By acquiring the chemical composition of the product flow in real time fit for industrial applications, Chemical Imaging Technology (CIT) offers new ways to classify and sort potatoes, which have been unthought-of, up to now. Thanks to this, foreign materials can be detected with a certainty that is much higher than that enabled by visual optical sorting processes. Besides, it is possible to acquire differences in the chemical structure of the potato and use them for industrial purposes. By way of example, we would like to mention that Sherlock Separator helps to eject sugar ends while French fries are being processed.

This patented technology is unique worldwide.

Exact definition of the potato using a full spectral analysis provided by CIT makes it possible to establish a new benchmark on the market when it comes to detecting and ejecting foreign bodies. Anything that is chemically different to the potato will automatically be identified as being a foreign body - no matter what the color, shape, surface or density of the object is. Problems with golf balls belong to the past.

The peel scanning function completes use in potatoes and enables exact control of the steam peeler. On the one hand, this helps to assure the quality of the peeling process. On the other hand, it contributes to maximizing the output. This function can be integrated in Sherlock Separator or is obtainable as an autonomous solution in Sherlock Observer.

The queen’s discipline of Chemical Imaging Technology is quantitative monitoring of substances contained in the potato. Dry substance and the content of reducing sugars, in particular, are extremely important for process control. Corresponding functions are being elaborated and can be offered as an upgrade soon.





Advantages CIT yields to potato sorting:


Summary of the functions:

Safe ejection of

all foreign materials, e.g.
  • metal;
  • stones;
  • glass;
  • paper/cardboard;
  • plastics;
  • ears of corn;
  • bones;
  • golf balls

Ejection of

product specific defects:
  • sugar ends, glassy ends;
  • peel residues;
  • rotten and putrid points;
  • color defects (e.g. green potato);
  • scurf;
  • Erwinia (a genus of Enterobacteriaceae bacteria)
Peel scanning function
  • monitoring of the peel residues, which helps to efficiently control the steam peelers
Chemo-metric monitoring (under way of elaboration)
  • monitoring of the content of dry substance



Fig. 4: CIT - Live view of potatoes with an SE defect (with a red frame) and potatoes with a peed residue (with a blue frame)


In simplified terms, “sugar ends”, which are also known under the synonyms “translucent ends”, “jelly ends” and “glassy ends”, denote concentration of sugars at the root end of potatoes that is caused by various environmental factors and will particularly occur in case of types of potatoes with long tubers, e.g. “Russet Burbank” and “Shepody”, which are often used for producing French fries. The phenomenon is very important in economic terms. For as is generally known, fructose and glucose, reducing sugars that are accumulated locally, will, in combination with amino acids, form brown pigments in the course of a heat induced Maillard reaction (form of nonenzymatic browning). These pigments can make products that are strongly heated/heating unsellable. The problem is that obvious browning will only occur at heating, i.e. at the customer’s, or, in the best case, in late process steps in the processing plant. This means that a lot of energy is input to production of goods that will be complained about, at the moment.



Optically this defect will only be visible if it is very distinct. Up to now, sorting according to this defect could only be done manually by trained personnel.
CIT has helped to solve this problem in an automated manner that can be used by large-scale industry.


Fig. 1: Non-fried potato half and fried sticks from the same potato with the SE defect on the right

Fig. 2: Non-fried potato half on the right and the same potato half with a visible SE defect (lower end) in CIT visualization behind that

Fig. 3: Fried potato half with an SE defect at the bottom