【作者】 李斌； 李恩惠； 郎宇曦； 田金龙； 龚二生； 王月华； 张炜佳； 孟宪军；

【Author】 Li Bin;Li Enhui;Lang Yuxi;Tian Jinlong;Gong Ersheng;Wang Yuehua;Zhang Weijia;Meng Xianjun;College of Food Science,Shenyang Agricultural University;

【机构】 沈阳农业大学食品学院；

【摘要】 本文探究了牛血清白蛋白(BSA)对蓝莓花色苷的保护作用。蓝莓花色苷中含量最高的单体-锦葵色素-3-半乳糖苷(M3G)与牛血清蛋白的结合机制通过荧光光谱和紫外吸收光谱检测,结果显示:M3G引起BSA的荧光淬灭为静态淬灭,结合位点约为1,通过热力学分析得出M3G与BSA之间相互作用是一个自发的过程,并以静电作用为主要作用力,结合距离3.5nm,分子之间可发生能量转移。同步荧光光谱结果表明,BSA的色氨酸残基、酪氨酸残基微环境疏水性减小,极性增加;圆二色谱显示M3G会改变BSA的二级结构,分子对接结果显示M3G主要通过氢键和静电作用结合在BSA的Ⅱ、Ⅲ域中,M3G结构中B环上的羟基与BSA发生结合。在光照、Vc+光照、蔗糖+光照三个处理条件下,加入BSA后对蓝莓花色苷稳定性起到保护效果,BSA浓度为0.15mg/mL时保护效果最好;抗氧化实验显示在与BSA结合后,花色苷的抗氧化能力受到了抑制,但在不利于花色苷稳定性的条件下,BSA能通过保护花色苷稳定性从而保留住花色苷抗氧化能力。更多还原

【Abstract】 The protective effects of BSA on blueberry anthocyanins was studied.The binding of BSA with malvidin — 3 — o —galactoside(M3G),the highest content monomer in blueberry anthocyanins,was examined by fluorescence and ultraviolet absorption spectroscopy.Results showed that M3G and BSA emitted a static quenching,and the binding site was approximately one.The thermodynamic analysis showed that the interaction between M3G and BSA was a spontaneous process with the electrostatic interaction as the main force.The transfer between molecules can occur with the distance of 3.5 nm.Synchronous fluorescence spectra showed that the hydrophobicity of the microenvironment of Try residues and Tyr residues decreased,and the polarity increased.CD spectra showed that the secondary structure of BSA would be changed by M3G.The results of molecular docking showed that M3G was mainly bound in the II and III domains of BSA by hydrogen bonds and electrostatic interaction.The hydroxy group on the B ring of MG was bound to BSA.Under light,Vc + light and sucrose + light conditions,the stability of blueberry anthocyanins was protected after adding BSA.When BSA was 0.15 mg/mL,the protective effect was best.The results of antioxidant tests showed that the antioxidant capacity of anthocyanins was inhibited after binding to BSA.However,under the conditions of unfavorable factors to anthocyanins stability,BSA could retain the antioxidant capacity of anthocyanins by protecting the stability of anthocyanins.更多还原