【作者】 王玉；

【导师】 Fran?oise NAU； 马莺；

【作者基本信息】 哈尔滨工业大学 ， 化学工程， 2015， 硕士

【摘要】 鸡蛋蛋黄作为一种优良的天然乳化剂,广泛应用于蛋黄酱的加工中。鸡蛋蛋清中蛋白质含量丰富,人体吸收利用率高,但是其乳化性却远不及鸡蛋蛋黄,因此如何提高蛋清蛋白的乳化性,使之能代替蛋黄作为蛋黄酱中的乳化剂成为了本研究的目标。本文首先对鸡蛋清蛋白酶解工艺进行了研究,分析了蛋白酶浓度以及热处理温度对其水解产物的乳化性质的影响,确定了提高鸡蛋清蛋白乳化性的最优酶解条件,结果表明,当耐热酶浓度为0.4%E/S、热处理温度为90℃/8min时蛋白水解物的乳化活性和乳化稳定性最高,其中乳化活性接近于蛋黄水平、乳化稳定性优于蛋黄的乳化稳定性;相比于未经过任何处理的鸡蛋清而言,酶水解以及酶失活热处理均有助于鸡蛋清水解物乳化活性及乳化稳定性的改善;分析水解过程中水解度以及蛋白表面疏水性发现,当酶处理与热处理共同作用于蛋白质时,乳化活性及乳化稳定性的增加或减少并不能简单地以水解度或者蛋白表面疏水性作为单一推测指标。对鸡蛋清蛋白水解物的应用研究发现,鸡蛋清经过酶解后可以替代蛋黄应用于蛋黄酱的加工,通过感官品评、质构测定以及热稳定性分析,实验确定了蛋清蛋黄酱的最佳配方为:蛋清水解物25%、油脂60%、醋10%、盐2%、芥末酱3%;草莓鸡蛋乳的最佳配方为:鸡蛋水解物82%、草莓酱8%、蜂蜜添加量10%。鸡蛋清蛋白是一个复杂体系,其乳化性质受多种因素的影响,本文仅探讨了水解度以及蛋白表面疏水性对乳化性质的影响,如何从酶水解以及热处理导致的蛋白质结构的变化上来认识其对乳化性质的影响,还有待进一步研究。更多还原

【Abstract】 Hen egg yolk,as an excellent emulsifying agent, has been widely used in the processing of mayonnaise. Hen egg white has a relative high content of protein which is easy to digest by humans, however, compared with egg yolk, hen egg white possesses a weaker emulsifying properties. In this case, the current study focuses on how to improve emulsifying properties of egg white so that it can replace yolk as an emulsifier in mayonnaise.Egg white was hydrolyzed by a thermostable enzyme at various concentration,followed by heat treatment at different temperatures. In this case, the optimal hydrolysis condition was determined: optimal emulsifying properties were obtained when enzyme concentration was 0.4% E/S, followed by heat treatment at 90 ℃ for 8min, of which emulsifying activity is equal to yolk and emulsifying stability is better than that of yolk;Compared with native egg white, either hydrolysis or heat treatment favors to the improvement of emulsifying properties; By analyzing degree of hydrolysis and surface hydrophobicity, results showed that neither of them can be the unique index for forecasting increase or decrease of emulsifying properties.In the application part of this study, results showed that hydrolyzed egg white can be used as a substitute of yolk as an emulsifier. Through sensory evaluation、TPA test and DSC test, two innovative egg products have been brought out-mayonnaise with hydrolyzed egg white and strawberry emulsion by egg white, optimal recipe for this new ‘mayonnaise’ was: hydrolyzed egg white 25%、oil 60%、vinegar 10%、salt 2%、mustard 3%; Optimal recipe for strawberry emulsion of egg white was hydrolyzed egg white 82%、 strawberry jam 8% and honey 10%.Egg white is a system whose emulsifying property is influenced by various factors,this study only focused on effects of degree of hydrolysis and surface hydrophobicity,and the impacts of hydrolysis and heat treatment on structural changes of proteins which are supposed to affect emulsifying properties need further investigation.更多还原