PROCESS FOR IMPROVED PRODUCTION OF ISOMALT

Description

[0001] The present invention relates to a process for the improved production of isomalt, in particular a particularly storage-stable and pure isomalt, from a carbohydrate mixture containing isomaltulose or isomaltulose and trehalulose as well as sucrose, which is characterized in particular by improved efficiency, process stability and reaction selectivity and yield, and the isomalt thus produced.

[0002] Isomalt (hydrogenated isomaltulose) is a sugar substitute whose main components are 1,6-GPS (6-O-α-D-glucopyranosyl-D-sorbitol) and 1,1-GPM (1-O-α-D-glucopyranosyl-D-mannitol). Due to its non-cariogenic, tooth-friendly properties, low calorific value, and low glycemic effect, isomalt has numerous nutritional benefits. According to the Joint FAO / WHO Expert Committee on Food Additives (JECFA) specification (69th JECFA (2008), published in FAO JECFA Monographs 5 (2008)), isomalt contains at least 98 wt% hydrogenated mono- and disaccharides (namely 1,6-GPS, 1,1-GPM, 1,1-GPS (1-O-α-D-glucopyranosyl-D-sorbitol), sorbitol and mannitol) and at most 2 wt% minor components, said isomalt containing at least 86 wt% 1,6-GPS and 1,1-GPM and 0 to 0.3 wt% reducing sugars (each based on the dry matter of the isomalt).An isomalt that is considered "sugar-free" under food law according to the JECFA specification, which also meets the European purity criteria for additives and requirements from standard works such as the FCC (Food Chemical Codex) and relevant isomalt monographs of the pharmacopoeias in Europe, the USA or Japan, is further distinguished by the fact that any individual secondary components that may be present are present in a maximum amount of 0.5 wt.% each and that the isomalt contains a maximum of 0.5 wt.% reducing and non-reducing sugars (e.g. mono- and disaccharides) (each based on the dry matter of the isomalt).

[0003] Isomalt is known in various forms. For example, as can be seen from DE 195 32 396 C2, isomalt can exist as a nearly equimolar mixture of 1,6-GPS and 1,1-GPM.

[0004] Other isomalt variants are characterized, for example, by an increased 1,6-GPS content (so-called 1,6-GPS-enriched isomalt), in particular by a 1,6-GPS content of 57 to 99 wt.% and a 1,1-GPM content of 43 to 1 wt.% (based on the main isomalt components). Due to this composition, they are endowed with increased sweetening power and solubility. As known from DE 195 23 008 A1 or EP 2 361 255 B1, such 1,6-GPS-enriched mixtures can be produced using ruthenium catalysts.

[0005] Isomalt is usually produced in a two-step process in which isomaltulose (also known as palatinose) is first extracted from sucrose using enzyme catalysis by sucrose glucosylmutases and then the isomaltulose is hydrogenated using hydrogen (H 2 ) using metal catalysis.

[0006] During the enzymatic isomerization of sucrose to isomaltulose, the 1,2-glycosidic bond between glucose and fructose in sucrose becomes a 1,6-glycosidic bond in isomaltulose. This transforms non-reducing sucrose, which contains no free aldehyde or keto group, into reducing isomaltulose, a keto disaccharide with a free keto group. The 1,6-glycosidic bond between glucose and fructose in isomaltulose is significantly more hydrolytically stable than the 1,2-glycosidic bond in sucrose, making isomaltulose significantly more resistant to acids and microbial fermentation.

[0007] On an industrial scale, isomalt is produced, as can be seen from EP 0 625 578 A1, starting from sucrose or a sucrose-containing starting mixture by subjecting the sucrose or the sucrose-containing starting mixture to an enzymatic isomerisation reaction using a sucrose glucosylmutase, which leads to the formation of a so-called "isomerised sucrose" which, as a rule, also contains, in addition to the isomaltulose, unreacted residual amounts of sucrose, also referred to as "residual sucrose".This "isomerized sucrose" obtained from the isomerization of the sucrose or sucrose-containing starting mixture, hereinafter also referred to as isomaltulose and sucrose-containing carbohydrate mixture, is then subjected to a hydrogenation reaction in order to reduce the isomaltulose and, if present in the carbohydrate mixture, trehalulose formed by another isomerization of the sucrose, to the disaccharide alcohols 1,6-GPS and 1,1-GPM and, if present, 1,1-GPS (1-O-α-D-glucopyranosyl-D-sorbitol, from trehalulose).

[0008] If the hydrogenation is carried out under standard process conditions in a neutral or alkaline environment, usually using Raney nickel catalysts (EP 0 625 578 A), the residual sucrose present in the "isomerized sucrose" remains unchanged, since sucrose is non-reducing due to its chemical structure and can neither be hydrolytically cleaved nor hydrogenated. However, the direct production of an isomalt with a higher 1,6-GPS content than the 1,1-GPM content is not readily possible using such a process.However, if sucrose is hydrogenated under normal process conditions in an acidic environment, the acid-labile sucrose is hydrolyzed to glucose and fructose, which are hydrogenated as reducing sugars to sorbitol and mannitol, as is evident from US Pat. Nos. 4,072,628, 3,963,788, and 4,950,812, which disclose the hydrogenation of sucrose using ruthenium-based catalysts. This is referred to as a "cleavage hydrogenation" of sucrose. Isomaltulose, on the other hand, remains stable even under acidic hydrogenation conditions due to its high acid stability and, as is evident from DE 195 23 008 A1, can be readily hydrogenated directly to isomalt, particularly using a ruthenium-based catalyst.

[0009] EP 2 361 255 B1 discloses the hydrogenation of a mixture of isomaltulose and "residual sucrose" using a ruthenium-based catalyst to produce isomalt. The sucrose is hydrogenated to sorbitol and mannitol via glucose and fructose under conditions that enable sucrose hydrolysis, and the isomaltulose is hydrogenated to 1,1-GPM and 1,6-GPS. The use of a ruthenium-based catalyst leads, in particular, to the production of an isomalt with a higher 1,6-GPS content than the 1,1-GPM content, which is advantageous for certain applications (DE 195 23 008 A1). However, due to the process conditions used in the described ruthenium-based processes, isomalt produced in this way exhibits a large number and quantity of by-products, which is undesirable for many applications.Under the specific process conditions of Examples 1 to 4 described in the publication, in particular temperatures of 90 and 120 °C and a pressure of 60 bar, the isomaltulose is converted only at a comparatively low conversion rate or energetically unfavorable high temperatures are used. In addition, the service life of the catalyst used is shortened, which leads to increased production costs. Furthermore, the presence of these by-products also reduces the purity of the resulting product and thus its marketability. On the one hand, the cleavage of sucrose to glucose and fructose achieved in the named process and the associated hydrogenation to the by-products sorbitol and mannitol is desirable insofar as it avoids undesirable large amounts of residual sucrose in the isomalt to be produced due to nutritional requirements.On the other hand, the monosaccharide alcohols sorbitol and mannitol, especially sorbitol, obtained from the splitting hydrogenation are often technologically disadvantageous because, due to their hygroscopicity, they make any drying steps in the isomal production process more difficult or at least more expensive and their presence in some applications, for example in hard caramels, leads to undesirable product properties such as stickiness, poor dimensional stability, such as runniness of the products (EP 1 776 015 B1), and poor storage stability.

[0010] Particularly in cases where sucrose-containing isomaltulose mixtures with a very low residual sucrose content - usually obtained enzymatically on an industrial scale from sucrose or sucrose-containing starting mixtures - are to be hydrogenated to isomalt, it may be desirable for the sucrose to pass through the hydrogenation process unchanged so that no sorbitol and mannitol are formed from it.

[0011] The increased hygroscopicity of the hydrogenated cleavage products of sucrose, in particular sorbitol, in relation to sucrose itself and to isomalt, furthermore reduces the storage life of isomalt, particularly in humid and hot climates, and makes it difficult to use isomalt in said humid and hot climates, particularly in sweets, for example hard candies, and particularly in medicines which require complex packaging.

[0012] DE 696 13 100 T2, WO 2005 / 021475 A1 and WO 03 / 104473 A2 disclose processes for the production of sugar alcohols from various sugar-containing starting preparations.

[0013] Although a number of processes are known for the production of isomalt from isomaltulose- and sucrose-containing carbohydrate mixtures obtained by enzymatic conversion of sucrose or sucrose-containing starting mixtures, there is still a need for processes that provide isomalt, in particular 1,6-GPS-enriched isomalt, in high purity and with a property profile optimized for specific areas of application from isomaltulose- and sucrose-containing carbohydrate mixtures, which are preferably obtained enzymatically from sucrose or sucrose-containing starting mixtures.

[0014] The present invention is based on the technical problem of overcoming the above disadvantages, in particular to provide a particularly process-stable, cost-effective process for producing isomalt, in particular one which has a higher 1,6-GPS than 1,1-GPM content, from an isomaltulose and sucrose-containing carbohydrate mixture, preferably obtained from a sucrose-glucosylmutase-catalyzed conversion of sucrose or sucrose-containing starting mixtures, which efficiently provides a particularly storage-stable isomalt, in particular for use in sweets, for example hard candies, with high purity of the main components 1,6-GPS and 1,1-GPM and in high yield.The invention also provides a particularly pure isomalt prepared by means of this process, in particular one which can be described as "sugar-free", in particular having a sugar content, in particular sucrose content, of at most 0.50 wt.% (based on dry matter of the isomalt) and at the same time being characterized by particularly low sorbitol and mannitol contents.

[0015] The present invention solves the technical problem underlying it by providing the present technical teaching, in particular the teaching of the independent claims and the preferred embodiments disclosed in the description and the dependent claims.

[0016] According to the invention, a process is provided for the continuous production of isomalt from a carbohydrate mixture containing isomaltulose and sucrose, comprising the process steps a) Providing a carbohydrate mixture containing isomaltulose and sucrose in an aqueous medium, containing 75.00 to 99.99% by weight of isomaltulose and 0.01 to 0.50% by weight of sucrose (each DM (dry substance), based on the total DM of the carbohydrate mixture), hydrogen and a ruthenium-based catalyst, b) converting the carbohydrate mixture to isomalt by continuously contacting the carbohydrate mixture present in the aqueous medium with the ruthenium-based catalyst and hydrogen at a space velocity of 0.25 to 1.5 h -1< , at a hydrogen pressure of 16.0 to 22.0 MPa and a pH of 2.0 to 6.0 to obtain an isomalt-containing product stream while setting a reaction temperature of at most 100 °C and c) obtaining the isomalt.

[0017] The present procedure is accordingly characterized in that in a first process step a) an isomaltulose and sucrose-containing carbohydrate mixture in an aqueous medium containing 75.00 to 99.99 wt.% isomaltulose and 0.01 to 0.50 wt.% sucrose, hydrogen and a ruthenium-based catalyst, in particular a supported catalyst, is provided and in a second process step b) the carbohydrate mixture present in the aqueous medium is brought into contact with the ruthenium-based catalyst and hydrogen in a continuous process, so that a reaction medium is obtained in which the conversion of the carbohydrate mixture to isomalt takes place.According to the invention, the carbohydrate mixture is brought into contact with the ruthenium-based catalyst and hydrogen at a space velocity of 0.25 to 1.5 h -1< , at a hydrogen pressure of 16.0 to 22.0 MPa (160 to 220 bar), at a pH of 2.0 to 6.0 and at a temperature of at most 100 °C, wherein preferably the isomaltulose is converted in step b) with a conversion rate of 99 to 100 mol-% and a selectivity of 97 to 100 mol-% to 1,6-GPS (6-O-α-D-glucopyranosyl-D-sorbitol) and 1,1-GPM (1-O-α-D-glucopyranosyl-D-mannitol) in order to obtain the isomalt in a third process step c).

[0018] The process according to the invention is characterized in particular and advantageously preferably in that, by utilizing the features defined in process steps a) and b), in particular the quantitatively defined isomaltulose- and sucrose-containing carbohydrate mixture as starting material and the process parameters specified in process step b), a process is provided which leads to a conversion rate of isomaltulose of 99 to 100 mol% and a selectivity of the conversion of isomaltulose to 1,6-GPS and 1,1-GPM of 97 to 100 mol%.

[0019] According to the invention, therefore, a process for the continuous production of isomalt from a carbohydrate mixture containing isomaltulose and sucrose is preferably provided, comprising the process steps a) Providing a carbohydrate mixture containing isomaltulose and sucrose in an aqueous medium, containing 75.00 to 99.99% by weight of isomaltulose and 0.01 to 0.50% by weight.-% sucrose (each TS (dry substance), based on the total TS of the carbohydrate mixture), hydrogen and a ruthenium-based catalyst, b) conversion of the carbohydrate mixture to isomalt by continuously contacting the carbohydrate mixture present in the aqueous medium with the ruthenium-based catalyst and hydrogen at a space velocity of 0.25 to 1.5 h -1< , at a hydrogen pressure of 16.0 to 22.0 MPa and a pH of 2.0 to 6.0 to obtain an isomalt-containing product stream while setting a reaction temperature of at most 100 °C, wherein the isomaltulose in step b) is converted with a conversion rate of 99 to 100 mol-% and a selectivity of 97 to 100 mol-% to 1,6-GPS (6-O-α-D-glucopyranosyl-D-sorbitol) and 1,1-GPM (1-O-α-D-glucopyranosyl-D-mannitol) is converted and c) obtaining the isomalt.

[0020] The invention therefore provides for the use of a carbohydrate mixture containing isomaltulose as the starting material for the process provided according to the invention, which has so-called "residual sucrose," i.e., a comparatively low proportion of sucrose, namely 0.01 to 0.50 wt.% sucrose. By adjusting the process parameters provided according to the invention, it is surprisingly possible, in a preferred embodiment, to obtain a product of particularly high purity with the advantages described below when using such a starting material.According to the invention, the above-defined starting material containing isomaltulose and a small proportion of sucrose is brought into contact with the ruthenium-based catalyst and hydrogen at a precisely defined space velocity of 0.25 to 1.5 h -1< , at a hydrogen pressure of 16.0 to 22.0 MPa and a pH of 2.0 to 6.0, in order to obtain an isomalt-containing product stream, wherein the reaction temperature of this isomalt-containing product stream may not exceed 100 °C. In particular, the reaction temperature of the isomalt-containing product stream is to be adjusted such that an isomaltulose conversion rate of 99 to 100 mol% with a selectivity of 97 to 100 mol% to 1,6-GPS and 1,1-GPM is achieved.

[0021] The process conditions used according to the invention are particularly gentle and lead to only a very minimal formation of by-products that are undesirable from a food safety and application-related perspective. In particular, it was surprisingly found that the sucrose present in the carbohydrate mixture used is neither cleaved nor hydrogenated despite the acidic hydrogenation conditions. This advantageously prevents the formation of sorbitol and mannitol from sucrose present in the carbohydrate mixture, which is undesirable in many applications.Since no sorbitol and mannitol are formed from the sucrose used during the process according to the invention, in cases where a defined maximum amount of sorbitol and mannitol is desired in the resulting isomalt for application-related reasons, for example, the amount of glucose and fructose possibly present in the isomaltulose- and sucrose-containing carbohydrate mixture used for the hydrogenation can be correspondingly larger.

[0022] The procedure provided according to the invention, using a maximum temperature of 100 °C in conjunction with the further features of the teaching according to the invention during the conversion of the carbohydrate mixture to isomalt, reduces energy costs and provides advantageous isomalt efficiently and quickly in a cost-effective process.

[0023] In a preferred embodiment, the process according to the invention can produce an isomalt which satisfies the JECFA specification and is also referred to below as JECFA-compliant isomalt. Such isomalt is characterized by a content of at least 98% by weight of hydrogenated mono- and disaccharides, namely 1,6-GPS, 1,1-GPM, 1,1-GPS, sorbitol and mannitol, and at most 2% by weight of secondary components, wherein this isomalt has at least 86% by weight of 1,6-GPS and 1,1-GPM and 0 to 0.3% by weight of reducing sugars (for example glucose and fructose) and wherein at most 0.5% by weight, in particular 0.01 to 0.50% by weight, in particular 0.01 to 0.49% by weight, in particular 0.01 to 0.05% by weight of sucrose (in each case based on the total weight of the dry matter of the isomalt) is present.

[0024] In a particularly preferred embodiment, the process according to the invention can also be used to produce an isomalt which is a particularly pure isomalt, also referred to here as high-purity isomalt. The high-purity isomalt produced in a preferred embodiment according to the invention corresponds to the Joint FAO / WHO Expert Committee on Food Additives specification (69th JECFA (2008), published in FAO JECFA Monographs 5 (2008)) and is accordingly a JECFA-compliant isomalt containing at least 98.00 wt.% hydrogenated mono- and disaccharides, namely 1,6-GPS, 1,1-GPM, 1,1-GPS, sorbitol and mannitol, and at most 2.00 wt.% secondary components, wherein the isomalt contains at least 98.00 wt.% 1,6-GPS and 1,1-GPM, 0 to 0.50 wt.% sorbitol, 0 to 0.50 wt.% mannitol and 0 to 0.30 wt.% reducing sugars (for example glucose and fructose), wherein individual 2 of the optionally present in this isomalt % by weight of secondary components in an amount of 0 to 0.50 wt.-% are present and wherein a total of at most 0.50 wt.% of reducing and non-reducing sugars (such as isomaltulose, isomaltose, sucrose, glucose or fructose) and a maximum of 0.5 wt.%, in particular 0.01 to 0.50 wt.%, in particular 0.01 to 0.49 wt.%, in particular 0.01 to 0.05 wt.% sucrose (in each case based on the total weight of the dry substance of the isomalt) are present. Such isomalt, also referred to here as high-purity isomalt, is preferably and advantageously characterized in particular by a particularly high proportion of the main isomalt components 1,1-GPM and 1,6-GPS, a small but present proportion of sucrose, a high purity with regard to by-products and by a low degree of hygroscopicity, in particular a low sorbitol and mannitol content.

[0025] In a preferred embodiment of the invention, in particular the formation of at least one, preferably all of the following substances or substance classes (by-products) is statistically significantly reduced compared to isomalt not obtained according to the invention: trisaccharide alcohols, non-reducing trisaccharides, glucosylglycerols, glucosyltetritols, glucosylpentitols, further glucosylglycitols, deoxydisaccharide alcohols, dideoxydisaccharide alcohols, glycerol, tetritols (for example erythritol or threitol), pentitols (for example ribitol (adonitol), arabitol, xylitol or lyxitol), deoxyhexitols, dideoxyhexitols, sorbitol, mannitol, galactitol, allitol, gulitol, idit, altrit, or talit.

[0026] The teaching of the present invention thus surprisingly provides a particularly selective, efficient, and gentle process for producing isomalt from a carbohydrate mixture containing sucrose and isomaltulose, or in one embodiment, sucrose, isomaltulose, and trehalulose. Contrary to expectations from the prior art, for example, EP 2 361 255 B1, the sucrose is not hydrogenated in a cleavage-type manner under acidic conditions during a ruthenium-based hydrogenation, but remains chemically unchanged and is not cleaved. Therefore, sorbitol and mannitol are not formed by sucrose cleavage and hydrogenation.The procedure according to the invention thus provides for avoiding the cleavage hydrogenation of sucrose to sorbitol and mannitol, in particular sorbitol, during the reaction of the sucrose-containing carbohydrate mixture containing isomaltulose or isomaltulose and trehalulose with hydrogen over a ruthenium catalyst to form isomalt, thus providing an isomalt that has excellent properties for further processing, for example, into sweets such as hard candies, dragees, chocolate, chewing gum, ice cream, baked goods, or medicaments. The inventors have surprisingly discovered that the sucrose present in small amounts in the starting material, i.e., the carbohydrate mixture, is not cleaved under the conditions according to the invention, i.e., in particular, pressure, temperature, pH, and space velocity.The "residual sucrose" which is usually contained in the "isomerized sucrose" obtained by glucosyl mutase-catalyzed conversion of sucrose or sucrose-containing starting mixtures advantageously does not contribute to an increase in the sorbitol and mannitol content in the resulting isomalt because it is not cleaved and not hydrogenated, so that higher glucose and fructose contents can optionally also be used in the isomaltulose and sucrose-containing carbohydrate mixture provided in process step a).

[0027] The process according to the invention is therefore also technologically advantageous in that a significantly lower temperature is required for the hydrogenation of isomaltulose than for the simultaneous splitting hydrogenation of sucrose, since a significantly higher temperature is necessary for the hydrogenation of glucose resulting from the splitting of sucrose in addition to fructose. Furthermore, complex and costly drying steps are reduced or avoided, which would otherwise result from the hygroscopicity of sorbitol and / or other by-products formed from the splitting hydrogenation of sucrose, thus enabling a simple, process-stable, and cost-effective production process for isomalt, in particular a 1,6-GPS-enriched isomalt. The low proportion of sucrose in the produced isomalt is advantageous in that, compared to pure sucrose, the produced isomalt is suitable for diabetics, gentle on teeth, and has a reduced calorific value.The sweetener produced according to the invention is characterized in particular by increased storage stability, especially in humid and hot climatic regions.

[0028] In the context of the present invention, "bringing into contact" means bringing the aqueous medium, in particular an aqueous solution, into physical contact with a catalyst and hydrogen while supplying hydrogen, in particular allowing the medium, in particular the solution, to flow past the catalyst, in particular through a catalyst bed containing the catalyst. Without being bound by theory, the catalyst accelerates the reaction of the isomaltulose or of the isomaltulose and trehalulose in the carbohydrate mixture containing isomaltulose or of the isomaltulose and trehalulose, as well as sucrose, with hydrogen.

[0029] Contacting the carbohydrate mixture with the ruthenium-based catalyst while adding hydrogen leads to a conversion of the carbohydrate mixture to isomalt. According to the invention, contacting the carbohydrate mixture with the ruthenium-based catalyst and hydrogen represents a hydrogenation of the carbohydrate mixture.

[0030] In the context of the present invention, the term "conversion of a carbohydrate mixture to isomalt" means that the isomaltulose present in the carbohydrate mixture is partially or completely converted, i.e., hydrogenated, with the aid of hydrogen to 1,6-GPS and 1,1-GPM. If other hydrogenatable components, such as trehalulose, are present in the carbohydrate mixture containing isomaltulose and sucrose, it can be provided that these are also converted, i.e., hydrogenated, during contact with the ruthenium-based catalyst, in particular trehalulose to 1,1-GPS and 1,1-GPM. According to the invention, during process step b), no conversion of the sucrose, in particular residual sucrose, present in the carbohydrate mixture containing isomaltulose or isomaltulose and trehalulose as well as sucrose takes place. Cleavage and / or hydrogenation of the sucrose is avoided according to the invention.

[0031] In the context of the present invention, the "reaction medium" obtained according to process step b) is understood to mean a medium which is formed upon continuous contacting of the carbohydrate mixture present in the aqueous medium under the influence of a ruthenium-based catalyst and with the supply of hydrogen, wherein, in a preferred embodiment, said medium comprises the components isomaltulose or isomaltulose and trehalulose provided in process step a) as well as sucrose and the products formed during the reaction, in particular 1,6-GPS and 1,1-GPM.

[0032] In the context of the present invention, the term "space velocity" is understood to mean the quotient of the volume flow of the carbohydrate mixture present in the aqueous medium and the volume of the ruthenium-based catalyst. Space velocity = V (liquid volume) / V (catalyst volume) per hour (m 3 < / h x m 3 < = 1 / h, also referred to as LHSV: liquid hourly space velocity). The volume of the catalyst refers to the macroscopic catalyst volume, regardless of the shape or structure of the catalyst.

[0033] In the context of the present invention, "continuously" means that the carbohydrate mixture present in the aqueous medium is brought into contact with the catalyst at a space velocity which is constantly greater than 0 h -1<.

[0034] In the context of the present invention, isomalt is understood to mean a sugar substitute which has 1,6-GPS and 1,1-GPM as its main component, in particular at least 86% by weight of 1,6-GPS and 1,1-GPM.

[0035] A "1,6-GPS-enriched isomalt" is an isomalt with a 1,6-GPS content that is greater than the 1,1-GPM content, i.e. a 1,6-GPS to 1,1-GPM ratio of >1 (based on the dry matter content of 1,6-GPS and 1,1-GPM in isomalt).

[0036] In a preferred embodiment, the term isomalt refers to a JECFA-compliant isomalt. In a particularly preferred embodiment, the term isomalt refers to a high-purity isomalt.

[0037] In the context of the present invention, a "JECFA-compliant isomalt" is understood to mean an isomalt which comprises at least 98% by weight of hydrogenated mono- and disaccharides, namely 1,6-GPS, 1,1-GPM, 1,1-GPS, sorbitol and mannitol, and at most 2% by weight of secondary components, wherein the isomalt contains at least 86% by weight of 1,6-GPS and 1,1-GPM, 0 to 0.3% by weight of reducing sugars and at most 0.50% by weight, in particular 0.01 to 0.50% by weight of sucrose (in each case based on the total weight of the dry matter of the isomalt).

[0038] In the context of the present invention, a "high-purity isomalt" is understood to mean an isomalt which contains at least 98% by weight of hydrogenated mono- and disaccharides, namely 1,6-GPS, 1,1-GPM, 1,1-GPS, sorbitol and mannitol, and at most 2.00% by weight of secondary components, wherein the isomalt contains at least 98.00% by weight of 1,6-GPS and 1,1-GPM, 0 to 0.50% by weight of sorbitol, 0 to 0.50% by weight of mannitol, 0 to 0.30% by weight of reducing sugars, individual ones of the aforementioned 2% by weight of secondary components, if present, in an amount of 0 to 0.50% by weight each and a total of at most 0.50% by weight of reducing and non-reducing sugars and at most 0.50% by weight, in particular 0.01 to 0.50% by weight of sucrose (each based on the total weight of the dry matter of the isomalt).

[0039] In the context of the present invention, the term "at least 98.00 wt.% hydrogenated mono- and disaccharides" is understood to mean the amount of hydrogenated mono- and disaccharides in the isomalt composition comprising at least 98.00 wt.%, which are selected from the group consisting of 1,6-GPS, 1,1-GPM, 1,1-GPS, mannitol and sorbitol.

[0040] In the context of the present invention, the term "at most 2.0 wt.% of secondary components" means all substances present in an isomalt composition which are not hydrogenated mono- or disaccharides selected from the group consisting of 1,6-GPS, 1,1-GPM, 1,1-GPS, mannitol and sorbitol.

[0041] In the context of the present invention, "individual minor components" are individual substances which, in their entirety, represent the minor components, and wherein these individual substances, for example isomaltose, sucrose, glucose, fructose, isomaltulose, glycerol, glucopyranosylidit, isomelezitose, are each individual substances belonging to the substance groups of monosaccharides, disaccharides, deoxydisaccharide alcohols, trisaccharides, glucosylglycerols, glucosyltetritols, glucosylpentitols, trisaccharide alcohols, glucosylated disaccharide alcohols or hydrogenated oligomers.

[0042] The contents of isomaltulose, trehalulose and / or sucrose in the carbohydrate mixture provided and determined according to the invention as well as the contents of 1,6-GPS (6-O-α-D-glucopyranosyl-D-sorbitol), 1,1-GPM (1-O-α-D-glucopyranosyl-D-mannitol), sucrose, 1,1-GPS (α-D-glucopyranosyl-1,1-D-sorbitol) and / or isomaltulose and optionally of other components present in the isomalt are preferably determined by means of GC-FID (GC flame ionization detector) or GC mass spectrometry, particularly preferably by means of GC-FID with a limit of quantification of 0.01 g / 100 g TS at a signal / noise ratio of at least 10:1 according to FCC General Information / Validation, United States Pharmacopeia and JECFA (1996), FNP52, Add / 4 (Joint FAO / WHO Expert Committee on Food Additives).

[0043] In connection with the present invention, unless otherwise stated and / or recognizable, the percentage proportions of individual components stated for a composition of components add up to 100% by weight of the composition within the respective percentage ranges stated.

[0044] If, in connection with the present invention, the first and second decimal places or the second decimal place are not specified in a number, these are to be set as 0.

[0045] If, in connection with the present invention, a "presence", a "containing" or a "having" of a component in an amount of 0 wt.% is mentioned, this means that the respective component is not present in a measurable amount, in particular is not present.

[0046] Unless otherwise stated, in the context of the present invention, the term "carbohydrate mixture" is understood to mean the carbohydrate mixture according to process step a), i.e. a mixture containing isomaltulose and sucrose or containing isomaltulose, trehalulose and sucrose.

[0047] The carbohydrate mixture used according to the invention comprises isomaltulose and sucrose, in particular consists of these.

[0048] In a preferred embodiment, the carbohydrate mixture comprises, in particular consists of, isomaltulose, trehalulose and sucrose.

[0049] In a particularly preferred embodiment, the carbohydrate mixture comprises isomaltulose and sucrose, as well as at least one further substance, in particular selected from the group consisting of fructose, glucose, isomaltose, trehalulose, and carbohydrate oligomers, in particular consisting of these. In a particularly preferred embodiment, the carbohydrate mixture comprises isomaltulose, trehalulose, and sucrose, as well as at least one further substance, in particular selected from the group consisting of fructose, glucose, isomaltose, and carbohydrate oligomers, in particular consisting of these.

[0050] In the context of the present invention, "oligomers of carbohydrates" are understood to mean oligomers and / or polymers of monosaccharides having at least three monosaccharide units 3 and having a homogeneous or heterogeneous monosaccharide composition.

[0051] The carbohydrate mixture preferably comprises isomaltulose and sucrose, as well as a substance selected from the group consisting of trehalulose and isomaltose, in particular consisting of these. In a particularly preferred embodiment of the present invention, the isomaltulose- and sucrose-containing carbohydrate mixture comprises, in addition to sucrose and isomaltulose, or in addition to sucrose, isomaltulose, and trehalulose, glucose, fructose, and isomaltose, in particular consisting of these, optionally together with carbohydrate oligomers.

[0052] In a particularly preferred embodiment of the present invention, the carbohydrate mixture comprises in each case at most 0.50 wt.%, in particular at most 0.40 wt.%, in particular at most 0.30 wt.%, in particular at most 0.20 wt.% (in each case TS based on total dry matter of the carbohydrate mixture) of glucose, fructose, oligomers of carbohydrates and / or isomaltose.

[0053] In a particularly preferred embodiment of the present invention, the carbohydrate mixture comprises at most 2.00 wt.%, in particular at most 1.00 wt.%, in particular at most 0.50 wt.%, in particular at most 0.40 wt.% (in each case TS based on total dry matter of the carbohydrate mixture) of a total amount of glucose, fructose, oligomers of carbohydrates and / or isomaltose.

[0054] In a particularly preferred embodiment of the present invention, the carbohydrate mixture comprises at most 0.50 wt.%, in particular at most 0.40 wt.%, in particular at most 0.30 wt.%, in particular at most 0.20 wt.%, in particular at most 0.10 wt.% (in each case TS based on total dry matter of the carbohydrate mixture) of glucose.

[0055] In a particularly preferred embodiment of the present invention, the carbohydrate mixture comprises at most 0.50 wt.%, in particular at most 0.40 wt.%, in particular at most 0.30 wt.%, in particular at most 0.20 wt.%, in particular at most 0.10 wt.% (in each case TS based on total dry matter of the carbohydrate mixture) of fructose.

[0056] In a particularly preferred embodiment of the present invention, the carbohydrate mixture comprises at most 0.50 wt.%, in particular at most 0.40 wt.%, in particular at most 0.30 wt.%, in particular at most 0.20 wt.%, in particular at most 0.10 wt.% (in each case TS based on total dry matter of the carbohydrate mixture) of isomaltose.

[0057] In a particularly preferred embodiment of the present invention, the carbohydrate mixture comprises at most 0.50 wt.%, in particular at most 0.40 wt.%, in particular at most 0.30 wt.%, in particular at most 0.20 wt.%, in particular at most 0.10 wt.% (in each case TS based on total dry matter of the carbohydrate mixture) oligomers of carbohydrates.

[0058] In a particularly preferred embodiment of the present invention, the carbohydrate mixture provided in process step a) contains no glucose or no fructose or no isomaltose, in particular no glucose and no fructose and no isomaltose, in particular no glucose and no fructose, in particular no glucose, in particular no fructose.

[0059] In a particularly preferred embodiment, the carbohydrate mixture provided in process step a) does not contain any oligomers of carbohydrates.

[0060] In a particularly preferred embodiment of the present invention, the carbohydrate mixture provided in process step a), containing isomaltulose or isomaltulose and trehalulose as well as sucrose, is a carbohydrate mixture obtained by reacting sucrose or sucrose-containing starting mixtures, in particular in an aqueous medium, in particular an aqueous solution, with sucrose glucosylmutases.

[0061] In a particularly preferred embodiment of the present invention, the carbohydrate mixture provided in process step a) is a so-called "isomerized sucrose", in particular one which has been produced enzymatically from sucrose or sucrose-containing starting mixtures, in particular as described in EP 0 625 578 A1.

[0062] With regard to the preparation of "isomerized sucrose" and the means for its preparation, the disclosure content in the said patent application is fully incorporated into the disclosure content of the present teaching.

[0063] The enzymatic conversion of sucrose or sucrose-containing mixtures into the carbohydrate mixture provided according to process step a), which is preferably provided according to the invention, is preferably an enzymatic conversion using a sucrose glucosylmutase. The conversion using a sucrose glucosylmutase can preferably be carried out using bacteria exhibiting sucrose glucosylmutase, in particular selected from the group consisting of Protaminobacter rubrum, Serratia plymuthica, Serratia marcescens, Erwinia rhapontici, Leuconostoc mesenteroides, Pseudomonos mesoacidophila, Agrobacterium radiobacter, and combinations thereof.

[0064] In a preferred embodiment, the invention therefore relates to a process wherein the isomaltulose- and sucrose-containing carbohydrate mixture provided in process step a) was obtained by enzymatic conversion of sucrose or a sucrose-containing starting mixture with a sucrose glucosylmutase.

[0065] The carbohydrate mixture, preferably obtained by means of sucrose glucosyl mutases from sucrose or sucrose-containing starting mixture, can either be provided directly according to process step a) and immediately thereafter reacted according to process step b) or, in a particularly preferred embodiment, a process step a0) to reduce the sucrose content can be carried out before the provision according to process step a).The optional process step for reducing the sucrose content provided in process step a0) is particularly necessary if the carbohydrate mixture provided in process step a) is to be obtained from a source, for example an "isomerized sucrose" obtained by enzymatic conversion of sucrose or a sucrose-containing starting mixture with a sucrose glucosyl mutase, in which a higher sucrose content is present and accordingly the sucrose content must be reduced to such an extent that a carbohydrate mixture with the sucrose content according to process step a) is obtained.

[0066] In a particularly preferred embodiment of the present invention, the carbohydrate mixture provided in process step a) is a carbohydrate mixture obtained by enzymatic conversion of sucrose or a sucrose-containing starting mixture with a sucrose glucosyl mutase and is subjected to a process step a0) to reduce the sucrose content to a content of 0.01 to 0.50 wt.% sucrose (dry matter based on total dry matter of the carbohydrate mixture).

[0067] In a particularly preferred embodiment of the present invention, process step a0) is a crystallization for partial separation of sucrose, a chromatography on ion exchangers for partial separation of sucrose, an enzymatic cleavage of sucrose, e.g. by means of invertase, while maintaining a residual sucrose amount of 0.01 to 0.5 wt.% or a combination of these processes.

[0068] In a particularly preferred embodiment of the present invention, the carbohydrate mixture provided in process step a) contains 0.01 to 0.45 wt.%, in particular 0.01 to 0.40 wt.%, in particular 0.01 to 0.35 wt.%, in particular 0.01 to 0.30 wt.%, in particular 0.01 to 0.25 wt.%, in particular 0.01 to 0.20 wt.%, in particular 0.01 to 0.15 wt.%, in particular 0.01 to 0.10 wt.%, in particular 0.01 to 0.09 wt.%, in particular 0.01 to 0.08 wt.%, in particular 0.01 to 0.07 wt.%, in particular 0.01 to 0.06 wt.%, in particular 0.01 to 0.05 wt.%, in particular 0.01 to 0.04 wt.%, in particular 0.01 to 0.03 % by weight, in particular 0.01 to 0.02 % by weight, in particular 0.02 to 0.50 % by weight, in particular 0.02 to 0.45 % by weight, in particular 0.02 to 0.40 % by weight, in particular 0.02 to 0.30 % by weight, in particular 0.02 to 0.20 % by weight, in particular 0.02 to 0.10 % by weight, in particular 0.02 to 0.08 % by weight, in particular 0.02 to 0.06 % by weight.-%, in particular 0.02 to 0.05 wt.%, in particular 0.02 to 0.04 wt.% sucrose (each based on the dry matter of the carbohydrate mixture).

[0069] Preferably, the sucrose content in the carbohydrate mixture provided in process step a) is 0.01 to 0.05 wt.% (based on the dry matter of the carbohydrate mixture).

[0070] In a particularly preferred embodiment of the present invention, the carbohydrate mixture provided in process step a) contains 76.00 to 99.99 wt.% isomaltulose, in particular 78.00 to 99.99 wt.%, in particular 80.00 to 99.99 wt.%, in particular 84 to 99.99 wt.%, in particular 86.00 to 99.99 wt.%, in particular 90.00 to 99.99 wt.%, in particular 92.00 to 99.99 wt.%, in particular 94.00 to 99.99 wt.%, in particular 96.00 to 99.99 wt.%, in particular 98.00 to 99.99 wt.%, in particular 76.00 to 99.80 wt.%, in particular 78.00 to 99.80 wt.%, in particular 80.00 to 99.80 wt.%, in particular 84.00 to 99.80 wt.%, in particular 86.00 to 99.80 wt.%, in particular 90.00 to 99.80 wt.%, in particular 92.00 to 99.80 wt.%, in particular 94.00 to 99.80 wt.%, in particular 96.00 to 99.80 wt.%, in particular 98.00 to 99.80 wt.%, in particular 76.00 to 99.50 wt.%, in particular 78.00 to 99.50 wt.%, in particular 80.00 to 99.50 wt.-%, in particular 84.00 to 99.50 wt.%, in particular 86 to 99.50 wt.%, in particular 90.00 to 99.50 wt.%, in particular 92.00 to 99.50 wt.%, in particular 94.00 to 99.50 wt.%, in particular 95.00 to 99.50 wt.%, in particular 96.00 to 99.50 wt.%, in particular 97.00 to 99.50 wt.%, in particular 98.00 to 99.50 wt.%, in particular 97.70 to 99.30 wt.% of isomaltulose (in each case based on the dry substance of the carbohydrate mixture).

[0071] In a particularly preferred embodiment, the carbohydrate mixture provided in process step a) preferably has an isomaltulose content of 86.00 to 99.99 wt.%, in particular 90.00 to 99.99 wt.%, in particular 95.00 to 99.99 wt.%, in particular 96.00 to 99.99 wt.%, in particular 97.00 to 99.99 wt.%, in particular 98.00 to 99.99 wt.%, in particular 98.50 to 99.99 wt.%, in particular 98.60 to 99.99 wt.% (in each case based on the dry matter of the carbohydrate mixture).

[0072] Preferably, the isomaltulose content of the carbohydrate mixture provided in process step a) is 86.00 to 99.99 wt.% isomaltulose (based on the dry matter of the carbohydrate mixture).

[0073] Preferably, the isomaltulose content in the carbohydrate mixture provided in process step a) is 98.00 to 99.80 wt.% isomaltulose (based on the dry matter of the carbohydrate mixture).

[0074] In a particularly preferred embodiment of the present invention, the carbohydrate mixture comprises trehalulose.

[0075] In a particularly preferred embodiment of the present invention, the carbohydrate mixture provided in process step a) contains 75.00 to 99.99 wt.% of isomaltulose and 0.01 to 0.50 wt.% of sucrose-containing carbohydrate mixture, 75.01 to 100.00 wt.%, in particular 80.00 to 95.00 wt.%, in particular 86.00 to 90.00 wt.%, in particular 90.00 to 99.00 wt.%, in particular 99.00 to 100.00 wt.%, in particular 75.01 to 99.99 wt.%, in particular 80.00 to 99.99 wt.%, in particular 90.00 to 99.99 wt.%, in particular 92.00 to 99.99 wt.%, in particular 94.00 to 99.99 wt.%, in particular 96.00 to 99.99 wt.%, in particular 98.00 to 99.99 wt.%, in particular 99.00 to 99.99 wt.%, in particular 75.01 to 99.80 wt.%, in particular 80.00 to 99.80 wt.%, in particular 85.00 to 99.80 wt.%, in particular 90.00 to 99.80 wt.%, in particular 98.00 to 99.80 wt.%, in particular 98.50 to 99.80 wt.%, in particular 98.60 to 99.80 wt.%, in particular 98.70 to 99.80 wt.-%, in particular 98.80 to 99.80 wt.%, in particular 98.90 to 99.80 wt.%, in particular 99.00 to 99.80 wt.%, in particular 99.10 to 99.80 wt.% of isomaltulose and sucrose, wherein optionally, adding up to 100 wt.% of the carbohydrate mixture, trehalulose, glucose, fructose, isomaltose and / or oligomers of carbohydrates are present (in each case based on the dry substance of the carbohydrate mixture).

[0076] Preferably, the sucrose and isomaltulose content in the carbohydrate mixture provided in process step a) is 98.00 to 99.99 wt.%, wherein optionally, adding up to 100 wt.% of the carbohydrate mixture, trehalulose, glucose, fructose, isomaltose and / or oligomers of carbohydrates are present (based on the dry substance of the carbohydrate mixture).

[0077] Preferably, the sucrose, isomaltulose and trehalulose content in the carbohydrate mixture provided in process step a) is 98.00 to 99.80 wt.% (based on dry matter of the carbohydrate mixture), wherein the isomaltulose content is 97.70 to 99.30 wt.%, the trehalulose content is 0.29 to 1.00 wt.% and the sucrose content is 0.01 to 0.05 wt.% (each based on dry matter of the carbohydrate mixture).

[0078] Preferably, the sucrose, isomaltulose and trehalulose content in the carbohydrate mixture provided in process step a) is 98.00 to 99.80 wt.% (based on the dry matter of the carbohydrate mixture), wherein the isomaltulose content is 97.70 to 99.30 wt.%, the trehalulose content is 0.29 to 1.00 wt.% and the sucrose content is 0.01 to 0.05 wt.% (each based on the dry matter of the carbohydrate mixture), and wherein glucose, fructose, isomaltose and / or oligomers of carbohydrates are present to add up to 100 wt.% of the carbohydrate mixture (based on the dry matter of the carbohydrate mixture).

[0079] Preferably, the sucrose, isomaltulose and trehalulose content in the carbohydrate mixture provided in process step a) is 98 to 99.80 wt.% (based on the dry matter of the carbohydrate mixture), wherein the isomaltulose content is 98.00 to 99.30 wt.%, the trehalulose content is 0.29 to 1.0 wt.% and the sucrose content is 0.01 to 0.05 wt.% (each based on the dry matter of the carbohydrate mixture).

[0080] Preferably, the sucrose, isomaltulose and trehalulose content in the carbohydrate mixture provided in process step a) is 98 to 99.80 wt.% (based on the dry matter of the carbohydrate mixture), wherein the isomaltulose content is 98.00 to 99.30 wt.%, the trehalulose content is 0.29 to 1.0 wt.% and the sucrose content is 0.01 to 0.05 wt.% (each based on the dry matter of the carbohydrate mixture), and wherein glucose, fructose, isomaltose and / or oligomers of carbohydrates are present to add up to 100 wt.% of the carbohydrate mixture (based on the dry matter of the carbohydrate mixture).

[0081] In a particularly preferred embodiment of the present invention, the isomaltulose- and sucrose-containing carbohydrate mixture provided in process step a) comprises 0.01 to 24.99 wt.% trehalulose, in particular 0.01 to 24.50 wt.%, in particular 0.01 to 21.00 wt.%, in particular 0.01 to 20.00 wt.%, in particular 0.01 to 19.00 wt.%, in particular 0.01 to 18.00 wt.%, in particular 0.01 to 17.00 wt.%, in particular 0.01 to 10.00 wt.%, in particular 0.01 to 5.00 wt.%, particularly preferably 0.50 to 25.00 wt.% trehalulose, in particular 0.50 to 23.00 wt.%, in particular 0.50 to 21.00 wt.%, in particular 0.50 to 20.00 wt.%, in particular 0.50 to 19.00 wt.%, in particular 0.50 to 18.00 wt.%, in particular 0.50 to 17.00 wt.%, in particular 0.50 to 10.00 wt.%, in particular 0.50 to 5.00 wt.%, particularly preferably 0.30 to 1.00 wt.%, particularly preferably 0.29 to 1.00 wt.%, particularly preferably 1.00 to 25.00 wt.-%, in particular 1.00 to 23.00 wt.%, in particular 1.00 to 21.00 wt.%, in particular 1.00 to 20.00 wt.%, in particular 1.00 to 10.00 wt.%, in particular 5.00 to 25.00 wt.%, in particular 5.00 to 23.00 wt.%, in particular 5.00 to 22.00 wt.%, in particular 5.00 to 20.00 wt.%, in particular 5.00 to 10.00 wt.%, in particular 10.00 to 25.00 wt.%, in particular 10.00 to 22.00 wt.%, in particular 10.00 to 20.00 wt.%, in particular 10.00 to 18.00 wt.% trehalulose (in each case based on the dry substance of the carbohydrate mixture).

[0082] The carbohydrate mixture preferably contains 0.30 to 1.00 wt.% trehalulose (based on the dry matter of the carbohydrate mixture).

[0083] If, in a further particularly preferred embodiment, the carbohydrate mixture also comprises trehalulose in addition to sucrose and isomaltulose, the carbohydrate mixture preferably contains 75.00 to 99.49 wt.% isomaltulose and 0.50 to 24.99 wt.% trehalulose, in particular 75.00 to 86.00 wt.% isomaltulose and 13.99 to 24.99 wt.% trehalulose (each based on the dry substance of the carbohydrate mixture).

[0084] In a particularly preferred embodiment of the present invention, the ratio of isomaltulose to trehalulose in the carbohydrate mixture (wt% in TS) is 98.00 to 99.50, in particular 98.50 to 99.40 parts of isomaltulose to 0.50 to 1.50, in particular 0.60 to 1.20 parts of trehalulose.

[0085] In a preferred embodiment, the ratio of isomaltulose to trehalulose (wt.% in TS) in the carbohydrate mixture is 3 to 1, in particular 4 to 1, in particular 10 to 1, in particular 85 to 1, in particular 150 to 1, in particular 1500 to 1, in particular 9998 to 1.

[0086] In a particularly preferred embodiment, the aqueous medium provided in process step a) is an aqueous solution, an aqueous suspension, an aqueous syrup or an aqueous colloidal composition.

[0087] In a preferred embodiment of the present invention, the dry matter content of the carbohydrate mixture present in an aqueous medium, in particular in an aqueous solution, is 10.00 to 60.00 wt.% (based on the total weight of the medium).

[0088] In a particularly preferred embodiment of the present invention, the dry matter content of the carbohydrate mixture present in aqueous solution is 15.00 to 60.00 wt.%, in particular 20.00 to 60.00 wt.%, in particular 30.00 to 60.00 wt.%, in particular 35.00 to 60.00 wt.%, in particular 40.00 to 60.00 wt.%, in particular 45.00 to 60.00 wt.%, in particular 50.00 to 60.00 wt.%, in particular 10.00 to 55.00 wt.%, in particular 10.00 to 50.00 wt.%, in particular 10.00 to 45.00 wt.%, in particular 10.00 to 40 wt.%, in particular 10.00 to 35.00 wt.%, in particular 10.00 to 30.00 wt.%, in particular 10.00 to 25.00 wt.%, in particular 10.00 to 20.00 wt.%, in particular 10.00 to 15.00 wt.%, in particular 20.00 to 50.00 wt.%, in particular 20.00 to 45.00 wt.%, in particular 20.00 to 30.00 wt.%, in particular 30.00 to 50.00 wt.%, in particular 35.00 to 50.00 wt.%, in particular 35.00 to 45.00 wt.-% (each based on the total weight of the medium, in particular the solution).

[0089] Preferably, the dry matter content of the carbohydrate mixture present in aqueous solution is 35.00 to 45.00 wt.%, based on the total weight of the medium.

[0090] In a particularly preferred embodiment, it is provided that the carbohydrate mixture provided in process step a) is heated, i.e. pre-tempered, in a process step a1) before the reaction provided in process step b).

[0091] In a particularly preferred embodiment, the carbohydrate mixture provided in process step a), in particular after carrying out an optional process step a0) reducing the sucrose content, is preheated before the reaction provided in process step b) to a temperature which corresponds at most to the reaction temperature according to process step b), in particular to a temperature which corresponds to the reaction temperature according to process step b).

[0092] In a particularly preferred embodiment, in a process step a1), the isomaltulose- and sucrose-containing carbohydrate mixture provided in process step a), in particular after carrying out an optional process step a0) which reduces the sucrose content, is preheated to a temperature of 30 to 80 °C, in particular 30 to 75 °C, in particular 30 to 70 °C, in particular 45 to 68 °C, in particular 46 to 67.5 °C.

[0093] In a particularly preferred embodiment, in a process step a1), the isomaltulose- and sucrose-containing carbohydrate mixture provided in process step a), in particular after carrying out an optional process step a0) reducing the sucrose content, is preheated to a temperature of 30 to 80 °C.

[0094] In a particularly preferred embodiment, in a process step a1), the isomaltulose- and sucrose-containing carbohydrate mixture provided in process step a), in particular after carrying out an optional process step a0) which reduces the sucrose content, is preheated to a temperature of 30 to 75 °C.

[0095] In a particularly preferred embodiment, in a process step a1), the isomaltulose- and sucrose-containing carbohydrate mixture provided in process step a), in particular after carrying out an optional process step a0) which reduces the sucrose content, is preheated to a temperature of 30 to 70 °C.

[0096] The carbohydrate mixture provided in process step a) or the carbohydrate mixture pre-tempered in optional form according to process step a1) is then fed to process step b), in particular into a reactor suitable for the reaction provided for in process step b).

[0097] In a preferred embodiment, the continuous process provided in process step b) is carried out in a fixed bed reactor.

[0098] In a preferred embodiment, the continuous process provided according to process step b) is carried out as a trickle-bed process, preferably in a trickle-bed reactor.

[0099] In a preferred embodiment, the continuous process can also be carried out in a fixed bed reactor operated as a bubble reactor.

[0100] In a preferred embodiment, the continuous procedure can also be carried out in a continuous stirred tank (CSTR) or in a stirred tank cascade.

[0101] In a particularly preferred embodiment of the invention, the hydrogen pressure in process step b) is 16.2 to 22.0 MPa, in particular 16.5 to 22.0 MPa, in particular 16.5 to 21.5 MPa, in particular 16.5 to 21.0 MPa, in particular 16.5 to 20.0 MPa, in particular 16.5 to 19.5 MPa, in particular 16.5 to 19.0 MPa, in particular 16.5 to 18.5 MPa, in particular 16.5 to 18.0 MPa.

[0102] In a preferred embodiment, the hydrogen pressure in process step b) is 17.0 to 22.0 MPa, in particular 17.0 to 21.0 MPa, in particular 17.0 to 20.0 MPa, in particular 17.0 to 19.5 MPa, in particular 17.0 to 19.0 MPa, in particular 17.0 to 18.5 MPa, in particular 17.5 to 22.0 MPa, in particular 17.5 to 19.0 MPa, in particular 17.5 to 18.5 MPa, in particular 17.5 to 18.0 MPa, in particular 18.0 MPa.

[0103] Preferably, the hydrogen pressure in process step b) is 16.5 to 21.0 MPa.

[0104] In a particularly preferred embodiment, the hydrogen pressure in process step b) is 16.00 to 19.00 MPa, in particular 16.00 to 17.00 MPa, in particular 16.5 MPa.

[0105] In a particularly preferred embodiment of the present invention, the space velocity in process step b) is 0.27 to 1.5 h -1< , in particular 0.3 to 1.5 h -1< , in particular 0.3 to 1.0 h -1< , in particular 0.3 to 0.9 h -1< , in particular 0.3 to 0.8 h -1< , in particular 0.3 to 0.7 h -1< , in particular 0.3 to 0.6 h -1< , in particular 0.3 to 0.5 h -1< , in particular 0.4 to 1.5 h -1< , in particular 0.4 to 1.25 h -1< , in particular 0.4 to 1.0 h -1< , in particular 0.4 to 0.8 h -1< , in particular 0.4 to 0.7 h -1< , in particular 0.4 to 0.6 h -1< , in particular 0.25 to 1.0 h -1< , in particular 0.25 to 0.9 h -1< , in particular 0.25 to 0.8 h -1< , in particular 0.25 to 0.7 h -1< , in particular 0.25 to 0.6 h -1< , in particular 0.25 to 0.5 h -1< , in particular 0.45 to 1.5 h -1< , in particular 0.46 to 1.5 h -1< , in particular 0.48 to 1.5 h -1< , in particular 0.48 to 1.0 h -1< , in particular exactly 0.3 h -1< , in particular exactly 0.4 h -1< ,in particular exactly 0.5 h -1< , in particular exactly 0.7 h -1< , in particular exactly 1.0 h -1< .,

[0106] In a particularly preferred embodiment of the present invention, the space velocity in process step b) is 0.25 to 0.9 h -1< .

[0107] In a particularly preferred embodiment of the present invention, the space velocity in process step b) is 0.3 to 0.9 h -1< .

[0108] In a particularly preferred embodiment of the present invention, the pH in process step b) is 2.0 to 5.5, in particular 2.0 to 5.4, in particular 2.0 to 5.3, in particular 2.0 to 5.0, in particular 2.0 to 4.0, in particular 2.5 to 6.0, in particular 2.5 to 5.8, in particular 2.5 to 5.5, in particular 2.5 to 4.0, in particular 2.7 to 3.3, in particular 2.8 to 3.0, in particular 3.0 to 6.0, in particular 3.0 to 5.5, in particular 3.0 to 5.0, in particular 3.0 to 4.5, in particular 3.0 to 4.0, in particular 3.0 to 4.0, in particular 4.0 to 6.0, in particular 4.0 to 5.5, in particular 4.0 to 5.0, in particular 4.0 to 4.5, in particular 4.0 to 4.0, in particular 4.0 to 6.0, in particular 4.0 to 5.5, in particular 4.0 to 5.0, in particular 4.0 to 4.5, in particular 4.5 to 6.0, in particular 4.5 to 5.5, in particular 4.5 to 5.0, in particular 5.0 to 6.0.

[0109] In a particularly preferred embodiment, the pH in process step b) is 2.5 to 6.0, in particular 2.5 to 5.8, in particular 2.5 to 5.5.

[0110] In a particularly preferred embodiment of the present invention, the pH in process step b) is 2.5 to 5.9.

[0111] In a particularly preferred embodiment of the present invention, the pH in process step b) is 3.4 to 5.9.

[0112] In a particularly preferred embodiment of the present invention, the reaction temperature is at most 98 °C, in particular at most 95 °C, in particular at most 91 °C, in particular at most 85 °C, in particular at most 82 °C, in particular at most 79 °C, in particular at most 78 °C, in particular at most 72 °C, in particular at most 70 °C, in particular at most 65 °C, in particular at most 60 °C, in particular at most 55 °C.

[0113] In a particularly preferred embodiment of the present invention, the reaction temperature in process step b) is 30 to 100 °C, in particular 30 to 98 °C, in particular 32 to 95 °C, in particular 30 to 91 °C, in particular 30 to 79 °C, in particular 30 to 75 °C, in particular 30 to 70 °C, in particular 30 to 60 °C, in particular 30 to 50 °C, in particular 40 to 100 °C, in particular 40 to 98 °C, in particular 40 to 95 °C, in particular 40 to 91 °C, in particular 40 to 79 °C, in particular 40 to 75 °C, in particular 40 to 70 °C, in particular 40 to 60 °C, in particular 45 to 100 °C, in particular 45 to 98 °C, in particular 45 to 95 °C, in particular 45 to 91 °C, in particular 45 to 79 °C, in particular 45 to 75 °C, in particular 45 to 70 °C, in particular 45 to 60 °C, in particular 50 to 100 °C, in particular 50 to 98 °C, in particular 50 to 95 °C, in particular 50 to 91 °C, in particular 50 to 80 °C, in particular 50 to 70 °C, in particular 50 to 60 °C,in particular 55 to 100 °C, in particular 55 to 98 °C, in particular 55 to 95 °C, in particular 55 to 91 °C, in particular 55 to 79 °C, in particular 55 to 75 °C, in particular 55 to 70 °C, in particular 60 to 100 °C, in particular 60 to 98 °C, in particular 60 to 95 °C, in particular 60 to 91 °C, in particular 60 to 79 °C, in particular 60 to 75 °C, in particular 60 to 70 °C, in particular 65 to 100 °C, in particular 65 to 98 °C, in particular 65 to 95 °C, in particular 65 to 91 °C, in particular 65 to 85 °C, in particular 65 to 79 °C, in particular 68 to 100 °C, in particular 68 to 98 °C, in particular 68 to 95 °C, in particular 68 to 91 °C, in particular 68 to 79 °C, in particular 70 to 100 °C, in particular 70 to 98 °C, in particular 70 to 95 °C, in particular 70 to 91 °C, in particular 70 to 79 °C.,

[0114] In a particularly preferred embodiment of the present invention, the reaction temperature in process step b) is 70 to 95 °C.

[0115] In a particularly preferred embodiment, in process step a1) the carbohydrate mixture is preheated to 30 to 70 °C and in process step b) a reaction temperature of 70 to 95 °C is set.

[0116] In a preferred embodiment of the invention, the isomaltulose is converted in process step b) at a conversion rate of 99.5 to 100 mol%, in particular 99.9 to 100 mol%, to 1,6-GPS (6-O-α-D-glucopyranosyl-D-sorbitol) and 1,1-GPM (1-O-α-D-glucopyranosyl-D-mannitol).

[0117] In a preferred embodiment of the invention, the isomaltulose is converted in process step b) with a selectivity of 98 to 100 mol%, in particular 99 to 100 mol%, in particular 99.5 to 100 mol%, to 1,6-GPS (6-O-α-D-glucopyranosyl-D-sorbitol) and 1,1-GPM (1-O-α-D-glucopyranosyl-D-mannitol).

[0118] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 30 to 95 °C, the space velocity is 0.3 to 0.9 h -1 < and the pH is 2.5 to 6.0.

[0119] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 50 to 95 °C, the space velocity is 0.3 to 0.9 h -1 < and the pH is 2.5 to 6.0.

[0120] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 80 to 95 °C, the space velocity is 0.3 to 0.9 h -1< and the pH is 2.5 to 6.0, in particular after preheating in a process step a1) to 30 to 80 °C.

[0121] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 70 to 95 °C, the space velocity is 0.3 to 0.9 h -1< and the pH is 2.5 to 6.0, in particular after preheating in a process step a1) to 30 to 75 °C.

[0122] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 70 to 95 °C, the space velocity is 0.3 to 0.9 h -1< and the pH is 2.5 to 6.0, in particular after preheating in a process step a1) to 30 to 70 °C.

[0123] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 30 to 79 °C, the space velocity is 0.3 to 0.9 h -1 < and the pH is 2.5 to 6.0.

[0124] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 50 to 79 °C, the space velocity is 0.3 to 0.9 h -1 < and the pH is 2.5 to 6.0.

[0125] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 70 to 79 °C, the space velocity is 0.3 to 0.9 h -1< and the pH is 2.5 to 6.0, in particular after preheating in a process step a1) to 30 to 75 °C.

[0126] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 70 to 79 °C, the space velocity is 0.3 to 0.9 h -1< and the pH is 2.5 to 6.0, in particular after preheating in a process step a1) to 30 to 70 °C.

[0127] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 30 to 95 °C, the space velocity is 0.3 to 0.9 h -1 < and the pH is 2.5 to 6.0.

[0128] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 50 to 95 °C, the space velocity is 0.3 to 0.9 h -1 < and the pH is 2.5 to 6.0.

[0129] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 70 to 95 °C, the space velocity is 0.3 to 0.9 h -1< and the pH is 2.5 to 6.0, in particular after preheating in a process step a1) to 30 to 80 °C.

[0130] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 70 to 95 °C, the space velocity is 0.3 to 0.9 h -1< and the pH is 2.5 to 6.0, in particular after preheating in a process step a1) to 30 to 75 °C.

[0131] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 70 to 95 °C, the space velocity is 0.3 to 0.9 h -1< and the pH is 2.5 to 6.0, in particular after preheating in a process step a1) to 30 to 70 °C.

[0132] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 30 to 79 °C, the space velocity is 0.3 to 0.9 h -1 < and the pH is 2.5 to 6.0.

[0133] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 50 to 79 °C, the space velocity is 0.3 to 0.9 h -1 < and the pH is 2.5 to 6.0.

[0134] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 70 to 79 °C, the space velocity is 0.3 to 0.9 h -1< and the pH is 2.5 to 6.0, in particular after preheating in a process step a1) to 30 to 75 °C.

[0135] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 70 to 79 °C, the space velocity is 0.3 to 0.9 h -1< and the pH is 2.5 to 6.0, in particular after preheating in a process step a1) to 30 to 70 °C.

[0136] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 30 to 95 °C, the space velocity is 0.25 to 0.9 h -1 < and the pH is 3.4 to 5.9.

[0137] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 50 to 95 °C, the space velocity is 0.25 to 0.9 h -1 < and the pH is 3.4 to 5.9.

[0138] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 70 to 95 °C, the space velocity is 0.25 to 0.9 h -1< and the pH is 3.4 to 5.9, in particular after preheating in a process step a1) to 30 to 80 °C.

[0139] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 70 to 95 °C, the space velocity is 0.25 to 0.9 h -1< and the pH is 3.4 to 5.9, in particular after preheating in a process step a1) to 30 to 75 °C.

[0140] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 70 to 95 °C, the space velocity is 0.25 to 0.9 h -1< and the pH is 3.4 to 5.9, in particular after preheating in a process step a1) to 30 to 70 °C.

[0141] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 30 to 79 °C, the space velocity is 0.25 to 0.9 h -1 < and the pH is 3.4 to 5.9.

[0142] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 50 to 79 °C, the space velocity is 0.25 to 0.9 h -1 < and the pH is 3.4 to 5.9.

[0143] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 70 to 79 °C, the space velocity is 0.25 to 0.9 h -1< and the pH is 3.4 to 5.9, in particular after preheating in a process step a1) to 30 to 75 °C.

[0144] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 70 to 79 °C, the space velocity is 0.25 to 0.9 h -1< and the pH is 3.4 to 5.9, in particular after preheating in a process step a1) to 30 to 70 °C.

[0145] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 30 to 95 °C, the space velocity is 0.25 to 0.9 h -1 < and the pH is 3.4 to 5.9.

[0146] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 50 to 95 °C, the space velocity is 0.25 to 0.9 h -1 < and the pH is 3.4 to 5.9.

[0147] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 70 to 95 °C, the space velocity is 0.25 to 0.9 h -1< and the pH is 3.4 to 5.9, in particular after preheating in a process step a1) to 30 to 80 °C.

[0148] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 70 to 95 °C, the space velocity is 0.25 to 0.9 h -1< and the pH is 3.4 to 5.9, in particular after preheating in a process step a1) to 30 to 75 °C.

[0149] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 70 to 95 °C, the space velocity is 0.25 to 0.9 h -1< and the pH is 3.4 to 5.9, in particular after preheating in a process step a1) to 30 to 70 °C.

[0150] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 30 to 79 °C, the space velocity is 0.25 to 0.9 h -1 < and the pH is 3.4 to 5.9.

[0151] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 50 to 79 °C, the space velocity is 0.25 to 0.9 h -1 < and the pH is 3.4 to 5.9.

[0152] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 70 to 79 °C, the space velocity is 0.25 to 0.9 h -1< and the pH is 3.4 to 5.9, in particular after preheating in a process step a1) to 30 to 75 °C.

[0153] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 70 to 79 °C, the space velocity is 0.25 to 0.9 h -1< and the pH is 3.4 to 5.9, in particular after preheating in a process step a1) to 30 to 70 °C.

[0154] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 30 to 95 °C, the space velocity is 0.25 to 1.5 h -1 < and the pH is 2.5 to 6.0.

[0155] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 50 to 95 °C, the space velocity is 0.25 to 1.5 h -1 < and the pH is 2.5 to 6.0.

[0156] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 70 to 95 °C, the space velocity is 0.25 to 1.5 h -1< and the pH is 2.5 to 6.0, in particular after preheating in a process step a1) to 30 to 80 °C.

[0157] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 70 to 95 °C, the space velocity is 0.25 to 1.5 h -1< and the pH is 2.5 to 6.0, in particular after preheating in a process step a1) to 30 to 75 °C.

[0158] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 70 to 95 °C, the space velocity is 0.25 to 1.5 h -1< and the pH is 2.5 to 6.0, in particular after preheating in a process step a1) to 30 to 70 °C.

[0159] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 30 to 79 °C, the space velocity is 0.25 to 1.5 h -1 < and the pH is 2.5 to 6.0.

[0160] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 50 to 79 °C, the space velocity is 0.25 to 1.5 h -1 < and the pH is 2.5 to 6.0.

[0161] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 70 to 79 °C, the space velocity is 0.25 to 1.5 h -1< and the pH is 2.5 to 6.0, in particular after preheating in a process step a1) to 30 to 75 °C.

[0162] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 21.0 MPa, the reaction temperature is 70 to 79 °C, the space velocity is 0.25 to 1.5 h -1< and the pH is 2.5 to 6.0, in particular after preheating in a process step a1) to 30 to 70 °C.

[0163] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 30 to 95 °C, the space velocity is 0.25 to 1.5 h -1 < and the pH is 2.5 to 6.0.

[0164] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 50 to 95 °C, the space velocity is 0.25 to 1.5 h -1 < and the pH is 2.5 to 6.0.

[0165] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 70 to 95 °C, the space velocity is 0.25 to 1.5 h -1< and the pH is 2.5 to 6.0, in particular after preheating in a process step a1) to 30 to 80 °C.

[0166] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 70 to 95 °C, the space velocity is 0.25 to 1.5 h -1< and the pH is 2.5 to 6.0, in particular after preheating in a process step a1) to 30 to 75 °C.

[0167] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 70 to 95 °C, the space velocity is 0.25 to 1.5 h -1< and the pH is 2.5 to 6.0, in particular after preheating in a process step a1) to 30 to 70 °C.

[0168] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 30 to 79 °C, the space velocity is 0.25 to 1.5 h -1 < and the pH is 2.5 to 6.0.

[0169] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 50 to 79 °C, the space velocity is 0.25 to 1.5 h -1 < and the pH is 2.5 to 6.0.

[0170] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 70 to 79 °C, the space velocity is 0.25 to 1.5 h -1< and the pH is 2.5 to 6.0, in particular after preheating in a process step a1) to 30 to 75 °C.

[0171] In a particularly preferred embodiment of the invention, the hydrogen pressure is 16.5 to 18.0 MPa, the reaction temperature is 70 to 79 °C, the space velocity is 0.25 to 1.5 h -1< and the pH is 2.5 to 6.0, in particular after preheating in a process step a1) to 30 to 70 °C.

[0172] In the context of the present invention, a "ruthenium-based catalyst" is understood to mean a catalyst which comprises elemental ruthenium and / or ruthenium oxide and / or a ruthenium-containing compound, for example a ruthenium salt.

[0173] In particular, the catalyst comprises 0.05 to 20.00 wt.%, in particular 0.05 to 5.00 wt.%, 0.10 to 20.00 wt.%, in particular 0.30 to 10.00 wt.%, in particular 0.50 to 5.00 wt.% ruthenium (in each case based on elemental ruthenium and the dry weight of the catalyst).

[0174] In a preferred embodiment, the ruthenium oxide can be sesquioxide, dioxide or tetraoxide.

[0175] In a preferred embodiment, the ruthenium salt can be ruthenium nitrosyl nitrate, ruthenium acetylacetonate, barium perruthenate, sodium perruthenate, a ruthenate such as magnesium, strontium, calcium, silver, barium, potassium or sodium ruthenate, a perruthenate such as sodium or potassium perruthenate, a ruthenium halide such as ruthenium dichloride, ruthenium trichloride, ruthenium tetrachloride, ruthenium pentafluoride, a ruthenium sulfide such as ruthenium disulfide or a chlorine salt of ruthenium such as potassium chloroperruthenate.

[0176] In the context of the present invention, the term "ruthenium" means elemental ruthenium or a ruthenium-containing compound, unless otherwise stated.

[0177] The ruthenium-based catalyst can be a monometallic catalyst, in particular having ruthenium alone as the catalytically active metal, or in a further embodiment can also be a bimetallic catalyst which contains another metal in addition to ruthenium, for example nickel, palladium, platinum, iridium, cobalt, rhenium, osmium, gold, silver, or copper.

[0178] If, according to a preferred embodiment, a bimetallic catalyst is present, this can, in a preferred embodiment, contain 5.00 to 95.00 wt.% ruthenium, preferably at least 50.00 wt.%, in particular at least 55 wt.% ruthenium (in each case based on elemental catalytically active metals and total weight of the catalytically active metals of the catalyst).

[0179] In a particularly preferred embodiment of the present invention, the ruthenium-based catalyst is a catalyst immobilized on a support.

[0180] In a particularly preferred embodiment of the present invention, the carrier is an acidic carrier, in particular an intrinsically acidic carrier, i.e. a carrier which has an acidic effect due to its chemical composition or a carrier which has an acidic effect by applying acidic functions.

[0181] In a particularly preferred embodiment of the present invention, this support is carbon, a metal oxide, in particular aluminum oxide (Al 2 O 3 ), titanium dioxide (TiO 2 ) or silicon dioxide (SiO 2 ), zirconium dioxide (ZrO 2 ), or a zeolite, for example a HY-type zeolite.

[0182] In a particularly preferred embodiment, the catalyst used according to the invention can be prepared in a known manner, as described in the textbook "Technical Catalysis - An Introduction" by Jens Hagen (VCH Weinheim, 1996), by first impregnating or coating the catalyst support with a solution of a ruthenium salt, then drying the thus treated support, heating it and exposing it to a reducing gas stream.

[0183] In process step b) according to the invention, the provided carbohydrate mixture is converted into isomalt and can be obtained, in particular isolated, from the aqueous reaction medium in the subsequent process step c). Conventional isolation methods, for example, crystallization methods, can be used for this purpose.

[0184] In a preferred embodiment, the isomalt in process step c) can be obtained in solid, dry form by appropriate isolation processes, e.g., crystallization and drying processes.

[0185] In a preferred embodiment, the isomalt present in liquid form can be dried by means of evaporators, dryers, in particular spray dryers, falling film evaporators, drum dryers or other conventional devices.

[0186] In a further embodiment, in process step c) the isomalt can be obtained in liquid, for example dissolved or suspended form, in particular by concentration steps, for example evaporation steps or membrane processes.

[0187] In a preferred embodiment, the isomalt obtained in process step c) can be in liquid, semi-liquid or dry form, in particular in crystalline form.

[0188] The present invention also relates to isomalt, which can be prepared by one of the processes according to the invention, in particular obtained in process step c).

[0189] In a preferred embodiment, the isomalt produced according to the invention in process step c) is a sugar substitute having 1,6-GPS and 1,1-GPM as its main components, in particular at least 86.00 wt.% 1,6-GPS and 1,1-GPM (based on the total dry matter content of the isomalt). In a preferred embodiment, this isomalt is a 1,6-GPS and 1,1-GPM-containing mixture with a 1,6-GPS to 1,1-GPM ratio of > 1, in particular 55 to 62 wt.% 1,6-GPS and 38 to 45 wt.% 1,1-GPM (based on the dry matter content of the total amount of 1,6-GPS and 1,1-GPM in isomalt).

[0190] In a particularly preferred embodiment, the isomalt produced according to the invention is a JECFA-compliant isomalt which comprises at least 98.00 wt.% hydrogenated mono- and disaccharides, namely 1,6-GPS, 1,1-GPM, 1,1-GPS, sorbitol and mannitol, and at most 2.00 wt.% secondary components, wherein the isomalt contains at least 86 wt.% 1,6-GPS and 1,1-GPM, 0 to 0.30 wt.% reducing sugars and at most 0.50 wt.%, in particular 0.01 to 0.50 wt.% sucrose (each based on total dry matter of the isomalt).

[0191] Such a JECFA-compliant isomalt is, in a preferred embodiment, a 1,6-GPS and 1,1-GPM-containing mixture with a 1,6-GPS to 1,1-GPM ratio of >1, in particular 55 to 62 wt.% 1,6-GPS and 38 to 45 wt.% 1,1-GPM (based on TS of the total amount of 1,6-GPS and 1,1-GPM in isomalt).

[0192] Isomalt, in particular JECFA-compliant isomalt, can be produced in a preferred embodiment from a carbohydrate mixture containing isomaltulose and sucrose provided in process step a), which comprises 86.00 to 99.99 wt.%, in particular 98.00 to 99.99 wt.% of isomaltulose and at most 0.50 wt.%, in particular 0.01 to 0.50 wt.% of sucrose (in each case TS (dry substance), based on the total TS of the carbohydrate mixture).

[0193] Isomalt, in particular JECFA-compliant isomalt, can in a preferred embodiment be produced from a carbohydrate mixture containing isomaltulose and sucrose provided in process step a), which comprises 86.00 to 99.99 wt.%, in particular 98.00 to 99.99 wt.% of isomaltulose and at most 0.50 wt.%, in particular 0.01 to 0.50 wt.% of sucrose and optionally, adding up to 100 wt.% of the carbohydrate mixture (TS), trehalulose, isomaltose, glucose, fructose and / or oligomers of carbohydrates, wherein, if oligomers of carbohydrates are present, these are present in an amount of at most 0.5 wt.% (in each case TS (dry matter), based on the total TS of the carbohydrate mixture).

[0194] Isomalt, in particular a JECFA-compliant isomalt, can in a preferred embodiment also be produced from an isomaltulose- and sucrose-containing carbohydrate mixture provided in process step a), which comprises 75.00 to 99.49 wt.% isomaltulose, 0.50 to 24.99 wt.% trehalulose and at most 0.50 wt.%, in particular 0.01 to 0.50 wt.% sucrose (in each case TS based on total TS of the carbohydrate mixture).

[0195] Isomalt, in particular a JECFA-compliant isomalt, can in a preferred embodiment also be produced from a carbohydrate mixture containing isomaltulose and sucrose, provided in process step a), which comprises 75.00 to 99.49 wt.% isomaltulose, 0.50 to 24.99 wt.% trehalulose and at most 0.50 wt.%, in particular 0.01 to 0.50 wt.% sucrose and, optionally adding up to 100 wt.% of the carbohydrate mixture (TS), isomaltose, glucose, fructose and / or oligomers of carbohydrates, wherein, if oligomers of carbohydrates are present, they are present in an amount of at most 0.50 wt.% (in each case TS (dry matter), based on the total TS of the carbohydrate mixture.

[0196] Isomalt, in particular a JECFA-compliant isomalt, can in a preferred embodiment also be produced from an isomaltulose- and sucrose-containing carbohydrate mixture provided in process step a), which comprises 75.00 to 86.00 wt.% isomaltulose, 13.99 to 24.99 wt.% trehalulose and at most 0.50 wt.%, in particular 0.01 to 0.50 wt.% sucrose (in each case TS based on total TS of the carbohydrate mixture).

[0197] Isomalt, in particular a JECFA-compliant isomalt, can in a preferred embodiment also be produced from a carbohydrate mixture containing isomaltulose and sucrose, provided in process step a), which comprises 75.00 to 86.00 wt.% isomaltulose, 13.99 to 24.99 wt.% trehalulose and at most 0.50 wt.%, in particular 0.01 to 0.50 wt.% sucrose and, optionally adding up to 100 wt.% of the carbohydrate mixture (TS), isomaltose, glucose, fructose and / or oligomers of carbohydrates, wherein, if oligomers of carbohydrates are present, they are present in an amount of at most 0.50 wt.% (in each case TS (dry matter), based on the total TS of the carbohydrate mixture.

[0198] The present invention also relates to the production of a high-purity isomalt, in particular the isomalt obtained in process step c), which preferably comprises at least 98.00 wt.% hydrogenated mono- and disaccharides, namely 1,6-GPS, 1,1-GPM, 1,1-GPS, sorbitol and mannitol, and at most 2.00 wt.% secondary components, wherein the isomalt contains at least 98.00 wt.% 1,6-GPS and 1,1-GPM, 0 to 0.50 wt.% sorbitol, 0 to 0.50 wt.% mannitol, at most 0.50 wt.%, in particular 0.01 to 0.50 wt.% sucrose, and 0 to 0.30 wt.%, in particular 0.01 to 0.30 wt.% reducing sugars, wherein individual secondary components optionally present in this isomalt are each present in an amount of 0 to 0.50 wt.% and where the sum of all reducing and non-reducing sugars does not exceed 0.50 wt.% (dry matter, based on total dry matter isomalt).

[0199] In a preferred embodiment, a high-purity isomalt can be produced from a carbohydrate mixture containing isomaltulose and sucrose, which is provided in process step a), and which comprises 98.00 to 99.99 wt.% isomaltulose and at most 0.50 wt.%, in particular 0.01 to 0.50 wt.% sucrose (in each case TS (dry substance), based on the total TS of the carbohydrate mixture).

[0200] Such a high-purity isomalt can be produced in a preferred embodiment from a carbohydrate mixture containing isomaltulose and sucrose, which is provided in process step a), and which comprises 98.00 to 99.99 wt.% isomaltulose and at most 0.50 wt.%, in particular 0.01 to 0.50 wt.% sucrose and optionally, adding up to 100 wt.% of the carbohydrate mixture (TS), trehalulose, isomaltose, glucose, fructose and / or oligomers of carbohydrates, wherein if glucose, fructose and / or oligomers of carbohydrates are present, these are each present in an amount of at most 0.5 wt.% (in each case TS (dry matter), based on the total TS of the carbohydrate mixture).

[0201] In a preferred embodiment, this high-purity isomalt is a 1,6-GPS and 1,1-GPM-containing mixture with a 1,6-GPS to 1,1-GPM ratio of >1, in particular 55 to 62 wt.% 1,6-GPS and 38 to 45 wt.% 1,1-GPM (based on TS of the total amount of 1,6-GPS and 1,1-GPM in isomalt).

[0202] In a particularly preferred embodiment, the JEFCA-compliant or high-purity isomalt obtained in process step c) contains at least 98.80 wt.%, preferably at least 99.00 wt.%, preferably at least 99.10 wt.% of hydrogenated mono- and disaccharides, in particular disaccharide alcohols (in each case based on the dry matter of the isomalt).

[0203] In a particularly preferred embodiment, the isomalt provided comprises at least 98.00, in particular at least 98.20 wt.%, preferably at least 98.50 wt.%, preferably at least 98.60 wt.%, preferably at least 98.70 wt.% of 1,6-GPS, 1,1-GPM and 1,1-GPS, preferably 1,6-GPS and 1,1-GPM (each based on the total dry weight of the isomalt).

[0204] In a preferred embodiment, the isomalt obtained in process step c) preferably comprises 0.01 to 0.45 wt.%, in particular from 0.01 to 0.42 wt.% sucrose, in particular from 0.01 to 0.49 wt.%, in particular 0.01 to 0.20 wt.%, in particular 0.01 to 0.04 wt.%, in particular 0.10 to 0.50 wt.%, in particular 0.02 to 0.04 wt.%, in particular 0.02 to 0.03 wt.% sucrose (in each case based on the total dry weight of the isomalt).

[0205] In a particularly preferred embodiment, the isomalt obtained in process step c) comprises at least 98.00 wt.%, preferably at least 98.20 wt.%, preferably at least 98.50 wt.% disaccharide alcohols, in particular 1,6-GPS and 1,1-GPM and optionally 1,1-GPS, and 0.01 to 0.40 wt.%, preferably 0.01 to 0.03 wt.% sucrose, 0.01 to 0.30 wt.% reducing sugars, at most 0.50 wt.% sorbitol and at most 0.50 wt.% mannitol, wherein the sum of all sugars, in particular isomaltulose, isomaltose, sucrose, fructose and glucose is at most 0.50 wt.% (TS, dry substance in each case based on TS isomalt).

[0206] In one embodiment, the isomalt obtained in process step c) preferably comprises at least 98.00 wt.% 1,6-GPS and 1,1-GPM and 0.01 to 0.05 wt.% sucrose (each TS, in each case based on TS isomalt).

[0207] In a particularly advantageous embodiment, isomalt enriched with 1,6-GPS is provided. Compared to 1,1-GPM, 1,6-GPS has a stronger sweetening power and higher solubility in water. In a particularly preferred embodiment of the present invention, the weight ratio of 1,6-GPS to 1,1-GPM in the resulting isomalt is > 1.

[0208] In a particularly preferred embodiment, the isomalt provided in process step c), in particular the JECFA-compliant isomalt provided, in particular the high-purity isomalt, is an isomalt with a 1,6-GPS to 1,1-GPM ratio of >1, namely 55 to 62 wt.% 1,6-GPS and 38 to 45 wt.% 1,1-GPM (based on TS of the total amount of 1,6-GPS and 1,1-GPM in the isomalt).

[0209] In a particularly preferred embodiment, in process step c) a 1,6-GPS-enriched isomalt is provided, in particular one which contains more than 57.00 to 99.00 wt.%, in particular 58.00 to 99.00 wt.%, of 1,6-GPS and less than 43.00 to 1.00 wt.%, in particular 42.00 to 1.00 wt.%, of 1,1-GPM, in particular 75.00 to 80.00 wt.% of 1,6-GPS and 25.00 to 20.00 wt.% of 1,1-GPM (in each case based on dry matter (DS) of the total amount of 1,6-GPS and 1,1-GPM).

[0210] In a further preferred embodiment, in process step c) isomalt is provided which contains 43.00 to 57.00 wt.% 1,6-GPS and 57.00 to 43.00 wt.% 1,1-GPM (each based on dry matter (DS) of the total amount of 1,6-GPS and 1,1-GPM).

[0211] In a particularly preferred embodiment, the isomalt provided in process step c) does not contain glucose.

[0212] In a particularly preferred embodiment, the isomalt provided does not contain fructose.

[0213] In a preferred embodiment, the isomalt provided does not contain sorbitol. In a preferred embodiment, the isomalt according to the invention does not contain mannitol.

[0214] In a preferred embodiment, the isomalt provided contains no sorbitol, no mannitol, no glucose and no fructose.

[0215] In a preferred embodiment of the invention, the isomalt provided in process step c) contains less than 0.01 wt.%, in particular no isomaltulose.

[0216] In a particularly preferred embodiment, the isomalt obtained in process step c) comprises at most 0.5 wt.%, in particular at most 0.2 wt.%, in particular at most 0.15 wt.%, in particular at most 0.1 wt.%, in particular at most 0.05 wt.%, in particular at most 0.01 wt.% glucose (based on the total weight of the dry substance of the isomalt).

[0217] In a particularly preferred embodiment, the isomalt provided comprises at most 0.5 wt.%, in particular at most 0.2 wt.%, in particular at most 0.15 wt.%, in particular at most 0.1 wt.%, in particular at most 0.05 wt.%, in particular at most 0.01 wt.% fructose (based on the total weight of the dry substance of the isomalt).

[0218] In a preferred embodiment, the isomalt obtained in process step c) comprises at most 0.5 wt.%, in particular at most 0.2 wt.%, in particular at most 0.15 wt.%, in particular at most 0.1 wt.%, in particular at most 0.05 wt.%, in particular at most 0.01 wt.% sorbitol (based on the total weight of the dry substance of the isomalt).

[0219] In a preferred embodiment, the isomalt obtained in process step c) comprises at most 0.5 wt.%, in particular at most 0.2 wt.%, in particular at most 0.15 wt.%, in particular at most 0.1 wt.%, in particular at most 0.05 wt.%, in particular at most 0.01 wt.% mannitol (based on the total weight of the dry substance of the isomalt).

[0220] In a preferred embodiment, the isomalt obtained in process step c) comprises at most 0.2 wt.%, in particular at most 0.1 wt.%, in particular at most 0.05 wt.%, of sorbitol, at most 0.2 wt.%, in particular at most 0.1 wt.%, in particular at most 0.05 wt.%, of mannitol, at most 0.2 wt.%, in particular at most 0.1 wt.%, in particular at most 0.05 wt.%, of glucose and at most 0.2 wt.%, in particular at most 0.1 wt.%, in particular at most 0.05 wt.%, of fructose, wherein the sum of the sugars contained in the isomalt, in particular isomaltulose, isomaltose, sucrose, glucose and fructose, is at most 0.50 wt.% (in each case based on the total weight of the dry matter of the isomalt).

[0221] In a particularly preferred embodiment of the present invention, the isomalt obtained in process step c) comprises 1,6-GPS, 1,1-GPM, and at least one further compound selected from the group consisting of α-D-glucopyranosyl-1,1-D-sorbitol (1,1-GPS), sorbitol, and mannitol. In a preferred embodiment, the sorbitol and mannitol contained in the isomalt do not originate from a sucrose conversion in process step b), but rather from glucose and fructose optionally contained in the carbohydrate mixture used in process step a).

[0222] In a particularly preferred embodiment of the present invention, the isomalt obtained in process step c) contains 50.00 to 60.00 wt.% 1,6-GPS, 35.00 to 45.00 wt.% 1,1-GPM and optionally 0.10 to 15.00, in particular 0.10 to 1.50 wt.%, in particular 0.10 to 1.00 wt.% 1,1-GPS, 0.00 to 0.50 wt.% mannitol, preferably no mannitol, 0.00 to 0.50 wt.% sorbitol, preferably no sorbitol and 0.01 to 0.50 wt.% sucrose, in particular 0.01 to 0.40 wt.%, in particular 0.01 to 0.30 wt.%, in particular 0.01 to 0.20 wt.%, in particular 0.01 to 0.04 wt.%, in particular 0.02 to 0.03 wt.%, in particular 0.03 to 0.04 wt.%, sucrose, preferably consists of this.

[0223] In a particularly preferred embodiment of the present invention, the concentration of sucrose in the isomaltulose- and sucrose-containing carbohydrate mixture provided in step a) up to the isomalt obtained in step c) is kept constant solely by adjusting the process parameters defined in step b). In a particularly preferred embodiment of the present invention, a process for producing isomalt is provided, in which the concentration of sucrose in the isomaltulose- and sucrose-containing carbohydrate mixture provided in process step a) is kept constant in process step b), in particular throughout the entire process, in particular the sucrose content in the isomalt obtained is exactly the same as the sucrose content in the isomaltulose- and sucrose-containing carbohydrate mixture provided.

[0224] In a particularly preferred embodiment of the present invention, the concentration of sucrose between the carbohydrate mixture provided in process step a) and the isomalt obtained in process step c) is kept constant, i.e. sucrose is not cleaved in process step b) and in particular is not cleaved and hydrogenated.

[0225] In a particularly preferred embodiment of the present invention, the concentration of sucrose between the carbohydrate mixture provided in step a) and the isomalt obtained in step c) is kept constant solely by adjusting the process parameters, i.e. hydrogen pressure, reaction temperature, space velocity and pH, i.e. sucrose is not cleaved in process step b), in particular not cleaved and not hydrogenated.

[0226] In the context of the present invention, "keeping constant" is understood to mean that the carbohydrate mixture provided in process step a) before the reaction in process step b) has the same sucrose content as the isomalt obtained after the reaction in process step c). Therefore, in process step b), the sucrose is not cleaved, in particular not cleaved and not hydrogenated. In a particularly preferred embodiment, the sucrose content is considered constant if, using a GC analysis method (GC-FID) with a limit of quantification of 0.01 g sucrose / 100 g dry matter, no change in the sucrose content occurs during the reaction according to process step b).According to the invention, it is particularly preferred for the determination of the sucrose contents before and after the reaction according to process step b) to determine the sucrose content (the two values obtained form a measurement pair) several times in each case, in particular 4 times, and to determine an average value for the sucrose content before and an average value for the sucrose content after carrying out process step b) (mean value determination by means of the upper bound method).

[0227] In a preferred embodiment, the sucrose content is considered to be kept constant if the mean value of the sucrose content in the carbohydrate mixture corresponds to the sucrose content in the isomalt obtained or if no significant difference is found between the mean values of the sucrose contents in the carbohydrate mixture and in the isomalt obtained by means of a difference t-test.

[0228] For the calculation using the difference t-test, the following formula is used using the obtained mean and measured values: τ = x ¯ A − x ¯ B 1 n − 1 ⋅ ∑ Δ x i − Δ x ¯ 2 ⋅ n where (x A ) is the mean value of the component content in the carbohydrate mixture, (x B ) is the mean value of the component content in the isomalt, (Δx) is the difference of the mean values (x A - x B ), (Δx i ) is the difference of the respective measurement pairs A (carbohydrate mixture) - B (isomalt), (n) is the number of measurement pairs of the carbohydrate mixture and the isomalt and (τ) is the test statistic.

[0229] A significant difference (99.9% significance level) between the mean values of the sucrose contents in the carbohydrate mixture and in the isomalt exists for n = 4 if the test statistic (τ) is greater than (t) = 12.924 (99.9% significance level, 3 degrees of freedom).

[0230] An optional separation of sucrose, in particular in a process step a0), before carrying out process step b) remains unaffected.

[0231] In a particularly preferred embodiment of the present invention, the isomalt can be used to produce products for human and / or animal consumption or pharmaceutical products.

[0232] The present invention therefore also relates to products for human and / or animal consumption or pharmaceutical products containing isomalt according to the invention.

[0233] In a preferred embodiment, the product for human consumption is a food or luxury item such as a confectionery, a filling for confectionery, hard and / or soft caramels, a fondant, a yogurt, a pastry, a chewing gum, an ice cream, a dairy product, a fruit preparation, a jam, a jelly or a smoothie.

[0234] Hard caramels made from at least 96.00% by weight of isomalt according to the invention (based on the total weight of the hard caramel) have a water absorption of a maximum of 1.30% by weight, in particular 1.20% by weight, in particular 1.10% by weight, in particular 1.00% by weight, in particular 0.90% by weight, in particular 0.80% by weight (each based on the total weight of the hard caramel) when stored open for three days at 30 °C and 65% relative humidity.

[0235] Hard caramels made from at least 96.00 wt.% of isomalt according to the invention (based on the total weight of the hard caramel) have a maximum water absorption of 6.0 wt.%, in particular 5.50 wt.%, in particular 5.00 wt.%, in particular 4.50 wt.%, in particular 4.00 wt.%, in particular 3.50 wt.%, in particular 3.00 wt.% (each based on the total weight of the hard caramel) when stored open for three days at 25 °C and 80% relative humidity.

[0236] The present invention therefore also relates to hard caramels containing isomalt according to the invention, in particular containing at least 96.00 wt.% of isomalt according to the invention (based on the total weight of the hard caramels), in particular hard caramels which are characterized by the maximum water absorptions specified above under the specified conditions.

[0237] Further advantageous embodiments emerge from the subclaims.

[0238] The invention is explained in more detail using the following example. Example Hydrogenation of isomaltulose, trehalulose and sucrose-containing solutions

[0239] The hydrogenations were carried out in a continuous high-pressure reactor using the trickle-bed process. The carbohydrate mixtures identified in Table 1 below were dissolved in water and preheated. 1.5% Ru / Al 2 O 3 spheres were used as catalyst. The reaction conditions used in the reactor (pressure, pH, LHSV, and reaction temperature), as well as the dry matter contents of isomaltulose, trehalulose, and sucrose, as well as glucose and fructose, in the total dry matter (dry matter) of the carbohydrate mixture to be hydrogenated (determined by GC-FID), are listed in Table 1.

[0240] The carbohydrate mixtures used according to reaction numbers 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, and 23 were heated to temperatures of 47.4 °C, 48.2 °C, 46.2 °C, 55.5 °C, 58.5 °C, 67.3 °C, 45.0 °C, 54.4 °C, 58.0 °C, 63.5 °C, 66.5 °C, 68.5 °C, 70.9 °C, 103 °C, 103 °C, 103 °C, 103 °C, 68 °C, 103 °C, 67.3 °C, 105 °C, 67 °C, and 105 °C and then reacted in the reactor at the reaction temperature specified in Table 1. Reaction numbers 14 to 23 represent non-inventive comparative runs. Table 1 Reaction No. Hydrogen pressure [MPa] PH value [-] LHSV [h -1< ] Reaction temperature [°C] TS-Isomaltulose [wt.%] TS-Trehalulose [wt.%] TS sucrose [wt.%] TS fructose [wt.%] TS glucose [wt.%] TS ref. [g / 100 g] 1 16,5 3,4 0,58 71,1 99,08 0,66 0,02 0,08 0,05 41,62 2 16,5 4,3 0,58 70,5 98,96 0,67 0,02 0,07 0,05 40,83 3 16,5 5,1 0,48 69,5 98,76 0,69 0,02 0,09 0,10 40,58 4 16,5 4,8 0,67 77,8 98,88 0,75 0,02 0,08 0,06 41,36 5 16,5 4,9 0,77 81,2 98,88 0,77 0,02 0,07 0,05 41,47 6 16,5 5,3 0,87 91,0 98,78 0,82 0,02 0,07 0,06 41,90 7 17,5 3,0 0,28 69,7 99,11 0,60 0,03 0,06 0,06 41,27 8 17,5 4,4 0,65 80,8 99,08 0,68 0,02 0,05 0,05 41,45 9 17,5 5,6 0,37 83,5 98,60 0,81 0,05 0,10 0,09 40,61 10 17,5 5,5 0,65 90,0 98,79 0,62 0,02 0,04 0,07 41,65 11 17,5 5,1 0,56 92,3 98,88 0,67 0,02 0,08 0,10 41,14 12 17,5 5,9 0,46 95,0 98,88 0,77 0,02 0,07 0,05 41,47 13 17,5 5,4 0,56 98,3 98,76 0,76 0,03 0,09 0,11 41,64 14 17,5 5,8 0,35 110,0 98,60 0,65 0,50 0,06 0,05 41,56 15 17,5 5,6 0,35 110,0 99,02 0,55 0,06 0,09 0,03 41,37 16 17,5 5,5 0,38 120,0 98,49 0,65 0,50 0,05 0,06 41,59 17 17,5 3,0 0,47 120,0 91,00 0,48 6,96 0,09 0,13 42,72 18 5,0 3,8 0,47 91,0 92,12 0,48 7,04 0,09 0,12 42,79 19 5,0 4,8 0,47 120,0 99,07 0,49 0,05 0,09 0,13 42,74 20 5,0 4,0 0,47 89,9 98,96 0,61 0,04 0,06 0,04 42,84 21 6,0 2,4 0,47 121 98,96 0,59 0,03 0,07 0,05 41,36 22 6,0 2,6 0,47 90 92,27 0,54 6,85 0,10 0,07 43,08 23 6,0 2,5 0,47 120 92,27 0,54 6,85 0,10 0,07 43,08 (Weight percentages based on total dry matter) (TS ref. is the dry matter content determined by refractometer) (Reaction numbers 14 to 23 represent non-inventive comparative runs) Table 2a Reaction No. TS-1,6-GPS [wt%] TS-1,1-GPM [wt.%] TS-1,1-GPS [wt%] TS-Mannitol [wt.%] TS sorbitol [wt.%] TS-Isomaltulose [wt.%] TS-Trehalulose [wt%] TS sucrose [wt%] 1 58,96 39,91 0,33 0,03 0,09 <0,01 <0,01 0,02 2 58,72 39,98 0,27 0,02 0,07 <0,01 <0,01 0,02 3 59,45 39,40 0,31 0,03 0,09 <0,01 <0,01 0,02 4 58,65 40,06 0,34 0,03 0,08 <0,01 <0,01 0,02 5 58,63 40,25 0,26 0,02 0,05 <0,01 <0,01 0,02 6 57,98 40,67 0,37 0,03 0,08 <0,01 <0,01 0,02 7 58,01 41,13 0,30 0,03 0,02 <0,01 <0,01 0,03 8 57,60 41,47 0,34 0,02 0,07 0,03 <0,01 0,02 9 57,52 41,46 0,30 0,04 0,10 0,03 <0,01 0,05 10 56,88 42,00 0,35 0,08 0,04 0,04 <0,01 0,02 11 56,47 42,23 0,38 0,03 0,09 <0,01 <0,01 0,02 12 56,71 41,75 0,34 0,02 0,05 <0,01 <0,01 0,02 13 56,11 42,15 0,41 0,04 0,10 <0,01 <0,01 0,03 14 49,24 43,55 1,66 0,20 0,28 <0,01 <0,01 0,22 15 49,11 43,95 1,73 0,05 0,12 <0,01 <0,01 0,02 16 48,16 43,10 1,90 0,19 0,30 <0,01 <0,01 0,18 17 42,29 40,22 1,78 1,87 4,27 <0,01 <0,01 0,24 18 52,20 39,78 0,18 1,07 3,31 0,05 <0,01 2,63 19 48,05 39,73 1,78 0,04 0,16 <0,01 <0,01 0,02 20 55,1 41,78 0,36 0,03 0,10 0,01 <0,01 0,01 21 43,82 40,20 2,36 0,49 1,01 <0,01 <0,01 <0,01 22 51,63 39,44 0,43 0,41 1,48 <0,01 <0,01 4,66 23 42,49 39,40 1,95 1,79 4,30 <0,01 <0,01 0,02 (Weight percentages based on total dry substance) (Reaction numbers 14 to 23 represent non-inventive comparative runs) Table 2b Reaction No. TS glucose [wt.%] TS fructose [wt.%] TS ref. [g / 100 g] Total TS 1,1-GPM and 1,6-GPS [wt.%] Total dry matter hydrogenated mono- and disaccharides [wt.%] Total secondary components [wt.%] Isomaltulose conversion [mol-%] Selectivity Isomalt [1,1-GPM and 1,6-GPS] [mol-%] 1 <0,01 <0,01 41,90 98,87 99,32 0,68 >99,99 99,20 2 <0,01 <0,01 40,98 98,70 99,06 0,94 >99,99 99,15 3 <0,01 <0,01 41,13 98,85 99,29 0,71 >99,99 99,51 4 <0,01 <0,01 41,66 98,71 99,15 0,85 >99,99 99,24 5 <0,01 <0,01 41,21 98,88 99,21 0,79 >99,99 99,41 6 <0,01 <0,01 41,79 98,65 99,12 0,88 >99,99 99,28 7 <0,01 <0,01 41,70 99,14 99,55 0,45 >99,99 99,44 8 <0,01 <0,01 41,34 99,07 99,50 0,50 99,97 99,40 9 <0,01 <0,01 40,96 98,98 99,42 0,58 >99,99 99,80 10 <0,01 <0,01 41,77 98,88 99,34 0,66 99,96 99,51 11 <0,01 <0,01 41,68 98,70 99,20 0,80 >99,99 99,23 12 <0,01 <0,01 41,06 98,46 98,88 1,12 >99,99 98,99 13 <0,01 <0,01 41,96 98,26 98,81 1,19 >99,99 98,91 14 <0,01 0,01 42,34 92,79 94,93 5,07 >99,99 93,56 15 <0,01 <0,01 42,27 93,06 94,96 5,04 >99,99 93,43 16 <0,01 <0,01 42,52 91,26 93,65 6,35 >99,99 92,12 17 0,11 0,03 43,04 82,51 89,75 10,25 >99,99 90,14 18 0,04 0,20 44,49 91,98 96,54 3,46 99,95 99,26 19 <0,01 <0,01 43,04 87,78 89,76 10,24 >99,99 88,09 20 <0,01 <0,01 43,18 96,88 97,35 2,65 99,99 97,32 21 0,10 0,03 41,96 84,01 87,87 12,13 >99,99 84,40 22 0,19 0,23 43,73 91,07 93,39 6,61 >99,99 98,12 23 0,04 0,04 43,64 81,89 89,94 10,06 <99,99 88,23 (Weight percentages are based on the total dry matter. Reaction numbers 14 to 23 represent non-inventive comparative runs. For all reaction runs, the sum of hydrogenated mono- and disaccharides was calculated according to the Joint FAO / WHO Expert Committee on Food Additives (JECFA), specification for isomalt (69th JECFA (2008), published in FAO JECFA Monographs 5 (2008)). The sum includes the added weight fractions of 1,1-GPM, 1,6-GPS, 1,1-GPS, mannitol, and sorbitol. The sum of the minor components is the difference between 100 and the sum of the hydrogenated mono- and disaccharides. TS ref. is the dry matter content determined by refractometer.)

[0241] Tables 2a and 2b show the compositions of the isomalts obtained.

[0242] It is shown that, compared to the products of reactions 14 to 23 not prepared according to the invention, a particularly pure isomalt was produced in reactions 1 to 13. Furthermore, it is shown that, surprisingly, the sucrose content remained constant from the sucrose content of the carbohydrate mixtures used in reactions 1 to 13 up to the resulting isomalt, whereas the content of 1,6-GPS, 1,1-GPM, and 1,1-GPS increased and the content of isomaltulose decreased.

Claims

1. A method for continuous production of isomalt from an isomaltulose- and sucrose-containing carbohydrate mixture, comprising the method steps a) Provision of an isomaltulose- and sucrose-containing carbohydrate mixture present in an aqueous medium, containing 75.00 to 99.99 wt.% isomaltulose and 0.01 to 0.50 wt.% sucrose (each DM (dry matter), based on total DM of the carbohydrate mixture), of hydrogen and a ruthenium-based catalyst, b) Conversion of the carbohydrate mixture to isomalt by continuously bringing the carbohydrate mixture present in the aqueous medium into contact with the ruthenium-based catalyst and hydrogen at a space velocity of 0.25 to 1.5 h-1, at a hydrogen pressure of 16.0 to 22.0 MPa and a pH of 2.0 to 6.0 to obtain an isomalt-containing product stream while setting a reaction temperature of at most 100 °C and c) Obtaining the isomalt.

2. The method of claim 1, wherein the isomaltulose and sucrose-containing carbohydrate mixture provided in method step a) was obtained by enzymatic conversion of sucrose or a sucrose-containing starting mixture with a sucrose-glucosylmutase.

3. The method of claim 2, wherein the isomaltulose and sucrose-containing carbohydrate mixture obtained by enzymatic conversion with a sucrose-glucosyl mutase from sucrose or a sucrose-containing starting mixture is subjected to a method step a0) for reduction of the sucrose content to a content of 0.01 to 0.50 wt.% sucrose (dry matter based on total dry matter of the carbohydrate mixture).

4. The method of one of claims 1 to 3, wherein in method step b) a reaction temperature of 70 °C to 95 °C, in particular 70 °C to 91 °C, is set.

5. The method of one of the preceding claims, wherein after method step a) and before method step b) the carbohydrate mixture provided in method step a) is preheated in a method step a1), in particular to a temperature of 30 to 80 °C, in particular 30 to 75 °C, in particular 30 to 70 °C.

6. The method of one of the preceding claims, wherein the isomaltulose is converted in method step b) at a conversion rate of 99 to 100 mol%, in particular 99.5 to 100 mol%.

7. The method of one of the preceding claims, wherein the isomaltulose in method step b) is converted with a selectivity of 97 to 100 mol%, in particular 98 to 100 mol%, to 1,6-GPS (6-O-α-D-glucopyranosyl-D-sorbitol) and 1,1-GPM (1-O-α-D-glucopyranosyl-D-mannitol).

8. The method of one of the preceding claims, wherein the isomaltulose- and sucrose-containing carbohydrate mixture provided in method step a) has 86 to 99.99 wt.% isomaltulose, in particular 98 to 99.99 wt.% isomaltulose, and 0.01 to 0.50 wt.% sucrose (each DM based on total DM of the carbohydrate mixture).

9. The method of one of claims 1 to 7, wherein the isomaltulose- and sucrose-containing carbohydrate mixture provided in method step a) has 75.00 to 99.49 wt.% isomaltulose, 0.30 to 24.99 wt.% trehalulose and 0.01 to 0.50 wt.% sucrose (each DM based on total DM of the carbohydrate mixture).

10. Method of one of the preceding claims 1 to 7 and 9, wherein the carbohydrate mixture provided in step a) has 75 to 86.00 wt.% isomaltulose, 0.01 to 0.50 wt.% sucrose and 13.99 to 24.99 wt.% trehalulose (each based on dry matter of the carbohydrate mixture).

11. The method of one of the preceding claims 1 to 10, wherein the dry matter content of the carbohydrate mixture present in the aqueous medium is 35 to 45 wt.% (based on total weight of the medium).

12. The method of one of the preceding claims, wherein the ruthenium-based catalyst is a catalyst immobilized on a carrier.

13. The method of one of the preceding claims, wherein the ruthenium-based catalyst is a monometallic or a bimetallic catalyst.

14. The method of claim 12 or 13, wherein the carrier is carbon, a metal oxide, in particular Al2O3, TiO2, SiO2, ZrO2 or a zeolite.

15. The method of one of the preceding claims, wherein the ruthenium content of the catalyst is 0.05 to 5.00 wt.%.

16. The method of one of the preceding claims, wherein the pH value in method step b) is 2.0 to 5.5.

17. The method of one of the preceding claims, wherein the concentration of sucrose in the carbohydrate mixture provided in step a) is kept constant up to the isomalt obtained in step c) solely by setting the method parameters defined in step b).

18. The method of one of the preceding claims, wherein the isomalt obtained in step c) has at least 98.00 wt.% hydrogenated mono- and disaccharides, at least 86.00 wt.% 1,6-GPS and 1,1-GPM, 0.01 to 0.50 wt.% sucrose and at most 0.30 wt.% reducing sugars (each DM (dry matter), each based on DM isomalt).

19. The method of one of the preceding claims, wherein the isomalt obtained in step c) has at least 98.00 wt.% hydrogenated mono- and disaccharides, at least 98.00 wt.% 1,6-GPS and 1,1-GPM, 0.01 to 0.50 wt.% sucrose, at most 0.30 wt.% reducing sugars, 0 to 0.50 wt.% sorbitol and 0 to 0.50 wt.% mannitol, wherein single secondary components possibly present in this isomalt are each present in an amount of 0 to 0.50 wt.% and wherein the sum of all reducing and non-reducing sugars is at most 0.50 wt.% (each DM (dry matter), each based on DM isomalt).

20. The method of one of the preceding claims, wherein the isomalt obtained in step c) is sorbitol-free.