Effect of Hydrostatic Pressure and Vacuum on Characteristics of Century Egg

Abstract

The objective of this research was to investigate the internal change of century egg in production process under hydrostatic pressure and vacuum conditions. The samples of duck egg that used in century egg production were immersed in alkaline solution at hydrostatic pressure of 1 and 2 bars, and 380 and 760 mmHg of hydrostatic vacuum. The samples of egg were random to evaluate internal change of some physical and chemical properties in term of percent of specific gravity increased, hardness of albumen, pH of albumen and yolk, and visible changing with image analysis every 2 days until 12 days. The results of studies indicate that percent of specific gravity increased, pH of albumen and yolk are increase when immersion time increases every pressure, but in contrast to the hardness of albumen. The hydrostatic pressure affect on percent of specific gravity increased clearly than hydrostatic vacuum, but in contrast of pH of albumen. The immersion time affect to change the color of albumen from transparent gel to dark brown every pressure. In addition, the eggs that immersed in alkaline at 2 bars for 6 days were suitable for produce century egg.  Index Terms-century egg, hydrostatic pressure, hydrostatic vacuum, immersion time

Choux Pastry Made from Egg Groups based on the Hen Age and Shelf Life of the Eggs

“…Two ways to escalate the shelf life of eggs are refrigeration and shell coating. For example, century eggs are made by coating eggshells from a green tea mixture with 4-5% NaOH and 4-5% NaCl [7,8]. Also, coatings can be made from a blend of calcium and nitric acid [9].…”