NaCl对冻藏期间冰全蛋功能性质的影响

Effect of NaCl on the Functional Properties of Frozen Whole Egg during Frozen Storage

为改善冰全蛋的功能性质,开发专用型冰全蛋产品,以鲜蛋为原料,研究了6个月冻藏期内不同添加量NaCl（0.5%、1%、2%和4%）对冰全蛋功能性质的影响,并结合理化性质的变化对其原因进行分析。结果发现,冰全蛋表面疏水性随冻藏时间延长和NaCl添加量的增加而升高,而总巯基和表面巯基含量均随冻藏时间的延长而降低,但随NaCl添加量的增加呈现复杂变化。冰全蛋的溶解度随冻藏时间的延长而降低,添加1%和2%的NaCl冰全蛋的溶解度明显高于空白组;随冻藏时间的延长,冰全蛋的起泡性整体呈下降趋势,泡沫稳定性整体呈上升趋势,其中添加2%的NaCl可以显著改善冰全蛋的起泡性,60～180 d后起泡性仍优于未冻藏未加盐冰全蛋,且优于鲜蛋。同时,凝胶强度及凝胶持水性均在冻藏初期增加而后持续下降,添加1%的NaCl可以显著改善冰全蛋的凝胶性,30 d后凝胶性仍高于未冻藏未加盐冰全蛋,且高于鲜蛋。所以添加一定量的NaCl可改善冰全蛋的功能性质,为开发专用型冰全蛋的生产提供理论指导。

This study aimed to improve the functional properties of frozen whole egg（FWE） for the purpose of developing FEW-based food products for special dietary use.The changes in the functional and physicochemical properties of FWE with NaCl added at 0.5%,1%,2% and 4% during six months of frozen storage were researched.With this aim,fresh liquid whole egg was added with NaCl,stirred thoroughly and quick-frozen before frozen storage.The results showed that the surface hydrophobicity of FWE was increased with increasing storage time and NaCl content.Total sulfhydryl content and surface sulfhydryl content were decreased with the extension of storage time,but they displayed irregular changes with NaCl content.Solubility was gradually decreased during storage time,and in terms of solubility,FWE with 1% and 2% NaCl added were better than the blank group significantly.The foaming capacity of FWE exhibited an overall decreasing trend,while the foam stability was changed reversely.The foaming capacity of FWE was significantly improved by adding 2%NaCl,and after frozen storage for 60–180 days,it was higher than that of the quick-frozen samples without NaCl addition and without storage and that of the fresh samples.Simultaneously,gel hardness and water holding capacity rose in the early storage period and then continuously declined.Moreover,gelling properties of FWE were obviously improved by adding 1%NaCl,and after 30 days of storage,they were higher than those of fresh egg and FWE without storage or NaCl addition.Therefore,we concluded that the functional properties of FWE could be effectively improved by adding an appropriate amount of NaCl,which can provided a theoretical guidance for the development of FEW-based food products for special dietary use.