GB2278039A

GB2278039A - High starch vegetable crisps and method for their manufacture

Info

Publication number: GB2278039A
Application number: GB9413823A
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; GB9413823D0; GB9314494D0; GB2278039B; GB2279860B; GB2279860A; AU7128694A; GB2278038A; GB9413822D0; AU695172B2

Description

2278039 1 HIGH STARCH VEGETABLE CRISPS AND METHOD FOR THEIR MANUFACTURE

The present invention relates to high starch vegetable crisps and to a method for their manufacture.

The production for potato crisps is well known and explored. There are however particular production problems relating to potato crisps. For this reason various chemical and other methods of blanching have been required and primary/ secondary and indeed tertiary drying steps have been used in order to provide a desired product. Such numbers of drying steps are unnecessary for the high starch raw materials utilised in the present invention and indeed counter-productive when vegetable crisps formed of materials other than potatoes are to be produced.

In GB-A-2099279 there is described the production of savory crisps made by frying thin slices of raw carrot for less than 2 minutes 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 become flaccid unless stored in really dry conditions. The reason that it takes up moisture is because carrots are a low starch product and have a relatively high sugar content. This allows moisture to take up rather more readily from the atmosphere, than in the case with the higher starch raw materials.

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 result in a good product. In the present invention it is envisaged that crisps of various raw material 2 types shall not be mixed in a single bag and to this end it must 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 applicants have now f ound that where vegetable crisps are made from raw materials having an initial starch content of over 15% and preferably over 20% by weight an excellent crisp can be made without requiring a heat curing step while maintaining good shelf life characteristics.

The first aspect of the invention is therefore to provide high starch vegetable crisps formed of one or more high starch vegetables which have good taste and maintain their friability for a significant period.

The second aspect of the invention provides a means whereby fried vegetable products can be given a long shelf life without a heat curing step, but only high starch raw materials are utilised initially. Further, a good quality product can be produced without any additives other than the vegetable materials and the cooking oil.

According therefore to the first aspect of the present invention there is provided a method for the production of a high starch vegetable crisp which comprises selecting a raw material with a starch content above about 15% by weight, 3 cleaning and slicing the raw material to a thickness between 1 and 3mm, cooking the said raw material in a refined vegetable oil at a temperature between 120 and 18WC for a predetermined period, and subsequently removing excess oil to provide a friable vegetable crisp. The cooking temperature should be selected such that when the raw material is added thereto the quantity, moisture content and other conditions should be such that the temperature of the oil f alls by no more than 120C and pref erably less than 100C.

The raw material maybe selected from a vegetable having a starch content between 20 and 30% by weight, and is preferably selected from at least one of taro, eddoes, cassava, dasheen, coco, plantain and colacassi.

The refined vegetable oil may be sunflower oil or a refined vegetable/peanut oil mixture.

The cooking conditions may be 150'C to 17WC for 90 to 180 seconds dependent on the raw material selected. obviously if the thickness of the slices is 3mm and the raw material has a high moisture content, the cooking time can exceed 180 seconds, but careful monitoring is required. Similarly, dry slices at imm would require careful monitoring if the cooking time rises much above 90 seconds and indeed shorter periods may then be indicated.

It will also be appreciated that lower temperatures can be 30 used, in which case the cooking time tends to rise. This has the effect of prolonging the manufacturing process. A higher temperature above 1801C however tends to results in burnt flavours at least in some of the final vegetable crisps and we have found by experiment that 150 to 1800C for 90 to 180 seconds is an ideal range for the particular vegetable oil (sunflower oil).

4 The removal of any excess oil is preferably affected by draining and/or by centrifugation. Centrifugation is best carried out in a plurality of steps each of which incorporate a 'If luf f ing-up" stage at the end of each centrifugation stage.

The f luf f ing-up procedure involves the separation of the slices before re-centrifugation.

The invention also comprehends a taro crisp comprising 42% to 45% starch, 3% to 5% sugar and up to 3.5% moisture; all by 10 weight.

The invention also comprehends an eddoe crisp comprising 45% to 47% starch, 2.5% to 4.5% sugar, and up to 4% moisture, all by weight.

is The invention also provides a cassava crisp comprising 50% to 53% starch, 3% to 5% sugar, and up to 4% moisture, all being by weight.

The invention also provides a dasheen crisp comprising 48% to 51% starch, 3% to 5% sugar, and up to 3.5% moisture; all by weight.

The invention also Provides a coco crisp comprising 45% to 48% starch, 2% to 4% sugar, and up to 3% moisture, all by weight.

The invention also provides a plantain crisp comprising 52 to 56% starch, 3 to 5% sugar, and up to 2.5% moisture, all by weight.

The invention finally provides a colacassi crisp comprising 43-0. to 47%> starch, 2% to 4% sugar, and up to 5% moisture, all by weight.

In the final aspect of the invention there is provided a method for the production of vegetable crisps from high starch raw materials having a starch content above 15% which comprises:cleaning and slicing a selection of said raw materials to a thickness between 1 and 3mm, 5 cooking the said raw materials in a selected ref ined vegetable cooking oil at a temperature between 120 and 1800C, and subsequently draining and/or centrifuging the resulting product; characterised in that the raw materials are cooked on a batch basis and that the conditions f or producing each set of vegetable crisps are the same for all raw materials with the exception of the time periods.

The present invention will now be described, with reference to the succeeding Table, by way of illustration only.

1 6 TABLE

PRODUCT FRIED STARCH STARCH SUGAR SUGAR OIL COOKING DRAINAGE DRYING DRYING ABSORPTION ORIGINAL FINAL PRODUCT BEFORE AFTER BEFORE AFTER TEMP. TIME TIME TEMP. TIME REQUIRED MOISTURE MOISTURE 01 c c by wt % by wt % by wt % by wt % by wt SECONDS MINUTES MINUTES % by wt % by wt Taro 43.0 21.2 43.4 1.5 3.7 1601152 100 00 00 00 68.5 2.6 Eddoe 30.0 22.5 46.1 1.7 3.3 1601155 160 10 00 00 v, 62.6 3.0 Cassava 37.5 29.6 51.2 1.3 2.9 1601150 135 10 00 00 89.9 2.6 Dasheen 33.0 21.8 49.0 1.9 4.0 1601152 105 10 00 00 65.2 1.9 Coco 28.0 22.0 46.8 1.4 3.0 1661152 160 05 00 00 63.1 2.1 Plantain 31.0 26.2 54.0 1.1 3,6 1601147 100-120 10 00 00 70.3 1.4 cc texture Colacassi 1 34.0 1 23.1 45.0 1 1.0 1 2.7 1 1601152 1 160 1 05 00 00 1 wr 1 83.4 1 4.0 7 A vegetable matrix is selected from the following raw materials:- Taro, eddoe, cassava, dasheen, coco, plantain and colacassi. These are selected according to availability and season and are subsequently peeled or cleaned as appropriate. The vegetables are then sliced into slices of about 1.5mm, preferably into neat rounds, and kept separate from each other and particularly from other vegetables with colouring, in 10 order to avoid staining.

Each batch of sliced vegetables is then cooked by frying in a ref ined vegetable oil at a temperature of 1600C for a length of time depending on the vegetable used.

For example, the following frying times are given for raw materials of 1. 5mm thickness at 160IC:- Taro - about 100 seconds; Eddo - about 160 seconds; Cassava - about 135 seconds; Dasheen - about 105 seconds; Coco about 160 seconds; Plantain - about 100 to 120 seconds depending upon texture; and Colacassi - about 160 seconds Generally, use of about 20% higher and lower than these figures are also useful.

It will be noted the timings, and only the timings, will change depending upon the initial moisture content of the vegetable raw material chosen.

When cooking has been effected the vegetable crisps when formed, are removed from the oil and all excess oil is drained off. In the preferred form of invention, the draining is 8 substituted by, or succeeded by, a centrifugation step in which each batch of cooked vegetables are centrifuged for a period, fluffed-up, i.e. manually or chemically re-separated, and centrifuged again. The fluffing- up process may be done 5 once or twice or more depending upon the initial raw material. The refined vegetable oil recovered may be used again.

The high starch vegetable crisps in accordance with this invention do not need a heat curing step as generally required for the low starch crisps and accordingly subsequent to the cooking stage the crisps may be allowed to cool to proceed to packing in the usual way.

However, a draining and/or centrifuging step is useful in that it reduces the amount of free oil and hence greasiness and also reduces free moisture. Similarly, an absorption step is helpful since it allows the oil to drain freely.

It sometimes desirable to optionally use a heat curing step 20 by using the cooked products to a temperature in the range of 600C to 750C for 40 to 70 minutes. This is particularly so when the high starch products of the invention are to be packaged with low starch crisps such as those described in our copending UK patent application.

The precise parameters are the production of the high starch crisps are given in the Table.

The invention relates therefore to the production of high starch vegetable crisps and to crisps so made.

9

Claims

1. A method for the production of a high starch vegetable crisp which comprises selecting a raw material with a starch content above 15% by weight, cleaning and slicing the raw material to a thickness of between 1 and 3mm, cooking said raw material in a refined vegetable oil at 10 a temperature between 1200C and 18TC for a predetermined period, and subsequently removing any excess oil to provide a friable crisp.

2. A method according to claim 1 wherein the raw material is selected f rom a vegetable having an initial starch content between 20% and 30% by weight.

3. A method according to either of claims 1 or 2 wherein the raw material is selected from at least one of taro, eddoe, cassava, dasheen, coco, plantain and colacassi.

4. - A method according to any preceding claim wherein the refined vegetable oil is sunflower oil or a refined vegetable oil/peanut oil mixture.

5. A method according to any preceding claim wherein the cooking conditions are 1500C to 1700C for about 90 to 180 seconds.

6. A method according to any preceding claim wherein the removal of excess oil is effected by draining and/or centrifugation.

7. A taro crisp comprising 42% to 45-0, starch, 3% to 5-% sugar, and up to 3.5% moisture, all by weight.

8. An eddo crisp comprising 45% to 47% starch, 2.5% to 4.5% sugar, and up to 4% moisture, all by weight.

9. A cassava crisp comprising 50% to 53% starch, 3% to 5% 5 sugar, and up to 4% moisture, all by weight.

10. A dasheen crisp comprising 48% to 51% starch, 3% to 5% sugar, and up to 3.5A moisture, all by weight.

11. A cocoa crisp comprising 45% to 47% starch, 2% to 4% sugar, and up to 3% moisture, all by weight.

12. A plantain crisp comprising 52% to 56% starch, 3% to 5% sugar, and up to 2.5A moisture, all by weight.

13. A colacassi crisp comprising 43% to 47% starch, 2% to 4% sugar, and up to 5% moisture, all by weight.

14. A method for the production of a taro crisp which comprises cleaning and slicing taro to a thickness of about 1.5.mm, cooking said slices in a refined vegetable oil, at a temperature of about 1600C for about 100 seconds, and subsequently draining and/or centrifuging the cooked product to provide a friable crisp.

15. A method for the production of an eddoe crisp which comprises cleaning and slicing eddoe to a thickness of about 1.5mm, cooking said slices in a refined vegetable oil, at a temperature of about 1600C for about 160 seconds, and subsequently draining and/or centrifuging the cooked product to provide a friable crisp.

16. A method for the production of a cassava crisp which comprises cleaning and slicing the cassava into a thickness of about 1.5mm, cooking said slices in a refined vegetable oil, at a temperature of about 16TC for about 135 seconds, 11 and subsequently draining and/or centrifuging the cooked product to provide a friable crisp.

17. A method f or the production of a dasheen crisp which comprises cleaning and slicing the dasheen to a thickness of about 1.5mm, cooking said slices in a refined vegetable oil, at a temperature of about 1600C for about 105 seconds, and subsequently draining and/or centrifuging the cooked product to provide a friable crisp.

18. A method f or the production of a cocoa crisp which comprises cleaning and slicing the cocoa to a thickness of about 1.5mm, cooking said slices in a refined vegetable oil, at a temperature of about 1600C for about 160 seconds, and subsequently draining and/or centrifuging the cooked product to provide a friable crisp.

19. A method for the production of a plantain crisp which comprises cleaning and slicing the plantain to a thickness of about 1.5mm, cooking said slices in a refined vegetable oil at a temperature of about 1600C for about 100 to 120 seconds, and subsequently draining and/or centrifuging the cooked product to provide a friable crisp.

20. A method for the production of a colacassi crisp which comprises cleaning and slicing the colacassi to a thickness of about 1. 5mm, cooking said slices in a refined vegetable oil at a temperature of about 160C for about 160 seconds, and subsequently draining and/or centrifuging the cooked product to provide a friable crisp.

2 1. A method for the production of vegetable crisps from high starch raw materials having a starch content of above 15% which comprises; cleaning and slicing selection of said raw materials to thickness between 1 and 3mm, cooking said raw materials in selected refined vegetable oil at a temperature between 12 1200C and 1800C, and subsequently draining and/or centrifuging the resulting product; characterised in that the raw materials are cooked on a batch basis and in that the conditions f or producing said vegetable crisps remain the same for all raw materials with the exception of time periods.

22. A method for the production of high starch raw material crisps substantially as hereinbef ore set f orth with ref erence to, and/or as illustrated in the Table accompanying this application.

23. A selection of vegetable crisps substantially as hereinbefore set forth with reference to, and/or as illustrated in the Table.

(3 Amendments to the claims have been filed as follows 1. A method f or the production of high starch vegetable crisp which comprises selecting a raw material from at least two of taro, eddoe, cassava, dasheen, coco, plantain and colacassi, all having starch content above 15% by weight, cleaning and slicing the raw material to a thickness of between 1 and 3mm, sequentially cooking said selected raw material types in refined vegetable oil at a temperature of 1200C and 1800C for predetermined period and subsequently removing any excess oil to provide at least two types of friable crisp.

2. A method according to claim 1 wherein the raw materials are selected from a vegetable having an initial starch content between 20% and 30% by weight.

3. A method according to either of claims 1 or 2 wherein the quantity, moisture content and other parameters of the raw materials are such that the temperature of the oil falls by more than 120C on initiation of cooking.

4. A method according to any preceding claim wherein the ref ined vegetable oil is sunf lower oil or a ref ined vegetable oil/peanut oil mixture.

5. A method according to any preceding claim wherein the cooking conditions are 1500C to 1700C for about 90 to 180 30 seconds.

7. A taro crisp comprising 42-o' to 45% starch, 3% to 55o-' sugar, and up to 3.5% moisture, all by weight.

14- 8. An eddo crisp comprising 45% to 47% starch, 2.5% to 4.5% sugar, and up to 4% moisture, all by weight.

9. A cassava crisp comprising 50% to 53% starch, 3% to 5% sugar, and up to 4% moisture, all by weight.

10. A dasheen crisp comprising 48% to 51% starch, 3% to 5% sugar, and up to 3.5.% moisture, all by weight.

12. A plantain crisp comprising 52% to 56% starch, 3% to 5% sugar, and up to 2.5.% moisture, all by weight.

15. A method f or the production of an eddoe crisp which comprises cleaning and slicing eddoe to a thickness of about 1.5mm, cooking said slices in a refined vegetable oil, at a temperature of about 1600C for about 160 seconds, and subsequently draining and/or centrifuging the cooked product to provide a friable crisp.

16. A method for the production of a cassava crisp which comprises cleaning and slicing the cassava into a thickness of about 1.5mm, cooking said slices in a refined vegetable oil, at a temperature of about 1600C for about 135 seconds, )5 and subsequently draining and/or centrifuging the cooked product to provide a friable crisp.

19. A method f or the production of a plantain crisp which comprises cleaning and slicing the plantain to a thickness of about 1.5mm, cooking said slices in a refined vegetable oil at a temperature of about 1600C for about 100 to 120 seconds, and subsequently draining and/or centrifuging the cooked product to provide a friable crisp.

20. A method for the production of a colacassi crisp which comprises cleaning and slicing the colacassi to a thickness of about 1. 5mm, cooking said slices in a refined vegetable oil at a temperature of about 160"C for about 160 seconds, and subsequently draining and/or centrifuging the cooked product to provide a friable crisp.

2 1. A method for the production of vegetable crisps from high starch raw materials having a starch content of above 15% selected from at least two of taro, eddoe, cassava, dasheen, coco, plantain and colacassi, which comprises; cleaning and slicing selection of said raw materials to a thickness of between 1 and 3mm, sequentially cooking said 1 b selected raw material types in a selected refined vegetable oil at a temperature between 12WC and 1800C and subsequently draining and/or centrifuging the result products, characterised in that the raw materials are cooked on a batch basis and in that the conditions f or producing said vegetable crisps remain the same for all raw materials with the exception of time periods.

22. A method for the production of high starch raw material crisps substantially as hereinbefore set forth with reference to, and/or as illustrated in the Table accompanying this application.

24. A package comprising an admixture of a high starch vegetable crisp as claimed in any one of claims 7 to 13 and a low starch vegetable crisp.