Numerical and experimental investigation of the effect of intact egg orientation and yolk positions on heat transfer and cold point location

This paper explores the effects of egg orientation and yolk position during thermal processing using computational fluid dynamics simulation and experimentation. A carboxymethyl cellulose suspension was used to simulate the egg white, and a two-dimensional model incorporated an air cell near the larger end. The simulation included four cases: two focused on vertical orientation with the yolk at the rear shell and the geometric center, and two on horizontal orientation with similar yolk positions. Repositioning the yolk in a horizontal orientation near the eggshell resulted in significant temperature variations. The findings show that a horizontal egg position, especially with the yolk near the eggshell, led to a significant 8%–16% reduction in heating times. This configuration also improved pasteurization efficiency, assessed by the F value, by about 13.8%. The study also revealed distinct flow patterns influenced by buoyancy forces, significantly related to temperature distribution inside the egg.