WO2010140963A2

WO2010140963A2 - An oat cereal product and method for making the same

Info

Publication number: WO2010140963A2
Application number: PCT/SE2010/050599
Authority: WO
Inventors: Sten Kvist
Original assignee: Pb Cereal Procsessing Ag
Priority date: 2009-06-01
Filing date: 2010-06-01
Publication date: 2010-12-09
Also published as: SE534934C2; WO2010140963A3; SE0900747A1

Abstract

The present invention relates to a method for producing an extruder cooked food product based solely on oat components, wherein previously non-heat treated, de-hulled oat grain is first dry milled into an endosperm-starch rich oat flour, containing active enzymes, and thereafter, mixed with oat dietary fibre, protein and oil derived from oat grains. Preferably the oat dietary fibre, oat protein and oil are obtained from oat grains that have not previously been heat/treated. If required the mix is mixed with water to form a slurry having a dry matter content of 60%-90% (w/w), said slurry is thereafter cooked in an extruder cooker and extruded to form an expanded food product having a crispy and puffed texture, said method inactivating all enzymes active in the endosperm-starch rich flour and slurry mix.

Description

AN OAT CEREAL PRODUCT AND METHOD FOR MAKING THE SAME

TECHNICAL FIELD

The present invention relates to a process for the production of an extruded ready to eat product containing only oat, as well as products obtained by said process.

BACKGROUND OF THE INVENTION

Oat is a well-known nutritious grain with many excellent properties, including health benefits. However, its use is rather limited due to the need to heat treat the grain prior to use and processing, in order to deactivate lipase and lipo-oxygenase type enzymes within the grain, as well as proteases, which can attack the fats and proteins within the kernel and rapidly develop rancidity and off-flavours in end products. This is mainly connected to the high level of fat in oat compared to other common cereals.

The heat treatment of the grain is mainly achieved by applying heat via steam to the grains after removal of any outer hull (de-hulling). This treatment somewhat swells and damages starch in the endosperm and also denatures some proteins (the desired effect).

This stabilizes the kernel towards longer term storage, but the heat damage to the starch component (the native granules) rather limits the further processing options for the grain.

It is suitable for rolling and flaking in the manner familiar in production of oat porridge, or for use as flakes in cereal formulations. However, If the heat treated grain is subsequently milled (e.g. roller-milled) in a manner to release an endosperm rich flour (analogous to wheat flour), that flour cannot be utilized in many applications, especially those that rely on the subsequent expansion of the starch granules.

A diet which is high in cereals such as oats has many commonly accepted advantages and benefits. Oats, for example are very rich in soluble and insoluble fibers, which can result in slower digestion and an extended sensation of fullness. Further advantages can include normalization of bowel function, reduction of occurrence of certain colonic diseases, even the lowering of serum cholesterol id sufficient oat derived beta glucan soluble fiber is ingested over a sustained period. It is hence beneficial for humans to eat oat and oat products, however, products rich in oats are often not convenience foods and require long preparation time, such as for example porridges. Other products, rich in oat fibers and other cereal fibers, tend to have a dry and rough mouthfeel. For animals kept as domestic pets, mainly cats and dogs, there is a substantial market for dry foods possessing a cereal base which provide the animals with daily nutrients. However, cereals such as wheat have a rather poor quality protein from a purely nutritional point of view and other proteins or protein hydroiysates derived from meat, blood, soya etc need to be added to boost the nutritional value of the dry food, along with fat to increase palatability for the animal. Oat is a more effective starting material from this point of view, with a relatively high protein content and that protein, unique amongst common cereals, is complete and nutritious, resembling soy protein and animal proteins in nutritional score and value. Oat also contains a relatively high content of good quality oil, with an excellent balance of fatty acids and rich content of antioxidants, which is also known to have an impressive effect on the coat of dogs, which is a prime selling point for dog food.

Ready-to-eat foods such as cereals and snacks containing whole grain cereals have traditionally been made as shredded products wherein whole grain berries have been cooked and tempered for some time, shredded and laminated into layers stacked on top of each other, cut and baked to form a unique crispy texture having a robust flavor. Starch-based compositions which have little or no gluten, such as oats, when mixed with water do not form a dough that is cohesive at room temperature and continuously machinable or sheetable. The machinability of such a dough can be improved by forming a dough under heating conditions but this takes place at the expense of a decreased shreddability.

Extrusion cooking is an alternative way of processing starch-based foods such as ready- to-eat cereals and snacks, along with production of dry pet foods. Extrusion cooking is often used to achieve high production rates, crisp and crunchy textures. However, fortification of such extruded products with insoluble and soluble dietary fiber to replace starch-based components as wheat flour may adversely affect the extrusion functionality or extrudability of the formulation. Generally, dietary fiber has a substantially higher water holding capacity than starch based components and therefore it is more difficult to expand a snack or Ready-to-eat formulation to achieve low bulk densities, uniform cell structure and crispiness, compared to a starch-based formulation which does not contain fortifying amounts of dietary fiber. Therefore, in order to produce an extrusion cooked cereal product it is conventional wisdom that at least part of the product has to be based on starch-rich comoonents such as wheat flour. As discussed above oats are generally considered a "health food" Besides containing dietary fiber, oats are an excellent source of thiamine, iron, and are also the only source of antioxidant compounds known as avenanthramides, these are believed to have properties which help to protect the circulatory system from arteriosclerosis Oat protein is nearly equivalent in quality to soy protein, which has been shown by the World Health Organization to be equal to meat, milk, and egg protein The protein content of the hull- less oat kernel (groat) ranges from 12-24%, the highest among cereals Therefore it would be very beneficial if convenience foods such as ready-to-eat cereals and snack, along with dry-pet foods, could be made based on a composition having a high content of components obtained from oat

The present invention provides a process for the mass production of extruded and expanded food products such as ready-to eat cereals and snacks, also formulations suitable for feeding to pets and animals, based solely on oat grain components The food products of the present invention have a pleasant taste (no strong typical "oaty" taste), very good and pleasing crispy, crunchy texture and generally very good organoleptic qualities The process of the present invention provides a range of excellent oat derived food products having a good and healthy, nutritionally balanced, composition of dietary fibre, protein, oil and carbohydrate The products produced by the process of the invention are suitable for use as snack and snack bases,, breakfast cereal and breakfast cereal bases, in pet-foods and pet-food bases, horse foods and for feeds The materials are prepared via use of any acceptable model of type food processing extruder, both single screw or twin screw types

SUMMARY OF THE INVENTION

The present invention relates to a method for producing an extruder cooked food product based solely on oat components, wherein previously non-heat treated, de-hulled oat grain is first dry milled into an endosperm-starch rich oat flour, containing active enzymes, and thereafter if required, mixed with water to a form a slurry having a dry matter content of 60%-90% (w/w), said slurry is thereafter cooked in an extruder cooker and extruded to form an expanded food product having a crispy and puffed texture, said method inactivating all enzymes active in the endosperm-starch rich flour In a preferred embodiment of the invention the slurry has a dry matter content of 70%- 85% (w/w).

The slurry is preferably cooked at a temperature of 120-150⁰C and a pressure of 60-80 bar.

In a more preferred embodiment of the invention the non-heat treated oat flour is mixed w /iitthh oat dietary fibre in the proportions ranging from 1 % - 99% non-heat treated oat flour 1 %-99% oat dietary fibre calculated on a dry matter basis, said method inactivating all enzymes active in the endosperm-starch rich flour and slurry.

In a preferred embodiment of the invention the proportion of non-heat treated oat flour to oat dietary fibre is 50% - 90% non-heat treated oat flour : 10%-50% oat dietary fibre.

In a more preferred embodiment of the invention the proportion of non-heat treated oat flour to oat dietary fibre is 70% - 80% non-heat treated oat flour : 20%-30% oat dietary fibre.

In one preferred embodiment of the invention the non-heat treated oat flour is mixed with oat dietary fibre, oat protein and oil obtained from oat grains in the proportions ranging from 3%-97% non-heat treated oat flour : 1 % - 95% oat dietary fibre : 1 %-95% oat protein : 1 %-95% oat oil.

In a further preferred embodiment of the invention the proportion of non-heat treated oat flour to oat dietary fibre, oat protein and to oat oil is 50%-90% non-heat treated oat flour : 4%-45% oat dietary fibre : 4%-45% oat protein ; 1 %-20% oat oil.

In a most preferred embodiment of the invention the proportion of non-heat treated oat flour to oat dietary fibre, oat protein and oat oil is 65%-80% non-heat treated oat flour : 10% - 25% oat dietary fibre: 5% - 20% oat protein : 2%-12% oat oil.

In one preferred embodiment of the invention the oat dietary fibre is non-heat treated oat dietary fibre.

In one preferred embodiment of the invention the oat dietary fibre is a non-heat treated oat dietary fibre fraction obtained in the wet state containing between 50% and 22% dry matter (w/w), one or more of the active enzyme of the group comprising amylases, amyloglucosidases and/or pullulanases, and enzyme activity from the native oat grain. In one embodiment of the invention the protein is derived from any part of the oat grain, oat protein concentrates or oat protein isolates containing protein derived from oat bran, oat endosperm, oat germ or whole oat grain.

In one preferred embodiment of the invention the protein and oil are provided as a protein/oil fraction in the wet state emanating from milled, non-heat-treated oat grain, and containing between 10-50 % dry matter (w/w).

In one preferred embodiment of the invention re-expansion of the expanded food product is achieved via hot air treatment in 250-270⁰C, for 1- 2 minutes, or via heating / frying in hot cooking oil.

In one preferred embodiment of the invention the expanded food product is coated with beta glucans derived from oat grains.

In one preferred embodiment of the invention the expanded food product is coated with one or more of the digestible carbohydrates of the group comprising amylodextrin, maltodextrin, glucose and maltose rich syrup derived from oat grains.

Furthermore the present invention also relates to a food product as obtained by the method according described above, said product only consisting of components obtained from oat grains and having a crunchy, crispy and puffed texture.

In one preferred embodiment of the invention the food product is a snack food.

In one preferred embodiment of the invention the food product is a breakfast cereal.

In one preferred embodiment of the invention the food product is a feed for pets of the group comprising dogs, cats, birds, fish and rodents.

In one preferred embodiment of the invention the food product is an animal feed for farm animals of the group comprising horses cattle and sheep.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the invention will be described in a non-limiting way and in more detail with reference to exemplary embodiments illustrated in the enclosed drawings, in which: Figure 1 is an overview of the basic steps of the extrusion process of present invention, and

Figure 2 is a schematic view of the steps for extruding non-heat treated oat flour and oat dietary fibre according to one embodiment of the invention, and Figure 3 is a schematic view of the steps for extruding non-heat treated oat flour, oat dietary fibre, protein and oil derived from oat grain according to a second embodiment of the invention, and

Figure 4 is a schematic view of the steps for extruding of non-heat treated oat flour, oat dietary fibre, protein and oil derived from oat grain according to a third embodiment of the invention

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

To produce the extrusion cooked oat product of the present invention, it is essential that the starting material, i e the de-hulled oat grain hasn't been heat treated Almost all, if not all, commercial processing of oat grain into groats or flour and oat bran, and subsequent processing of said fractions, employs an initial steam or heat treatment on the grains to stabilise fats in the grain via denaturing of lipases and lipo-oxygenase enzymes (ι e active proteins), which if not inhibited by for example heat rapidly can lead to rancidity However, there are several advantages arising from not heat-treating the oat grain By not heat treating the de-hulled oat grain before milling oat into flour and bran, the starch grains within the endosperm flour fraction are not damaged or gelatinised in any significant way The proteins (mainly globulins) within the starchy endosperm are not denatured Furthermore, many of these proteins are enzymes and these remain active within the flour The oat endosperm flour thus obtained is therefore a unique product in terms of accepted norms in oat-processing

A further example of the advantages of not heat-treating the oat grain can be seen in patent application WO 2005/048735, wherein there is provided an efficient, cost effective industrial process for the extraction of valuable fractions from milled oat grains (Figure 1 ) This invention is characterised in that previously non-heat treated, de-hulled oat grain is first dry milled to an endosperm-starch rich fraction (the flour fraction) and a coarser endosperm-reduced fraction (the bran fraction) The hulls are discarded or can optionally be used for energy production The bran fraction which comprises between 45 % and 55 % of the milled grain is thereafter further utilised without any further heat treatment prior to wet-processing The milled bran fraction is added to water and treated sequentially with a starch degrading α-amylase enzyme, followed by an optional second hydrolysis step using an enzyme, or combination of enzymes, from the group comprising amyloglucosidases and pullulanases The enzyme treatments are optionally performed in combination with aqueous wet-milling A further optional step is enzyme inactivation by wet heat treatment, followed by the spontaneous or centrifugal separation of the hydrolysate mix into a top-layer rich in soluble dietary fibre, mainly β-glucans, an aqueous layer containing amylo- and malto-dextπns and a lower layer containing proteins, oils and the insoluble fibrous portion of the gram The lower layer is easily separated into a protein/oil containing fraction and a fraction containing the insoluble dietary fibres via a decanting step However, according to the method within WO 2005/048735, the mixed layer of insoluble fibre and protein/oil is readily achieved as a distinct phase in steps wherein a 3-phase decanter is utilised within the process to facilitate centrifugal fractionation During the aqueous wet-treatment and fractionation (using amylase enzymes) of the coarser "bran" fraction in the process described in WO 2005/048735, the intact nature of residual starch granules present in the bran (as a result of not heat-treating the oat grain), facilitates the separation of the slurry into three distinct fractions the clean beta glucan rich top layer, the aqueous amylodextπn and rnaltodextπn rich layer and a lower layer containing mainly the proteins and oil and the insoluble fibrous portion of the grain This spontaneous separation does not occur in oat grains that have been heat treated prior to dry-milling The different fractions have separate and valuable end uses as discussed in WO 2005/048735

The Glucan Rich Fraction

This fraction contains 30-35 % beta glucan soluble dietary fibre, most of the remainder comprising amylo-and malto-dextπns resulting from enzymatic hydrolysis of oat starch This fraction is a nutriceutical food ingredient, a functional food ingredient and can be processed further into an excellent range of products for cosmetic and related skin-care applications The Protein/oil fraction

This fraction is a unique and valuable product It contains 45-65%, typically 55%, protein, derived from the residual germ and endosperm collected within the bran fraction, and up to 20% oil, which also emanates from both residual endosperm and germ The oil is very rich in poly-unsaturated fatty acids, phospholipids and glycolipids (known collectively as "polar lipids") and antioxidants and holds a full vitamin E (tocopherol) complex The blend of protein and oil contains all these compounds in active, intact forms The oat protein also has a high level of essential amino acids, such as lysine, arginine and tryptophane (important in pet food) It is unique amongst cereal proteins in being complete and nutritious, resembling soy protein and animal proteins in nutritional score and value

If not used as a single, powdered oil / protein rich ingredient, the oil and protein fractions can be separated into distinct component ingredients In niche markets, this can increase the value of the total mix Oat oil is, for example, a valuable ingredient for the personal care market

Oat Dietary Fibre

This is the healthy, insoluble fibre component from oat grain, substantially free of starch It is fundamentally clean oat bran that has a high water-binding capacity and low taste It is a useful material for addition to many food products as a water-binding and textuπsing component The oat dietary fibre emanating from the process of WO 2005/048735 can optionally be produced with some of the healthy beta glucan originally located in the sub- aleurone layer of the grain still present on the fibre surface, along with residual arbinoxylan soluble fibres This increases the nutriceutical nature of these fibres

The fibre can be further separated to get access to the valuable aleurone protein and aleurone oil, both highly interesting nutritional and cosmetics ingredients

E xt ru s i o n p roces s a ceo rd i n g to the i ny e n 11 o n

In the present invention the inventors have found that selected mixtures of these unique fractions can be recombined with the fine oat flour which was obtained as a by-product during the milling step in WO2005/048735 The mix is processed in an extrusion cooker to produce a high fibre food product based solely on oat-derived components Depending on the target end product, the mix and processing regime, including processing conditions can be adjusted to produce processed materials with optimal nutritive balance or excellent sensual, mouth-feel, textural and crunchy qualities that has not previously been observed for a fibre rich product that is based exclusively on components derived from oats

The explanation to the surprising quality of the food product of the present invention is as pointed out above, the essential feature in the process of WO2005/048735, to use oat grain that has not been heat treated as starting material This is contrary to standard practice in the oat processing industry, in which the de-hulled grain is inevitably heat- treated, normally via a live steam treatment, to de-activate and denature enzymes such as lipases and lipo-oxygenases that can cause rancidity in the grain due to breakdown of native fats and oils In addition, proteases can catalyse the formation of bitter peptides from flour proteins These enzymes are also deactivated by such applied heat The oat flour obtained during the dry-milling step in the process described above, has consequently not been heat treated or thermally shocked in any way, which gives processing advantages also in the present invention in that the starch in the oat flour used is not substantially gelatinised the granules are therefore available for further swelling, puffing etc via heat and moisture treatment, for example as in extruder cooking

Example 1 extrusion of non-heat treated oat flour

The milling of non-heat treated oat grain results in a flour fraction that is still veiy active in terms of viable enzymes which is advantageous as discussed above Typically, the oat flour fraction obtained during the milling process of WO2005/048735 has approximately the following content carbohydrates 73 %, proteins 9 %, fat 4 %, beta-glucans 1 % and dietary fibre 5% (calculated on a dry matter basis) However, due to the high fat level in oat flour relative to other cereal flours such as wheat flour, enzymes such as lipases and lipo-oxygenases can cause the development of off-flavours in the unheated oat flour within 24 hours of milling Therefore, in order to enable further use of the flour obtained in the process of WO2005/048735 in foods and feeds of the present invention, it is necessary to deactivate these enzymes by heat treatment However, it is very difficult and problematic to treat oat flour with steam in a manner analogous to the method used on the intact oat grain The solution to this problem is therefore to heat treat and deactivate enzymes in an extruder / extruder cooker

Flour, (circa 100 kg) milled from whole, non-heat-treated oat grain, mainly derived from the endosperm of said non-heat treated oat grain, having a water content typically ranging from 10-14%, was mixed with more water providing a slurry containing milled oat flour, and having a final dry matter content ranging between 65% - 85% (w/w) The mix was pre-conditioned and mixed and thereafter cooked in a Wenger X-25 model extruder cooker at a temperature ranging from 120 - 150⁰C and at pressures ranging from 60 bar- 85 bar The extruder has a capacity of 300- 1000 kg throughput The cooked mixture was extruded through a single hole die having a diameter of 7 5 mm, exiting as an expanded continuous sausage that optionally proceeded into post extrusion treatment and thereafter drying and cooling before packaging (see Fig 1 )

Surprisingly, this leads to a cooked product that is particularly low in oaty taste, has a pleasant texture and can be shaped into puffs, pellets or flakes etc This is attributed to the undamaged nature of the oat starch granules in the non-heat treated flour, and their availability for expansion during extruder cooking This is not encountered in normal and practised oat processing The product was stable, in that no off flavours developed over weeks of monitoring The material was fiee of residual lipase or protease activity

The person skilled in the art realizes that the invention is not limited to the use of an extruder cooker having a single screw but also other extruder cookers e g those having a twin screw will also be suitable for use in the present invention

Example 2 extrusion of oat dietary fibre

The oat dietary fibre fraction emanating from the process of WO 2005/048735 provides a useful material for addition to many food products as a water-binding and textuπsing component Typically, the oat dietary fibre fraction obtained during the wet-fractionation 5 process of WO2005/048735 has approximately the following content carbohydrates 12 %, proteins 24 %, fat 9 %, beta-glucans 12 % and dietary fibre 33 % (calculated on a dry matter basis) The oat dietary fibre can optionally be produced with some of the healthy beta glucan originally located in the sub-aleurone layer of the grain still present on the fibre surface, along with residual arbinoxylan soluble fibres This increases the

10 nutriceutical nature of these fibres However, this oat dietary fibre fraction contains an active enzyme used as a processing aid and some residual enzyme activity from the non heat treated oat bran taken into the process, when exiting from the production process sequence of WO 2005/048735 These enzyme need to be heat de-activated during a final step before use, along with drying of the product Therefore, this oat dietary fibre slurry

J s can be fed directly into the extrusion cooker, skipping the optional step of enzyme inactivation as well as the drying step at the end of the wet-fractionation process All enzymes are conveniently deactivated directly in the extruder

Circa 120 kg of the oat dietary fibre fraction, in a wet state, containing between 50% and 22% dry matter non-deactivated amylase enzyme, and some residual enzyme activity 20 from the native oat grain that is obtained directly from the wet fractionation of oat bran, is heated and cooked in an extruder as described in example 1

This led to a product free of residual enzyme activity that had a surprisingly pleasant taste and texture, and residual moisture content of around 5 % Thus, the oat dietary fibre fraction emanating from the process of WO 2005/048735 provides an excellent starting 5 material that is very suitable for use in the present invention Furthermore, the extrusion cooking process proves an excellent way to de-activate all enzyme activity within the material

Example 3 extrusion of non-heat treated oat flour and oat dietary fibre

To create a food product that can be used as a ready-to-eat food suitable for human 0 and/or animal consumption, a mix between oat dietary fibre and non-heat treated oat flour was created

86 Kg of Odi flour mainly deiiveu from the eπdυbμeim of non-heat tieated oat yiaiπ, having a dry matter content of 88% (w/w), is mixed with 97 kg of the dietary fibre fraction obtained directly from the wet fractionation of oat bran emanating from the process of WO 2005/048735, which contains 24 % (w/w) dry matter This resulted in 184 kg of mixed slurry having a dry matter content of 53 9 % The dry matter content of the mass was then increased to at least 70% by further blending and drying using a fine grinder or a flash ring drier of the type used to dry wheat gluten or starch Such a device is optionally used to adjust moisture contents of mixes of non-heat treated flour, and wet fractions extracted from oat bran according to the process of WO 2005/048735 that have not been dried This can be performed in a fine grinder or other suitable drying system, such as a flash drier, including a ring flash drier (Figure 1 ) These adjustments can be from dry matter contents of initial mixes of between 40 %- 60 % up to 70% - 85% dry matter, prior to feeding to an extruder pre-conditioning mixer or directly to an extruder These driers generate only moderate actual temperatures within the product, and do not therefore cause protein denaturation Active enzymes within the product are not appreciably deactivated via these drying regimes The resultant slurry mixture was fed to the extruder pre-conditioner and then to extruder, post extruder and dryer as described in example 1 (see Fig 2)

The extruded products created were free of residual enzyme activity and had a good, neutral taste, a satisfying crispy /crunchy, texture and mouth-feel Furthermore, the heat and shear forces applied within the extruder deactivated any enzymes utilised during processing of the grain, along with endogenous enzymes present within the native oat grain especially within the non-heat treated flour utilised, but also within bran derived fractions)

The oat dietary fibre fraction emanating directly from the wet-extraction process of WO 2005/048735 provides an excellent starting material to be mixed with the non-heat treated endosperm-starch rich oat flour and used in the present invention , The extrusion cooking of the mix of non-heat treated oat flour and the oat dietary fibre emanating in its wet state from the process of WO 2005/048735, provides and facilitates a very convenient and effective deactivation of enzymes, both native and those added as processing aids during the process of WO 2005/048735, and results in a surprisingly good product in terms of taste, texture and mouthfeel However, this does not exclude the use, in such a mix, of oat dietary fibre from other sources and produced by other methods than the process disclosed in WO 2005/048735, either in combination with the oat dietary fibre produced in the process disclosed in WO 2005/048735, or as a complete replacement for this fibre, mixed with the non-heat-treated oat flour as a base for the extrusion cooking step as described herein Preferably the proportion of the non-heat treated flour to oat dietary fibre, whether the oat dietary fibre was obtained by the process of WO 2005/048735 or from some other source can range from, when calculated on a dry matter basis, 1 % - 99% non-heat treated flour 1%-99% oat dietary fibre, preferably 50%-90% non-heat treated flour 10%"50% oat dietary fibre, most preferably 70%-80% non-heat treated flour 20% - 30% oat dietary fibre In each mix, dry matter content prior to extrusion, is adjusted where necessary by adding water to form a slurry having a 60%-90 %, preferably 70%-85 % dry matter content (w/w)

Example 4 extrusion of a mix of non-heat treated oat flour, the oat dietary fibre fraction and the protein / oil fractions obtained directly from the process of WO 2005/04873

In order to further improve the nutritional content of the extruded oat product the oat dietary fibre fraction and non-heat treated oat flour from example 3, were fed into the extruder together with some of the protein/oil fraction obtained in the process of WO 2005/048735 Typically, the protein/oil fraction obtained during the wet-fractionation process of WO2005/048735 has approximately the following content carbohydrates 14 %-18%, proteins 45%~55 %, fat 15 %-25%, beta-glucans 1 % and dietary fibre 4-6% (calculated on a dry matter basis) Moisture was supplied to the mix by feeding non-dried oat dietary fibre and non-dried protein/oil fraction, which typically has a dry matter content of 10-50 % (w/w), to the extruder along with the non-heat treated oat flour The non-heat treatment of the flour leads to a material containing live, active enzyme components These enzymes will be very active when the non-heat treated oat flour is mixed with the wet oat dietary fibre fraction and the protein/oil fraction, prior to extrusion This activity will affect fibres (both soluble and insoluble) in the fractions, and cause limited protein hydrolysis This activity, prior to extrusion deactivation, will affect the end product and contribute to improved crunch, crispiness and texture This can only be achieved using non-heat treated, active oat flour 85 2 kg of oat flour mainly derived from the endosperm of non-heat treated oat grain, having a dry matter content of 88 %( w/w), is mixed with 58 3 kg dietary fibre fraction obtained from the wet fractionation of oat bran as a slurry of 24% (w/w) dry matter content, and with 39 3 kg of the protein /oil fraction obtained directly from the wet fractionation of oat bran, as a slurry of 28% dry matter content Both the non-dried oat dietary fibre and protein /oil fractions are obtained directly from the wet fractionation of oat bran according to the process of WO2005/04873 This resulted in 182 8 kg of a mixed mass of 54 7 % dry matter content The dry matter content of the mass was then increased to at least 70% by further blending and drying using a fine grinder or even a flash ring drier of the type described in Example 3 The resultant slurry mix was fed to the extruder pre-conditioner and then to extruder, post extruder and dryer as described in example 1 (see Fig 3)

This led to the creation of a surprisingly good tasting product with pleasant taste (no strong typical "oaty" taste), very good and pleasing crispy and crunchy texture with 5 generally very good organoleptic qualities The products were free of residual enzyme activities and are stable for months in ambient storage By blending the fractions obtained from the wet-fractionation of the oat bran along with the non-heat treated oat flour fraction emanating from the same processing, and putting them through an extruder, there is created a base ingredient that can be used for food or feed products such as breakfast 10 cereals, snacks and pet foods

The oat dietary fibre fraction and protein and oil fraction emanating from the process of WO 2005/048735 provide excellent starting materials that are very suitable for use in the present invention This does not exclude the use of dietary fibre, proteins or oil obtained from oat grains produced by other methods than the process disclosed in WO

15 2005/048735 as a starting material Indeed, oat protein rich material, derived from any part of the oat grain, oat protein concentrates, containing protein derived from oat bran, from oat endosperm, from oat germ or "whole oat grain", or oat protein isolates from the equivalent parts of the grain, or the whole oat grain, with protein levels ranging from 20%- 99%, can be utilised Likewise, oat derived materials and fractions rich in oat oil,

20 containing 15% -100 % oat oil, can also be utilised Preferably, the proportion of the non- heat treated flour to oat dietary fibre, oat protein and oat oil, whether the oat dietary fibre, oat protein and oat oil were obtained by the process of WO 2005/048735, or from some other source, can range from, when calculated on a dry matter basis, 3%-97% non-heat treated oat flour 1 % - 95% oat dietary fibre 1 %-95% oat protein 1 %-97% oat oil, 5 preferably 50%-90% non-heat treated oat flour 4%-45% oat dietary fibre 4%-45% oat protein 1 %-20% oat oil, most preferably 65%~80% non-heat treated oat flour 10% - 25% oat dietary fibre 5% - 20% oat protein 2%-12% oat oil Within each mix, the dry matter content prior to extrusion, is adjusted where necessary to between 60%-90%, preferably 70-85 % (w/w) 0 Example 5 extrusion of a mix of non-heat treated oat flour and the protein / oil / oat dietary fibre fraction obtained directly from the process of WO 2005/048735

Products and mixes eαuivalent to those described in Example 4 above can be achieved using a product obtained from the process described in WO 2005/048735, in which the protein/oil and oat dietary fibre rich fractions obtained are not separated from each other during the process, e g when a 3-phase decanter is utilised in steps in said process Hence as far as further processing for extrusion of products is concerned, the mix of these fractions in the wet state is already achieved In this case, a mix of oat dietary fibre and protein / oil fractions contains active processing enzyme such as added amylase, and 5 some small activity due to residual native enzymes not de-activated during the wet- process The combined fraction is conveniently deactivated and dried via extrusion cooking, in co-mixes with the non-heat-treated oat flour, to give products equivalent to those described in example 4

86 kg of Oat flour mainly derived from the endosperm of non-heat treated oat grain, and 10 98 kg of the fraction emanating from the process of WO 2005/048735 containing both the oat dietary fibre and the protein/oil , which contains 26% dry matter (w/w), resulting in 184 kg mixed slurry of 55% dry matter content which thereafter was increased to at least 70% by further blending and drying using a fine grinder or even a flash ring drier of the type described in Example 4 The resultant slurry mix was fed to the extruder pre- 15 conditioner and then to extruder, post extruder and dryer as described in example 1 (see Fig 4)

In the slurry mix, prior to extrusion, the proportions of the non-heat treated oat tlour to oat dietary fibre, oat protein and oat oil in this example can range from (calculated on a dry matter basis) 3% 97% non-heat treated oat flour 1 % - 95% oat dietary fibre 1 %-95% oat 20 protein 1 %-97% oat oil, preferably 50%-90% non-heat treated oat flour 4%-45% oat dietary fibre 4%-45% oat protein 1 %^»20% oat oil, most preferably 65%-80% non heat treated oat flour 10% - 25% oat dietary fibre 5% - 20% oat protein 2%-12% oat oil Within each mix the dry matter content prior to extrusion, is adjusted where necessary to between 60% 90%, pteferably 70-85 % (w/w) 5 Extruded products equivalent to those described in example 4 were obtained, with good texture, crunchiness and organoleptic qualities, along with the nutritional qualities also attributed therein Further treatments of the extruded products produced according to the invention

The extruded products produced from such blends as described in examples 4 and 5 have typical product specification of

The extruded product has several beneficial properties

1 All enzymes naturally present in the native source oat grain, or added as processing aids during wet-fractionation, are deactivated

2 A good, satisfying Crunchy - Crispy texture is obtained

3 Products have a good, but neutral, taste - less oat taste than normally encountered in oat based products Easily further flavoured if wished

4 Healthy, nutritionally balanced, composition of, protein, oil, dietary fibre and carbohydrate

5 Contains only oats - no other cereal grains or additives, unless specifically desired

The improved taste and crunchiness of the extruded product, compared to other extruded cereal products, is a direct result of the combined dry and wet milling as well as the wet- fractionation processes that takes place prior to extrusion The surprising aspect of this invention is the creation of a range of excellent oat derived products via combination of unique oat derived ingredients in an extruder and cooking them in said extruder, in order to deactivate live enzymes in the previously non-heat treated oat flour and the oat dietary fibre fraction emanating form wet-fractionation of oat bran A further consequence of the findings within the invention is the creation of extruded products with a good and healthy, nutritionally balanced, composition of protein, oil, dietary fibre and carbohydrate These products are suitable for use as snacks, breakfast cereal bases, in pet-foods and animal feeds amongst others The fractions can be recombined in various proportions according to target end products and nutritional and quality requirements for such products Below are some examples of further treatments of the extruded product of the present invention It should be emphasized that the treatments presented in these examples should not be limiting to the invention, but other solutions, uses, objectives, and functions within the scope of the invention should be apparent for the person skilled in the art

Example 6 post extrusion treatment - shaping and drying

To produce a snack type product, cooked materials emanating from the extruder from the previous examples 1 -5 and as described in preferred embodiments, were then fed into a second, forming extruder (Wenger) and the extrudate fed through a multi-head die forming continuous flat ribbons of cooked dough of width 2 2 cm and thickness of about 2 5 mm These ribbons were then chopped into 3 cm lengths and the product was dried in a continuous air drier Re-expansion of the dried strips was achieved via hot air treatment (250-270⁰C 1- 2 minutes), or via heating / frying in hot cooking oil

This resulted in products with a crunchy, crisp texture that had good taste and mouthfeel Products resembled a puffed crackers or puffed nachos in texture and mouthfeel

Example 7 coating with beta glucans

To further improve the nutπticeutical quality of the extruded product it can be coated with an oat beta glucan rich layer, said beta glucans having been extracted from oat bran according to WO 2005/048735, or any other reasonable method The beta glucan rich fraction obtained according to WO 2005/048735 has a content of beta glucans of 15% - 75% (calculated on a dry matter basis) and can be applied at levels up to 30% of the total product dry mass, by any reasonable method, including, but not restricted to, dusting, rolling in dry powder, powder mixing, spraying of a solution of the beta glucan rich fraction and subsequent drying This boosts the content of beta glucan in the products and increases the nutπceutical value of the extruded materials

Example 8 coating with digestible carbohydrates

In a further variation, to increase the digestible carbohydrate content of the extruded products, to add some further sweetness, and to increase the possibility to stick extruded particles together and / or to stick other components of a finished snack or breakfast cereal composition to the extruded products, the extruded product can also be coated with an oat amylodextπn and maltodextrin rich layer, said amylodextπns and malto dextπns having been produced and extracted from oat bran according to WO 2005/048735, or from oat bran or oat gram by any other reasonable method The dextrin (i e amylodextrin and maltodextrin) rich fraction obtained according to WO 2005/048735 has a content of 5 oat starch derived dextπns of 80% - 99% (calculated on a dry matter basis) and can be applied at levels up to 40% of the total product dry mass, by any reasonable method, including, but not restricted to, dusting, rolling in dry powder, powder mixing, spraying of a solution of the amylodextrin or maltodextrin rich fraction and subsequent drying

The dextrin (ι e amylodextrin and maltodextrin) fraction emanating from the process0 according to WO 2005/048735 can be further hydrolysed using amyloglucosidase and amylase enzyme preparations (e g the commercially available products such as Novozymes BAN, Termomyl classic and amg 300 L, or SAN Extra, and similar preparations) to a glucose and maltose rich syrup, which can also be applied to the extruded products as described, with similar or equivalent effects 5 The addition of beta glucan rich fractions of materials as described does not exclude the addition of amylodextrin and dextrin rich materials as also described, or vice versa

Example 9 mixing with other cereals

Furthermore, the extruded products can be further extended and/or in some cases modified, via the addition of a flour emanating from another cereal such as corn, wheat,0 rye, barley or rice The levels of addition can be from 0 5% - 30% (calculated on dry matter basis)

Example 10 mixing oi coating with other flavours

Furthermore, the extruded products can be fuither extended and/or in some cases modified by the addition of natural or artificial flavouring substances, either to the slurryb mix prior to the extrusion, or afterwards as a coating on the cooked and dried product

Possible end products that can be obtained from the method of the invention

Below are some examples of products that can be obtained using the process of the present invention The person skilled in the art recognizes that the invention is not limited0 to the examples presented below but may encompass further examples of end products that are not disclosed herein Example 11 Snacks

Snack foods are typically designed to be portable, ready-to-eat and satisfying Processed snack foods are designed to be less perishable, more durable, and/or more appealing than prepared foods Generally, they often contain substantial amounts of sweeteners, preservatives, and appealing ingredients such as chocolate, peanuts, and specially designed flavors (such as flavored potato chips) Snack foods are often subjectively classified as junk food, they have little or no nutritional value, and are not seen as contributing towards general health and nutrition With growing concerns for diet, weight control and general health, government bodies are recommending that people make a conscious effort to eat more healthy, natural snacks - such as fruit, vegetables, nuts and cereal grains - while avoiding high-calorie, low-nutrient junk food Using the process of the present invention it is now possible to produce a ready-to-eat snack that is a healthier alternative to other starch based snacks

The product of the present invention has a good, neutral taste and can easily be flavoured, either by the addition of natural or artificial flavouring substances, or components from other grains such as corn, wheat or barley, rice or rye The addition of components from the other grains, such as flours, can also have beneficial effect on product texture and mouthfeel

Example 12 Breakfast cereal Studies have shown that eating whole-grain breakfast cereals seven or more times per week was associated with a lower risk of heart failure Breakfast cereals that contain at least 25 percent oat or bran content were classified as whole grain cereals A breakfast cereal (often simply called cereal) is a packaged food product intended to be consumed as part of a breakfast It is usually eaten cold as a ready-to-eat meal and mixed with a liquid, such as milk or water, though occasionally nuts and fruit are also added With the process of the present invention there is provided a base for a breakfast cereal that has a healthy, nutritionally balanced, composition of dietary fibre, protein, oil and carbohydrate derived solely from oat Furthermore the product has a crispy and crunchy texture that is usually associated with common breakfast cereals As the product of the present invention has a good, neutral taste, it can easily be flavoured, either by the addition of natural or artificial flavouring substances, or components from other grains such as corn, wheat or barley rice rve The addition of components from the other qrains, such as flours, can also have beneficial effect on product texture and mouthfeel To produce a good breakfast cereal product (crispy puffed oat product), as a stand alone cereal formulation, or as a component for adding to other cereal mixes such as mueslis, a muliti-hole die can be fitted to the outlet of the extruder cooker (as in examples 1 -5) with typical dimensions of around 2mm diameter A chopper knife, or similar such device, located next to the die could be utilised to create the cereal pieces from each string emanating from the die holes

Example 13 Pet foods suitable for dogs, cats, birds, fish or rodents

Dry pet food generally consists of approximately 60% cereal ingredients To improve on the taste of the pet food, fat is added to the mix It is difficult to achieve high fat concentrations in the manufacturing process and therefore the uniquely bound protein/oil fraction obtained in the wet-fractionation process disclosed in WO 2005/048735 provides 6% fat in the cereal mix This means less animal fat needs to be added to the final mix

The oat oil, with its excellent balance of fatty acids and rich content of antioxidants, is also known to have an impressive effect on the coat of dogs, which is a prime selling point for dog food

To increase protein content, and because of the poor protein quality normally associated with cereal (e g wheat) proteins, and to improve flavour, recovered meat protein and meat protein hydrolysates, and even soy protein and hydrolysates, are added to the feed

The oat protein is of very high nutritional quality (close to that of meats and soy) hence there is a distinct nutritional advantage to have this as the protein base in the food, reducing the need to add more expensive proteins into the formula

The addition of components from other grains (e g corn, wheat, barley, rice, rye) such as flours can have beneficial effect on product texture and mouthfeel

Example 14 feed for farm animals such as horses, cattle or sheep

Claims

1 A method for producing an extruder cooked food product based solely on oat components, characterized in that previously non-heat treated, de-hulled oat grain is first dry milled into an endosperm-starch rich oat flour, containing active enzymes, and thereafter if required, mixed with water to a form a slurry having a dry matter content of 60%-90% (w/w), said slurry is thereafter cooked in an extruder cooker and extruded to form an expanded food product having a crispy and puffed texture, said method inactivating all enzymes active in the endosperm-starch rich flour

2 A method according to claim 1 , wherein the slurry has a dry matter content of 70%-85% (w/w)

3 A method according to claim 1 , wherein the slurry is cooked at a temperature of 120-150⁰C and a pressure of 60-80 bar

4 A method according to claims 1 3, wherein the non-heat treated oat flour is mixed with oat dietary fibre in the proportions ranging from 1 % 99% non-heat treated oat flour 1 %-99% oat dietary fibre calculated on a dry matter basis, said method inactivating all enzymes active in the endosperm-starch rich flour and slurry

5 A method according to claim 4, wherein the proportion of non-heat treated oat flour to oat dietary fibre is 50% - 90% non-heat treated oat flour 10%-50% oat dietary fibre

6 A method according to claim 5, wherein the proportion of non-heat treated oat flour to oat dietary fibre is 70% - 80% non-heat treated oat flour 20%-30% oat dietary fibre

7 A method according to claim 1 , wherein the non-heat treated oat flour is mixed with oat dietary fibre, oat protein and oil obtained from oat grains in the proportions ranging from 3%-97% non-heat treated oat flour 1 % - 95% oat dietary fibre 1 %- 95% oat protein 1%-95% oat oil A method according to claim 7, wherein the proportion of non-heat treated oat flour to oat dietary fibre, oat protein and to oat oil is 50%-90% non-heat treated oat flour

4%-45% oat dietary fibre 4%-45% oat protein 1 %-20% oat oil

A method according to claim 8, wherein the proportion of non-heat treated oat flour to oat dietary fibre, oat protein and oat oil is 65%-80% non-heat treated oat flour

10% - 25% oat dietary fibre 5% - 20% oat protein 2%-12% oat oil

A method according to one or more of claims 4-9, wherein the oat dietary fibre is non-heat treated oat dietary fibre

A method according to one or more of claims 5-10, wherein the oat dietary fibre is a non-heat treated oat dietary fibre fraction obtained in the wet state containing between 50% and 22% dry matter (w/w), one or more of the active enzyme of the group comprising amylases, amyloglucosidases and/or pullulanases, and enzyme activity from the native oat grain

A method according to one or more of claims 7 1 1 , wherein the protein is derived from any part of the oat grain, oat protein concentrates or oat protein isolates containing protein derived from oat bran oat endosperm, oat germ or whole oat grain

A method according to one or more of claims 7-1 1 , wherein the protein and oil are provided as a protein/oil fraction in the wet state emanating from milled, non-heat- treated oat grain, and containing between 10-50 % dry matter (w/w)

A method according to one or more of claims 1 - 13, wherein re-expansion of the expanded food product is achieved via hot air treatment ιn250-270°C fot 1 - 2 minutes, or via heating / frying in hot cooking oil

A method according to one or more of claims 1 - 13, wherein the expanded food product is coated with beta glucans derived from oat grains

A method according to one or more of claims 1 -13 , wherein the expanded food product is coated with one or more of the digestible carbohydrates of the group comprising amylodextrin, maltodextrin, glucose and maltose rich syrup derived from oat grains A food product as obtained by the method according to one or more of the claims 1 -16, characterized in that it only consists of components obtained from oat grains and that it has a crunchy, crispy and puffed texture

A food product according to claim 17, wherein the food product is a snack food

A food product according to claim 17, wherein the food product is a breakfast cereal

A food product according to claim 17, wherein the food product is a feed for pets of the group comprising dogs, cats, birds, fish and rodents

A food product according to claim 17, wherein the food product is an animal feed for farm animals of the group comprising horses cattle and sheep