How is the quality of eggs classified internationally?

The international understanding of quality eggs varies in different dimensions, and the corresponding views are also different. If we observe from the breeding mode, New Zealand once divided eggs into four grades in the early years. Caged eggs come from laying hens that are confined in narrow grid cages. They cannot stretch their wings, and some farms even cut their beaks to prevent fighting. The breeding goal is mainly to maximize egg production efficiency, with the lowest welfare level. The activity space for a single chicken is even less than the size of an A4 paper. Non cage raised eggs allow laying hens to walk freely, spread their wings, and even take sand baths, and have access to appropriate outdoor space. At the same time, modern equipment such as automatic feeding and egg picking can be used to achieve large-scale breeding, with a higher welfare level than cage raised eggs. In addition to indoor activity areas, free range eggs can also freely forage outdoors when the weather is suitable. They can exhibit natural behaviors such as sand bathing and nest building. In addition to feeding, they can also independently collect grass seeds and small insects, providing outdoor free activity space and a high level of welfare. On the basis of free range farming, organic eggs are fed with organic feed without chemical additives throughout the entire process, without the use of growth hormones and antibiotics. They are raised in full compliance with organic certification standards, with the highest welfare level and traceable control throughout the breeding process.

However, in the internationally recognized egg quality rating standards, there are usually four levels. The mainstream system is based on the grading system of the US Department of Agriculture (USDA), combined with common standards in many countries around the world, and divided into core grades based on freshness and internal quality. AA grade is a premium grade with a Haff value of 72 or above, processing time not exceeding 48 hours, air chamber height within approximately 3.2 millimeters, thick egg white, firm yolk, no blood spots, requiring full process cold chain control. It is the only basic grade that can be directly eaten raw and is usually only allowed to be sold in regular supermarkets. Grade A is considered high-quality, with a Haff value between 60 and 72, an air chamber height not exceeding 4.7 millimeters, clear and transparent egg whites, slightly distinct yolk contours, and no blood spots. It is a common circulating fresh egg in supermarkets worldwide and is recommended to be consumed within 28 days after laying eggs. B-grade is processing grade, with a Haff value between 30 and 60, an air chamber height greater than 4.7 millimeters, thin protein and loose yolk, and can only be used for industrial purposes such as baking and egg liquid processing. It cannot be directly sold as fresh eggs. C-grade is a sub quality grade with a Haff value not exceeding 30. The internal quality of the eggs has severely deteriorated and there is a risk of spoilage. They are completely unsuitable for human consumption and can only be used for non food processing.

In addition to the ordinary grading mentioned above, there are also many high-quality egg categories with higher positioning in the international market. For example, raw eggs are controlled according to the standards established by Japan after 38 years of development, with strict management of Salmonella, no gamey smell, and a freshness level of AA or above. They are considered the quality benchmark of the global egg industry and are suitable for direct consumption or making soft boiled eggs. Selenium rich or nutrient fortified eggs are made by adding targeted nutrients such as selenium and Omega-3 to the feed, resulting in significantly higher specific nutritional content than regular eggs, making them suitable for consumer groups with special dietary needs. There is another product called the latest fresh egg, which is required to be delivered to consumers within 5 days after delivery according to the grading standards of the former Soviet Union. The eggshell is clean, the height of the air chamber is less than 4 millimeters, and it is specially designed for special groups such as children and patients. Its nutritional value and freshness are prominent. However, this standard is almost no longer in use and has been replaced by new alternative standards.

Overall, the international market's classification of egg quality is not based on a single standard, but covers multiple dimensions such as breeding welfare, freshness, internal quality, microbial safety, and nutritional enhancement. Consumers can make judgments based on the intended use, certification label, and storage conditions when making actual choices.