Texture and Microstructure of Cooked Whole Egg Yolks and Heat‐Formed Gels of Stirred Egg Yolk

Abstract

Hardness, cohesiveness, and springiness of heated intact egg yolks were determined by an Ins&on compression test. Hardness increased as temperature was increased from 75" to 90°C and as time of heating was increased from 10 to 30 min. Cohesiveness and springiness increased as temperature was increased from 75" to 80°C and as time was increased from 10 to 30 min. Egg yolks from cooked shell eggs were lower in all textural parameters than gels formed from stirred egg yolk. Low scores for cohesiveness and springiness were indicative of the crumbliness of yolk from cooked shell eggs; crumbliness was attributed to structural characteristics. The microstructure consisted of adjoining polyhedral grains, which showed no evidence of crosslinking. Grains appeared to be equivalent to yolk spheres, ranging in size from 40 to 100 pm. The structure of a stirred yolk gel consisted of a highly crosslinked protein matrix containing spheres (S-35 ym) and granules (l-2 pm).

Effect of salting processes on chemical composition, textural properties and microstructure of duck egg

“…These polyhedral granules were formed by yolk spheres with similar sizes. 25 The microstructure of salted egg yolk visualized by SEM indicated that polyhedral granules were aligned closely when the salting proceeded, mainly due to dehydration during salting, regardless of salting process. The greater the reduction in moisture content, the more tightly the granules were packed.…”

Texture of Cooked Egg Yolk as Influenced by Physical Manipulation of Raw Egg Yolk and Salt Brining of Shell Eggs

“…Woodward and Cotterill (1987a) hypothesized that stirring caused changes in the microstructure of raw EY that resulted in changes in the textural properties of cooked EY. Fujii et al (1973) reported that EY in its native state consisted of yolk spheres packed tightly together in the form of polyhedral structures.…”

Effect of Different Cations in Pickling Solution on FTIR Characteristics of Pidan White and Yolk in Comparison to the Fresh Duck Egg

“…Woodward and Cotterill (1987) reported that egg white gel examined with SEM was very coarse with large irregularly shaped voids. Nevertheless, ovalbumin gels showed the homogeneous microstructure (Heertje & Van Kleef 1986).…”