METHOD FOR THE MANUFACTURE OF A MILK SUBSTITUTE PRODUCT

Description

[0001] The invention relates to a method for producing a milk substitute product, in particular oat milk.

[0002] Due to the increasing vegan lifestyle, there is a need for fresh and environmentally friendly alternatives to non-vegan products. Besides meat alternatives, this also includes dairy alternatives, which generally contain a plant-based main ingredient that acts as a flavor and nutrient provider in a water suspension. In oat milk, for example, oats serve as the flavor and nutrient provider. To preserve the slightly sweet taste of milk, the starch in the oats must be broken down into sugar, a process that involves several steps.Typically, oat milk is produced in industrial plants in several stations, each dedicated to a specific process step. While this allows for the production of large quantities of oat milk, it is disadvantageous because it involves manufacturing for stock, delivering the finished milk alternative to consumers in packaging, and also results in relatively high energy consumption. Therefore, in the interest of freshness, there is a need to establish decentralized, local production with minimal effort and to reduce delivery volume by supplying only the proportionally small proportion of raw ingredients in milk alternatives to the consumer.

[0003] DE 20 2012 103 875 U1 discloses a device for producing an oat beverage. The device comprises a heatable first container and a second container, with a buffer vessel arranged between the first and second containers. This buffer vessel serves to cool the heated oat suspension from the first container. The finished oat beverage is then dispensed via a bottom outlet valve located on the second container. A disadvantage of the device is its use of multiple containers arranged in a cascade configuration. This results in a correspondingly large footprint and makes the device very complex in design, leading to high maintenance and operating costs.

[0004] CN 113 349 320 A shows a device for producing an oat beverage, in which spatially separated processing stations or separate stations connected to each other via supply lines are provided. A disadvantage here, too, is that the device is not very space-saving and is also quite complex in design.

[0005] CN 216 704 118 U discloses a device for producing an oat beverage, comprising a container with an outlet for dispensing the finished oat beverage. Two mixing containers are arranged on the top of the container, each with a motor on its top for driving a rotary motion of stirring elements projecting into the mixing container and arranged on a rotating axis. The ingredients to be mixed are fed in through laterally arranged inlets and, after mixing, are conveyed through the outlets, which can be closed off with valves, into the container below. The device further includes a cleaning unit comprising several cleaning nozzles supplied with water via a water inlet. A disadvantage of the device shown is that, in addition to the container with the outlet for dispensing the finished oat beverage, it includes an additional mixing container.The device's design is not very compact, making it unsuitable for producing fresh oat drinks in smaller spaces. Furthermore, it lacks a heating element, meaning the elevated temperatures required for producing fresh oat milk cannot be achieved.

[0006] DE 102 45 862 A1 discloses a device for mixing powdered substances in liquids, comprising a container with an inner shell, an upper opening, and a lower conical end with an outlet. A lid is arranged on the upper opening, the lid having connections for a water rinsing device, a vacuum line, and a compressed air line. A container holding device is also provided on the lid, connected to a feed line for supplying the powdered substance. A container can be inserted into the container holding device and is connected via a delivery line, which can be shut off by a shut-off device, to a storage container containing the powdered substance. To open a feed valve, a vacuum is created in the container, which causes the valve to open and the powdered substance to be drawn into the container.Furthermore, a stirring device is provided, comprising a motor above the lid and a stirring rod inserted into the container. A heating jacket is arranged in the lower part of the container.

[0007] DE 25 05 594 A1 discloses a process for producing food from plant seeds for mammals and humans, in which either alpha-amylase alone or additionally amylglucosidase is added to a mash of crushed legume material at an initial temperature below 65°C, and the temperature is then raised to 70–85°C, maintaining this temperature for at least 15 minutes. Hydrolysis conditions are further described, involving a temperature of 50–60°C and a hydrolysis duration of 3–6 hours. The process requires a period of over 24 hours for complete saccharification. To stabilize the amylase, the pH for saccharification is lowered to an acidic environment, which is then raised with the aid of an alkali after the enzymatic treatment.A disadvantage of the process is the use of temperatures above 60°C, which entails a corresponding energy requirement for production, or the need for several hours to complete the process in order to produce the food.

[0008] EP 1 502 643 A1 discloses a method for producing a foodstuff from a liquid and a solid, which are mixed together in a container with a stirring element, and a device for producing a foodstuff. The device comprises a container into which the liquid and the solid can be automatically filled, wherein a stirring device with a stirring element projects into the container. The container sits on a drip tray, with a heated roof arranged above the drip tray, which prevents condensation of steam rising from the container. The liquid is taken directly from a water line or from a water tank, which is arranged behind a storage container for the solid, wherein the water tank is heated.

[0009] WO 00 / 22938 A2 discloses a process for producing cereal suspensions with the flavor of natural cereals and intact beta-glucan. The cereal suspension is subjected to enzymatic treatment using at least one hydrolase. The hydrolase is selected from the group comprising beta-amylase, alpha-amylase, amyloglucosidase, and pullulanase.

[0010] WO 02 / 065855 A2 discloses a process for the production of an oat beverage, using alpha-amylase and beta-amylase. The basic ingredient is pregelatinized rolled oats, wet-milled and added.

[0011] WO 2021 / 099457 A1 discloses a process for the production of an oat drink, wherein the process involves the use of a thermophilic endo-alpha amylase and another enzyme with beta-glucanase activity, in which the thermally stable enzymes are exposed to particularly high temperatures of 70-90°C.

[0012] The object of the invention is to provide a method for producing a milk substitute product, wherein the method is designed to be energy-saving, efficient and time-saving.

[0013] The aforementioned problem is solved according to the invention by a method for producing a milk substitute product according to claim 1.

[0014] According to one aspect of the invention, a process for producing a milk substitute is described, comprising in a first process step the provision of a dry ingredient mixture comprising at least one main plant ingredient, wherein the main plant ingredient is dry-milled oat flour and the milk substitute to be produced is oat milk, a first enzyme, a second enzyme, and a co-factor for heat-stabilizing one of the enzymes. The heat-stabilizing co-factor is CaCl₂, and the weight ratio of the co-factor to the enzyme that is heat-stabilized by the co-factor is between 1:1 and 2.5:1, preferably between 1.66:1 and 2:1. Furthermore, the weight ratio of the oat flour to water is between 1:4 and 1:10, preferably between 1:7 and 1:9. The first enzyme is a heat-stable endo-alpha amylase.Furthermore, the amount of the first enzyme, based on the dry oat content, is between 0.2 and 0.6 wt%, preferably 0.4 wt%. The second enzyme is a heat-insensitive maltogenic alpha-amylase. The amount of the second enzyme, based on the dry oat content, is between 0.15 and 0.45 wt%, preferably 0.3 wt%.

[0015] In a second process step, water is provided at a maximum temperature of 60 °C. In a third step, the dry ingredient mixture is added to the water while stirring to obtain a suspension. In a fourth step, the finished milk substitute is extracted within 40 to 60 minutes of adding the dry ingredient mixture. The process is advantageous because it is energy-efficient, requiring only a relatively low temperature. Furthermore, the process duration is short, lasting only 40 to 60 minutes until the finished milk substitute is extracted. This short time is ensured by using an energy-saving, yet sufficiently high temperature to maintain good enzyme activity. This temperature is still too high for the heat-sensitive enzyme to function properly on its own.The enzyme is therefore thermally stabilized by the addition of a co-factor. This allows the process to be carried out at the desired temperature of a maximum of 60°C.

[0016] The process is particularly preferably carried out using the apparatus described below, wherein the water is provided in a container, stirring is carried out by a stirring device, and the finished milk substitute is dispensed from the outlet of the container. Preferably, the dry ingredient mixture is added through an inlet provided in a lid.

[0017] The preferred apparatus for carrying out the above-described method according to the invention for producing a milk substitute comprises a container with an inner shell defining a cavity and an upper opening for receiving the ingredients required for producing the milk substitute, and an outlet for dispensing the ready-to-eat milk substitute. The apparatus further comprises a lid arranged on the opening of the container, a stirring device for stirring and dispersing the ingredients received in the container, the stirring device comprising at least one driven, rotatable stirring element arranged in the cavity. The apparatus further comprises a cleaning device for the automated cleaning of at least the inner shell of the container and a heating device for heating the inner shell of the container.The device is characterized by the fact that the closure element can be adjusted via a drive motor between a closed position, in which the closure element seals the inlet, and an open position, in which the closure element opens the inlet. The device has the advantage that only a single container is required for the production of the milk substitute, and all necessary process steps can be carried out simultaneously within that container. The device is advantageously suited for use in smaller spaces, such as a café kitchen or private residence, and is powered by a standard household electrical outlet. Furthermore, the device can also be used in retail outlets such as stores.The lid preferably includes a first inlet through which a dry mixture of ingredients can be fed into the container's cavity. Advantageously, the lid further includes a second inlet through which water can be fed into the container's cavity. Even more preferably, the lid includes a third inlet through which a low-viscosity liquid, particularly oil, can be fed into the container's cavity. The addition of oil is frequently carried out as a refining step in the production of milk substitutes. The stirring device present in the apparatus for manufacturing the milk substitute is advantageously used to mix in and distribute the oil.It is advantageous that the lid does not need to be removed from the container for adding the ingredient mixture and other components such as water and oil; instead, the addition of the ingredients is advantageously automated with the lid closed.

[0018] In a preferred embodiment, the lid includes a closure device with a locking element for selectively opening and closing the first inlet. More preferably, the closure device is further configured to sequentially open and close the second and third inlets. Advantageously, the closure device ensures that the respective inlets are not contaminated by splashing or rising vapors during the opening of one of the other inlets and the introduction of the respective ingredient, or during the manufacturing process. For example, this prevents the dry ingredient mixture from coming into premature contact with the water during its addition.

[0019] Advantageously, the closure element has a first through-opening which can be moved between the closed position and the open position relative to the inlet by adjusting the closure element.

[0020] In a further advantageous embodiment of the device, the cover comprises an upper cover part and a lower cover part, with the closing element being movably arranged between the upper and lower cover parts. Advantageously, the upper cover part has the first inlet, and the lower cover part has a first through-opening, which is arranged congruently below the first inlet. The upper and lower cover parts are rigidly connected to each other. Advantageously, by moving the closing element and the through-opening in the closing element, the passage between the first inlet and the first through-opening of the lower cover part is either blocked or opened.

[0021] In a first preferred embodiment, the closure element is rotatable. Advantageously, the closure element can be easily rotated by a rotating drive element, allowing for a particularly precise and reliable repositioning of the opening in the closure element by rotation. Alternatively or additionally, the closure element can also be guided linearly.

[0022] The heating device is preferably arranged between the outer surface of the inner jacket and insulation surrounding the container. Advantageously, maintaining a specific temperature inside the container does not require excessively high heating power, since the heating device is in direct contact with the inner jacket and heat loss through the insulation is minimized. The heating device is expediently designed as a heating sleeve. Advantageously, the heating device can be easily replaced and does not come into contact with the manufactured product.

[0023] The endo-alpha amylase was preferably obtained from bacteria, preferably from Bacillus amyloliquefaciens. The maltogenic alpha amylase was preferably obtained from a fungus, preferably from Aspergillus oryzae.

[0024] Further advantages, developments and features of the invention will become apparent from the following description of several preferred embodiments and from the dependent claims.

[0025] The invention will now be explained in more detail with reference to the accompanying drawings and a preferred embodiment of the invention. Fig. 1 shows a preferred embodiment of a device for producing a milk substitute in a side view. Fig. 2 shows the device for producing a milk substitute made of Fig. 1 in a cross-sectional view. Fig. 3 shows the in Fig. 1 and Fig. 2 The lid of the device for producing a milk substitute is shown in an exploded view.

[0026] Fig 1Figure 1 shows a preferred embodiment of a device 1 for carrying out the inventive method for producing a milk substitute in a side view. The device 1 comprises a container 2 designed as a batch container, in which all essential reaction processes for producing the milk substitute are carried out. The container 2 has a cylindrical shape, with the bottom 2a of the container 2 being rounded. An outlet 3 is arranged at the bottom 2a of the container 2, through which the ready-to-eat milk substitute can be removed in the outflow direction A.

[0027] A first valve 4 and a first pump 5 are arranged between the bottom 2a of the container 2 and the outlet 3. The valve 4, in combination with the pump 5, advantageously allows for the extraction of a precise quantity of the milk substitute.

[0028] In addition to outlet 3, a first supply line 7, which can be shut off via a second valve 6, and a second supply line 9, which can be shut off via a third valve 8, are connected to the bottom 2a of container 2. The first supply line 7 and the second supply line 9 are connected, on one side, to a water connection 10 and, on the other side, to a cleaning container 11. The cleaning agent contained in the cleaning container 11 can be pumped, together with the water supplied via the water connection 10, into the interior of container 2 via supply lines 7 and 9 by means of a cleaning pump 12, so that the interior can be regularly cleaned of residues of the prepared milk substitute products. Alternatively, however, only the water can be used for cleaning.A heat exchanger 13 is provided in the inlet of the water connection 10, so that the cold water coming from the water connection 10 can be preheated before being fed into the interior of the container 2, which enables more efficient and thorough cleaning.

[0029] Container 2 is connected by a Fig. 1 The lid 14, outlined with a dashed line, can be closed, and the ingredients necessary for the production of the milk substitute can be supplied through the lid 14 to the interior of the container 2. For this purpose, the lid 14 has an inlet 15 on its upper side, which is connected to the water connection 10. Advantageously, the water connection 10 can be used both for cleaning the interior of the container 2 and for supplying the water required for the production of the milk substitute.

[0030] Furthermore, an additional inlet 16 for a low-viscosity liquid, in particular oil, is provided on the upper side of the lid 2. The low-viscosity liquid can advantageously be pumped from a liquid reservoir 17 connected to the inlet 16 into the reservoir 2 by means of a pump 18. By appropriately controlling the pump 18, precise metering of the low-viscosity liquid can thus be achieved.

[0031] The device 1 further comprises an ingredient mixing container 19, which is shown partially cut away. As can be seen, a feed device 20, designed as a screw conveyor, is arranged in the ingredient mixing container 19 and is driven by a first drive motor M1. Advantageously, the ingredient mixture present in the ingredient mixing container 19 is transported into a filling hopper 21 by actuating the first drive motor M1 and the screw conveyor 20, which is thereby rotated. The filling hopper 21 is connected to the lid 14. In addition, the first drive motor M1 also generates a vibration, which is transmitted to the ingredient mixing container 19, so that the dry ingredient mixture in the ingredient mixing container can reliably fall downwards towards the screw conveyor 20 and is also evenly distributed.

[0032] A second drive motor M2 is arranged in the center of the lid 14, which drives a stirring device located in the container 2. Furthermore, a third drive motor M3 is arranged laterally to the side of the second drive motor M2 on the top of the lid 14, with the third drive motor M3 driving a closure device provided in the lid 14. The operation of the closure device, which is not shown here, will be described below in relation to the Fig. 3 explained in more detail.

[0033] Fig. 2 The device 1 for the production of a milk substitute product is shown. Fig. 1in a cross-sectional view. This view shows that an inlet 41 is provided on the top of the lid 14, which is connected to the filling funnel 21. It can also be seen that the lid 14 comprises an upper lid part 22, which is rotationally fixed to a lower lid part 23. A closure element 24 is arranged between the upper lid part 22 and the lower lid part 23, and is rotatable about a central axis of rotation R. The upper lid part 22, the lower lid part 23, and the closure element 24 together form part of a closure device 25, which can automatically open and close the lid 14 to supply the ingredient mixture, the water, and the low-viscosity liquid, preferably oil. The construction of the closure device 25 is described below with reference to the Fig. 3 explained in more detail.

[0034] Furthermore, in Fig. 2The structure of container 2 can be seen. Container 2 comprises an inner shell 26 with an upper opening 2b, insulation 27 arranged on the outside of container 2, and a heating device 28 designed as a heating sleeve, which is arranged radially between the inner shell 26 and the insulation 27. Advantageously, container 2 is designed to be heated. In particular, heating the inner shell 26 advantageously makes it possible to heat the ingredients supplied to container 2 for the production of the milk substitute to a predefined temperature and to maintain this predefined temperature for a longer period of time.

[0035] The inner jacket 26 has a circumferential collar 26a at its upper end, the circumferential collar 26a being arranged between the lower cover part 23 and several L-shaped retaining pieces 50 for attaching the container 2 to a frame (not shown here). An outlet-side opening 26b is provided in the center of the underside of the inner jacket 26, which connects to the outlet 3. Fig. 1 It can be connected. Advantageously, the milk substitute product produced directly in container 2 can be taken directly from container 2.

[0036] The device 1 for producing a milk substitute further comprises a stirring device 29, which is guided by the Fig. 2The agitator 29 is driven by the second drive motor M2 shown. The agitator 29 comprises a hollow cylindrical sleeve 30, which passes centrally through the lid 14 and projects into the cavity 31 bounded by the inner wall 26 of the container 2. The hollow cylindrical sleeve 30 is penetrated by a stirring rod 32, which is rotated about the axis R by the second drive motor M2 (see figure). Fig. 1 The mixing bell 33 is rotatably driven. A mixing bell 33 is arranged at a lower end of the sleeve 30, which projects into the cavity 31 and is pressed into the sleeve 30. A rotary bearing 34 is arranged in the mixing bell 33, which radially supports a lower section of the stirring rod 32 and further advantageously minimizes vibrations of the stirring rod 32. A stirring element 35 is arranged in a lower end of the stirring rod 32, which comprises blades projecting radially from the stirring rod 32.

[0037] It can further be seen that the first supply line 7 is led into the cavity 31 and a first cleaning nozzle 36 of a cleaning device 60 is attached to a first end 7a of the first supply line 7 that projects into the cavity 31. Similarly, the second supply line 9 is also led into the cavity 31 and a second cleaning nozzle 37 is attached to a first end 9a of the second supply line 9 that projects into the cavity 31. The first cleaning nozzle 36 is arranged at a first height and the second cleaning nozzle 37 at a second height, the second height being greater than the first height, so that the inner casing 26 and the stirring device 29 are accessible over their entire extent through the cleaning nozzles 36 and 37.The cleaning nozzles 36, 37 advantageously ensure that the water or the mixture of water and cleaning agent supplied by the first supply line 7 and the second supply line 9 is injected into the cavity 31 at increased pressure, thus achieving fully automatic cleaning.

[0038] Fig. 3 shows the in Fig. 1 and Fig. 2The lid 14 of the device for producing a milk substitute is shown in an exploded view. This view particularly illustrates the construction of the closure device 25 integrated into the lid 14. The closure device 25 comprises a drive motor M3, the drive motor M3 having an output shaft 38 which is rotationally fixed to a pinion 39. To fix the drive motor M3 and the pinion 39 coupled to the output shaft 38 to the upper lid part 22 of the lid 14, the lid 14 has a drive housing 40. The drive housing 40 has an opening 40a through which the output shaft 38 is guided.

[0039] The pinion 39 engages with the locking element 24 located between the upper cover part 22 and the lower cover part 23. For this purpose, the locking element 24 has external teeth 24a on its outer circumference, which mesh with the pinion 39. This advantageously ensures that the locking element 24 can be rotated reliably and precisely. The upper cover part 22 has, on its upper surface 22a, an inlet 15 for water, an inlet 16 for the low-viscosity liquid, and an inlet 41 for the dry ingredient mixture, the inlet 41 being able to be connected to the filling funnel 21. Furthermore, the upper cover part 22 has a central bore 22b through which the sleeve 30 of the stirring device 29 passes (see Fig. 2 ) can be conducted.

[0040] The closure element 24, like the upper lid part 22, has a central bore 24b, which, in the assembled state, is penetrated by the sleeve 30 of the stirring device 29. The central bore 22b of the upper lid part 22 and the central bore 24b of the closure element 24 have the same diameter and are congruent when the lid 14 is assembled. Furthermore, the closure element 24 has a first through-hole 24c and a second through-hole 24d arranged radially between the central bore 24b and the external toothing 24a. The first through-hole 24c corresponds to the inlet 41 for the ingredient mixture and has approximately the same inner diameter as the inlet.

[0041] In the Fig. 3As shown in the illustration, the first opening 24c is aligned with the inlet 41 for the dry ingredient mixture. In contrast, the second opening 24d is located between the inlet 15 for the water and the inlet 16 for the low-viscosity liquid. Advantageously, by rotating the closure element 24 about the central axis of rotation R, the individual inlet openings 15, 16, and 41 can be opened and closed sequentially, thus enabling controlled dosing of the individual components of the milk substitute product to be manufactured.

[0042] The lower lid part 23 is designed as a perforated disc and, in addition to a central bore 23a, has a first through-hole 23b, a second through-hole 23c, and a third through-hole 23d. The central bore 23a has a slightly smaller inner diameter than the central bore 24a of the closure element 24 or than the central bore 22a of the upper lid part 22. The first through-hole 23b is located congruently below the inlet 41 for the ingredient mixture. Similarly, the second through-hole 23c is located congruently below the inlet 15 for the water, and the third through-hole 23d is located congruently below the inlet 16 for the low-viscosity liquid. Advantageously, a passage for the respective ingredients is opened or closed by rotating the closure element 24.

[0043] Several preferred embodiments of methods according to the invention for producing a milk substitute are described below, particularly using the described apparatus 1 for producing a milk substitute. All subsequent embodiments relate to the production of oat milk. The embodiments of a method for producing oat milk described below are generally characterized in that they produce an oat suspension with low viscosity and increased sugar content using the apparatus described above, and the method is particularly energy- and time-efficient.

[0044] The typical process for producing oat milk comprises three basic steps: First, gelatinization occurs, in which the starch contained in the oats is made accessible to enzymes by transitioning into an aqueous phase. This step involves the swelling of the starch volume by heating above the gelatinization temperature, the incorporation of water into the double helix structure of the amylopectin, and the release of amylose molecules into the aqueous phase. Second, the starch solution is liquefied by the breakdown of its branched structure, for example, by pullulanases, which cleave the branched amylopectin molecules, leaving behind amylase chains. Third, saccharification takes place, i.e., the breakdown of starch chains into short-chain sugar molecules, such as...Maltose in typical milk amounts (e.g., 3.5–6.0 g / 100 g). A distinction is typically made between maltogenic saccharification to maltose and glucoamylase saccharification to glucose.

[0045] In the process according to the invention, the three process steps mentioned above are carried out simultaneously in a single process step at a low temperature, which advantageously leads to a significant reduction in production time and at the same time to a reduction in energy consumption. In particular, no high heating power is required, so that the process can also be carried out in a small area using a simple household electrical connection.

[0046] To optimize the process for producing oat milk, various experiments were conducted in which the influence of the reaction time, the enzyme concentration, the temperature and the selection of a co-factor were investigated.

[0047] In a first experiment, a mixture of ingredients consisting of a heat-stable bacterial endo-alpha-amylase (EC 3.2.1.1) (E1), here BAN®< from Novozymes®<, and a heat-unstable, fungal maltogenic alpha-amylase (EC 3.2.1.1) (E2), here Fungamyl®< from Novozymes®<, sodium chloride (NaCl), CaCl₂ as a heat-stabilizing co-factor, and oat flour, which is dry-milled from whole, dehulled grain and untreated, in particular not pre-gelatinized, was added to water at 60 °C. The resulting suspension was stirred continuously for 90 minutes. The composition of the ingredient mixture and the other experimental conditions are summarized in Table 1. Table 1: Experimental conditions, Experiment 1 Weight of NaCl [g] 0.50 Weight CaCl₂ [g] 1.50 Total stirring time [min] 90 Temperature [°C] 60 Weight of endo-alpha amylase [g] 0.80 Weight of maltogenic alpha amylase [g] 0.60 Weight ratio oat flour:water [w:w] 1:9 Weight of oat flour [g] 100

[0048] In this first experiment, samples of the oat suspension were taken after 40 minutes and subsequently at 10-minute intervals, cooled to 4 °C, and analyzed for their sugar content using high-performance liquid chromatography (HPLC). The results are shown in Table 2 below: Table 2: HPLC measurement results, 1st trial Time of sampling [min] Fructose (%) Glucose (%) Sucrose (%) Maltose (%) Total sugars (%) 40 0 0.5 0.1 3.7 4.3 50 0 0.6 0.1 3.8 4.5 60 0 0.6 0.1 3.9 4.6 70 0 0.6 0.1 3.9 4.6 80 0 0.6 0.1 3.9 4.6 90 0 0.6 0.1 4 4.7

[0049] In this experiment, the fermentation time shows only a relatively small increase in the total sugar content of 0.4 percentage points after 90 minutes compared to 40 minutes. This indicates that the target sugar content of 4.5%, typical for oat milk beverages, is already 85% reached after 40 minutes and 100% reached after 50 minutes.

[0050] In a second experiment to investigate the influence of enzyme concentration, the experimental conditions summarized in Table 3 were used: Table 3: Experimental conditions, 2nd experiment Weight of NaCl [g] 0.25 Weight CaCl₂ [g] 0.75 Total stirring time [min] 90 Temperature [°C] 60 Weight of endo-alpha amylase [g] 0.40 Weight of maltogenic alpha amylase [g] 0.30 Weight ratio oat flour:water [w:w] 1:9 Weight of oat flour [g] 100

[0051] In comparison to the experimental conditions of the first experiment (see Table 1), the amount of table salt NaCl, co-factor CaCl2 and the amount of the two enzymes added to the oat flour was halved, while the other experimental parameters were maintained.

[0052] Similar to the first experiment, samples of the oat suspension were taken after 40 minutes and subsequently at 10-minute intervals in this second experiment. The samples were cooled to 4 °C and analyzed for their sugar content using high-performance liquid chromatography (HPLC). The results are shown in Table 4 below. Table 4: HPLC measurement results, 2nd trial Time of sampling [min] Fructose (%) Glucose (%) Sucrose (%) Maltose (%) Total sugars (%) 40 0.0 0.3 0.2 3.7 4.2 50 0.0 0.4 0.1 3.5 4.0 60 0.0 0.4 0.1 3.5 4.0 70 0.0 0.4 0.1 3.7 4.2 80 0.0 0.4 0.1 3.7 4.2 90 0.0 0.4 0.1 3.7 4.2

[0053] As a result of doubling the amount of enzyme, the total sugar content is increased by between 6% and 13% or 0.3 to 0.5 percentage points.

[0054] In a third two-part series of tests to determine the temperature dependence, the test conditions summarized in Tables 5 and 6 were used. Table 5: Experimental conditions, 3rd series of experiments, 1st part Weight of NaCl [g] 1.00 Weight CaCl₂ [g] 0.00 Total stirring time [min] 70 Temperature [°C] 60 Weight of endo-alpha amylase [g] 0.40 Weight of maltogenic alpha amylase [g] 0.30 Weight ratio oat flour:water [w:w] 1:9 Weight of oat flour [g] 100 Table 6: Experimental conditions, 3rd series of experiments, 2nd part Weight of NaCl [g] 1.00 Weight CaCl₂ [g] 0.00 Total stirring time [min] 70 Temperature [°C] 70 Weight of endo-alpha amylase [g] 0.40 Weight of maltogenic alpha amylase [g] 0.30 Weight ratio oat flour:water [w:w] 1:9 Weight of oat flour [g] 100

[0055] In the third series of experiments, no co-factor was added to the oat flour; only NaCl and the two enzymes were used. Furthermore, the processing time was limited to a maximum of 70 minutes in both parts of the experiment. The only other difference between the two parts of the experiment was the temperature of the suspension, which was 60 °C in the first part of the experiment (Table 5) and 70 °C in the second part (Table 6).

[0056] Here too, samples of the oat suspension were taken after 40 minutes and subsequently at 10-minute intervals, cooled to 4 °C, and analyzed for their sugar content using high-performance liquid chromatography (HPLC). For the experimental conditions shown in Table 5 at 60 °C, the following sugar content measurements were obtained: Table 7: HPLC measurement results, 3rd series of experiments, part 1 Time of sampling [min] Fructose (%) Glucose (%) Sucrose (%) Maltose (%) Total sugars (%) 40 - 0.26 - 2.91 3.17 50 - 0.27 - 2.90 3.17 60 - 0.28 - 2.82 3.10 70 - 0.26 - 2.81 3.07

[0057] When the temperature of the suspension was raised to 70 °C, the following measured values ​​for the sugar content were obtained in comparison: Table 8: HPLC measurement results, 3rd series of experiments, part 2 Time of sampling [min] Fructose (%) Glucose (%) Sucrose (%) Maltose (%) Total sugars (%) 40 - 0.13 0.10 1.68 1.91 50 - 0.00 0.10 1.61 1.71 60 - 0.13 0.11 1.63 1.87 70 - 0.14 0.12 1.67 1.93

[0058] It can be seen that by lowering the temperature from 70 °C to 60 °C, an increase in the total sugar content of 60%, or 1.2 percentage points, can be achieved. This is primarily due to the inactivation of maltogenic alpha-amylase at temperatures above 60 °C.

[0059] In a fourth two-part experiment series, the dependence of the manufacturing process of an oat suspension on the proportion of the co-factor CaCl₂ was investigated. The experimental conditions summarized in Tables 9 and 10 were used for this purpose: Table 9: Experimental conditions, 4th series of experiments, part 1 Weight of NaCl [g] 0,25 Weight CaCl₂ [g] 0.75 Total stirring time [min] 70 Temperature [°C] 70 Weight of endo-alpha amylase [g] 0.40 Weight of maltogenic alpha amylase [g] 0.30 Weight ratio oat flour:water [w:w] 1:9 Weight of oat flour [g] 100 Table 10: Experimental conditions, 4th series of experiments, 2nd part Weight of NaCl [g] 0,5 Weight CaCl₂ [g] 0.5 Total stirring time [min] 90 Temperature [°C] 60 Weight of endo-alpha amylase [g] 0.40 Weight of maltogenic alpha amylase [g] 0.30 Weight ratio oat flour:water [w:w] 1:9 Weight of oat flour [g] 100

[0060] The corresponding HPLC measurement results for the sugar content in the oat suspension are shown in Tables 11 and 12. Table 11: HPLC measurement results, 4th series of experiments, part 1 Time of sampling [min] Fructose (%) Glucose (%) Sucrose (%) Maltose (%) Total sugars (%) 40 0.0 0.19 0.15 2.40 2.74 50 0.0 0.20 0.11 2.29 2.60 60 0.0 0.22 0.10 2.33 2.65 70 0.0 0.18 0.11 2.28 2.57 Table 12: HPLC measurement results, 4th series of experiments, part 2 Time of sampling [min] Fructose (%) Glucose (%) Sucrose (%) Maltose (%) Total sugars (%) 40 0.0 0.4 0.1 3.6 4.1 50 0.0 0.4 0.1 3.5 4.0 60 0.0 0.4 0.1 3.6 4.1 70 0.0 0.4 0.1 3.7 4.2 80 0.0 0.4 0.1 3.7 4.2 90 0.0 0.5 0.1 3.8 4.4

[0061] Comparing the first part of the third experimental series (Table 7) without co-factor and the second experiment with co-factor CaCl₂ (Table 4), a 17 to 25% higher degree of saccharification and a 0.7 to 1.0 percentage point higher total sugar content are achieved at 60 °C. At 70 °C, comparing the measurement results for the second part of the third experimental series (Table 8) with the first part of the fourth experimental series (Table 11), a 28 to 32% higher total sugar content is achieved. Comparing the second experiment (Table 4) with the second part of the fourth experimental series (Table 12), it can be seen that the co-factor CaCl₂ already has a heat-stabilizing effect at a mass ratio of 1.66:1 (w / w) with the maltogenic alpha-amylase.

[0062] Furthermore, an experiment was conducted using the apparatus described above to produce a milk substitute. The experimental conditions are shown below in Table 13: Table 13: Test conditions for experiment with device 1 Weight of NaCl [g] 1.11 Weight CaCl₂ [g] 3.33 Total stirring time [min] 60 Temperature [°C] 60 Weight of endo-alpha amylase [g] 1.78 Weight of maltogenic alpha amylase [g] 1.33 Weight ratio oat flour:water [w:w] 1:9 Weight of oat flour [g] 444

[0063] These experimental conditions correspond to the parameters preferably desired in practice for a process according to the invention for the production of oat milk. The corresponding HPLC measurement results for the sugar content in the oat suspension when taken after 60 minutes are shown below in Table 14: Table 14: HPLC measurement results, experiment with device 1 Time of sampling [min] Fructose (%) Glucose (%) Sucrose (%) Maltose (%) Total sugars (%) 60 0.0 0.40 0.1 3.7 4.20

[0064] As a result, the target value for the total sugar content of 4.5% is almost achieved and the ratio of maltose to glucose of about 9 is within the desired range.

[0065] In summary, the experiments described above demonstrate that oat milk can be produced by combining a co-factor and two alpha-amylases at a maximum temperature of 60°C, resulting in high enzyme activity and stability. This allows for the advantageous production of oat milk using a particularly simple manufacturing process, which essentially involves only adding the correct ingredient mixture to water at a maximum temperature of 60°C and stirring continuously for a maximum of 60 minutes. This process combines or simultaneously carries out the three process steps necessary for the production of grain suspensions, which were previously performed sequentially / cascaded: gelatinization, liquefaction, and saccharification.Particularly advantageous is the fact that the production of oat milk requires only a container with a stirring device and a heating option for the container to maintain the temperature of the oat suspension, with energy consumption also being relatively low due to the relatively low temperature of 60°.

Claims

1. A method for producing a milk substitute product in the form of oat milk, comprising providing a dry ingredient mixture comprising at least one main plant ingredient in the form of dry ground oat flour, a first enzyme, wherein the first enzyme is in the form of heat-stable endo-alpha-amylase and the amount of the first enzyme is between 0.2 and 0.6 percent by weight based on the dry oat content, a second enzyme, wherein the second enzyme is a heat-unstable maltogenic alpha-amylase and the amount of the second enzyme is between 0.15 and 0.45 percent by weight based on the dry oat content, and a cofactor for heat stabilization of one of the enzymes, wherein the heat-stabilizing cofactor is CaCl2 and the weight ratio of CaCl2 to the one enzyme which is heat-stabilized by the cofactor is between 1:1 and 2.5:1, providing water with a maximum temperature of 60 °C. adding the dry ingredient mixture to the water while stirring to obtain a suspension, wherein the weight ratio of oat flour to water is between 1:4 and 1:10, preferably between 1:7 and 1:9, and removing the milk substitute product within a period of 40 to 60 minutes after adding the dry ingredient mixture.