烘烤对核桃蛋白二级结构、表面疏水性及乳化性的影响

Influence of roast processing on secondary structure,surface hydrophobicity and emulsifying properties of walnut protein

摘要: 研究了烘烤增香过程对核桃蛋白的二级结构、表面疏水性以及乳化性的影响,采用扫描电镜、圆二色谱等仪器进行分析。结果表明,烘烤处理的蛋白微结构成片状,α-螺旋结构从42.7%降低至27.6%,β-转角从17.3%增加到25.3%,无规则卷曲从24.7%增加到32.7%,β折叠比例不变。界面张力从20.98减少为18.49,表面疏水性从316.14降低为297.55。使用turbiscan多重光散射仪对蛋白与三种植物油形成的乳化液进行分析,其中烘烤处理的蛋白与花生油形成乳化液稳定性指数为15.98,与大豆油形成的乳化液稳定性指数为14.53,与葵花籽油形成的乳化液稳定性指数为14.55,相比较于未处理蛋白形成的乳化液稳定性均显著下降。

Abstract: The properties of roasted walnut proteins were investigated in this study.The micro- structure observed by SEM were turned from vesicular to flaky.The amount of α- helix conformation of roasted protein was reduced from42.7% to 27.6%,the amount of β- turn was increased from 17.3% to 25.3%,the amount of random coil was increased from 24.7% to 32.7%,the amount of β- pleated sheet was not changed. The interfacial tension was declined from 20.98 to 18.49,the surface hydrophobicity was declined from 316.14 to 297.55.Three kinds of vegetable oil and toasted protein were emulsified. The stability index of peanut oil was 15.98,the soybean oil was14.53,the sunflower seed oil was 14.55.