The present invention relates to a method for making a co-processed product, said product comprising a starch and at least one further component.

Background

It is known that a granular starch can be made cold-swelling through a series of processes, such as drum drying, cooking in alcohol and spray-cooking. The latter is described, among other places, in European patent specification no. EP 0 032 296. Using spray-cooking of starch achieves the effect that the starch maintains its granular structure, but swells in cold water.

In the traditional spray-cooking process of starch, a suspension of starch in water is used. This suspension is fed into a reaction chamber, where the starch is cooked. It is then atomised through a nozzle into a drying chamber, where it is dried in a hot air stream. Hereby a dried product is obtained, which consists of intact gelatinised starch grains. When these come into contact with cold water, they will absorb water and make it viscous.

If the starch is not chemically modified before being subjected to spray-cooking, it will have the same advantages and disadvantages as the corresponding non- gelatinised starch (except for its ability to swell in cold water). This means that it is highly sensitive to temperature, pH and mechanical impact. A starch solution will also retrograde over time. Retrograding is often an undesirable process, in which amylose molecules can be deposited in such a way as to form a lattice that displaces water. Furthermore, a relatively so-called long structure of particularly potato starch is obtained by heat impact of excessive duration. Once the starch has gelatinised, it is even more responsive to enzymatic influence/decomposition than the corresponding non-gelatinised starch. Brief description of the invention

It is an object of the present invention to provide a simple method for the making of products, the making of which has previously required several process steps, and of products with properties that are not known from existing products in the market.

Such a provision is achieved with the present invention, which relates to a method for making a co-processed product consisting of at least two components, of which a first component comprises a granular starch, and a second component comprises a non-granular hydrocolloid, a protein, an oil or another fat, said method comprising the steps of:

- Making a solution, a suspension or a dispersion of the second component in water

Adding the first component

- Heating the mixture made using steam

- Drying the heated mixture in a so-called spray-cooker using hot air so as to obtain a dried powder in the form of a fine powder or larger agglomerates.

Most hydrocolloids do not appear in a granular form, but since starches also belong to the group of hydrocolloids, the terms granular and non-granular are used to emphasise that the first component primarily comprises starches in granular form, whereas starches comprised by the second component are primarily in non-granular form after dissolution in water. In an embodiment of the invention, the first component is added in such a way, possibly in the form of a suspension, that the mixture made has the form of a suspension.

In an embodiment of the invention, the first component consists of one or more granular starches. In an embodiment of the invention, the second component consists of one or more hydrocolloids, one or more proteins, one or more oils and/or one or more other fats.

In an embodiment of the invention, the first component comprises one or more granular starches from the group comprising potato starch, corn starch, wheat starch, tapioca starch and rice starch, including variants with a high amylopectin content and/or a high amylose content.

In an embodiment of the invention, the first component consists of one or more granular starches from the group comprising potato starch, corn starch, wheat starch, tapioca starch and rice starch, including variants with a high amylopectin content and/or a high amylose content.

In an embodiment of the invention, the first component comprises one or more granular starches which have undergone one or more of the following treatments: bleaching, acid hydrolysis, alkali treatment, enzymatic treatment, oxidation, esterification and etherification.

In an embodiment of the invention, the first component consists of one or more granular starches which have undergone one or more of the following treatments: bleaching, acid hydrolysis, alkali treatment, enzymatic treatment, oxidation, esterification and etherification.

In an embodiment of the invention, the second component comprises one or more hydrocolloids from the group consisting of starches (including modified starches), pectins, guar gum, xanthan gum, gellan gum, konjac gum, acacia gum, locust bean gum, carrageenans, semi-refined carrageenans, alginates and cellulose derivatives.

In an embodiment of the invention, the second component consists of one or more hydrocolloids from the group consisting of starches (including modified starches), pectins, guar gum, xanthan gum, gellan gum, konjac gum, acacia gum, locust bean gum, carrageenans, semi-refined carrageenans, alginates and cellulose derivatives.

In an embodiment of the invention, the second component comprises one or more proteins from the group consisting of soy proteins, milk proteins, wheat proteins, corn proteins, potato proteins, whey proteins, pea proteins and animal proteins, including gelatine.

In an embodiment of the invention, the second component consists of one or more proteins from the group consisting of soy proteins, milk proteins, wheat proteins, corn proteins, potato proteins, whey proteins, pea proteins and animal proteins, including gelatine.

In an embodiment of the invention, the second component comprises one or more oils and/or one or more other fats from the group consisting of vegetable oils or fats and animal oils or fats.

In an embodiment of the invention, the second component consists of one or more oils and/or one or more other fats from the group consisting of vegetable oils or fats and animal oils or fats.

In an embodiment of the invention, the second component appears in the solution, suspension or dispersion first made in a concentration of between 0.05% and 10%, preferably between 3% and 4%, of the total mass of the solution, suspension or dispersion made.

In an embodiment of the invention, the first component is added in an amount constituting between 10% and 50%, preferably between 30% and 40%, of the total mass of the mixture made. In an embodiment of the invention, the mixture made is heated to a temperature of between 50°C and 300°C, preferably between 175°C and 210°C.

In an embodiment of the invention, the hot air used to dry the heated mixture has a temperature of between 50°C and 300°C, preferably between 225°C and 275°C.

In a further embodiment of the invention the method comprises the step of adding one or more salts.

It has surprisingly been found that the addition of salt preferably before heating the mixture of the first - and second components may provide a better association between the starch granules and the second component.

In this context, a preferred embodiment is, when the second component comprises one or more hydrocolloids. In an embodiment of the invention the one or more salts are added to the water used to make a solution, a slurry or a dispersion of the second component.

In a further embodiment of the invention the one or more salts are added to the solution, slurry or dispersion of the second component.

In an embodiment of the invention the one or more salts are added to the first component before adding the first component to the solution, slurry or dispersion of the second component. In a further embodiment of the invention the one or more salts are added to the mixture of the first- and the second components before the heating step.

In an embodiment of the invention the salt comprises monovalent and/or divalent cations. In a further embodiment of the invention the salt comprises Na ⁺ , K ⁺ , Ca ²⁺ , Mg ²⁺ and any combinations thereof.

In an embodiment of the invention the concentration of salt is between 0.001 - 3% by weight of the granular starch, 0.005 - 2% or 0.01 - 1% by weight of the granular starch.

In a further embodiment of the invention the salt is selected from the group consisting of chlorides, carbonates, bicarbonates, phosphates, nitrates, sulphates, organic acid salts and any combination thereof.

Examples of organic acid salts are citrates, acetates and propionates.

The figures Figure 1 shows viscosity data (RVA-data)f or guar-gum-coated potato starch according to embodiments of the invention compared to non-coated potato starch and a physical blend of potato starch and guar gum.

Light grey: Guar-gum- coated native potato starch with 5% guar gum in component 2, the viscosity after 10 minutes being about2400 cP.

Dark grey: Guar-gum- coated native potato starch with 10% guar gum in component 2, the viscosity after 10 minutes being about 4100 cP.

Medium grey: Native potato starch, the viscosity after 10 minutes being about 1400 cP.

Black: Physical blend of native potato starch with guar gum, the viscosity after 10 minutes being about 1500 cP.

Figure 2 shows viscosity data for carrageenan-coated potato starch with added calcium-salt according to an embodiment of the invention (dark curve) compared to non-coated potato starch (light curve) Figure 3 shows photos of coated starch particles taken through a microscope, the fairly round coated particles having a size of about 1 mm in diameter.

Detailed description of the invention

It has been shown that by suspending starch in an aqueous solution, a suspension or a dispersion of other food ingredients or additives before this mixture is processed in the spray-cooker, a number of new properties can be achieved for the combination of starch and food ingredient/additive, which cannot be achieved by a simple powder mixture of the two components. The relevant food ingredients/additives will typically belong to the group consisting of starches and/or other hydrocolloids, proteins and fats.

For instance, the mixture for processing in the spray-cooker is obtained by first making a solution of a hydrocolloid and then adding a starch. The making of such a hydrocolloid solution typically requires heavy agitation and in certain instances also the application of heat. The starch is added so that the desired mixture is obtained in the form of a suspension. A second option is to make a hydrocolloid solution and a starch suspension and then mix the two components. In principle, this method leads to the same result, but requires more water and more tanks.

A natural element in connection with heating of starch in an aqueous solution is that a release of amylose takes place while the starch grain is swelling. This is a part of the gelatinisation process. However, in connection with spray-cooking of a granular starch in a hydrocolloid solution, no release of amylose takes place during the gelatinisation, as the heating and drying process takes place so fast that such release does not have time to take place. Instead, a complete or partial coating of the individual gelatinised starch grains with the hydrocolloid is achieved. When this coated starch grain is subsequently used to thicken an aqueous medium, the effect is achieved that the starch grain swells together with the hydrocolloid, but will still be protected by a membrane of this hydrocolloid. This provides several benefits:

Amylose cannot penetrate through the hydrocolloid barrier, and therefore only minimal retrograding of the starch will take place when storing the thickened product.

Delayed swelling of the starch occurs, the hydrocolloid absorbing the water slower and/or delaying the transport of water into the starch grain. This achieves a delay of the viscosity formation. Among other things, this helps prevent lumping, and the starch-hydrocolloid complex will therefore be more and easier usable than a pure starch.

The protective membrane of hydrocolloid around the starch grains protects them against mechanical decomposition into fragments as a consequence of the mechanical impacts to which they are exposed, for example in connection with agitation and pumping. This avoids decrease of the viscosity, as the best bonding of the water is achieved with intact starch grains. Furthermore, the protective membrane provides a certain protection against thermal impact and the impact from low pH.

When the starch grain is protected by a membrane of hydrocolloid, starch- decomposing enzymes, such as amylases, amyloglucosidases or pullulanases, cannot come in communication with the starch and thus cannot decompose it. This means that no new decomposition of the starch begins when it comes into contact with saliva (and thus amylase) in the oral cavity, and that the starch will be completely or partially protected against attacks from human starch-decomposing enzymes throughout the gastrointestinal tract. The starch will thus have been rendered completely or partially resistant and will function as a dietary fibre in the human organism (see e.g. European patent specification no. EP 1 841 332). When, during the spray-cooking process, the starch grain comes in very close contact with the hydrocolloid, a certain interaction takes place between starch molecules on the surface of the starch grain and the hydrocolloid. This results in new functional properties, for example in the form of a different texture and/or a different gel-forming structure which is not seen in the starch alone, in the hydrocolloid alone or in a simple power mixture of starch and hydrocolloid. Correspondingly, the hydrocolloid can be replaced by a mixture of hydrocolloids, a protein or a mixture of proteins or a mixture of hydrocolloid(s) and protein(s).

During the spray-cooking process, a coating of the individual gelatinised starch grain is achieved, and the advantages can be equalled to those achieved by using a single hydrocolloid. However, the protection against decomposition in the human digestive tract will be lesser if only protein(s) are used.

Since certain fats are able to form complex bonds with amylose, a spray-cooking of a starch suspension results in a fat dispersion system or an oil/water emulsion in a coating of the individual gelatinised starch grain with a membrane of oil or fat. The advantages are the same as for protein coating.

In the same manner as mentioned above, different combinations of hydrocolloid, protein and oil/fat or mixtures thereof can be used to achieve coating of the gelatinised starch grains.

It has surprisingly been found by the present inventor that addition of salt to the water used for making a solution, a slurry or a dispersion of the second component may effect an even better binding of the second component to the granular starch of the first component. An increased interaction between the starch granules and the second component may be seen. This may be particularly useful, when the second component comprises

hydrocolloids, for example carrageenans, semi-refined carrageenans, alginates and low-ester pectins.

In this way, the robustness of the protective membrane or full- or partial coating of hydrocolloid around the starch grains may be enhanced and the benefits achieved and described here above may be further improved.

In particular the viscosity of a mixture of the hydrocolloid- coated starch granules in water may rise to a constant level, maintaining this level for prolonged periods when measured, for example, in a Rapid Visco Analyzer (=RVA), indicating stability against mechanical degradation of the coated granules.

The salt is preferably added to the water before adding the second component.

Nevertheless, it is also possible to first add the second component to the water and then adding the salt to the solution, slurry or dispersion of the second component in water.

Furthermore, the salt may also be added to the first component, before adding the first component to the second component.

The salt may also be added to the mixture of the first- and second components before the heating of the mixture. In order to achieve a similar coating of gelatinised starch grains using methods from the prior art, it has previously been necessary to first spray-cook the starch and then coat the starch grains using known coating techniques. For instance, this could take place in a fluid bed, where a solution of hydrocolloid or a second coating component is sprayed on the dry, but gelatinised starch grains simultaneously with the water evaporating. Such known methods consequently require more process steps and more evaporation of water, which in both instances increases costs and is more time- consuming than the method according to the present invention.

Embodiments of the invention are now further explained by way of examples. Examples Example 1

Coated starch granules were prepared in the following manner:

Guar gum in an amount of about 5% w/w based on the potato starch was dissolved in water and the solution was cooled to room temperature. Native potato starch was added to the solution, and the mixture was spray-cooked.

The procedure was repeated for a 10% w/w guar gum solution, again the 10% w/w referring to the amount of starch used.

The amount of native potato starch in both cases was about 35%w/w of the final mixture,

The so obtained guar-gum-coated potato starch granules were subjected to RVA viscosity measurements.

A dry blend of native potato starch and guar gum of similar starch- and guar gum content was prepared for control and subjected to RVA viscosity measurement as well.

RVA- viscosity measurements were done with 4% by weight of dry matter in water according to standard procedures and at 20 °C.

Fig. 1 shows RVA viscosity data for the 5% guar-coated granules (light-grey curve), the 10%) guar-coated granules (dark-grey curve), native potato starch (medium-grey curve) and the dry blend of potato starch with guar gum (black curve).

The benefits resulting from the present coating method are seen in that the coated products according to embodiments of the invention have a low viscosity to begin with which then increases over time to a fairly stable value. In contrast, the starch alone and the physical blend of starch and guar are both behaving very similar in having a very steep rise to initially high viscosity which diminishes over time to values below the viscosity of the coated products.

The viscosity for the coated products depends on the amount of guar gum used in the preparation, the higher amount of guar gum giving the highest viscosity.

The comparatively slow rise in viscosity for the coated products is advantageous because the formation of lumps and agglomerates of granules is diminished.

Example 2

Coated starch granules were prepared in the following manner:

Carrageenan in an amount of about 5%w/w of the starch used is dissolved in water comprising 0.05% (w/w with respect to starch) of calcium chloride.

Native potato starch in an amount of about 30%w/w of the final mixture was added to the carrageenan-calcium chloride solution and the mixture was spray-cooked.

The so obtained carrageenan-coated potato starch granules were subjected to RVA- viscosity measurement.

RV A- viscosity measurements were done with 4% by weight of dry matter in water according to standard procedures and at 20 °C.

Fig. 2 compares the coated product (dark curve) with native potato starch (light curve).

It is clearly seen that the coated starch has a low intrinsic viscosity which rises over time to a fairly constant level, again indicating the good mechanical stability of the coated product. The potato starch behaves as already described in Example 1. Example 3

Coated starch samples were dyed with Toluidine Blue. Polysaccharides (except starches) will form a blue to purple colour.

By microscopy it was seen that the starch particles had fairly uniform polysaccharide coatings confirming the effectiveness of the coating process. Fig. 3 shows photos taken through a microscope. The coated individual starch granules are seen, having a size of about 1 mm in diameter, the particles having fairly round shape.