EGCG修饰后提高了EWP的抗氧化活性。因此，通过碱性法将EWP与CT或EGCG偶联是提高EWP利用价值的有效途径。
The aim of this present study was to improve the oxidative stability of egg white protein (EWP) through catechin (CT) and epigallocatechin gallate (EGCG) covalent modification via an alkaline method at pH 9.0. Effects of CT and EGCG conjugation on the antioxidant activities, physicochemical and structural properties of EWP were comprehensively studied. The results indicated that CT and EGCG modification altered the isoelectric point value of EWP to lower pH, thus the solubility of EWP conjugates at pH 3.8 decreased, especially after EGCG conjugation. In addition, the antioxidant activities of EWP–CT and EWP–EGCG conjugates were 2.88 and 3.52 fold (2-diphenyl-1-picrylhydrazyl radical scavenging activities), 2.60 and 7.91 fold (ferric reducing powers) higher than that of the unmodified EWP. Moreover, the CT or EGCG conjugation resulted in an increase in alpha-helix formation with a decrease in the β-sheet formation, indicating that the secondary structure of EWP became more compact after CT or EGCG modification, and Trp and Tyr residues were involved into the conjugation reaction of EWP with CT or EGCG. Furthermore, CT and EGCG conjugation obviously improved the emulsifying stability of EWP, due to the improvement of the antioxidant activity after being modified by the CT or EGCG. In conclusion, CT or EGCG conjugation with EWP via an alkaline method was an effective way to improve the utilization value of EWP.
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影响因子：
4.4
作者：
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影响因子：
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影响因子：
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Duh, PD