IE43842B1 - Improvements relating to food products - Google Patents

Abstract

A semi-manufactured product, which can be converted into a food product by boiling, baking or frying, is produced by a) extruding a dough, which has been formed by mixing a dough mixture of one or more edible starches or starch-containing materials together with less than 3.5%, based on the dry weight of the dough mixture, of a non-toxic ionic salt with water, the overall starch content of the dough and the amount of free gelatinised starch being chosen so that a partially gelatinised product having a semi-translucent appearance is formed after extrusion; b) cutting the extruded product immediately or shortly after extrusion into pieces of predetermined shape or property; and c) drying the pieces at a temperature of up to 60 DEG C to a moisture content of 9 to 13% to form a semi-manufactured product. The semi-manufactured product obtained is used in particular for the production of cereal-based snack products.

Description

The present' invention relates to a method of producing a food product and is an improvement in or modification of the invention described and claimed in Belgian Patent Specification No. 821144.

Our said Specification describes a method of preparing a simulated pasta snack product, or a half-product therefor, which includes the steps of (a) forming a dough by admixing with water a dry mix of 20-80% of a dehydrated potato product wherein the starch cells contained in said product are substantially unbroken,· 20-80% of ungelatinisea starch (as herein defined); and less than 3.5% of a non-toxic ionic salt; (b) passing the said dough through an extruder under conditions of pressure and temperature to effect partial gelatinisation of the starch contained in the dough and to produce an extruded semi-translucent product, (c) cutting the extruded product into piecelets of a pre-determined shape or configuration immediately or shortly after extrusion; (d) drying the cut piecelets at a temperature of up to 60°C to a moisture content of 9-13% t^ form a halfproduct and if desired, effecting cooking of said half· t:;·?,1 - 2 €S8.;a product.

We have now found that the dehydrated potato product and/or the ungelatinised starch used in the dough mix of the method of our said Specification can be replaced by one or more other starch or starch-containing materials (as described below) to produce food products having desirable taste and texture characteristics. Indeed by the use of different starch-containing materials and additional ingredients, 'snack products and other food products having a wide variety of different flavours and textures can be obtained.

According to the present invention we provide a method of preparing a food product, or a half-product therefor, which includes the steps of a) extruding a dough formed by admixing with water a dough mix of one or more edible starch or starch-containing materials together with less than 3,5% (based on the dry weight of the dough mix) of a non-toxic ionic salt (other than a dry dough mix of 20-807» of a dehydrated potato product wherein the starch cells are substantially unbroken; 20-807. of ungelatinised starch; and less than 3.57. of a non-toxic ionic salt), the total starch content, of the dough and the amount of free gelatinised starch therein being selected so as to provide a partially gelatinised product of semitranslucent appearance (as hereinafter defined) after ' extrusion; (b) cutting the extruded product into piecelets of a pre-determined shApe or configuration immediately or shortly after extrusion; (c) drying the cut piecelets at a temperature of up to 60°C to a moisture content of {9-137. to form a half-product and, if desired, (d) effecting cooking of said half-product.

The method according to the invention is particularly useful for preparing snack products, particularly simulated pasta snack products. It can however also be used for tha production of other food products such as for -example breakfast cereals, - 3 It should be noted that the percentages given herein for the amounts of the various ingredients in the dough mix are based on the dry weight of the dough mix.

By free gelatinised starch we mean starch freed from the starch cells of the material from which it is derived.

The expression product of semitranslucent appearance is used herein to define a product which is intermediate in appearance between an opaque product (indicating that the extruded product contains an insufficient amount of free gelatinised starch)and a translucent product (indicating that the extruded product contains an excessive amount of free gelatinised starch).

It Is possible to determine objectively whether a product has a semi-translucent appearance by directly comparing it with other products produced from the same dough mix which have opaque and translucent appearances respectively. An extruded product is regarded as having a translucent appearance (in contrast to a semi-translucent appearance) when the amount of light which it transmits does not increase when the amount of free gelatinised starch in the product Is further increased, i.e. when its translucency is at a maximum. It will be appreciated that the amount of light transmitted by extruded products of. semi-translucent and translucent appearance will vary according to the - 4 ingredients of the dough mix used in the preparation thereof, and thus that the semi-translucent appearance of a particular extruded product must be assessed by comparison with opaque and translucent extruded products prepared from the same dough mix.

It is necessary to select carefully the ingredient(s) of the dough in order to ensure that the extrudate contains the desired amount of free gelatinised starch after extrusion. If the amount of free gelatinised starch in the extrudate is too low then a hard dense food product is obtained after cooking the half-product. On the other hand, if the amount of free gelatinised starch in the extrudate is too high then the cooked food product is too light in density. In order to produce an extrudate fulfilling the above-specified conditions, it is generally preferable to use a dough mix containing from 2 t0 25 ''•i and advantageously from to io %,of free gelatinised starch and to carry out the extrusion under conditions of temperature and pressure such that the extrudate contains from 3 to 30 %» and advantageously from 5 to 15 %, of free gelatinised starch. We have found that up to 30% of ungelatinised starch originally present in the dough mix may be gelatinised in the extruder by the application of suitable temperatures - 5 and pressures. Preferred levels of free gelatinised starch in the extrudate will generally vary within the abovementioned range depending upon the particular ingredients employed in the dough mix but appropriate levels can readily be selected by reference to the appearance of the extrudate in the manner described above.

The total starch content of the dough mix preferably amounts .to 30 to 95% by weight of the mix.

With particular regard to the ingredients of the dough mix we have found that for example the- dehydrated potato product used in our said Specification can be replaced at least in part by one or more other starchcontaining materials derived from edible vegetable products provided that the dough mix thus obtained has the desired content of free gelatinised starch. As with the dehydrated potato product, these other starch-containing materials are advantageously materials in which the starch cells are substantially unbroken. It should be noted that the term vegetable product is used herein in its widest sense to denote any product of vegetable as opposed to animal origin. Such,· vegetable products include cereals such as rice, wheat, rye, barley and oats, as well as tubers such as tapioca. The vegetable products can ba employed in the dough mixture in the form of flours, e.g. wheat flour, rye'flour,. tapioca flour, oat flour, semolina, barley flour, rice flour and various bean flours. .- 6 43842 Other pre-processed cereal-based materials such as bread crumbs and toasted wheat flakes can also be used.

The dough mix can contain for example 20-80% by weight of the above materials, if desired including in part the dehydrated potato product used in our said Specification.

The dough mix may also include, if desired, ungelatinised starch as described in our said Specification derived from natural products such as potato, rice, wheat, ]0 maize, rye, oats, and beans. A mixture of two or more such starches can be employed if desired. The presence of such ungelatinised' starch can have an important effect upon the texture of the final product in addition to any flavour imparted by the use of particular starch containing materials. The dough mix may thus for example contain a total of 20-80% by weight of ungelatinised starch.

Similarly, the dough mix may also contain an amount of pre-gelatinised starch as described in our 2Q said Specification and derived from such natural products as potatoes, rice, wheat, maize, rye, oats, etc. i A mixture of two or more pregelatinised starches can if desired be used, the dough mix containing for example a total of 2-20%, preferably 4 to 15'.'',by weight of - 7 43842 the pregelatinised starch. The amount of pregelatinised starch used can be selected, conveniently within the above limits, having regard to the proportion of free gelatinised starch in the other'ingredients of the dough mix, to provide the desired proportion of free gelatinised starch in the dough mix as a whole whereby upon processing in accordance with the present invention a product of the required texture is obtained. Thus for example when the dough mix comprises a pre-processed cereal-based material such a bread crumbs or toasted wheat flakes which itself has a relatively high free gelatinised starch content, the amount of added pregelatinised starch can be adjusted accordingly. - 8 43842 We have found that the incorporation of sodium chloride or other non-toxic ionic salt such as potassium chloride, potassium bromide, sodium acetate or sodium citrate in the dry mix in an amount of less than 3.5%, and pref5 erably more than 0.5%, has an Important and desirable effect on the texture of the final product and the choice of the specified quantities of the ionic salt represents an important feature of the present invention. Sodium chloride can be employed if a savoury product is desired while, on the other hand, if a sweetened product is desired, we may use a different non-toxic ionic salt which does not impair the sweetening effect of sweetening agents present. The quantity of ionic salt in the dough mix can also be used to control the uptake of oil when the half-product is fried in oil to effect cooking.

The dough mix is formulated with water to form a dough of the desired consistency. The dough preferably has a moisture content of up to 45% and not less than % at a temperature of, for example, 20 - 30 °C.

The dough is then passed through an extruder where it is subjected to temperature and pressure con* - 9 <3 8 42 ditions to provide a partially gelatinised product as described above. The temperature to which the dough is subjected in the extruder is preferably below 90° C, a temperature range of 50 - 75°G being especially preferred. The temperature of the dough upon extrusion should preferably be maintained below 90°C in order to avoid excessive expansion. A pressure o of 70 - 160 Kg/cm , advantageously 90 - 115 Kg/cm , is generally employed in the extruder.

The extruder employed in the method according to the invention may conveniently be a conventional screw-type pasta press. Standard pasta dies can be employed in the extrusion head to give the extrudate the desired shape or configuration, e.g. squares, tubes sticks, spirals, spins, grills etc. - 10 43843 The dough extrudate is preferably cut into piecelets immediately after leaving the extrusion head and while it is still in a plastic state. However, in some cases it may be desirable to delay cutting the extrud5 ate until it has travelled a distance of up to 50cms for example from the head in order to ensure it is in a suitable form for cutting into well-defined shapes.

Thus, for example, with some extrudates, e.g. those in the form of tubes, if cutting is effected too near the head, the ends of the cut pieces may be pinched together as a result of the cutting process which could be undesirable from the point of view of product appearence. The cutting of the extrudate can be effected in conventional manner, e.g. by means of a short or long goods cutter or similar device.

The cut piecelets are then dried under carefully controlled conditions. The drying temperature should not exceed 60°C to avoid the formation of a hard coating on the surface of the piecelets, the drying temperature - 11 43842 preferably being in the range of 30 - 50°C. The drying is generally effected over a period of 5-20 hours, advantageously 6-10 hours, conveniently in a drum drier. The above drying times can however be reduced by the use of electric or microwave heating.

The drying is preferably effected at a relative humidity of at least 50% (in order to avoid the formation of a hard coating on the surface of the piecelets) and not more than 80%.

The half-product prepared by drying the extrudate is in the form of hard, brittle piecelets which, if desired, can be stored for prolonged periods in sealed containers.

The half-product can for example be cooked by means of a frying or puffing operation in order to produce a cooked product. To produce an expanded snack product the frying operation may be carried out advantageously by quick frying the piecelets in edible oil, e.g. vegetable oil at a temperature of 175® to 22O°C, preferably 185 to 205°C, the oil content in the final product preferably being less than 20%. <3843 The puffing operation may advantageously comprise a salt, hot air or gun puffing operation. As an alternative to the above frying or puffing bperations, the half-product can be cooked by boiling in water.

After cooking, the half-product can be salted, sweetened or otherwise flavoured prior to packaging.

However, in order to ensure the flavour or nutrient value of the final product, various additional ingredients can also be added to the Initial dough.

Examples of such ingredients include flavour enchanci.ng agents such as monosodium glutamate, antioxidants such as butylated hydroxy anisole, butylated hydroxy toluene and propyl gallate, homogenising agents, sweetening agents such as sugars, saccharin and sorbitol, and nutrients such as protein materials, especially soy protein, minerals and vitamins.

The following Examples according to the present invention illustrate the effect of varying the compostion of the dough mix specifically described in the Examples of our said Specification; for convenience, the ingredients of the latter dough mix are designated as followsr13 43843 FORMULATION ACCORDING TO OUR PRIOR SPECIFICATION CODE INGREDIENTS A Potato Starch (ungelatinised) B Potato Granule (partially gelatinised) C Pre-gelatinised Potato Starch D Salt E Further additive In the following examples, the process for preparing the snack product was carried out within the following parameters:Dough moisture content Temperature of dough Temperature in extruder Pressure in extruder Drier temperature Drier time Relative humidity in driers Moisture content of half product Frier temperatures ,· -45% < 90°C < 75°C - 160 Kg/cm2 30 - 60°C -20 hours. - 80% - 13% 175 - 220cC. - 14 43843 Example 1 a) The potato granule component of the mix (B) was partially replaced with other cereal flours. The other Ingredients were kept at the % levels of the above-mentioned formulation.

Composition of Dough A - Potato starch 45% B - (Potato granules 5% (Wheat flour 40% or Rye flour or Tapioca flour or Oat flour C - Pregelatinised Potato Starch 7% D - Salt 3% Snack products were produced by a process according to the present invention carried out within the abovementioned parameters. After frying, the resulting products had interesting textures and flavours. b) The potato granule component of the mix (B) was 20 completely replaced with other cereal flours. The other ingredients were kept at the % levels of the above-mentioned formulation. - 15 43843 Composition of Dough A - Potato Starch 45% B - Semolina 45% or Rye flour or Barley flour or Oat flour . or Tapioca flour or Rice flour or Breadcrumbs or Gram Bean flour or Toasted Wheat flakes .

C - Pregelatinised potato 7% flour D - Salt 3% Snack products were produced by a process according to the present invention carried out within the abovementioned parameters. After frying, the resulting products had interesting textures and flavours. However, products made using semolina, barley and oats, had lower expansion resulting in harder texture. c) lb) was repeated maintaining the same ratio between A and B and increasing the proportion of pregelatinised potato starch (C) to achieve greater expansion.

Composition of Dough A - Potato Starch A3.5% B - Semolina A3.5% or Barley flour or Oat flour ” C - Pregelatinised Potato Starch 10.0% D - Salt 3% Snack products were produced by a process according to the present invention carried out within the abovementioned parameters. After frying, the resulting product had satisfactory rate of expansion and retained the interesting background flavour of the cereal used.

Example 2 Potato starch (A) was replaced with various other starches and potato granules (B) were replaced with other flours.

Composition of Doughs a) A - Wheat starch 45% B - Semolina A5% 'or Rye flour or Barley flour or .5 438 AS Oat flour 45% or Tapioca flour ” or Breadcrumbs or Gram flour or Toasted wheat flakes C - Pregelatinised potato starch 7% D - Salt b) A - Maize starch B - Semolina or Rye flour or Barley flour or Oat flour or Tapioca flour or Breadcrumbs or Gram bean flour or Toasted wheat flakes 3% 45% 45% II II II II II II II C - Pregelatinised Potato starch 7% D - Salt 3% c) A - Tapioca 45% B - Semolina 45% or Rye flour or -'38 4 3 Barley flour 45% or Oat flour or Tapioca flour or Breadcrumbs or Gram beam flour or Toasted wheat flakes C - Pregeiatinised Potato starch 7% D - Salt 3% Each of Dough Compositions a), b) and c) was converted to a snack product by a process according to the present 10 invention carried out within the above-mentioned parameters.

In all three cases the fried products had interesting textures and flavours, in particular, those produced from the doughs containing semolina, rye flour, breadcrumbs, gram bean flour and toasted wheat flakes. However, in some cases the products had harder textures, and it is thought that softer textures would be obtainable if desired from an increase in the proportion of pregelatinised potato starch in the dough composition used.

Example 3 Pregelatinised potato starch (C) was replaced with <3843 other pregelatinised starches to ascertain whether any textural changes can be produced.

Composition of Doughs a) A - Wheat starch 45% 5 B - Wheat flour or Rye flour or Breadcrumbs or Gram bean flour or • Toasted Wheat flakes n tt It tl tt C - Pregelatinised wheat starch 7% 10 D - Salt 3% b) A - Maize starch 45% 15 B - Wheat flour or Rye flour or Breadcrumbs or Gram Bean flour or Toasted wheat flakes 45% tf tt II tl C - Pregelatinised maize starch 7% D - Salt 3% Snack products were produced by a process according 20 to the present invention carried out within the above- <381S -mentioned parameters. Fried products showed very similar characteristics to those prepared with pregelatinised potato starch.

Example 4 Formulation changes are made where A and B are replaced either by one ingredient or by more than two ingredients.

Composition of Doughs a) A & B Breadcrumbs 92% C Pregelatinised Potato Starch 5% D Salt 3% b) A Potato starch 28.5% B Potato granules 28.5% Tapioca flour 28.5% C Fregelatinised potato starch 7% D Salt 3% E Soya flour 4.5% Snack products were produced by a process according to the present invention carried out within the abovementioned parameters. In both cases snack products having interesting textures and flavours were obtained. 43843 More complete details of five experiments are given below.

Example 5 The following ingredients were intimately mixed according to the formula below: Maize starch Λ 5% Semolina A 5% Pregelatinised potato starch 7% Salt 3% The ingredients were mixed for ten minutes in a LO vertical mixer, the moisture content of the mix obtained being 12%. The dry mix was introduced to a standard pasta press where the moisture content was adjusted to 32% and further intimate mixing took place prior to extrusion. After mixing, the dough material was compressed ,5 by an auger-type screw, extruded through a die and face cut into short lengths. The compression barrel had a hot water jacket which reached average temperatures of 50-60°C and the mix was compressed to pressures of 90-115 Kg/cm .

A standard pasta die was used which produced tubular shaped pieces approximately 30 mm. in length, 15.0 mm. external diameter and with a wall thickness of about 0.9 mm. '3843 The extrudate had a white translucent appearance and was malleable. After extrusion, the half product was slowly dried in a batch drier under conditions similar to those of a continuous drier. The final moisture content of the half-product obtained was 10.5-12%. The product 5 had hard and brittle textures and could be storable in sealed containers for prolonged periods.

The half-product was fried in vegetable oil at a temperature of 205°C for about 14 seconds. The puffed material showed an expansion in diameter of 1.3-1.5 times and the uptake of oil was 14-18 per cent on a total weight basis. Finally, the puffed product was either salted or coated with flavouring. The resulting product was a high quality snack with a well defined shape and golden-brown colour.

Example 6 The following ingredients were intimately mixed.

Maize starch 45% Rye flour 45% Pregelatinised Potato starch 7% 20 Salt 3% - 23 438 43 The dough material was then processed as described in Example 5 subject however to the following modifications :Moisture content of mix = 13.2% Moisture content of dough « 32%.

Extrudate (length >= 30 mm. (external diameter = 15.0 trm. (wall thickness = 1.2 mm.

Final product expansion in diameter - 1.4 - 1.6 times.

Final product appearance * dark brown and speckled.

Example 7 The following ingredients were intimately mixed.

, Tapioca 45% Breadcrumbs 45% Pregeiatinised potato starch 7% Salt 3% The dough material was then processed as described in Example 5 subject however to the following modifications :Moisture content of mix - 10.3% Moisture content of dough 30.5% Extrudate (length » 30 mm. (external diameter 15.5 mm. (wall thickness 2.1 mm.

Final product expansion in diameter 1.4 - 1.7 times. '304 ,Ί Final product appearance - light brown.

Example 8 .

The following ingredients were intimately mixed.

Tapioca 45% Gram bean flour 45% 5 Pregelatinised potato starch 7% Salt 3% The dough material was then processed as described in Example 5 subject however to the following modificationsiMoisture content of mix »9.8% Moisture content of dough 28% Extrudate (length * 30 mm. (external diameter 14.5 mm. (wall thickness 1.4 mm.

Final product expansion in diameter 1.2 - 1.4 times. Final product appearance - golden brown.

Example 9 The following ingredients were intimately mixed.

Wheat starch 45% Toasted wheat flakes 45% Pregelatinised potato starch 7% 20 Salt 3% 43843 The dough material was then processed as described in Example 5 subject however to the following modifications:Moisture content of mix = 11.2 Moisture content of dough = 31.8 Extrudate (length = 30 mm. (external diamter 15 mm. (wall thickness « 1.3 mm.

Final product expansion on diameter « 1.4 - 1.6 times. Final product appearance » brown, speckled.

Claims (19)

1. A method of preparing a food product, or a halfproduct therefor, which includes the steps of a) extruding a dough formed by admixing with water a dough mix of one or 5 more edible starch or starch-containing materials together with less than 3.5% (based on the dry weight of the dough mix) of a non-toxic ionic salt (other than a dry dough mix of 20-80% of a dehydrated potato product wherein the starch cells are substantially unbroken; 20-80% of ungelatinised io starch; and less than 3.5% of a non-toxic ionic salt), the total starch content of the dough and the amount of free gelatinised starch therein being selected so as to provide a partially gelatinised product of semi-translucent appearance (as hereinbefore defined) after extrusion; 15 (b) cutting the extruded product into piecelets of a pre-determined shape or configuration immediately or shortly after extrusion; (c) drying the cut piecelets at a temperature of up to 60°C to a moisture content of 9-13% to form a half-product, and, if desired, (d) effecting 20 cooking of said half-product.

2. A method as claimed in claim 1 wherein the said mix contains 2 to 25% of free gelatinised starch.

3. A method as claimed in claim 2 wherein the said mix contains 3 to 10% of free gelatinised starch. - 27

4. A method as claimed in any of the preceding claims wherein the extruded product contains 3 to 30% of free gelatinised starch.

5. A method as claimed in claim 4 wherein the extruded 5 product contains 5 to 15% of free gelatinised starch.

6. A method as claimed in any of the preceding claims wherein the said mix contains a total of 30 to 95% by weight of starch.

7. A method as claimed in any of the preceding claims 10 . wherein the dough mix includes a starch-containing material in which the starch cells are substantially unbroken.

8. A method as claimed in claim 7 wherein the dough mix contains 20-80% by weight of a starch-containing material in which the starch cells are substantially 15 unbroken.

9. A method as claimed in any of the preceding claims wherein the said mix includes an ungelatinised starch ingredient.

10. A method as claimed in claim 9 wherein the mix 2o contains 20-80% by Weight of the ungelatinised starch ingredient.

11. A method as claimed in any of the preceding claims wherein the said mix includes a pre-gelatinised starch ingredient. - 28 43843

12. A method as claimed in claim 11 wherein the said mix contains 2-20% by weight of the pre-gelatinised starch ingredient.

13. A method as claimed in claim 12 wherein the said mix contains 4 to 15% by weight of the pre-gelatinised starch ingredient.

14. A method as claimed in any of the preceding claims wherein the said mix contains more than 0.5% but less than 3.5% of the non-toxic ionic salt.

15. A method as claimed in any of the preceding claims wherein the dough has a moisture content of 25 to 45%.

16. A method as claimed in any of the preceding claims wherein the extrusion of the dough is effected at a temperature of 50-75 °C.

17. A method as claimed in any of the preceding claims wherein the cut piecelets are dried at a temperature of 30-50 °C.

18. A method as claimed in any of the preceding claims wherein the cut piecelets are dried at a relative humidity of 50-80%.

19. A method as claimed in any of the preceding claims wherein the half-product is cooked by frying or puffing.