以蛋清液为研究对象,比较了高密度CO2(DPCD)、脉冲电场(PEF)及热处理等方式对蛋清液功能性质及蛋白结构的影响。结果表明:DPCD处理使蛋清蛋白的溶解度、起泡性及乳化性能大幅降低;PEF处理降低了蛋清蛋白的溶解度,却在不同程度上提高蛋清液的起泡性和乳化性能;热处理提高了蛋清蛋白的溶解度,但降低了蛋清蛋白的起泡性和乳化性能。蛋清液分别经DPCD、PEF和热处理后,蛋清蛋白的结构发生改变,蛋白质部分变性,导致疏水基团外露,表面疏水性有不同程度的增强,其中热处理的影响大,使疏水性跟对照相比提高近1倍。热处理引起的蛋白聚集程度要大于DPCD处理对蛋清蛋白的影响,PEF处理对蛋清蛋白的影响为轻微。综合以上结果,PEF处理的综合效果要好于其他2种处理。

Egg white was chosen as a substrate to compare the changes of functional properties and protein structure after treated by dense phase CO 2( DPCD),pulsed electrical fields( PEF),and heat,respectively.The results showed that DPCD treatment could reduce the solubility,foaming and emulsifying properties of egg white protein to a large extent.PEF treatment decreased the solubility of egg white protein,but in varying degrees to improve its foaming and emulsifying properties.Heat treatment increased the solubility of egg white protein,but lowed its foaming and emulsifying properties.The structure of egg white protein changed and partial proteins denatured after treated by DPCD,PEF and heat,which led to the exposed hydrophobics and the increase in the surface hydrophobicity,in which,heat treatment had the greatest impact and led to nearly double hydrophobic compared with the control.The degree of protein aggregation caused by heat treatment was higher than by DPCD treatment,and the effect of PEF treatment was the slightest.Therefore,as described above,PEF treatment was better than the other treatments.