Gelation properties and the improvement of water soluble protein from fish

研究了添加和不添加卵清蛋白(OVA)对鱼水溶浓缩蛋白(WSPC)的诱导凝胶作用。在凝胶形成前，研究了油酸钠对水溶蛋白悬浮液粘弹性的影响。结果表明，氢键促进了材料动态弹性模量的提高。用WSPC进行的流变学测试表明，虽然WSPC不能单独通过添加戊酸钠形成凝胶，但即使在室温下与OVA混合也可以形成凝胶。含有戊酸钠的WSPC-OVA混合凝胶具有良好的微观结构，与脂肪酸诱导的OVA凝胶相当。FT-IR分析显示，分子间β-SHA板伴随着戊酸钠诱导的卵白蛋白凝胶的形成而形成聚集带。然而，WSPC和OVA混合凝胶的二级结构变化不明显，因为混合蛋白中没有明显的聚集带。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.