Methods for sugar regulation

Abstract

The present invention relates to a method for preparing a food product comprising hydrolyzed starch, and to products obtainable by the method. The method has the advantage of increasing the amount of sugar (i.e. maltose) produced by hydrolysis compared to conventional methods of starch hydrolysis, and presents the additional advantage of providing good processability for the food product.

Description

Technical Field

[0001] The present invention relates to a method for preparing a food product comprising hydrolyzed starch. In particular, the present invention relates to a method for preparing a food product comprising hydrolyzed starch having a higher amount of maltose than conventional hydrolysis methods. The method of the present invention also presents the beneficial effect of providing good processability for the food product. Background Art

[0002] There is increasing concern about the impact of sugar content, in particular sucrose content, in food products, so lower levels of this sugar are generally desired. Sugar content is a particularly important concern in the production of food products for infants and / or children, and in some countries, the addition of sucrose is completely banned for regulatory reasons.

[0003] The absence of crystallized sucrose has a significant impact on the processability of [drum-dried cereals] as it results in lower film thermoplasticity and therefore affects drum drying output. Compensating for the loss of thermoplasticity is challenging, and one possible solution is to increase the maltose produced by flour hydrolysis to maintain similar drum drying performance.

[0004] In current manufacturing methods for preparing starch-containing food products, amylolytic enzymes are used to decompose starch and reduce product viscosity. High viscosity products are difficult to handle in production lines, so starch is treated with enzymes that result in lower viscosity. Starch degradation also results in the production of disaccharides, specifically maltose, etc.

[0005] To maximize maltose production, an off-line hydrolysis process can be implemented, but the cost of such a production line is high.

[0006] Therefore, new methods for hydrolyzing starch to produce larger amounts of maltose compared to conventional methods would be advantageous. Summary of the invention

[0007] Therefore, the object of the present invention is to provide a method for solving the above-mentioned problems of the prior art related to the level of sugars in foods containing hydrolyzed starch. More specifically, the object of the present invention is to provide a method for providing a food product containing hydrolyzed starch with a higher amount of maltose compared to conventional hydrolysis methods.

[0008] Another object of the present invention is to provide a method for preparing a food product comprising hydrolyzed starch having a higher amount of maltose compared to conventional hydrolysis methods and still resulting in good processability of the food product during its preparation.

[0009] Therefore, one aspect of the present invention relates to a method for preparing a food product comprising hydrolyzed starch, the method comprising the following steps:

[0010] a) providing a feedstock comprising both starch and at least one amylolytic enzyme,

[0011] b) providing the following ingredients: water, optionally at least one additional amylolytic enzyme and optionally one or more other ingredients,

[0012] c) mixing the raw materials of step a) and the ingredients of step b),

[0013] d) adjusting the temperature of the mixture of step c) to a temperature comprised between 55° C. and 75° C.,

[0014] as well as

[0015] e) simultaneously with step d), subjecting said mixture of step c) to high shear mixing,

[0016] f) incubating the mixture of step e) such that the desired degree of hydrolysis is achieved, thereby obtaining a food product comprising hydrolyzed starch.

[0017] A further aspect of the invention relates to a food product obtainable or obtained by the method of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a simplified process diagram of an in-line hydrolysis plant, showing an apparatus according to the process of the invention (ring layer mixer, hence the abbreviation RLM) or a conventional apparatus (e.g. a pipeline plant including a hydrolysis tank (ZL), equipped with a direct steam injector, hence the abbreviation DSI).

[0019] The present invention will now be described in more detail hereinafter. DETAILED DESCRIPTION

[0020] definition

[0021] Before discussing the present invention in further detail, the following terms and conventions are first defined.

[0022] The term "Celsius" or °C means degrees Celsius.

[0023] The numerical ranges used herein are intended to include each value and subset of values ​​contained in the range, whether specifically disclosed or not. In addition, these numerical ranges should be understood to provide support for claims involving any value or subset of values ​​within the range. For example, the disclosure of 1 to 10 should be understood to support ranges of 1 to 10 (including 1 and 10), 2 to 8, 3 to 7, 1 to 9, 3.6 to 4.6, 3.5 to 9.9, etc. All singular features or limitations mentioned in the present invention should include corresponding plural features or limitations, and vice versa, unless otherwise indicated or clearly implied to the contrary in the context of the reference to these contents.

[0024] In the context of the present invention, the expression "at a temperature in the range of X to Y" is intended to mean that any temperature between temperatures X and Y is included, such temperatures X and Y being also included in the range unless otherwise specified.

[0025] The term "and / or" used in the context of "X and / or Y" should be interpreted as "X" or "Y", or "X and Y".

[0026] Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art.

[0027] The term "starch" as used herein refers to a polysaccharide macromolecule used by most plants for energy storage. It consists of a large number of glucose units connected by glycosidic bonds. The two high molecular weight components of starch are amylose and amylopectin. Starch is found, for example, in cereals, tubers and beans. Examples of tubers include potatoes, sweet potatoes, cassava, yams, etc. Examples of beans include beans (such as pinto beans, red beans, navy beans), peas, lentils, chickpeas, peanuts, etc. When the term "starch" is used in the context of the present invention, it can refer to starch from one plant source or a mixture of starches from different plant sources.

[0028] The term "cereal" as used herein refers to any grass cultivated for the edible portion of its kernel. Examples of cereals are wheat, rice, corn, barley, rye, oats, buckwheat, millet, quinoa, sorghum, and the like.

[0029] The term "food product" as used herein refers to a finished product suitable for human consumption and / or an intermediate preparation intended to deliver a finished product after undergoing additional processing steps including heat treatment. Specific non-limiting examples of finished food products are biscuits, crackers, cereals (breakfast and baby cereals), breads, baked products, pizzas, cereal milk drinks, toddler foods, etc. Specific non-limiting examples of preparations intended to deliver a finished product after undergoing additional processing steps are batters, doughs, slurries, etc.

[0030] In the context of the present invention, "infant cereal" products identify two main categories: complete cereal products that require reconstitution with water because they already contain all the essential nutrients delivered by the meal; and standard cereal products intended for reconstitution with milk, infant formula, follow-on formula and / or GUM.

[0031] In the context of the present invention, the term "whole family cereal" identifies a composition comprising cereals suitable for consumption by children and adults. For example, whole family cereals are reconstituted with (whole fat or skimmed) milk and consumed in the form of porridge.

[0032] The term "gelatinization" as used herein refers to the process of swelling and opening of starch granules, wherein the intermolecular bonds of the starch molecules in the starch granules are broken, resulting in the binding of water and the irreversible dissolution of the starch granules in water. The determination of the gelatinization temperature is well known to those skilled in the art and can be performed, for example, by Kofler hot stage microscopy (see further Table 1 and notes) or, for example, differential scanning calorimetry (DSC).

[0033] Gelatinization temperature refers to the temperature (or temperature range) at which starch gelatinizes. Different species of plants produce starches that may have different gelatinization temperatures, and these are well known in the art. The gelatinization temperature ranges of some starches are shown in Table 1 below by way of example.

[0034] Table 1: Typical gelatinization temperatures for some starches

[0035] Starch type Gelatinization temperature range (℃)* wheat 58-61-64 Rice 68-74-78 Corn (maize) 62-67-72 potato 58-63-68 Cassava 59-64-69 Glutinous corn 63-68-72 Sorghum 68-74-78

[0036] * Determined by Kofler hot stage microscopy (start-midpoint-end) (“Starch: Chemistry and Technology”, edited by James BeMiller and Roy Whistler, Food Science and Technology International Series, Third edition 2009).

[0037] The term "amylolytic enzyme" as used herein refers to any enzyme that can convert starch into dextrins and sugars (monosaccharides or disaccharides). Examples of amylolytic enzymes include amylases and pullulanases. Examples of amylases include α-amylases, β-amylases, γ-amylases.

[0038] Method of the present invention

[0039] In conventional methods for preparing starch-containing foods, the viscosity of starch presents a problem. In order to avoid viscosity accumulation, enzymatic hydrolysis of starch is usually performed, which can lead to the production of maltose, etc. The present invention is based on the following surprising discovery: compared to conventional hydrolysis methods, the implementation of the method of the present invention produces a food product containing hydrolyzed starch with a higher amount of maltose.

[0040] It is believed that maltose production is the result of two types of enzymes working in concert: (1) endogenous β-amylase in wheat flour; directly forming maltose; (2) added BAN (α-amylase); forming lower amounts of dextrin (to allow the β-amylase to work) and maltose. Without being bound by theory, it is believed that each temperature results in a different combination of enzyme activity levels (because enzymes are temperature sensitive), thereby determining a different balance between the above-mentioned activities (1) and (2), and therefore determining a different degree of maltose production.

[0041] In the studies conducted by the inventors, it was surprisingly found that the production of maltose was confirmed to depend on the mixing conditions implemented for step e). Specifically, this results in that maltose formation can be further increased at a temperature in the range of 55°C to 75°C under high shear mixing conditions. Without being bound by theory, it is believed that under high shear conditions, mixing is more effective and the associated temperature distribution within the equipment is more uniform (narrower temperature profile distribution). Therefore, the lower maltose content obtained with a high shear mixer (specifically with annular layer mixer) at a temperature in the range of 55°C to 75°C can be explained by the narrower temperature distribution within the equipment and the resulting higher slurry fraction exposed to a temperature of 65°C, where maltose seems to be preferentially formed (as shown in the results of Example 4).

[0042] In particular, the inventors have surprisingly found that higher amounts of maltose are formed using the process of the present invention operating at a temperature in the range of 55°C to 75°C under high shear mixing.

[0043] The inventors have also surprisingly found that, using the method of the present invention, good processability can be obtained for the slurry subjected to a drum drying process. As shown in Example 6 of the present invention, the sump behavior obtained according to the method of the present invention is surprisingly bubbling.

[0044] The "bubbling" sump in a twin cylinder drum dryer is a key process condition for good film formation in subsequent drum drying. Bubbling in the sump allows mixing of the slurry in the sump and prevents surface drying. If the sump is not bubbled, it is usually necessary to increase the water content in the slurry to avoid surface drying and roller drying and the resulting reduction in total solids. A reduction in total solids is undesirable because it results in a reduction in output.

[0045] Thus in one embodiment, the method of the present invention relates to a method for preparing a food product comprising hydrolyzed starch, the method comprising the following steps:

[0046] a) providing a feedstock comprising both starch and at least one amylolytic enzyme,

[0047] b) providing the following ingredients: water, optionally at least one additional amylolytic enzyme and optionally one or more other ingredients,

[0048] c) mixing the raw materials of step a) and the ingredients of step b),

[0049] d) adjusting the temperature of the mixture of step c) to a temperature in the range of 55°C to 75°C, and

[0050] e) simultaneously with step d), subjecting said mixture of step c) to high shear mixing,

[0051] f) incubating the mixture of step e) such that the desired degree of hydrolysis is achieved, thereby obtaining a food product comprising hydrolyzed starch.

[0052] In one aspect, the process of the invention provides a food product comprising hydrolyzed starch, which food product comprises a higher amount of maltose than a food product obtainable via conventional processes not comprising high shear mixing in step e).

[0053] raw material

[0054] The methods of the present invention involve providing a feedstock comprising both starch and at least one amylolytic enzyme.

[0055] Some embodiments relate to methods according to the invention, wherein the starting material is a plant preparation, such as a preparation of a portion of a plant comprising a majority of the plant's starch storage granules. In some embodiments, such preparations may also include other parts of the plant, such as stems, leaves, etc. Such plant preparations typically also comprise at least one amylolytic enzyme.

[0056] In a particular embodiment, the raw material is a dried plant preparation, such as a flour. Thus, the raw material can be selected from flours of one or more cereal grains, such as flours selected from wheat flour, rice flour, corn flour, barley flour, rye flour, oat flour, buckwheat flour, millet flour, quinoa flour, sorghum flour; flours made from one or more tubers such as potato, cassava; flours made from legumes, such as pea flour; or combinations thereof.

[0057] In one embodiment, the raw material comprises at least a portion of wheat flour.

[0058] The term "dry" as used herein refers to containing water in the range of 0.01% w / w to 20% w / w, such as 0.01% w / w to 16% w / w, 0.01% w / w to 15% w / w, 0.01% w / w to 12% w / w, 0.01% w / w to 8% w / w, 0.01% w / w to 5% w / w, 0.01% w / w to 3% w / w, such as 0.01% w / w to 0.5% w / w%, or for example substantially free of water. For example, wheat flour may contain up to 15% moisture (w / w), such as 12% w / w to 15% w / w, 12% w / w to 14% w / w or 12% w / w to 13% w / w, and is considered a dry plant preparation.

[0059] The term "flour" as used herein refers to a ground product. The particle size or particle size distribution of the flour is not considered to be critical to the method. Plant preparations in the form of flours suitable as raw materials for preparing hydrolyzed starch are known in the art, and the selection of such preparations is also within the skill of those skilled in the art.

[0060] Endogenous amylolytic enzymes

[0061] The raw material of the method of the present invention includes both starch and at least one amylolytic enzyme. At least one amylolytic enzyme present in the raw material may be an endogenous amylolytic enzyme. In other words, the raw material may contain an amylolytic enzyme that is not added by human intervention, but is extracted together with the starch (granules) from the plant material, i.e., an endogenous amylolytic enzyme. Examples of endogenous amylolytic enzymes include alpha-amylases, beta-amylases, and gamma-amylases. In one embodiment, the endogenous amylolytic enzyme is a beta-amylase.

[0062] In one embodiment, the invention relates to a process according to the invention, wherein in step d) the temperature of the mixture of step c) is adjusted to a temperature in the range of 55° C. to 75° C. Such temperature adjustment is simultaneously subjecting the mixture of step c) to high shear mixing as described in step e).

[0063] Provide water

[0064] The method of the present invention comprises providing water and mixing with the raw material. The enzymatic hydrolysis of starch requires the presence of water. If the raw material is provided in a dry form, such as, for example, a dried plant preparation, such as, for example, a plant meal, the water can be provided by one or more of steam injection, adding water, providing an additional component containing water, providing an aqueous solution of at least one additional amylolytic enzyme, or a combination thereof.

[0065] If the feedstock is not in dry form, but contains more than 20% w / w water, or, for example, more than 15% w / w water, the water may be considered to be provided at least in part by the feedstock. In some embodiments, more water may also be provided, for example, by one or more of steam sparging, adding water, providing an additional ingredient containing water, providing an aqueous solution of at least one additional amylolytic enzyme, or a combination thereof.

[0066] In certain embodiments, providing water comprises providing water in the form of steam. In certain embodiments, the water in steam form is provided by means of steam injection such as direct steam injection. In other embodiments, the water in steam form is provided by means of steam injection (wherein the ingredients are sprayed in a steam atmosphere). The advantage of direct steam injection is that the mixture of the raw material, the optional water provided from the above-mentioned other sources, the at least one additional amylolytic enzyme and any optional additional ingredients is quickly heated while adding water.

[0067] Direct steam injection may be achieved by any suitable means, and the selection of such means is within the skill of one of ordinary skill in the art.

[0068] In one embodiment, when the water is provided at least partly in the form of steam, this provision of steam may occur simultaneously with steps d) and e).

[0069] Some embodiments relate to a method according to the invention, wherein the total solids content of the mixture (step c) is in the range of 20% w / w to 60% w / w, such as 30% w / w to 60% w / w, such as 35% w / w to 60% w / w, such as such as 40% w / w to 60% w / w, such as 45% w / w to 60% w / w, such as 50% w / w to 60% w / w, such as 55% w / w to 60% w / w; or for example 20% w / w to 55% w / w, 20% w / w to 50% w / w, 20% w / w to 40% w / w; or for example 30% w / w to 50% w / w, or 30% w / w to 40% w / w.

[0070] Additional amylolytic enzymes

[0071] The method of the present invention comprises a step in which optionally at least one further amylolytic enzyme is added to the raw material and mixed together with the raw material. Thus, in step b) also an amylolytic enzyme other than the amylolytic enzyme provided in step a) may be provided and in step c) all ingredients are mixed.

[0072] In some embodiments, at least one additional amylolytic enzyme is provided in addition to the endogenous amylolytic enzyme provided in step a).

[0073] The at least one additional amylolytic enzyme may be any suitable amylolytic enzyme, e.g., an amylase (such as an alpha-amylase and / or a beta-amylase) and / or a pullulanase. In a particular embodiment, the at least one additional amylolytic enzyme is one or more of an alpha-amylase and a beta-amylase. In a particular embodiment, the at least one additional amylolytic enzyme is an alpha-amylase. In some embodiments, the present invention relates to a method according to the present invention, wherein the at least one additional amylolytic enzyme comprises or consists of an amylase, e.g., an alpha-amylase, that is not endogenous to the provided feedstock.

[0074] As mentioned above, the at least one additional amylolytic enzyme may be provided as an aqueous solution.

[0075] Amylolytic enzymes are commercially available from several distributors, such as DuPont, Novozymes, DSM, BioCatalysts.

[0076] Additional Ingredients

[0077] In some embodiments of the present invention, one or more other ingredients are included. One or more additional ingredients can be any ingredients suitable for food. In a specific embodiment, the one or more other ingredients added in step b) are not affected by the temperature and high shear mixing of steps d) and e). The example of one or more other ingredients can be fat such as oil, protein or amino acid source, carbohydrate source such as sugar and / or prebiotics, minerals, vitamins, etc.

[0078] In some embodiments of the method, the food product obtained by the method of the present invention is itself a finished food product. In such embodiments, at least one other ingredient is provided in step b), such as one or more ingredients, such as, for example, fats such as oils, protein or amino acid sources, carbohydrate sources such as natural or refined sugars and / or prebiotics, minerals, fruit ingredients, milk-based ingredients and vitamins. In one embodiment, fats such as oils are provided in step b).

[0079] Mixing and premixing

[0080] The method of the present invention comprises the step of mixing the raw materials of step a) and the ingredients of step b).

[0081] It is believed that such mixing is critical and therefore can be accomplished in any suitable manner. The choice of mixing method is within the skill of one skilled in the art.

[0082] In some embodiments of the method according to the invention, step c) of mixing the raw materials of step a) and the ingredients of step b) is carried out before step d). This means that the raw materials and ingredients are mixed before the temperature adjustment carried out in step d). This is called "premixing".

[0083] However, it is not necessary to premix the ingredients: the dry ingredients and water can be fed directly into a high shear mixer such as a ring layer mixer.

[0084] In other specific embodiments, the mixing step c) is carried out simultaneously with step d). For example, the raw materials of step a) and the ingredients of step b) can be fed into a container, heated therein and mixed simultaneously. In one embodiment, steps c), d) and e) are carried out simultaneously in a ring layer mixer.

[0085] In step d) the temperature is adjusted

[0086] The method of the present invention comprises step d) wherein the temperature of the mixture obtained in step c) is adjusted to a temperature in the range of 55 to 75° C., such as 60 to 70° C. The temperature is adjusted while high shear mixing the mixture.

[0087] In some embodiments, the degree of gelatinization of the starch is above 40% w / w, such as above 50% w / w, such as above 55% w / w.

[0088] In a particular embodiment, step d) (adjusting the temperature of the mixture of step c) to a temperature in the range of 55°C to 75°C, such as 60°C to 70°C) is performed by direct steam injection.

[0089] High shear mixing

[0090] The process of the present invention comprises the step of subjecting the mixture of step c) to high shear mixing, for example by using a high shear mixer.

[0091] High shear mixing may be for a period of 0.5 seconds to 10 minutes, such as 1 second to 10 minutes, such as 1 second to 5 minutes, such as 1 second to 3 minutes, such as 1 second to 120 seconds, such as 1 second to 90 seconds, such as 1 second to 60 seconds.

[0092] High shear mixing may homogenize the mixture over a period of 1 second to 10 minutes, such as 1 second to 5 minutes, such as 1 second to 3 minutes, such as 1 second to 120 seconds, such as 1 second to 90 seconds, such as 1 second to 60 seconds.

[0093] In certain embodiments, the high shear mixing homogenizes the mixture over a period of time from 1 second to 50 seconds, such as from 1 second to 40 seconds, such as from 1 second to 30 seconds.

[0094] In this context, homogenization means that the starch particles are swollen and dispersed, preferably uniformly, in the medium.

[0095] The high shear mixing is performed simultaneously with the temperature adjustment as described above. As discussed, it is believed that the simultaneous temperature adjustment and high shear mixing work together to hydrolyze the starch while maximizing the production of maltose.

[0096] Shear forces are misaligned forces that push one part of a body in one direction and another part of the body in the opposite direction.

[0097] In some embodiments, the present invention relates to the method of the present invention, wherein the high shear mixing in step e) can be achieved by using a high shear mixer. The high shear mixer disperses the ingredients or ingredient mixture into a main continuous phase, such as a solid, semi-liquid or liquid phase. Typically, a mobile rotor or impeller is used together with a fixed component called a stator to produce high shear. Therefore, a high shear mixer can be defined as a mixer comprising a rotor and at least one stator. Examples of high shear mixers are well known in the art and include, for example, annular layer mixers.

[0098] Non-limiting examples of high shear mixers according to the present invention are: annular layer mixers, homogenizers, paddle mixers, pin mixers, granulators, pelletizers and high shear pumps.

[0099] In one embodiment of the present invention the high shear mixing in step e) is not an extruder.In one embodiment the high shear mixer according to the present invention is not an extruder.

[0100] The term "high shear mixing" as used herein may be defined as mixing where such shear may be achieved by using a ring layer mixer, for example, under the conditions described in the Examples.

[0101] Ring layer mixer

[0102] Any device capable of achieving high shear mixing and allowing simultaneous regulation of temperature may be used.

[0103] A particular embodiment of the present invention relates to the process according to the present invention, wherein the high shear mixing step e) is achieved by using a high shear mixer, in particular a ring layer mixer.

[0104] Annular layer mixers deliver high peripheral speeds. The resulting centrifugal force drives the product outward into an annular layer on the side wall of the container. The high speed difference between the rotating agitator and the mixing bowl combined with the use of different mixing elements ensures high shear mixing.

[0105] When using annular layer mixers, direct steam injection is simple to implement, which is a further advantage of using annular layer mixers. This is due to the fact that the injection can be performed at atmospheric pressure.

[0106] Some embodiments relate to the process according to the invention, wherein steps c) to e) are carried out in a ring-layer mixer. Other embodiments relate to at least a portion of steps c) up to and including step f) being carried out in a ring-layer mixer.

[0107] Particular embodiments relate to the process of the invention, wherein steps a) to e) are carried out in a ring-layer mixer. As described below, other embodiments relate to the process of the invention, wherein steps a) to c) are carried out prior to using a ring-layer mixer (i.e., a premixing step) and steps d) to e) are carried out in a ring-layer mixer.

[0108] Other specific embodiments relate to the process of the invention, wherein direct steam injection is used to adjust the temperature in step d) and an annular layer mixer is used for high shear mixing in step e).

[0109] In one embodiment of the present invention, the speed of the annular layer mixer may be in the range of 500 rpm to 2500 rpm.

[0110] Incubation

[0111] The process according to the invention comprises a step f) of incubating the mixture obtained by high shear mixing in step e) such that the desired degree of hydrolysis is achieved.

[0112] The incubation step involves the step of keeping the mixture of step e) at a certain temperature for a certain period of time. The incubation allows the enzyme to work to hydrolyze the starch. In some embodiments, mixing may occur during the incubation period. Mixing avoids precipitation, and / or is conducive to uniform and stable temperature characteristics. In a specific embodiment, the mixing in step f) is not high shear mixing.

[0113] In some embodiments, the incubation in step f) is carried out at a temperature in the range of 55°C to 75°C, for example between 60°C and 70°C; for a time period ranging from 1 minute to 24 hours, such as 1 minute to 12 hours, such as 1 minute to 10 hours, such as 1 minute to 8 hours, such as 1 minute to 7 hours, such as 1 minute to 6 hours, such as 1 minute to 5 hours, such as 1 minute to 4.5 hours, such as 1 minute to 4 hours, such as 1 minute to 3.5 hours, such as 1 minute to 3 hours, such as 1 minute to 2.5 hours, such as 1 minute to 120 minutes, such as 2 minutes to 80 minutes, such as 10 minutes to 80 minutes, 10 minutes to 60 minutes; or for example 1 minute to 10 minutes, 1 minute to 8 minutes, or 1 minute to 5 minutes, or for example 2 minutes to 10 minutes.

[0114] Additional Steps

[0115] A further embodiment relates to the method according to the invention further comprising the step g) subjecting the mixture obtained by high shear mixing according to steps a) to f) to an additional heat treatment.

[0116] The purpose of the heat treatment in step g) is to reduce the microbial load of the product, and to inactivate enzymes, including inactivating at least one additional amylolytic enzyme of step b). Therefore, the temperature and time period of the heat treatment of step g) will be selected to meet these two requirements and can be carried out in any suitable manner. The selection method and the appropriate temperature and time are considered to be within the skill range of those with knowledge in the art. The heat treatment of step g) can be carried out, for example, by bringing the temperature of the homogenized mixture to a temperature in the range of 90 degrees Celsius to 170 degrees Celsius for a period of 2 seconds to 5 minutes.

[0117] In a particular embodiment, the temperature in step g) is brought to a temperature in the range of 100 degrees Celsius to 140 degrees Celsius for a period of time of 4 seconds to 60 seconds.

[0118] In some specific embodiments, the heat treatment of step g) is performed by direct steam injection.

[0119] The heat treatment of step g) may be performed after step e), such as directly after step e).

[0120] Method of the present invention may also include one or more additional steps, wherein one or more additional ingredients are added to the mixture. These ingredients may be any ingredients suitable for manufactured food products. In particular, it is desirable to be included in the final food product but the ingredients that may be subject to the negative impact of heating and / or high shear mixing of, for example, step c) and d) may be advantageously added at the time point after these steps. The example of the ingredients that may be subject to negative impacts includes heat-sensitive nutrients, such as heat-sensitive vitamins and / or probiotics. For example, one or more additional ingredients may be added immediately after step e), such as after step e) and before step f), or such as after step e), or such as after step e) and before step f). In some embodiments, one or more additional ingredients may be added immediately after step f), such as after step f) and before any additional step. Those skilled in the art will appreciate the requirement of conventional ingredients (comprising heat-sensitive nutrients), and can determine at what time point these ingredients may be added.

[0121] In some embodiments, the method of the invention further comprises a step i) of cooling the mixture obtained by the previous step. Cooling can be achieved by any suitable means and can for example reach a temperature in the range of -20°C to 18°C, such as for example 0°C to 10°C, such as 0°C to 5°C.

[0122] In some embodiments, the methods of the invention further comprise the steps of drying, such as drum drying and grinding, to produce a dry product that can be reconstituted prior to use.

[0123] In one embodiment, wherein the optional ingredients are added in step b), the process comprises a drying step j). Drying is defined as the application of heat under controlled conditions to remove the water present in the liquid or semi-liquid food and obtain a solid product.

[0124] In one embodiment, this step j) is a drum drying step.

[0125] The principle of the drum drying process (or rotary drum drying) is to apply a thin film of material to the smooth surface of a continuously rotating steam-heated metal drum. The film of drying material is continuously scraped off by fixed knives located opposite the point of application of the liquid or semi-liquid material. The dryer consists of a single drum or a pair of drums with or without satellite drums.

[0126] Drum drying is a conventional drying technique in the art. Those skilled in the art will be able to select appropriate drum drying temperature and speed to prepare food products according to the method of the present invention.

[0127] In such embodiments, the obtained product may be a finished baby food or whole family cereal product that is consumed in the form of porridge after reconstitution as described above.

[0128] Products obtainable by the method

[0129] In a second aspect the present invention relates to a food product obtainable by a method according to the present invention. In one embodiment of this aspect the present invention relates to a product obtainable by a method according to the present invention.

[0130] The food product according to the present invention can be described as comprising hydrolyzed starch and an increased amount of maltose. In this context, the term "increased amount of maltose" refers to an increased amount of maltose compared to the amount of maltose produced by a conventional starch hydrolysis process (such as the process described in Example 1). In particular, the amount of maltose is increased compared to a starch hydrolysis process that does not include steps d) and e) of the process of the present invention.

[0131] In a particular embodiment the invention relates to a product according to the invention wherein the amount of maltose present is increased by up to 100%, such as 90%, such as 80%, such as 70% compared to a conventional process such as shown in Example 5 (76%).

[0132] In other embodiments, the invention relates to a product according to the invention comprising maltose in an amount of 1% to 19%, such as 1% to 15%, or 15% to 19%, or for example 5% to 10%, of the amount of maltose present in a corresponding product produced by a conventional process. In a further embodiment, the invention relates to a product comprising more than 9% w / w, such as 9% w / w to 12% w / w, 9% w / w to 19% w / w, or 16% w / w to 30% w / w maltose.

[0133] The product of the invention may be a liquid product, comprising hydrolysed starch, or the liquid may be dry.The product may be an ingredient or a complete food.

[0134] In some embodiments of the method, the obtained food product is an intermediate. This means that the obtained food product is an ingredient itself and will therefore be further processed, for example by combining with further ingredients to achieve a final food product.

[0135] Finished food products refer to food products that are sold to consumers. Examples of final food products include infant formula (e.g., in powdered form or ready-to-drink), cereals, beverages, etc.

[0136] It should be noted that embodiments and features described in the context of one aspect of the invention are also applicable to the other aspects of the invention.

[0137] All patent and non-patent references cited in this application are hereby incorporated by reference in their entirety.

[0138] The present invention will now be described in further detail in the following non-limiting examples.

[0139] Example

[0140] Comparative Example 1: Conventional online hydrolysis device

[0141] In this example of a conventional in-line hydrolysis process (wherein the hydrolysis is carried out in the production line of the finished food product), wheat flour, water and optional other ingredients (e.g., sucrose, oil, etc.) are mixed in a preparation tank. The slurry is then pumped into a pipe. An alpha-amylase solution is injected online; steam is then injected to reach the optimal temperature for enzyme activity (e.g., 65° C.). Amylase can also be added to the initial liquid batch preparation tank. The slurry is then further treated at this optimal temperature for a certain residence time (corresponding to the incubation of step f) before a final heat treatment (e.g., above 120° C. for 20 seconds) for hygienic reasons and enzyme inactivation, depending on the degree of hydrolysis required (e.g., 2 minutes to 10 minutes). The slurry (containing about 45% w / w solids) is then subjected to a drum drying process (heat treatment step, corresponding to step j) according to the method of the present invention to provide a finished food product that can then be ground and packaged for commercial use.

[0142] The drum drying process is carried out in a twin-cylinder drum dryer at a temperature comprised between 150° C. and 190° C., such as between 185° C. and 190° C., and at a speed comprised between 0.5 rpm and 5 rpm, such as between 1 rpm and 2 rpm.

[0143] Example 2: On-line hydrolysis method of the present invention

[0144] The process of the present invention may also be incorporated as an in-line hydrolysis process in a process for preparing a finished food product.

[0145] In one example of the method according to the invention, the conventional steps of "enzyme dosing - steam injection - incubation" as described above in Example 1 are replaced by a ring layer mixer.

[0146] An RLM with a capacity of 10 liters is used, wherein the speed is set between 400 rpm and 3000 rpm (e.g., between 1500 rpm and 2000 rpm). The RLM has different inlets, wherein the first inlet is used to introduce the mixture of ingredients and the second inlet is used to introduce the enzyme solution. Steam is injected via the third inlet. Steam is used to bring the temperature of the powder and enzyme mixture in the tank to a temperature of 65° C., which is measured by a probe. Thus, the ingredient mixture is heated and homogenized. The resulting treated mixture is output from the annular layer mixer to a holding tube. The treated mixture is incubated at 65° C. for a period of more than 1 minute to allow the enzyme to further hydrolyze.

[0147] The key feature of the high shear mixer is to allow the steam and amylase to mix.

[0148] Figure 1 is a simplified process diagram of an in-line hydrolysis unit showing equipment according to the process of the invention (Ring Layer Mixer - RLM) or conventional equipment (eg, Static Mixer - ZL).

[0149] Comparative Example 3: Conventional online hydrolysis device at alternative temperature

[0150] In order to compare the samples with those obtained according to the method of the invention, drum dried cereal samples were prepared as described in Example 1, but operated at a temperature of either 40°C or 80°C.

[0151] Comparative Example 4: In-line hydrolysis apparatus with annular layer mixer at alternative temperature

[0152] In order to compare the samples with those obtained according to the method of the invention, drum dried cereal samples were prepared as described in Example 2, but operated at a temperature of either 40°C or 80°C.

[0153] Example 5: Comparison of maltose content

[0154] The reduction of maltose was measured in different apparatuses with a ring layer mixer [the apparatus described in Comparative Examples 1 or 3] and without a ring layer mixer [the apparatus described in Example 2].

[0155] Sugar distribution was analyzed in drum-dried prototypes (obtained in a manner similar to that described in the examples above and reported in Table 1) (HPAEC method)

[0156] Table 1: Maltose values

[0157]

[0158] Table 1 shows that the amount of maltose produced in the apparatus using a high shear mixer (ring-layer mixer) and a temperature of 65°C was significantly increased compared to the conventional (and ring-layer mixer) apparatus at all temperatures.

[0159] Example 6: Comparison of Tank Behavior

[0160] The sump behavior of the slurries obtained as described above for Examples 1 to 4 before drum drying in a twin-cylinder apparatus was studied. The results obtained are given in the following Table 2:

[0161] Table 2

[0162]

[0163] As mentioned above, obtaining a "bubbling" sump in a twin cylinder drum dryer is a key process condition for good film formation. Bubbling in the sump allows mixing of the slurry in the sump and prevents surface drying. If the sump is not bubbled, it is usually necessary to reduce TS to avoid surface drying and roller drying problems. A reduction in TS is not desirable because it results in reduced output.

[0164] From the results reported in Table 2, it follows that the hydrolysis temperature affects the tank "bubbling degree". At 80°C, the central tank no longer bubbles and the total solids must be reduced by 2% to be able to form a suitable film under the operating conditions studied. A 3% reduction in TS leads to an 11% reduction in output. At 65°C and lower temperatures, the tanks exhibit bubbles, allowing the total solids (TS) to be maintained at 50% with a suitable film formation and a subsequent advantage in output.

[0165] As shown by the results reported in Examples 5 and 6, the process of the present invention not only allows the preparation of food products comprising hydrolyzed starch with increased maltose content, but also achieves good processability of the slurry, which translates into an output comparable to conventional hydrolysis conditions.

Claims

1. A method for preparing a food product comprising hydrolyzed starch, the method comprising the following steps: a) providing a raw material containing both starch and at least one amylolytic enzyme, b) providing the following ingredients: water, optionally at least one additional amylolytic enzyme and optionally one or more other ingredients, c) mixing the raw materials of step a) and the ingredients of step b), d) adjusting the temperature of the mixture of step c) to a temperature in the range of 60°C to 70°C, and e) simultaneously with step d), subjecting the mixture of step c) to high shear mixing using a ring layer mixer, f) incubating the mixture of step e) such that the desired degree of hydrolysis is achieved, Thereby a food product comprising hydrolyzed starch is obtained, wherein said food product comprises an increased content of maltose compared to those food products obtainable in a corresponding process wherein step e) is not carried out under high shear mixing using a ring layer mixer.

2. The process according to claim 1, wherein step d) is performed by direct steam injection.

3. The method according to claim 1 or 2, wherein the high shear mixing in step e) causes the mixture to be homogenized within a time period of 1 second to 50 seconds.

4. The method according to claim 1 or 2, wherein the starting material is a plant preparation.

5. The method according to claim 4, wherein the raw material is selected from flour of one or more cereal grains; Flours made from one or more tubers; flours made from pulses; or combinations thereof.

6. The method according to claim 5, wherein the flour of the one or more cereal grains is a flour selected from the group consisting of wheat flour, rice flour, corn flour, barley flour, rye flour, oat flour, buckwheat flour, millet flour, quinoa flour, sorghum flour.

7. The method according to claim 5, wherein the tuber is selected from potato, cassava.

8. The method of claim 5, wherein the flour made from legumes is pea flour.

9. The method of claim 5, wherein the raw material comprises wheat flour.

10. The method of any one of claims 1, 2, and 5-8, wherein the at least one additional amylolytic enzyme provided in step b) comprises an amylase that is not endogenous to the provided feedstock. The method of claim 10 , wherein the amylase is an α-amylase.

12. The method according to any one of claims 1, 2, 5-8 and 11, wherein the total solid content of the mixture of step c) is in the range of 20% w / w to 60% w / w.

13. The method according to any one of claims 1, 2, 5-8 and 11, further comprising the steps of: g) additional heat treatment of the mixture obtained according to steps a) to f) by high shear mixing using a ring layer mixer, The additional heat treatment of step g) is carried out after step f).

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