Multi-walled carbon nanotubes (MWCNT)-tannase composite was investigated as an immobilized biocatalyst on the basis of its facile preparation, low cost, and excellent aqueous dispersibility. Cross-linked tannase enzymes, obtained in the presence of glutaraldehyde, were composited with MWCNT via physical adsorption. Multiple techniques were applied to investigate, and corroborate the successful adsorption of cross-linked tannase onto the MWCNT structure. Green tea infusion extract post-treatment using the composite preparation showed elevated radical scavenging activities relative to the control. Green tea infusion extract exhibited a markedly reduced EC₅₀ value on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals following its treatment with the enzyme composite, which represents 20%–34% enhancement in its free radical scavenging capacity. Stoichiometry and number of reduced DPPH were determined and compared. The antioxidative potential of a widely consumed, health-beneficial green tea is elevated by the treatment with MWCNT-tannase composite.

中文翻译：

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交联鞣酸酶-碳纳米管复合物提高绿茶提取物的抗氧化能力

多壁碳纳米管（MWCNT）-鞣酸酶复合物因其制备简便、成本低和优异的水分散性而被研究为一种固定化生物催化剂。在戊二醛存在下获得的交联单宁酶通过物理吸附与多壁碳纳米管复合。应用多种技术来研究并证实交联单宁酶成功吸附到 MWCNT 结构上。使用复合制剂后处理的绿茶浸液提取物显示出相对于对照物的自由基清除活性升高。绿茶浸液提取物的 EC ₅₀显着降低用酶复合物处理后 2,2-二苯基-1-苦基肼 (DPPH) 自由基的值，表明其自由基清除能力提高了 20%–34%。测定并比较化学计量和还原的DPPH的数量。通过使用多壁碳纳米管-鞣酸酶复合物进行处理，可以提高广泛食用的、有益健康的绿茶的抗氧化潜力。