Lead-free preserved eggs have gained popularity due to their superior taste, low cost, and ease of production. One notable method was developed by the National Academy of Agricultural Sciences of China on April 6, 2000, and is protected under a national invention patent titled “Lead-free Preserved Eggs and Cured Eggs.†This technique has been widely adopted in major egg-producing regions across the country due to its stable performance and high efficiency.
The process begins with selecting fresh eggs. Using sensory evaluation and the tapping method, eggs that are unsuitable for processing—such as cracked, sand-shelled, or oil-coated eggs—are carefully removed. By gently tapping each egg, one can detect small cracks based on the dull sound they produce. These eggs should not be used as they may compromise the final product's quality.
Next, the ingredients are prepared according to seasonal variations. For spring, autumn, and winter, the formula includes 0.55 kg of salt-free core material, 5 kg of salt, 1 kg of tea powder (96% purity), 5.5 kg of sodium hydroxide, and 14 kg of lime, all dissolved in 100 kg of water. In summer, the proportions change slightly, using 0.6 kg of pickled core material, 5 kg of salt, 0.5 kg of tea, and 6 kg of sodium hydroxide, along with adjusted amounts of lime.
Once the ingredients are mixed and cooled, the core material is added, and the solution is left to stand for 48 hours to ensure uniform distribution. The effective concentration of the liquid is then determined through acid-base titration, aiming for a total alkalinity of 4.5–5.0%. If testing equipment is unavailable, empirical methods like checking sample eggs or using egg white can help adjust the concentration.
Afterward, the selected eggs are placed into clean containers, covered with the prepared liquid, and left to marinate. The temperature during this phase is crucial, typically maintained between 20°C and 22°C, with adjustments made seasonally. Proper management of temperature ensures optimal penetration of the curing agents and promotes even solidification and discoloration of the eggs.
During the maturation period, which lasts 30–40 days, regular monitoring is essential. If temperatures are too high, cooling measures may be necessary; if too low, insulation can help. Once matured, the eggs are carefully removed, washed with a caustic soda solution, and inspected for quality.
Quality checks involve visual inspection, shaking, tapping, and light testing. Each step helps identify broken, immature, or defective eggs. Finally, the eggs are coated with mud or a protective film to extend shelf life and enhance appearance. Storage methods vary, including original tank storage, sealed packaging, or wrapped in nylon bags, depending on the season and environment.
The final product must meet strict quality standards, including sensory attributes like color, texture, and flavor, as well as physical and chemical indicators such as moisture content, pH, and bacterial levels. Lead-free preserved eggs not only offer a unique taste but also ensure safety and longevity, making them a popular choice in both traditional and modern food industries.
Acid-Base Balance of Medicine,Acid-Base Balance,Calcium Gluconate Injection,Finished Pharmaceutical Product,Acid-Base Balance Agent
NOUVASANT GROUP LTD. , https://www.nouvasant.com