Histological structures of native and cooked yolks from duck egg observed by SEM and cryo-SEM.
A method was used to fix duck egg yolk while retaining its original sol structure to elucidate the fine structure of native yolk by using fixation with liquid nitrogen and cryo-scanning electron microscopy (cryo-SEM). Native yolk spheres showed a polyhedron shape with a diameter at approximately 50 to 100 μm and packed closely together. Furthermore, the interior microstructure of the native yolk spheres showed that a great amount of round globules ranging from 0.5 to 1.5 μm were embedded in a continuous phase with a lot of voids. After cooking, the sizes of the spheres were almost unchanged, and the continuous phase became a fibrous network structure observed by SEM with chemical fixation probably constituted of low density lipoprotein (LDL). The fine structure of the native yolk can be observed by cryo-SEM; however, the microstructure of yolk granules and plasma from cooked shell eggs can be observed by SEM with chemical fixation.
Hsu
Kuo-Chiang
KC
Department and Graduate Institute of Nutrition, China Medical University, No 91 Hsueh-Shih Road, Taichung 40402, Taiwan, Republic of China.
Chung
Wen-Hsin
WH
Lai
Kung-Ming
KM
D000818:Animals; D020285:Cryoelectron Microscopy; D004372:Ducks; D004530:Egg Yolk / Q000648:ultrastructure*; D005404:Fixatives; D006358:Hot Temperature; D008855:Microscopy, Electron, Scanning
D005404:Fixatives