American onion packing houses chose for optical grading technology

February, 23, 2016

A large number of the American onion packing houses have chosen for the Optical Grading technology of Ellips. “The method in which products are graded on external and internal quality has caused a significant change in the onion sector “, explains Erwin Bakker. “This technology enables a significant reduction in manual labor while providing a higher quality product on a consistent basis. If required, packers are able to conduct “quality control” sorting on the onions just prior to packing.”

“The external quality system is able to detect and sort on most common defects including, balding,  sour skin, external rot, black mold, sprouting, misshapen/doubles and mechanical damage. The internal quality system is capable of detecting internal rot (core, ring & neck) along with certain other internal characteristics including early stage sprouting.” Erwin proceeds.

“We have compared our system with the manual sorting process. The result was that by manual sorting 50% of the rejected onions were good onions and in the bag there were still too many onions with internal defects. After installation the onions in the bag did match the norm and only 20% of the rejected onions were good. With manual sorting the supply had to be reduced to make inspection possible and after automation this was not necessary. The benefits were evident. It will not be long before the retailer will demand from the packer that they use an internal detection system. In one case this has already happened.”

“The size module measures properties of the onions and uses the tale and root plate of the product as orientation. Special algorithms take care of the lose skins which can still be sticking to the onion. The measurements have been made more reliable by looking at the product from various angles. The onion is rotated under the camera and multiple images are taken of the same product. In this manner we can measure the diameter, length, and surface area. By rotating the products, 10 images are made of each product. In the Ellips TrueSort Software Imperial units or Metric Units can be selected for Weight and Size classes. Diameters are calculated with an accuracy of 0.1mm.”


“Our TrueSort-technology is used by more than 3.000 sorters all over the world. TrueSort is capable of measuring the internal- and external quality of fruit and vegetables. Our grading software can be used on new as well as existing older machines”, concludes Erwin.