GB2278038A

GB2278038A - Low starch vegetable crisps and method for their production

Info

Publication number: GB2278038A
Application number: GB9413822A
Authority: GB
Inventors: David Dorricott; Paul Gayler
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-07-12
Filing date: 1994-07-08
Publication date: 1994-11-23
Anticipated expiration: 2014-07-08
Also published as: WO1995002336A1; GB2278038B; GB2278039A; GB9413823D0; GB9314494D0; GB2278039B; GB2279860B; GB2279860A; AU7128694A; GB9413822D0; AU695172B2

Abstract

The invention comprises a method for the production of a vegetable crisp which comprises selecting a raw material with a starch content below 10%, cleaning and slicing the raw material to a thickness of between 1mm and 3mm, cooking said raw material in a refined vegetable oil and subsequently subjecting said cooked material to a heat curing step at a temperature above 30 DEG C for a period sufficient to harden the product and remove any residual moisture. The raw material may be selected from carrot, turnip, swede, parsnip, celeriac, amba haldhi, sweet potato or beetroot.

Description

LOW STARCH VEGETABLE CRISPS AND METHOD FOR THEIR PRODUCTION The present invention relates to a low starch vegetable crisp and a method for their production.

The production of potato crisps is well known and well explored. There are however particular production problems relating to potato crisps relating essentially to the high proportion of starch in a potato product. For this reason various chemicals and other methods of blanching are required and primary and secondary and indeed even tertiary drying steps are utilized in order to provide a desired product. Such numbers of drying steps are unnecessary for vegetable crisps if the process is well thought through, and indeed counterproductive when low starch vegetable crisps formed of other materials other than potatoes are to be produced.

In GB-A-2099279 there is described the production of savoury crisps made by frying thin slices of raw carrot less than 2mm thick in an edible oil at about 1850C. Such a product is satisfactory when first made, but tends to take up moisture from the air and becomes flaccid unless stored even in really dry conditions.

One of the problems with the production of vegetables crisps has been that unlike where a single raw material has used, the various raw materials require different treatments in order to make a friable crisp. Low starch raw materials require a drying step as well since otherwise the eventual product is likely to go flaccid during storage. Further, because of the wide range of materials used it is difficult to get a single production process which can be used on all batches of raw materials which results in a good product. In the present invention it is envisaged that crisps of various raw material types shall be mixed in a single bag and to this end they must not take up moisture from each other or from the air. This is difficult to achieve unless cooking has essentially been completed in all cases.

It is also a problem that if a wide variety of raw materials are used it would normally be the question that times, temperatures and other treatments would differ widely. The present invention seeks, in part at least, to unify the process so that good friable crisps are made merely by using the same production techniques in each case but varying the dwell times of the raw materials during the cooking and the necessary drying periods.

The present invention has a first object therefore the provision of vegetable crisps formed of one or more vegetables which have a good taste and maintain their friability for a considerable period.

A second aspect of the invention provides means whereby cooked vegetable products can be given a more certain shelf life by heat curing of the cooked product prior to packaging. Further a good quality comestibles product can be produced by the methods of the present invention without any additives other than the raw vegetable material and cooking oil, although seasoning such as salt may be added if desired.

In a third aspect of the invention a method for the production of vegetable crisps is provided wherein the conditions for producing all the vegetable crisp types are substantially similar even though some of the cooking requirements for each raw material may differ, the arrangement being such that substantially only time periods are changed. This allows a production line to operate in constant conditions with the cooking step be adjusted by time rather than parameters. Thus succeeding batches of different raw materials can be cooked without altering the production line set up significantly.

This allows different raw materials to be crisped and admixed with other batches without impairing shelf life.

According therefore to a first aspect of the invention there is provided a method for the production of a vegetable crisp which comprises: selecting a raw material with a starch content below 10% by weight, cleaning and slicing the raw material to a thickness between lmm and 3mm, cooking said raw material in a refined vegetable oil at a temperature between 12 OOC and 18 OOC and subsequently subjecting said raw material to a heat curing step at a temperature above 300C for a period sufficient to prevent greasiness and prolong shelf life.

In a preferred form of the invention raw material is selected so as to have a starch content below 4% and a sugar content between 1.2% and 10.5%. The raw material may be selected from any one or more of carrot, turnip, swede, parsnip, celeriac, amba haldhi, sweet potato (white or African), sweet potato (orange or American) and beetroot. The refined vegetable oil may be a sunflower oil and or a refined vegetable/peanut oil mixture. In such an arrangement the cooking conditions may comprise a temperature in the range of 1500C to 1700C for a time period of 70 to 180 seconds.

The heat curing step may include a draining and/or a centrifugation step to remove surplus oil prior to the heat curing process. The curing step may be effected at a temperature generally inn the range of 600C to 800C for a period of 30 to 90 minutes. The preferred form of this heat curing step is effected at about 720C to give a curing time of between 40 and 80 minutes.

In a second method according to the present invention there is provided a method for the production of vegetable crisps having a starch content below 10% which comprises: cleaning and slicing a selection of said raw materials to a thickness of between lmm and 3mm, batch cooking said raw materials in said a selected refined cooking oil at a temperature between 1200C and 1800C, and subsequently subjecting the batches of cooked raw materials to a heat curing step at a selected temperature of above 30"C for a time sufficient to prevent greasiness and drive off any free residual moisture; characterised in that the conditions for producing all said vegetable crisp batches are substantially the same with exception of time periods.

The heat curing step may include the steps of draining and/or centrifuging the cooked products. Where centrifuging is effected the cooked products are placed in the centrifuge which may be compartmentalized. The centrifuge is spun to remove oil. The centrifuging is then stopped and the partially spin drained product is separated manually or mechanically before re-centrifugation. This process is called "fluffing up", and may be repeated several times.

It will be appreciated that these methods of production allow a production line to be set up for the production of different batches of raw materials for forming vegetable crisps. The only parameter which needs to be altered therefore is time which can be more readily controlled than temperature, original moisture content etc.

The method of the present invention also comprehends a method for ascertaining the suitability of a vegetable raw material for conversion into a vegetable crisp without the necessity for a heat curing step which method comprises assaying the starch content of the raw material whereby those materials with a starch content under 5% are designated as a requiring a heat curing step, those with a starch content over 15 are designated as those not requiring the heat curing step.

In a further aspect of the present invention there is provided a carrot crisp which comprises 0.5% to 1.5% starch, 8.5% to 10.5% sugar and up to 4.5% moisture, all by weight.

The invention also provides a turnip crisp comprising 1.4% to 2.9% starch, 6.5% to 8.5% sugar and up to 3% moisture, all by weight.

The invention also provides a swede crisp comprising 4.3% to 5.9% starch, 10% to 12% sugar and up to 3% moisture, all by weight.

The invention also provides a parsnip crisp comprising 9.5% to 11.5% starch, 13% to 16% sugar and up to 4% moisture, all by weight.

The invention also provides a celeriac crisp comprising 25% to 30% starch, 6.5% to 8.5% sugar and up to 4% moisture, all by weight.

The invention also provides an amba haldhi crisp comprising 8% to 10% starch, 9% to 11.5% sugar and up to 5% moisture, all by weight.

The invention also provides a sweet potato (white) crisp comprising 3% to 5% starch, 11% to 13% sugar and up to 2.5% moisture, all by weight.

The invention also provides a sweet potato (orange) crisp comprising 4% to 6% starch, 9.5% to 11.5% sugar and up to 3% moisture, all by weight.

Finally, the invention also provides a beetroot crisp comprising 1% to 5% starch, 10% to 12% sugar and up to 5% moisture, all by weight.

In each case the crisp may be cooked in a refined vegetable oil such as sunflower oil and/or may be added on a 50/50 basis to peanut oil. The crisp batches may in each case be subjected to a heat curing step after cooking as hereinbefore described.

The invention will now be described by way of illustration only, with reference to the following examples.

A plurality of vegetable raw materials was selected from those having a starch content below 4% by weight. These were as follows: carrot, turnip, swede, parsnip, celeriac, amba haldhi, sweet potato (white), sweet potato (orange) and beetroot.

These were peeled and cleaned as necessary and sliced into pieces of about 1.5mm and as near as possible into neat rounds, and kept separate from each other and particularly from other vegetables to avoid staining. Each batch of sliced vegetable is then cooked in a refined sunflower oil at a temperature of 1600C for the length of time depending upon the vegetable used. The cooking time is shown in the Table, the upper figure of 1600C being the initial cooking temperature, whereas the lower figure is the temperature to which the oil may fall as a result of contact with cold moist slices, the temperature fall rising again to the predetermined value.

Also shown in the Table is the cooking time. This in respect of the carrot for example, is 80 seconds but in respect of the swede is for example, 170 seconds. It will thus be seen that by utilising a selected raw material type with a starch content below a predetermined value and a standardised cooking temperature is possible by alteration of the time to cook a wide variety of raw materials successfully into crisps.

The heat curing step usually commences with a short drainage period of between 5 and 10 minutes. Thereafter a heat curing temperature is selected, in this case 72"C. A thin layer of the cooked components are spread under a heat lamp or in a heated cupboard or at least in a heat curing facility for a heat curing time period.

The curing time may be between 40 and 80 minutes at 720C.

Other temperatures and times may also be used. For example, the drying time at about 300C will be at about 8 hours but at temperatures much higher than 720C there is a risk that some of the cooked raw materials may acquire a burnt flavour.

Although temperatures higher than 720C can be utilised, higher levels of skill and knowledge are required to provide consistent products.

In the heat curing facility an absorbative base such as a paper sheet may be positioned to assist in the removal of excess cooking product and oil by absorption.

If reference is made to the Table below the parameters of the raw materials, the treatment and the final moisture content are given. It will be noted that in all cases that the moisture content is always below 4% and in many cases below 3%. This assists in providing the product with a long shelf life.

TABLE 1

PRODUCT FRLED STARCH STARCH SUGAR SUGAR OlL COOKlNG DRALNAGE DRYlNG DRYlNG ABSORPTlON ORlGlNAL FlNAL PRODUCT BEFORE AFTER BEFORE AFTER TEMP. TlME TlME TlME TlME REQUlRED MOLSTURE MOLSTURE %by wt % by % by wt % by wt % by wt C SECONDS MlNUTES C MlNUTES % by wt % by wt Carrot 15.0 0.0 1.0 5.2 9.3 160/155 80 05 72 50 / 91.8 2.8 Turnip 15.0 0.0 2.1 3.9 7.5 160/152 80 05 72 50 / 54.3 1.8 Swede 18.0 0.2 5.1 4.2 11.0 160/150 170 10 72 40 / 91.7 1.9 Parsnip 28.0 2.6 10.3 8.6 14.2 160/150 100 10 72 50 / 88.3 2.7 Celenac 17.6 0.4 27.8 1.6 7.6 160/155 110 10 72 80 / 90.7 2.7 Amba Haldhi 27.0 3.5 9.1 6.1 10.6 160/155 160 10 72 40 / 88.6 3.7 Sweet Potato 43.0 0.1 3.9 4.4 11.8 160/140 150 05 72 40 / 77.6 1.3 (Whito) Sweet Potato 31.0 0.2 5.2 4.3 10.6 160/145 80 05 72 50 83.3 2.1 (Orange) Bootroot 22 0.0 2.0 5.7 11.2 160/148 145 10 72 55 87.5 3.5

Claims

CLAIMS 1. A method for the production of vegetable crisps which comprises: selecting a raw material with a starch content below 10% by weight, cleaning and slicing the raw material to a thickness of lmm to 3mm, cooking said raw material in a refined vegetable oil at a temperature between 12 OOC and 18 OOC and subsequently subjecting said raw material to a heat curing step at a temperature above 3000 for a time sufficient to prevent greasiness and to drive off residual moisture.
2. A method according to claim 1 wherein the raw material has a starch content below 4% by weight and a sugar content between 1.2% and 10.5% by weight.
3. A method according to either one of claims 1 or 2 wherein the raw material is selected from any one or more of carrot, turnip, swede, parsnip, celeriac, amba haldhi, sweet potato (white), sweet potato (orange) and beetroot.
4. A method according to any preceding claim wherein the refined vegetable oil is sunflower oil and/or a refined vegetable/peanut oil mixture.
5. A method according to claim 4 wherein the cooking conditions are in the range of 1500C to 170"C for a time period of 70 to 180 seconds.
6. A method according to any preceding claim includes draining and/or a centrifugation step to remove surplus oil from the cooked products.
7. A method according to any preceding claim wherein the heat curing step is effected at a temperature of 60"C to 800C for a period of 30 to 90 minutes.
8. A process according to claim 7 wherein the heat curing step temperature is about 720C and the curing time is between 40 to 80 minutes.
9. A method for the production of a carrot crisp which comprises: cleaning and slicing a carrot to a thickness of about 1.5mm, cooking said carrot slices in a refined vegetable oil at a temperature of about 1600C for 70 to 90 seconds, draining and/or centrifuging the cooked carrot product and allowing it to cool to 650C to 750C, and subjecting said carrot crisp product to heat curing at that temperature for about 50 minutes to provide a carrot crisp having a final moisture content below 3% by weight.
10. A method for the production of a turnip crisp which comprises: cleaning and slicing a turnip to a thickness of about 1.5mm, cooking said turnip slices in a refined vegetable oil at a temperature about 1600C for 70 to 90 seconds, draining and/or centrifuging the cooked turnip product and allowing it to cool to 650C to 750C, and subjecting said turnip crisp product to heat curing at that temperature for about 60 minutes to provide a turnip crisp having a final moisture content below 2.5t by weight.
11. A method for the production of a swede crisp which comprises: cleaning and slicing a swede to a thickness of about 1.5mm, cooking said swede slices in a refined vegetable oil at a temperature about 1600C for 150 to 180 seconds, draining and/or centrifuging the cooked swede product and allowing it to cool to 65"C to 75"C, and subjecting said swede crisp product to heat curing at that temperature for about 40 minutes to provide a swede crisp having a final moisture content below 2.3% by weight.
12. A method for the production of a parsnip crisp which comprises: cleaning and slicing a parsnip to a thickness of about 1.5mm, cooking said parsnip slices in a refined vegetable oil at a temperature about 1600C for 90 to 110 seconds, draining and/or centrifuging the cooked parsnip product and allowing it to cool to 650C to 75"C, and subjecting said parsnip crisp product to heat curing at that temperature for about 50 minutes to provide a parsnip crisp having a final moisture content below 3% by weight.
13. A method for the production of a celeriac crisp which comprises: cleaning and slicing celeriac to a thickness of about 1.5mm, cooking said celeriac slices in a refined vegetable oil at a temperature about 1600C for 100 to 120 seconds, draining and/or centrifuging the cooked celeriac product and allowing it to cool to 65"C to 750C, and subjecting said celeriac crisp product to heat curing at that temperature for about 80 minutes to provide a celeriac crisp having a final moisture content below 3% by weight.
14. A method for the production of an amba haldhi crisp which comprises: cleaning and slicing amba haldhi to a thickness of about 1.5mm, cooking said amba haldhi slices in a refined vegetable oil at a temperature about 1600C for 150 to 170 seconds, draining and/or centrifuging the cooked amba haldhi product and allowing it to cool to 650C to 750C, and subjecting said amba haldhi crisp product to heat curing at that temperature for about 40 minutes to provide an amba haldhi crisp having a final moisture content below 49s by weight.
15. A method for the production of a sweet potato (white) crisp which comprises: cleaning and slicing sweet potato (white) to a thickness of about 1.5mm, cooking said sweet potato (white) slices in a refined vegetable oil at a temperature about 1600C for 140 to 160 seconds, draining and/or centrifuging the cooked sweet potato (white) product and allowing it to cool to 650C to 75"C, and subjecting said sweet potato (white) crisp product to heat curing at that temperature for about 40 minutes to provide a sweet potato (white) crisp having a final moisture content below 1.6% by weight.
16. A method for the production of a sweet potato (orange) crisp which comprises: cleaning and slicing sweet potato (orange) to a thickness of about 1.5mm, cooking said sweet potato (orange) slices in a refined vegetable oil at a temperature about 16 OOC for 70 to 90 seconds, draining and/or centrifuging the cooked sweet potato (orange) product and allowing it to cool to 650C to 750C, and subjecting said sweet potato (orange) crisp product to heat curing at that temperature for about 55 minutes to provide a sweet potato (orange) crisp having a final moisture content below 2.5t by weight.
17. A method for the production of a beetroot crisp which comprises: cleaning and slicing a beetroot to a thickness of about 1.5mm, cooking said beetroot slices in a refined vegetable oil at a temperature about 1600C for 130 to 160 seconds, draining and/or centrifuging the cooked beetroot product and allowing it to cool to 65"C to 750C, and subjecting said beetroot crisp product to heat curing at that temperature for about 55 minutes to provide a beetroot crisp having a final moisture content below 4% by weight.
18. A method for the production of batches of vegetable crisps having a starch content below 10% which comprises: cleaning and slicing a selection of low starch raw materials to a thickness between lmm and 3mm, cooking said raw material in a selected refined cooking oil at a temperature between 1200C and 1800C, and subsequently subjecting said cooked raw materials to a heat curing step at a selected temperature above 300C for a period sufficient to prolong shelf life by removal of residual moisture, characterised in that conditions in producing all said batches of vegetable crisps are substantially the same with the exception of time periods which are individually selected.
19. A method according to claim 18 wherein the cooking temperatures is between 1500C and 1700C, wherein the refined cooking oil is a refined vegetable oil and/or a peanut oil, wherein the selected temperature is between 1600C and 1800C and the period is between 1 and 5 minutes.
20. A carrot crisp comprising 0.3% to 1.8% starch, 8.5% to 10.5% sugar and up to 4.5% moisture, all by weight.
21. A turnip crisp comprising 1.3% to 2.9% starch, 6% to 8% sugar and up to 3% moisture, all by weight.
22. A swede crisp comprising 4% to 6% starch, 10% to 12% sugar and up to 3% moisture, all by weight.
23. A parsnip crisp comprising 9.5% to 11.5% starch, 13% to 16% sugar and up to 4% moisture, all by weight.
24. A celeriac crisp comprising 25% to 30% starch, 6.5% to 8.5% sugar and up to 4% moisture, all by weight.
25. An amba haldhi crisp comprising 8% to 10% starch, 9% to 11.5% sugar and up to 5% moisture, all by weight.
26. A sweet potato (white) crisp comprising 3% to 5% starch, 11% to 13% sugar and up to 2.5% moisture, all by weight.
27. A sweet potato (orange) crisp comprising 4% to 6% starch, 9.5% to 11.5% sugar and up to 3% moisture, all by weight.
28. A beetroot crisp comprising 1% to 3% starch, 10% to 12% sugar and up to 5% moisture, all by weight.
29. An admixture of a selection of vegetable crisps substantially as hereinbefore set forth with reference to, and/or as illustrated in, the foregoing Table, or as claimed in any of claims 20 to 28.

29. A crisp according to any one of claims 20 to 28 cooked in a refined vegetable oil and having been subjected to a heat curing step after cooking.

30. A method for ascertaining the suitability of a vegetable raw material for conversion into a crisp without the necessity for a heat curing step, which method comprises: assaying the starch content of the raw material and designating those with a starch content of under 5% as requiring a heat curing step, and those with a starch content of over 15% as not a heat curing step, all percentages by weight.

31. A method for the production of a vegetable crisp substantially as hereinbefore set forth with reference to, and/or as illustrated, in the foregoing Table.

32. A vegetable crisp substantially as hereinbefore set forth with reference to, and/or as illustrated in, the foregoing Table.

Amendments to the claims have been filed as follows 1. A method for the production of vegetable crisps which comprises: selecting raw materials with a starch content below 10% by weight from any one or more of turnip, swede, parsnip, celeriac, amba haldhi, sweet potato (white), sweet potato (orange) and beetroot, cleaning and slicing the raw material to a thickness of lmm to 3mm, and cooking said raw materials in a refined vegetable oil at a temperature between 12 OOC and 1800C and subsequently subjecting said cooked products to a heat curing step at a temperature between 300C and 800C for a time sufficient to prevent greasiness and to drive off residual moisture.

2. A method according to claim 1 wherein the raw material has a starch content below 4% by weight and a sugar content between 1.2% and 10.5% by weight.

3. A method according to either of claims 1 or 2 wherein the cooking of each raw material occurs sequentially, and wherein the final products after heat curing are admixed for sale.

4. A method according to claim 3 wherein at least two of said raw material types are selected and cooked sequentially.

5. A method according to claim 4 wherein the cooking conditions are in the range of 1500C to 1700C for a time period of 70 to 180 seconds.

6. A method according to any preceding claim includes draining and/or a centrifugation step to remove surplus oil from the cooked products.

7. A method according to any preceding claim wherein the heat curing step is effected at a temperature of 60"C to 800C for a period of 30 to 90 minutes.

8. A process according to claim 7 wherein the heat curing step temperature is about 720C and the curing time is between 40 to 80 minutes.

9. A method for the production of a turnip crisp which comprises: cleaning and slicing a turnip to a thickness of about 1.5mm, cooking said turnip slices in a refined vegetable oil at a temperature about 1600C for 70 to 90 seconds, draining and/or centrifuging the cooked turnip product and allowing it to cool to 650C to 750C, and subjecting said turnip crisp product to heat curing at that temperature for about 60 minutes to provide a turnip crisp having a final moisture content below 2.5% by weight.

10. A method for the production of a swede crisp which comprises: cleaning and slicing a swede to a thickness of about 1.5mm, cooking said swede slices in a refined vegetable oil at a temperature about 1600C for 150 to 180 seconds, draining and/or centrifuging the cooked swede product and allowing it to cool to 650C to 750C, and subjecting said swede crisp product to heat curing at that temperature for about 40 minutes to provide a swede crisp having a final moisture content below 2.3% by weight.

11. A method for the production of a parsnip crisp which comprises: cleaning and slicing a parsnip to a thickness of about 1.5mm, cooking said parsnip slices in a refined vegetable oil at a temperature about 1600C for 90 to 110 seconds, draining and/or centrifuging the cooked parsnip product and allowing it to cool to 65"C to 75"C, and subjecting said parsnip crisp product to heat curing at that temperature for about 50 minutes to provide a parsnip crisp having a final moisture content below 3% by weight.

12. A method for the production of a celeriac crisp which comprises: cleaning and slicing celeriac to a thickness of about 1.5mm, cooking said celeriac slices in a refined vegetable oil at a temperature about 1600C for 100 to 120 seconds, draining and/or centrifuging the cooked celeriac product and allowing it to cool to 650C to 750C, and subjecting said celeriac crisp product to heat curing at that temperature for about 80 minutes to provide a celeriac crisp having a final moisture content below 3% by weight.

13. A method for the production of an amba haldhi crisp which comprises: cleaning and slicing amba haldhi to a thickness of about 1.5mm, cooking said amba haldhi slices in a refined vegetable oil at a temperature about 1600C for 150 to 170 seconds, draining and/or centrifuging the cooked amba haldhi product and allowing it to cool to 650C to 750C, and subjecting said amba haldhi crisp product to heat curing at that temperature for about 40 minutes to provide an amba haldhi crisp having a final moisture content below 4% by weight.

14. A method for the production of a sweet potato (white) crisp which comprises: cleaning and slicing sweet potato (white) to a thickness of about 1.5mm, cooking said sweet potato (white) slices in a refined vegetable oil at a temperature about 1600C for 140 to 160 seconds, draining and/or centrifuging the cooked sweet potato (white) product and allowing it to cool to 65"C to 75"C, and subjecting said sweet potato (white) crisp product to heat curing at that temperature for about 40 minutes to provide a sweet potato (white) crisp having a final moisture content below 1.6% by weight.

15. A method for the production of a sweet potato (orange) crisp which comprises: cleaning and slicing sweet potato (orange) to a thickness of about l.5mm, cooking said sweet potato (orange) slices in a refined vegetable oil at a temperature about 1600C for 70 to 90 seconds, draining and/or centrifuging the cooked sweet potato (orange) product and allowing it to cool to 65"C to 750C, and subjecting said sweet potato (orange) crisp product to heat curing at that temperature for about 55 minutes to provide a sweet potato (orange) crisp having a final moisture content below 2.5% by weight.

16. A method for the production of a beetroot crisp which comprises: cleaning and slicing a beetroot to a thickness of about 1.5mm, cooking said beetroot slices in a refined vegetable oil at a temperature about 1600C for 130 to 160 seconds, draining and/or centrifuging the cooked beetroot product and allowing it to cool to 65"C to 75"C, and subjecting said beetroot crisp product to heat curing at that temperature for about 55 minutes to provide a beetroot crisp having a final moisture content below 4% by weight.

17. A method for the production of batches of vegetable crisps having a starch content below 10% and selected from turnip, swede, parsnip, celeriac, amba haldhi, sweet potato (white), sweet potato (orange) and beetroot which comprises: cleaning and slicing a selection of low starch raw materials to a thickness between lmm and 3mm, cooking said raw material in a selected refined cooking oil at a temperature between 120"C and 1800C, and subsequently subjecting said cooked raw materials to a heat curing step at a selected temperature above 30"C for a period sufficient to prolong shelf life by removal of residual moisture, characterised in that conditions in producing all said batches of vegetable crisps are substantially the same with the exception of time periods which are individually selected.

18. A method according to claim 18 wherein the cooking temperatures is between 1500C and 1700C, wherein the refined cooking oil is a refined vegetable oil and/or a peanut oil, wherein the period is between 1 and 5 minutes.

19; A beetroot crisp comprising 1% to 3% starch, 10% to 12% sugar and up to 5% moisture, all by weight.

20. A turnip crisp comprising 1.3% to 2.9% starch, 6% to 8% sugar and up to 3% moisture, all by weight.

21. A swede crisp comprising 4% to 6% starch, 10% to 12% sugar and up to 3% moisture, all by weight.

22. A parsnip crisp comprising 9.5% to 11.5% starch, 13% to 16% sugar and up to 4% moisture, all by weight.

23. A celeriac crisp comprising 25% to 30% starch, 6.5% to 8.5% sugar and up to 4% moisture, all by weight.

24. An amba haldhi crisp comprising 8% to 10% starch, 9% to 11.5% sugar and up to 5% moisture, all by weight.

25. A sweet potato (white) crisp comprising 3% to 5% starch, 11% to 13% sugar and up to 2.5% moisture, all by weight.

26. A sweet potato (orange) crisp comprising 4% to 6% starch, 9.5% to 11.5% sugar and up to 3% moisture, all by weight.

27. A crisp according to any one of claims 20 to 27 cooked in a refined vegetable oil and having been subjected to a heat curing step after cooking.

28. A method for the production of a vegetable crisp substantially as hereinbefore set forth with reference to, and/or as illustrated, in the foregoing Table.