GB2071478A

GB2071478A - Treatment of seeds for foodstuffs

Info

Publication number: GB2071478A
Application number: GB8103629A
Authority: GB
Original assignee: United Biscuits Ltd; United Biscuits UK Ltd
Current assignee: United Biscuits Ltd; United Biscuits UK Ltd
Priority date: 1980-02-14
Filing date: 1981-02-05
Publication date: 1981-09-23
Also published as: GB2071478B

Abstract

Foodstuffs, e.g. for mixing with other edible materials, are made by comminuting and impregnating edible seeds, compressing into flakes and drying. Wheat, rice or barley, for instance, cut into 3 to 7 pieces per seed, may be used. The product may be used as a meat extender, or in puddings, soups or other convenience foods.

Description

SPECIFICATION Foodstuff manufacture This invention relates to the manufacture of foodstuffs and is concerned, in particular, with methods of manufacture which involve the treatment of edible seeds. The invention can be carried out using any edible seeds which are suitable for the manufacture of foodstuffs, whether for human or animal consumption.

Wheat is used as the starting material in many processes for the manufacture of foodstuffs. Wheat is only one example of edible seeds which can undergo treatment according to this invention and many other seeds can also be used in carrying out the process of the present invention. The main purposes of many of the treatment steps carried out on wheat, when preparing foodstuffs by many of the known processes, are to yield a product which has improved texture or other properties and which also can be cooked or otherwise prepared for consumption more quickly andlor easily. Another purpose is to incorporate or combine with the wheat various supplements or additives, such as vitamins, minerals, flavours and colours.For instance, GB-PS 1030328 relates to quick-cooking foodstuffs made from grains, seeds or farinaceous foodstuffs having a starch content in excess of 50%, by impregnating the foodstuff with an aqueous solution of sodium chloride until a uniform penetration is achieved. The resultant foodstuff can be cooked quickly, is stable when stored and retains most of the essential food elements in the rice or other food product from which it is made.

Impregnation with an additive, whether it is an aqueous solution of sodium chloride or some other material, is a step incorporated in many foodstuff manufacturing processes. For instance, GB-PS 1466479 describes the production of a foodstuff from edible seeds, e.g. wheat, maize, rye or rice, by partially softening the seeds to prevent shattering thereof under pressure, applying pressure to the partly softened seeds to produce cracks or fissures therein, thereafter applying an additive to the seeds and impregnating the seeds with the additive through the cracks or fissures. The first step involving partial softening can be effected in many ways, including partly hydrating and heating the seeds, e.g. wheat being soaked for 5 minutes and steamed for 30 minutes at atmospheric pressure.The second step of applying pressure can be effected internally, e.g. by heating at atmospheric pressure or under pressure, with or without a sudden pressure release, or preferably the pressure is applied externally, by impact or by passing the seeds between rollers.

Where the resultant product is to be consumed as whole seeds, the pressure is applied externally so that the compressed seeds return in a marked degree to their original shape; it is also possible to compress the seeds to a greater extent, so that they do not return to their original shape. The compression is conveniently effected by passing the seeds between rollers, the gap between which is set so as to provide the charactierstics desired in the final product. In both the first step and the second step, the seeds are not pulverised or shattered. The cracks and fissures caused by the compression step render the seeds highly absorbent, so that they are conditioned to receive the additive applied in the third step.

It has now been discovered that edible seeds can be successfully made into useful foodstuffs having many desirable properties by a process which incorporates various treatment steps, including impregnation with or application of an additive, but wherein the additive is contacted with the edible seeds before a step involving the application of pressure. Another distinguishing feature of the present invention is that the process is applied, not to whole seeds or seed products such as maize grits produced by cracking, but to a seed product made by subjecting seeds to a comminution treatment effected such as by cutting. This invention enables foodstuffs to be manufactured, using wheat or other edible seeds, which have many desirable properties, including those mentioned in the prior patent specifications cited above and also including further desirable properties.

According to this invention, a process of manufacture of a foodstuff is provided, which comprises impregnating a comminuted edible seed product with an additive applied in liquid form, subjecting the resultant product to the application of pressure so that the seed pieces are formed into flakes and then drying the flakes to a pre-determined moisture content.

Preferably, the edible seed product used in carrying out the process is cut or otherwise sub-divided into pieces having a predetermined size range, which is most conveniently expressed in terms of the number of pieces of each wheat, rice, barley or other grain produced, namely 2 to 8 pieces per seed.

Preferably each seed is cut into 3 to 7 and, most preferably, 5 or 6 pieces. These figures are not intended to take account of minute pieces which may well be produced in comminuting the seeds. In this connection, therefore, all indications as to the number of pieces into which a seed is subdivided, in effecting the first comminuting step of the process of the invention, are given exclusive of fines, which are any pieces or particles having a maximum dimension less than 0.2 mm.

It is preferable for the product, after application of the additive, to be tempered, for instance by being left for a conditioning period of e.g. up to 30 mins., after it has come into contact with the additive. As a result of tempering, substantially complete absorption of the brine or other additive occurs and the comminuted impregnated wheat or other seed product again becomes a free-flowing material, before it goes on to the compression stage.

The additive preferably comprises an aqueous solution of at least one inorganic or organic foodstuff component. In one embodiment of the invention, the additive comprises aqueous NaCI brine and the seed product is impregnated so as to have a salt content of up to 3% by weight; in another, it comprises an aqueous sugar solution.

A preferred feature of the process of the invention is the inclusion, in the additive, of an emulsifier, as a processing aid.

Another preferred feature is to subject the seeds, after the application of the additive and any conditioning step and before the compression step, to a heat treatment, desirably so as to enhance the penetration of the additive into the treated seeds.

One such heat treatment involves steaming the impregnated comminuted seeds, e.g. at a temperature in the range from 700 to 95"C and typically for 5 to 20 minutes at atmospheric pressure. A further preferred feature is to increase the moisture content of the impregnated product.

After the crushing step whereby the individual grain pieces are rolled into flakes, typically 0.6 to 2.0 mm in thickness, drying can be effected by any conventional method, e.g. by passing the material through an up-draught orfluidized bed or cross-flow dryer. A preferred air temperature in the drying step is from 85" to 95"C. It will be appreciated that the seed pieces will be art a lower temperature while drying is going on. A preferred final moisture content lies in the range from 4% to 12% by weight.

In comparison with the process described in the aforesaid GB-PS 1466479, the process according to the invention can be carried out more quickly and has the further advantages that there is no stickiness or tendency to agglomeration of the comminuted seed product to which the additive has been applied and that the final foodstuff product has an improved capacity to absorb water, which can be a valuable property in determining the recommended preparative technique to be followed by the consumer.

In order to enable the invention to be more fully understood, the following general description is given, by way of illustration, of the way of putting the invention into effect in the manufacture of foodstuffs. A number of variants which can be employed in carrying out the process of this invention are also given.

The selected edible seed material, e.g. wheat, is first cleaned, if required, and may then be treated to a procedure which, in known manner, removes part of the seed material, such as the wheat bran. The amount of cleaned starting material removed may be up to 12% by weight. This preliminary preparation step may consist alternatively of pearling, in the case of barley, or husk removal, e.g. of rice. It will be appreciated that commercial edible seed materials may already have been given preliminary treatments by the supplier. After any such cleaning and other preparatory treatments, the seed material is then comminuted to a desired range of particle sizes, by being subjected to cutting, kibbling or some other technique, which separates each wheat grain or other seed into pieces.Such treatment typically comminutes the seed material into particles whose sizes, taken as the maximum diameter, range from 2 to 5 mm. Fines produced at this stage may be regarded as any particles or pieces having a maximum dimension of 0.2 mm. It is preferable to express the range of sizes of the cut seed pieces as the number of pieces, excluding fines, produced from each wheat, rice, barley, corn or other individual grain or other edible seed. This comminution subdivides the seeds, preferably into 2 to 8 pieces per grain. Typically, the subdivision is effected by the application of forces operating in shear rather than by crushing or cracking. Where the selected seed is wheat, soft biscuit wheats are preferred, though any wheats can be used.

An aqueous solution of one or more selected additives, e.g. salt, phosphates, flavouring agents or surface-active agents, is then applied, possibly with gentle tumbling or other agitation, and the additive solution is preferably left in contact with the kibbled or cut seed material until substantially complete absorption has occurred and the product again is a free-flowing particulate material. This conditioning stage typically lasts for 5 to 20 minutes after initial contact between the seed material and the additive solution.

The comminuted and impregnated product is then preferably steamed at atmospheric pressure and at a temperature in the range from 70" to 95"C, for instance, for a period of 5 to 20 minutes, and immediately following the steaming step the product is crushed by being passed between smooth rolls running in contact with one another. It has been found that the rolls can be set so as to produce flakes of varying thicknesses. Preferably, the flakes have a thickness in the range from 0.6 to 2.0 mm. This drastic treatment alters the character of the grain pieces by converting them into flakes, which are then fed to a drying apparatus, such as those mentioned above, and dried e.g. to a final moisture content in the range from 4% to 12% by weight.

The final treated product is readily digestible and is highly suitable for incorporation into other foodstuffs, for instance by being used as an extender for sausage, burger and like products.

The additive typically comprises an aqueous salt solution, most preferably in the form of a saturated NaCI brine, and the impregnation step is carried out so as to give a product containing 0 to 3% NaCI by weight and preferably 2.5% by weight. An emulsifier is desirably included, not so as to have an emulsifying effect, but more to serve as a processing aid in the steps following impregnation. Phosphates may be incorporated, especially in seed products which will later be admixed with comminuted meat products, in order to have the benefit of the effect of phosphates on meat systems. Thus, the additive formulation may also contain, say, 0.1% glyceryl monostearate (GMS), or distilled glycerides, in the form of "Emuldan HA 52" or "Dinodan" or other proprietry emuisifiers, together with, for instance, 0.05% of sodium tripolyphosphate, all amounts being percentages by weight. While tempering can be carried out for 5 to 20 mins and, in general, up to 30 mins, it can last for longer periods and it has also been found that, if the impregnated product is tempered overnight, it is unnecessary to include an emulsifier in the product.

Moisture contents vary from stage to stage of the process and different ranges of values can also apply in each stage. Typically, the moisture content of the impregnated product is not more than 20% and is increased, by steaming or otherwise, to not less than 22%. Prior to the compression stage, the product may typically have a moisture content of 22% to 27%. The flake thickness produced after the compression stage depends on the conditions used and to some extent on the selected material, a flake thickness in the range from 0.8 to 1.2 mm being preferred for wheat flakes, from 0.6 to 0.8 mm being preferred for rice flakes and from 1.4 to 2.0 mm being preferred for barley flakes.

The invention also consists in a food product comprising comminuted edible seeds having an additive incorporated therein by impregnation followed by forming into flakes and drying.

In order that the present invention may be fully understood and appreciated, the following Examples of the manufacture of various products are given, by way of illustration. In these Examples, percentages are by weight.

EXAMPLE 1 Wheat-based Meat Extender (a) Comminution. Cleaned British-grown biscuit wheat was subjected to bran removal by conventional means, the treatment being effected so as to remove 10% of the original wheat. The resultant material was then subjected to cutting carried out so that, excluding fines, i.e. particles having a maximum dimension of 0.2 mm, each wheat grain was divided into 2 to 8 pieces.

(b)lmpregnation. An additive composition was made up in the form of a saturated aqueous solution containing salt (NaCI) and, as a processing aid, a distilled glyceride emulsifier known under the trade-name "Emuldan". This composition was formulated and then used to impregnate the treated cut wheat material so that the resultant product contained 2.5% of salt and 0.1% of emulsifier. Tempering was then effected, so as to allow the moisture content of the product to become more uniform throughout the mass, by leaving the impregnated product to stand for 30 mins. Following the tempering step, the product was steamed for 5 mins. at a temperature of 900-950C and this produced a final moisture content of 26%.

(c) Compression. The impregnated, tempered and steamed product was then subjected to compression, by being passed between crushing rolls set so as to compress the seed pieces into flakes having a thickness in the range from 0.8 to 1.2 mm.

(d) Drying. The wheat flakes so obtained were then dried, by being treated in a fluid bed dryer apparatus for 15 mins. at an air temperature of 90"C. The resultant dried wheat flakes have a moisture content of 12% and can be stored for extended periods. The wheat flake product is suitable for incorporntioii into comminuted meat products of all kinds, including sausages and burgers, as a cereal binder and filler.

EXAMPLE2 Rice-based Quick-cooking Milk Pudding (a) Comminution. US regular long-grain white rice was cut into pieces, the degree of cutting being such that, excluding fines as in Example 1, each rice grain was divided into 3-4 pieces.

(b) Impregnation. The cut rice product was then impregnated with an aqueous sugar solution containing, as a processing aid, 0.4% "Amidan" (GMS).

The impregnated product was tempered for 30 mins, before being steamed for 10 mins. at an air temperature greater than 90"C. The resultant material had a moisture content of 22% and contained 5.0% sugar.

(c) Compression. The material so obtained was compressed between metal rolls which were set so that the treated pieces of rice grain were rolled into flakes having a thickness in the range from 0.6 to 0.8 mm.

(d) Drying. The rice flakes were finally dried for 10 mins., for instance in the kind of apparatus described in Example 1, part (d), so as to have a final moisture content of 12%. The processed rice flakes so obtained are a quick-cooking product and can be reconstituted into a pudding in 5 mins, by being simmered in milk. A similar quick-cooking rice product can also be made readily, using round-grain rice, by appropriately modifying the processing conditions.

EXAMPLE 3 Barley-based Quictcooking Product (a) Comminution. Pearl barley was comminuted or kibbled in such a way as to subdivide each pearled barley grain (excluding fines) into 2 to 5 pieces.

(b) Impregnation. The cut barley was then impregnated with a saturated NaCI brine to a salt content of 2.5%. Steaming of the brined barley was carried out for 10 mins. at a temperature greater than 90"C.

(c) Compression. The softened barley product obtained after the brining and steaming steps was rolled into flakes having a thickness in the range from 1.4 to 2.0 mm.

(d) Drying. The flaked barley was dried to a final moisture content of 12%, using the technique described in the corresponding steps of Examples 1 and 2.

Untreated pearl barley, e.g. the starting material used in this Example, requires a cooking time in boiling water of at least 60 mins. The efficacy of the process of the invention is demonstrated by the fact that, by contrast, the product of Example 3 reconstitutes in boiling water in 3 mins., to have a texture, flavour and appearance very similar to untreated barley cooked in the conventional manner (i.e. in boiling water for at least 60 mins). The quick-cooking flake barley product of Example 3 is excellently suited to use in packet soups, stew packs and convenience foods.

Claims

1. A process of manufacture of a foodstuff, which comprises impregnating a comminuted edible seed product with an additive applied in liquid form, subjecting the resultant product to the application of pressure so that the seed pieces are formed into flakes and then drying the flakes to a predetermined moisture content.

2. A process according to claim 1, wherein prior to being impregnated with the additive edible seeds are comminuted into from 2 to 8 pieces per seed.

3. A process according to claim 2, wherein the seeds are comminuted into from 3 to 7 pieces per seed.

4. A process according to claim 2 or 3, wherein the seeds are comminuted into 5 or 6 pieces per seed.

5. A process according to any preceding claim, wherein the comminuted seed product comprises wheat, rice or barley.

6. A process according to any preceding claim, wherein prior to being comminuted the edible seeds are cleaned, if required, and subjected to removal of up to 12% by weight thereof.

7. A process according to any preceding claim, wherein the additive comprises an aqueous solution of at least one inorganic or organic foodstuff component.

8. A process according to claim 7, wherein the additive comprises aqueous NaCI brine and the seed product is impregnated so as to have a salt content of up to 3% by weight.

9. A process according to claim 7, wherein the additive comprises an aqueous, sugar solution.

10. A process according to any of claims 7 to 9, wherein an emulsifier is included as a processing aid in the additive.

11. A process according to any preceding claim, wherein the edible seed product is tempered after impregnation with the additive.

12. A process according to claim 11, wherein tempering is effected by allowing the product to stand for up to 30 mins after being impregnated.

13. A process according to any preceding claim, wherein the moisture content of the impregnated product is increased prior to the application of pressure.

14. A process according to any preceding claim, wherein the impregnated product is steamed at a temperature in the range from 70 to 95"C.

15. A process according to claim 14, wherein steaming is effected for 5 to 20 mins.

16. A process according to any of claims 13 to 15, wherein the moisture content of the impregnated product is increased from not more than 20% to not less than 22% by weight.

17. A process according to claim 16, wherein the moisture content prior to the application of pressure is in the range from 22% to 27% by weight.

18. A process according to any preceding claim, wherein the seed pieces are formed into flakes having a thickness in the range from 0.6 to 2.0 mm.

19. A process according to claim 18, wherein the seeds are wheat and the wheat flakes have a thickness in the range from 0.8 to 1.2 mm.

20. A process according to claim 18, wherein the seeds are rice and the rice flakes have a thickness in the range from 0.6 to 0.8-mm.

21. A process according to claim 18, wherein the seeds are barely and the barley flakes have a thickness in the range from 1.4 to 2.0 mm.

22. A process according to any preceding claim, wherein the seed flakes are dried to a moisture content of 4% to 12% by weight.

23. A process according to any preceding claim, wherein the seed flakes are dried at an air temperature of 85 to 95"C.

24. A process according to claim 1, substantially as described with reference to the foregoing Examples.

25. A foodstuff, when made or containing a product made by a process according to any preceding claim.

26. A food product comprising comminuted edible seeds having an additive incorporated therein by impregnation followed by forming into flakes and drying.

27. A meat extender comprising wheat comminuted into 2 to 8 pieces per wheat grain having an additive impregnated therein and formed into flakes dried to a predeterm;ned moisture content.

28. A meat product containing an extender according to claim 27.

29. A quick-cooking rice product comprising additive-impregnated flakes of predetermined moisture content made from rice comminuted into 2 to 8 pieces per rice grain.

30. A quick-cooking barley product comprising additive-impregnated flakes of predetermined moisture content made from barley comminuted into 2 to 8 pieces per barley pearl.