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.
Department and Graduate Institute of Nutrition, China Medical University, No 91 Hsueh-Shih Road, Taichung 40402, Taiwan, Republic of China.
Kuo-Chiang
KC
Hsu
Wen-Hsin
WH
Chung
Kung-Ming
KM
Lai
D000818:Animals; D020285:Cryoelectron Microscopy; D004372:Ducks; D004530:Egg Yolk / Q000648:ultrastructure*; D005404:Fixatives; D006358:Hot Temperature; D008855:Microscopy, Electron, Scanning
D005404:Fixatives