Gelation properties and the improvement of water soluble protein from fish

研究了含卵清蛋白（OVA）或不含卵清蛋白（OVA）的鱼类水溶性浓缩蛋白（WSPC）的醋酸钠诱导凝胶化。在凝胶形成之前，研究了油酸钠对水溶性蛋白悬浮液粘弹性的影响。结果表明，氢键的加入促进了动态模量的增加。用WSPC进行的流变学测试表明，虽然单独加入WSPC不能通过添加己酸钠形成凝胶，但在室温下与OVA混合也能形成凝胶。含有乙酸钠的WSPC-OVA混合凝胶具有与脂肪酸诱导的OVA凝胶相当的微观结构。傅里叶变换红外光谱分析显示，分子间β-片的聚集带伴随着乙酸钠诱导的卵细胞凝胶的形成。然而，WSPC和OVA混合凝胶的二级结构变化并不清楚，因为混合蛋白中没有发现显著的聚集带。需要进一步研究以阐明混合凝胶的形成机理。

Sodium caprate-induced gelation was investigated for water-soluble protein concentrate(WSPC) from fish with or without ovalbumin(OVA). Prior to the gel formation, effects of sodium oleate on the viscoelasticity of water-soluble protein(WSP) suspension were investigated. It was indicated that hydrogen bondings facilitated increase in dynamic modulus. Rheological measurements using WSPC indicated that although WSPC alone could not form a gel by the addition of sodium caprate, it formed a gel by the mixing with OVA even at room temperature. The WSPC-OVA mixed gel containing sodium caprate had fine microstructure which was comparable to that of fatty acid-induced OVA gel. Aggregation bands due to intermolecular β-sheet with concomitant formation of sodium caprate-induced OVA gel appeared on FT-IR analysis. However, secondary structural changes of the mixed gel from WSPC and OVA was not clear, since remarkable aggregation band in the mixed protein was not found. Further study is necessary to clarify the mechanism for formation of the mixed gel.