State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China.
State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China.
Food Chem. 2016 May 15;199:314-22. doi: 10.1016/j.foodchem.2015.12.035. Epub 2015 Dec 9.
The interactions of α- and β-casein with malvidin-3-O-glucoside (MG), the major anthocyanin in grape skin anthocyanin extracts (GSAE), were examined at pH 6.3 by fluorescence, fourier transform infrared (FTIR) and circular dichroism (CD) spectroscopy. The binding constant (KS), binding force and effects of the interactions on the caseins conformation and GSAE stability were investigated. The results showed that α- and β-casein bound with MG via hydrophilic (van der Waals forces or hydrogen bonding) and hydrophobic interactions, respectively. α-Casein had a slightly stronger binding affinity toward MG than β-casein, with respective KS values of 0.51×10(3)M(-1) and 0.46×10(3)M(-1) at 297K. The secondary structures of α- and β-casein were changed by MG binding, with a decrease in α-helix and an increase in turn for α-casein and no change in α-helix and a decrease in turn for β-casein. The casein-anthocyanin interaction appeared to have a positive effect on the thermal, oxidation and photo stability of GSAE.
在 pH 值为 6.3 时，通过荧光、傅里叶变换红外（FTIR）和圆二色性（CD）光谱法研究了 α-和 β-酪蛋白与葡萄皮花色苷提取物（GSAE）中主要花色苷矢车菊素-3-O-葡萄糖苷（MG）的相互作用。研究了相互作用对酪蛋白构象和 GSAE 稳定性的影响，并考察了结合常数（KS）、结合力。结果表明，α-和 β-酪蛋白分别通过亲水（范德华力或氢键）和疏水相互作用与 MG 结合。α-酪蛋白与 MG 的结合亲和力略高于 β-酪蛋白，在 297K 时，KS 值分别为 0.51×10(3)M(-1)和 0.46×10(3)M(-1)。MG 结合改变了 α-和 β-酪蛋白的二级结构，α-螺旋减少，转角增加，α-螺旋不变，β-螺旋减少。酪蛋白-花色苷相互作用似乎对 GSAE 的热、氧化和光稳定性有积极影响。
