马铃薯基乳液作为脂肪替代物对鱼糜凝胶品质影响研究

为了研究马铃薯基乳液（potato based emulsion, PE）对鱼糜凝胶品质的影响， 本研究将玉米油（corn oil，CO）或PE按不同添加量（0%~14%）与鱼糜混合，以鱼糜凝胶质构、水分、色泽、分子间相互作用、流变特性和微观结构为考察指标，探究PE作为脂肪替代物对鱼糜凝胶品质的影响及机理。 结果显示，在相同的油添加量下，与CO相比，PE能避免油滴对鱼糜凝胶质构特性和持水能力产生的劣化效果，使样品表现出更高的弹性模量和粘度，其中，6%油含量PE样品的硬度从1 073 g（0%油含量样品）提升到1 159 g，而6%油含量CO样品的硬度降低至837 g；另外，横向弛豫时间结果表明，PE抑制了不易流动水向由水的转变，使更多的不易流动水被束缚，这可能增强了光线漫反射，从而使PE样品白度更高；微观结构和分子间作用力测定结果表明PE样品中油滴分布更均匀，氢键、疏水相互作用和二硫交联更强，凝胶网络因淀粉颗粒的填充效应而更致密；十二烷基硫酸钠-聚丙烯酰胺凝胶电泳结果表明 ，PE组中油滴对鱼糜蛋白交联的干预程度更小。研究表明，PE可作为脂肪替代物提升鱼糜凝胶制品品质。本研究可为淀粉基脂肪替代物的开发及其在鱼糜凝胶产品中的应用提供理论基础。

The effect of potato-based emulsion as a fat substitute on the quality of surimi gels

To investigate effects of potato-based emulsion (PE) on the quality of surimi gels, corn oil (CO) or PE was mixed with surimi at different additive levels (0%~14%), and the effects of PE as a fat replacer on the quality and mechanism of surimi gels were investigated by texture, moisture, color, intermolecular interactions, rheological properties, and microstructure of the surimi gels. At the same oil addition level, PE could avoid the degrading effect of oil droplets on the textural properties and water-holding capacity of surimi gels compared with CO, so that the samples exhibited higher elastic modulus and viscosity; in addition, the results of transverse relaxation time showed that PE inhibited the transition from immobile to free water, so that more immobile water was bound, which might enhance the diffuse reflection of light, thus resulting in the higher whiteness of the PE samples. The results of microstructure and intermolecular force measurements showed that the oil droplets in PE samples were more uniformly distributed, the hydrogen bonding, hydrophobic interactions and disulfide cross-linking were stronger, and the gel network was denser due to the filling effect of starch granules; the results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the neutralization of oil droplets in the PE group intervened less in the cross-linking of surimi proteins. These results indicate that PE can be used as a fat substitute to improve the quality of surimi gels, and this study provides a theoretical basis for the development of starch-based fat substitutes and their application in surimi products.