咸鸭蛋清脱盐前后凝胶性质比较

The gel properties of salted duck egg white pre and post desalination

以鲜鸡蛋清和鲜鸭蛋清为对照,研究咸鸭蛋清脱盐前后凝胶特性的变化。结果表明,咸蛋清的凝胶点79.5℃,最低凝胶浓度质量分数2%。而脱盐后的咸蛋清凝胶点83.5℃,最低凝胶浓度质量分数5%;在相同蛋白质浓度的条件下,咸鸭蛋清低于75℃加热时凝胶硬度小于脱盐咸蛋清,高于75℃时咸鸭蛋清的凝胶硬度大于脱盐咸蛋清;咸鸭蛋清的凝胶硬度在加热40min后基本稳定,而脱盐后的咸蛋清要在60min后才达到稳定;咸鸭蛋清在pH10时凝胶硬度值最大,脱盐后的咸蛋清在pH5和pH10时均有凝胶硬度最大值。两步加热法对咸蛋清的凝胶硬度影响不大,但能提高脱盐后咸蛋清的凝胶硬度。

This article studied the gel properties of salted duck egg white （SEW） pre and post desalination,comparing with the fresh chicken egg white and the fresh duck egg white respectively. The result indicated that the gel point of the SEW was 79.5 ℃,the lowest gelatin concentration quality score was 2%. the gel point of the desalted duck egg white （DEW） was 83.5 ℃,the lowest gelatin concentration quality score was 5%. Under the same value of protein concentrations,the gel hardness of SEW was lower than DEW when heated below the temperature 75 ℃. But when heated above 75 ℃, the gel hardness of DEW was the lower one. The gel hardness of SEW was stable after had been heated for about 40 min, and the DEW was stable for about 60 min. The maximum of SEW gel hardness was pH10, and DEW was both pH5 and pH10. The two step heating method had little effect to the gel property of SEW, but greatly improved the gel property of DEW.