Can an Optical Sorter Detect Foreign Material in Garlic, and How Should I Test It?

An optical sorter can detect foreign material in garlic when the contaminant has a visible difference in color, shape, texture or surface appearance. The reliable way to confirm the result is a controlled test using the same garlic and impurities found in production.

Detection starts with visible contrast

Optical sorting works by evaluating what the camera can see. A dark stone on light garlic may be easy to distinguish. A dry stem may also have a clear shape or color difference. However, a pale piece of soil, a dusty clove or a contaminant hidden under overlapping garlic may be much more difficult.

That is why a buyer should not ask only whether an optical sorter can detect “foreign material.” The more useful question is whether it can detect the specific material in the specific garlic lot.

Which garlic defects should be included in the test?

WESORT’s garlic optical sorting solution can be evaluated with target groups such as:

1. Stones and hard dark particles.
2. Roots, stems and dried plant material.
3. Soil pieces and field debris.
4. Moldy or visibly abnormal garlic.
5. Peeled and unpeeled pieces when the appearance is distinguishable.
6. Broken cloves or other visible shape defects.

The list should reflect the real plant. A test based only on easy, high-contrast examples may give the buyer an unrealistic expectation.

How to prepare a meaningful sample

Prepare a mixed sample containing good garlic, every target foreign material, borderline pieces and the normal dust or surface condition seen during production. Keep a small reference portion of each category so the result can be checked after the run.

Tell the supplier the product form, size range, moisture condition, expected impurity level and desired sorting direction. Whole bulbs, peeled cloves and broken cloves may require different feeding and inspection arrangements.

How the test should be evaluated

Do not judge the test only by how much material enters the reject bucket. Review both streams:

1. How much target foreign material remains in accepted garlic?
2. How much good garlic enters the reject stream?
3. Does the result remain stable across repeated runs?
4. Does a second pass improve the commercial result?
5. Does heavy dust or overlap change the outcome?

This evaluation gives a clearer picture of the balance between impurity removal and good-product retention.

When optical sorting needs process support

Optical sorting is not designed to replace every cleaning step. Large stones, loose soil, leaves and heavy field debris may be better handled by screening, destoning or other mechanical preparation before the camera inspection stage.

Pre-cleaning also helps stabilize feeding. When garlic pieces overlap less and their surfaces are easier to see, the sorting program has more consistent visual information to work with.

Why repeated runs matter

A single run can hide variability. Garlic size, moisture and impurity distribution may change from one portion to another. Run the test several times and keep the same feed rate, air conditions and sorting direction.

If the plant operates with multiple grades or suppliers, test more than one representative lot. The final program may need adjustment when the material changes.

Conclusion

An optical sorter can detect visible foreign material in garlic when the target has sufficient visual contrast and the product is presented consistently. WESORT recommends defining the defect list first, testing real samples and measuring both reject removal and good-product retention.

https://www.wesortcolorsorter.com/
Shenzhen Wesort Optoelectronics Co., Ltd.