Rheological properties in fatty acid salt-induced p-lactoglobulin gel and the changes of secondary structure during the gelation

在本研究中，我们发现在室温下，只有在蛋白质溶液中加入脂肪酸盐（FAS），如己酸钠，才能形成透明的β-乳球蛋白（P-LG）凝胶。我们通过动态粘弹性分析研究了fas诱导凝胶的神学性质。此外，我们还利用傅里叶变换红外光谱分析了凝胶化过程中蛋白质二级结构的变化。在β-LG蛋白中，原始β-sheet含量占主导地位，分子间β-sheet条带随着分子内β-sheet含量的减少而增加。凝胶形成后，在80℃下加热30 min，观察到经过热处理后分子间β-片带明显增加。这些结果表明，与热诱导凝胶相比，fas诱导的β-LG凝胶形成时蛋白质构象的变化较小。

In this study, we found that transparent gels of β-lactoglobulin (P-LG) were formed only by the addition of fatty acid salts (FAS), such as sodium caprate, to the protein solutions at ambient temperature. We investigated the Theological properties of the FAS-induced gel by the analyses of dynamic viscoelasticity. Furthermore we analysed the changes in the secondary structure of proteins during the gelation step by Fourier transform infrared (FT-IR) spectroscopy. In β-LG protein in which the original contents are predominant β-sheet, intermolecular β-sheet bands increased with the decrease in the content of intramolecular β-sheet. FAS-induced gel was heated at 80℃ for 30 min after the gel was formed, and much increment of the intermolecular β-sheet bands by heat treatment was observed. These results suggest that the formation of FAS-induced gels of β-LG were accompanied by less marked changes in the protein conformation than those in heat-induced gels.