全蛋液贮藏过程中凝胶性能下降原因的研究
Study of the decrease of gel properties of liquid whole egg during storage
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摘要: 全蛋液经过巴氏杀菌后在4℃下冷藏过程中,其凝胶硬度和持水性不断下降,15d时凝胶硬度和持水性分别下降了35%和20%,导致全蛋液使用效率降低。为探索全蛋液凝胶能力变化的原因,测定了全蛋液储藏15d内蛋白质表面疏水性和巯基含量,并进行了电泳分析。结果显示,全蛋液中蛋白质表面疏水性在贮藏期不断上升,表面巯基和总巯基不断下降,还原SDS-PAGE和非还原SDS-PAGE均显示贮藏期间,蛋液蛋白质组分无显著分子聚集。上述结果表明,疏水聚集引起的凝胶网络不均匀以及二硫键不断下降引发凝胶弱化可能导致了全蛋液贮藏过程凝胶性能的不断下降。Abstract: The gel strength and water holding capacity of the liquid whole egg after pasteurization during storage in 4℃ were determined. The results showed that gel strength and water holding capacity decrease 35% and 20% respectively.To investigate the reasons of the decline of the gel properties of LWE, change of sulfhydryl content and surface hydrophobicity were determined and their influence to gel properties were discussed. The results showed that protein surface hydrophobicity increased and total protein sulfhydryl groups decreased continuously during storage.Reduced and non-reduced SDS-PAGE showed that protein constitute kept stable without new strips appears.All these results suggested that the decrease of gelling ability of liquid whole egg may due to the disorderly gathering of protein and decreased disulfide group formed during storage.Both of these reasons may lead to the nonuniform gelling and decrease of the strength and water-holding capacity of whole egg gel during storage.