Studies On Texture And Flavor Of Salty Yolk

Salted egg is a kind of traditional food with particular texture and nutrition, which is popular among consumers at home and abroad. In this thesis, contents of basic components in yolks and salted-yolks were measured, separately. Then, the objective method of testing the special granulation texture of yolk was studied, and texture changes of yolks were investigated during the salted process. Meantime, volatile flavor compounds of yolks were analyzed. Certain theoretical basis and data base were provided for eggs industry.Chicken egg yolk, duck egg yolk, salty chicken egg yolk and salty duck egg yolk were boiled in water for15mins and separated from egg white. The egg yolk was equidistantly divided into four layers from yolk core to external and numbered1,2,3,4. The results showed that the contents of protein and fat in duck egg yolk were more than chicken egg yolk. After salted, the emulsification structure of fat and protein was destroyed, protein was denatured, oil droplets were got together and egg yolk oil was exudated. Contents of protein, fat and ash in egg yolk increased, moisture content decreased, the3th and4th layers of egg yolk contained more protein, fat and ash than1st and2nd layer.After salted, the texture of yolk changed harder, and egg yolk index increased gradually. The longer salted, the egg yolk index tended to1. A/BC cutter probe and HDP/SR spread ability rig of TA. XT. Plus were used to test the special characteristics of salted yolks, dates of hardness, area, peaks+number and linear distance were collected. Through contrasting the coefficient of variation and analyzing with sensory evaluation, HDP/SR spread ability rig was determined to indicate the granulation texture of salted yolk.Volatile compounds of chicken egg yolk, duck egg yolk, salty chicken egg yolk and salty duck egg yolk were analyzed, separately, by headspace solid-phase micro-extraction (HS-SPME) and gas chromatography-mass spectrometry (GC/MS). About60volatiles were determined and divided into7classes:21alcohols,11alkanes,2aldehydes,4ketones,7aromatics,9esters,5other compounds (1furan,1hydrindene,2pyrimidine, and1thiazole). After pickled, types and contents of volatile compounds were changed. The contents of esters, pyrimidine, and thiazole were increased, which probably formed the special flavor of salty yolk.