Explainer · Defects and grading
How to identify soft-shelled or shell-less eggs during grading
A soft-shelled or shell-less egg has a weak, incomplete or missing shell. Brazil's RIISPOA requires Class A eggs to have a shell of normal shape, smooth, clean and intact, so these eggs leave Class A. With the membrane intact and the egg harmless, it falls to Class B; if the membrane also breaks, it is unfit for human consumption.
Updated · 4 min read
What is a soft-shelled or shell-less egg?
A soft-shelled egg is one whose shell lacks normal firmness, being too thin and flexible to protect the contents. A shell-less egg is the extreme case: the shell has not formed completely and the egg is protected only by the shell membrane.
For grading, the two cases are the same problem, because the shell no longer does its job as a barrier. A thin-shelled egg is a different case: it still has a firm shell and is covered in thin-shelled eggs.
Why does a soft-shelled egg leave Class A?
It leaves because Class A requires a shell and cuticle of “normal shape, smooth, clean, intact” (Decree 9.013/2017, art. 225, I). A soft or missing shell does not meet that description, so the egg cannot be sold as Class A.
The destination depends on the membrane. If it is intact and the egg is harmless, the egg falls into Class B, which is for industrial processing only (art. 226, I and sole paragraph). If the membrane also breaks and the contents are exposed, the egg is unfit for human consumption (art. 500, VII).
| Situation | Classification | Basis |
|---|---|---|
| Soft or missing shell, membrane intact, egg harmless | Not Class A; Class B, for industrial processing only | RIISPOA, art. 225, I; art. 226, I and sole paragraph |
| Shell and membrane broken, contents exposed | Unfit for human consumption | RIISPOA, art. 500, VII |
| Egg soiled with faecal material | Unfit as it is | RIISPOA, art. 500, V |
How do you recognise a soft-shelled egg on the line?
In practice, a soft-shelled egg shows on the surface: the shell looks dull, uneven or out of the usual pattern, and in some cases bare areas appear where the membrane is exposed. The appearance varies with the degree of the defect, so visual checks should be made by someone who knows the batch.
A surface camera sees that appearance, but it does not measure hardness or thickness. It may grade as clean an egg that shows no dirt and no visible crack. So image recognition is a support check, not proof.
What should you do with these eggs on the grading line?
Treat a soft-shelled egg as outside Class A from the grading stage, not only at the point of sale. The steps below keep that separation and leave a record of it.
- Separate the egg from the Class A flow as soon as it is recognised, at sorting or at manual review.
- Confirm on candling whether the membrane is intact, because that decides between Class B and unfit.
- Record the quantity and batch of the separated eggs, to keep traceability.
- Send each group to the destination the rules give: Class B for industrial processing, or treatment as unfit.
- Review the calibration with labelled soft-shelled eggs, to learn what the camera lets through.
How does Vigiovo handle soft-shelled eggs?
Vigiovo has no class of its own for soft shells. Its classes are clean, dirty, cracked and unverified, and each depends on what the image shows: dirt on the shell, visible cracks, or an outline that does not allow a reliable measurement. Vigiovo does not measure the hardness or thickness of the shell.
A soft-shelled egg whose surface is within the colour limits and shows no visible crack can be graded clean. When the outline falls outside the expected shape, the egg is marked unverified and sent to manual review, instead of receiving a grade. Details in how it works.
What are the limits of a camera for soft-shelled eggs?
The camera sees the surface, and a soft shell is a defect of firmness and thickness that the surface does not show clearly. A camera reduces the work for the team, but it does not replace manual review or batch sampling.
Frequently asked questions
Can a soft-shelled egg be sold as Class A?
- No. Class A requires a shell of normal shape, smooth, clean and intact (RIISPOA, art. 225, I). A soft or missing shell does not meet that. If the membrane is intact and the egg is harmless, it can go to Class B, which is for industrial processing (art. 226).
What is the difference between a soft-shelled egg and a thin-shelled egg?
- A thin-shelled egg still has a firm shell and, if it has no crack, can meet Class A. A soft-shelled or shell-less egg has lost firmness or the shell itself, so it does not meet art. 225, I, which requires a shell of normal shape and intact.
Can a camera identify soft-shelled eggs?
- Only in part. A surface camera sees how the shell looks, such as dullness, unevenness and bare areas, but it does not measure hardness or thickness. A soft-shelled egg that looks clean and crack-free can pass as clean, so manual review and sampling remain necessary.
Sources
- Decreto nº 9.013/2017 (RIISPOA), Presidência da República (Brasil)
How Vigiovo helps
Vigiovo grades eggs on the conveyor as clean, dirty, cracked or unverified, in real time, with deterministic computer vision: every decision comes with the measurements behind it, on an ordinary CPU.