METHOD FOR PROCESSING POTATOES

Abstract

The present invention relates to a method for processing potatoes, comprising the provision of potatoes and the possible removal of the skin from said potatoes before further processing of the potatoes takes place. In this method potatoes are visually monitored for defects and then subdivided into good and bad potatoes, after which the potatoes are separated and additionally treated to selectively remove defective elements such as wireworms, rust, blackening, scab and eyes.

Claims

1. A method for processing potatoes, comprising the provision of potatoes and the possible removal of the skin from said potatoes before further processing of the potatoes takes place, which method comprises the following steps: i) visually monitoring potatoes for defects; ii) grading potatoes as visually approved potatoes and visually rejected potatoes on the basis of step i); iii) separating the visually approved potatoes from the visually rejected potatoes; iv) subjecting the aforesaid visually rejected potatoes to further treatment, comprising the selective removal of defective elements from the visually rejected potatoes so as to obtain additionally treated potatoes and potatoes comprising defective elements; v) subjecting the aforesaid additionally treated potatoes to further processing.

2. A method according to claim 1, characterised in that the potatoes that have been subjected to step i) comprise potatoes whose skin has been removed.

3. A method according to claim 1, characterised in that the selective removal of defective elements according to step iv) is carried out by using one or more cutting means selected from the group of water jet, laser jet, drill, cutter and knife.

4. A method according to claim 1, characterised in that step iv) comprises taking one or more digital images of visually rejected potatoes, analysing the one or more digital images, positioning the cutting means on the basis of said one or more analysed digital images and selectively removing defective elements from the visually rejected potatoes by cutting out the aforesaid defective elements, wherein the aforesaid one or more cutting means are brought into contact with the aforesaid, visually rejected potatoes.

5. A method according to claim 1, characterised in that step iv) further comprises separating the defective elements cut away by the aforesaid one or more cutting means.

6. A method according to claim 5, characterised in that said separation is carried out by passing the thus additionally treated potatoes over a number of rollers positioned one behind another, wherein the interspace between the rollers is variable.

7. A method according to claim 4, characterised in that step iv) further comprises visually monitoring the thus additionally treated potatoes (again) and separating, on the basis of the visual monitoring step thus carried out, the defective elements that have been cut away by the aforesaid one or more cutting means.

8. A method according to claim 1, characterised in that the one or more cutting means comprise one or more cutting dies, wherein the circumferential dimension of the one or more cutting means is larger than the circumferential dimension of the object to be cut.

9. A method according to claim 8, characterised in that the one or more cutting dies have a circular shape.

10. A method according to claim 9, characterised in that said circular shape is circumferentially provided with one or more projections.

11. A method according to claim 8, characterised in that the one or more cutting dies are star-shaped.

12. A method according to claim 8, characterised in that the step of bringing the aforesaid one or more cutting means into contact with the aforesaid visually rejected potatoes is carried out in such a manner that the contact with cutting means of the circular cutting die type takes place at an earlier stage than the contact with cutting means of the type selected from star shape and circular shape circumferentially provided with one or more projections.

13. A method according to claim 12, characterised in that the step of bringing the cutting means of the star-shaped type into contact is carried out only on the defective elements that were previously cut away by the aforesaid one or more cutting means.

14. A method according to claim 8, characterised in that the step of bringing said one or more cutting means into contact with said visually rejected potatoes is carried out using one or more cutting dies of the circular type circumferentially provided with one or more projections.

15. A method according to claim 1, characterised in that the defective elements to be removed are selected from the group of wireworms, rust, blackening, scab, eyes and combinations thereof

16. A method according to claim 1, characterised in that the peeled or unpeeled potatoes are sliced before step i) is carried out.

17. A method according to claim 1, characterised in that the peeled or unpeeled potatoes are chipped before step i) is carried out.

18. A method according to claim 2, characterised in that removing the skin of the potatoes is carried out by supplying steam.

19. A method according to claim 1, characterised in that the peeled or unpeeled potatoes are placed on a conveyor belt, after which the potatoes present on the conveyor belt are subjected to step i).

20. A potato obtained by carrying out the method as defined in claim 1, from which potato defective elements selected from the group of wireworms, rust, blackening, scab, eyes and combinations thereof have been removed.

21. A potato according to claim 20, characterised in that the potato has been processed into one or more of slice, stick, cube and section.

Description

EXAMPLE 1

[0049] From an amount of potatoes, unwanted elements such as stones, soil clinging to the potatoes and the like are removed in a preparatory treatment 1. Subsequently, the skin is removed from the cleaned or pre-processed potatoes 12, using a steam peeling device 2, which manner of peeling should not be regarded as limitative. It is not desirable that the peeled potatoes are subjected to a new peeling step at any time during the process to be described hereinafter.

[0050] According to the schematic representation in FIG. 1, the potatoes 13, from which the skin has thus been removed, are sliced in the cutting means 3 and put on a conveyor belt. It will be understood that the cutting of the potatoes into slices must not be construed as limitative, but that also other forms, such as cubes, chips, viz. sticks, and sections can be obtained in the cutting means 3. The conveyor belt with the sliced potatoes 14 is passed through a monitor 4, where visual recordings of the sliced potatoes are made. Based on those recordings, the flow of potatoes 15 thus supplied is separated in the separation installation 5 into a flow of visually approved potatoes 18 and a flow of visually rejected potatoes 16. In the figure it is indicated that the flow of visually approved potatoes 18 is subjected to a new separating step in the separation installation 6. In the separation installation 6, a flow of visually approved potatoes 21 and a flow of visually rejected potatoes 17 are formed. An additional separating step is carried out on the visually approved potatoes 21 in the separation installation 7, in which a flow of visually approved potatoes 24 and the flow of visually rejected potatoes 19 are obtained. The flows 16, 17 and 19 are combined into a flow 27 and supplied by means of a conveyor belt to an apparatus 8, which takes digital images of the flow 27 of visually rejected potatoes. Using a computer and software, the images are analysed, on the basis of which analysis the cutting means 9 is controlled. The cutting means may comprise three separate cutting stations, with cutting knives of the circular type being used in cutting station 9a, cutting knives of the circular type provided with projections being used in cutting station 9b and cutting knives of the star-shaped type being used in cutting station 9c. The cutting stations 9a, 9b and 9c are disposed downstream of the apparatus 8 that takes the digital images. The thus analysed potato slices 28 present on the conveyor belt are transported to the cutting means 9, in particular the cutting stations 9a, 9b and 9c, which cutting stations are controlled on the basis of the analyses carried out by the computer and software. In the cutting stations 9a, 9b and 9c, three different types of cutting dies are used, with the first cutting operation being carried out by circular cutting dies in the cutting station 9a. If desired, the obtained sliced parts exhibiting defects can be subjected to a further cutting operation in the cutting station 9b, using a circular cutting die circumferentially provided with one or more projections. It is also possible to carry out only one type of cutting operation in the cutting means 9, for example using a circular cutting die circumferentially provided with one or more projections.

[0051] After the defective elements have been selectively cut away, so-called loose defective elements and good potato slices are present in the flow 29 on the conveyor belt. Such loose defective elements are discharged by passing the flow 29 of defective elements and good potato slices through a separating station 10, for example a sliver remover, where the smaller parts 20 are discharged through the interspaces between the rollers. The thus obtained flow 30 of good potato slices that do not fall through the interspaces between the rollers is additionally passed through a separating station 11, where a separation into a flow 32 of good potatoes and a flow 31 of the effective potatoes takes place. The separating station 11 is preferably controlled in the same manner as the separation installations 5, 6, 7.

[0052] The flow 32 can be further processed, together with the flow 24, in a usual manner. Although mention is consistently made of potato slices in the above-discussed example, it should be understood that the invention is not limited thereto. Although mention is made in the description of the figures of three separation installations 5, 6 7, it should be understood that the invention is not limited to a special number of separation installations. Furthermore, it may be decided not to use a separating station 11 in certain embodiments and pass the flow 30 through one of the separation installations 5, 6 and 7. Furthermore, the cutting means 9 is not limited to a special number of cutting stations.

EXAMPLE 2

[0053] The same operations as in example 1 were carried out, with this difference that the potatoes subjected to a preparatory treatment were not subjected to a peeling step. Thus, no use was made of a steam peeling device 2, but the cleaned or pre-processed potatoes 12 were directly supplied to the cutting means 3, after which the subsequent steps as described in Example 1 were carried out. If desired, the good potatoes obtained in the flow 24 and the flow 32 could be additionally subjected to a peeling step (not shown).