Abstract:Changes in chemical and physical properties of duck egg of saline salting and plant ash salting were determined in this manuscript.The results indicated that the DHA content in egg yolk of saline salting was more than two times of that of plant ash salting,but the stearic acid content was only two thirds of that of plant ash salting and no significant differences in other fatty acids.No differences in protein patterns of either egg white or egg yolk were observed of saline salting and plant ash salting.For egg white,ovalbumin was the major protein with molecular weight(MW) of 45kDa and egg yolk was low-density lipoproteins(LDL) apoprotein with MW of 100kDa and high-density lipoprotein(HDL) apoprotein with MW of 46kDa and 66kDa.Hardening ratio of egg yolk of plant ash salting was higher than that of saline salting,and oil exudation ratio of saline salting was lower than that ofplant ash salting.Much more pore canals were observed in egg shell surface of of plant ash salting than that of saline salting and its surface was much rougher.The diameter of shell membrane fibers were also shorter than that of saline salting due to dehydration.It’s obviously observed that oil in egg yolk lipoprotein were separated from apoprotein by using this two methods,but oil separated of plant ash salting were more than that of saline salting and the diameter of the protein granule were at range of 0.2～2 μm.
