Comparison · Running the line
Should the camera come before or after candling in egg grading?
Before candling, the camera removes dirty and visibly cracked eggs, so the interior examination works on a cleaner batch. After candling, it measures eggs that have already passed the interior check, so separation happens at the end of the line. The order is not a regulatory requirement, but a camera placed before candling is usually the more practical choice.
Updated · 4 min read
What does the camera do before candling?
Before candling, the camera examines the shell of each egg and removes the dirty and visibly cracked ones. The interior examination then works on a cleaner batch, and eggs the camera cannot see in full are marked unverified.
Article 223 lists the general assessment of the cleanliness and integrity of the shell (item I) before the examination by candling (item II). The cited text does not fix the physical position of each step on the line, so the order is an operational choice.
What does candling see that the camera cannot?
Candling shows the inside of the egg, such as the air cell, the yolk and blood spots, plus fine cracks that do not show on the shell. For Class A, the air cell must not exceed 6 mm and must be stationary (RIISPOA, art. 225).
A surface camera sees none of that. So the camera does not replace candling in either position, and the comparison between the two is only about which eggs reach the interior check.
When the camera comes first, what about pre-selection?
When washing happens before candling, pre-selection is mandatory and removes the dirty cracked eggs and the cracked eggs (MAPA, question 24). It also sets aside the cracked eggs with clean shells, which go for breaking (MAPA, question 24).
A camera before candling can remove the dirty and visibly cracked eggs, but it does not carry out that step on its own, because pre-selection has its own purpose of separating the clean cracked eggs. See egg pre-selection for the cases where it is required.
What changes if the camera comes after candling?
After candling, the camera measures the shell of eggs that the interior check has already examined. Dirty and visibly cracked eggs reach the interior check and are removed only afterwards, so candling works on a larger batch.
This position is not wrong, but it puts more work on the step that is mandatory and has to be done with care. The table sums up the differences between the two positions.
| Criterion | Camera before candling | Camera after candling |
|---|---|---|
| Shell dirt | Removed before the interior check | Reaches the interior check, removed afterwards |
| Visible crack | Removed before the interior check | Reaches the interior check, removed afterwards |
| Batch that candling examines | Cleaner, without visibly dirty or cracked eggs | Complete, including dirty and visibly cracked eggs |
| Hairline crack and interior | Not seen by the camera; left to candling | Not seen by the camera; left to candling |
| Pre-selection, where mandatory | Does not replace it | Does not replace it |
| Load on candling | Lower, since visible defects are out first | Higher, since it receives every egg |
Which order should you choose in practice?
For most lines, a camera before candling makes more sense, because it takes out the shell defects it sees best and leaves the rest of the batch for the interior check. This is a practical assessment, not a requirement of the regulation.
If a line uses electronic candling equipment, MAPA requires manual checking by a validated sampling system and a procedure described in the self-control programme (question 34). A surface camera is not that equipment. To see how the records support this step, read manual or automatic grading records and inspecting every egg or sampling.
Frequently asked questions
Can the camera replace candling?
- No, in either position. Candling is its own step under article 223 and shows the inside of the egg, which a surface camera cannot see. The camera measures the shell and can remove dirty and visibly cracked eggs before the interior check.
Does the camera count as electronic candling?
- No. MAPA question 34 covers electronic equipment with results equivalent to traditional candling, with manual checking by a validated sampling system. A camera that sees only the shell does not perform that function, so the rule does not apply to it.
Is there a mandatory order between the camera and candling?
- In the cited texts, the regulation does not fix the physical position of the steps. It lists the shell assessment before candling, and pre-selection is mandatory only on some flows with washing before candling (question 24). A camera before candling is a practical choice.
Sources
- Decreto nº 9.013/2017 (RIISPOA), Presidência da República (Brasil)
- Perguntas e respostas sobre a Portaria MAPA nº 612/2022 (versão de 05/06/2023), Ministério da Agricultura e Pecuária (MAPA)
- Como o Vigiovo classifica ovos sem IA / How Vigiovo grades eggs without AI, Vigiovo
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.