Comparison of heat- and pressure-induced gelation of β-lactoglobulin aqueous solutions studied by small-angle neutron and dynamic light scattering

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• 作者：Noboru Osaka ; Shin-ichi Takata ; Takuya Suzuki ; Hitoshi Endo ; Mitsuhiro Shibayama
• 关键词：β ; -Lactoglobulin ; Gelation ; Pressure
• 刊名：Polymer
• 出版年：2008
• 出版时间：10 June 2008
• 年：2008
• 卷：49
• 期：12
• 页码：2957-2963
• 全文大小：992 K

文摘

The gelation mechanism of β-lactoglobulin (bLG) aqueous solutions was investigated by dynamic light scattering (DLS) and small-angle neutron scattering (SANS). Temperature- and pressure-jump experiments, respectively, abbreviated as T-jump (from 20 to 75 °C; T-jump) and P-jump (from 0.1 to 315 MPa) were carried out and the time evolution of gel structure was monitored by DLS and SANS as a function of time. The gelation threshold was determined by DLS as the point when nonergodicity appeared. In the case of T-jump, a rapid increase of the time-average scattered intensity, I_T, and a steep decrease of the initial amplitude of the intensity–intensity time correlation function, , were observed at the gelation threshold. On the other hand, P-jump showed a gradual increase of the I_T and a continuous decrease of the . It was revealed by SANS that bLG underwent thermal denaturation, resulting in a formation of gels consisting of densely aggregated unfolded bLG oligomers. On the other hand, the pressure-induced gels were found to be a fractal aggregates consisting of primary particles of bLG monomers. The difference in the gel structure as well as gelation mechanism between bLGs treated by T-jump and P-jump is discussed in comparison with T-induced and P-induced microphase separation of amphiphilic block copolymers in water [Osaka N, Shibayama M. Phys Rev Lett 2006;96:048303].