Process for insoluble fiber composition

Abstract

The present invention relates to a process for preparing for preparing an insoluble fiber composition having a reduced amount of sulphur dioxide. The present inventors have demonstrated that the sulphur dioxide content can be eliminated up to 100% without adversely affecting the nutritional value content of the insoluble fiber composition.

Description

PROCESS FOR INSOLUBLE FIBER COMPOSITIONCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of European Application No. 24179521.0, filed June 3, 2024, which is incorporated by reference herein in its entirety.FIELD OF THE INVENTION

[0002] The invention relates to a process for preparing an insoluble fiber composition having a reduced amount of sulphur dioxide. The present invention further relates to the insoluble fiber composition obtainable from said process. The present invention further relates to a use of a reducing agent to remove sulphur dioxide from an insoluble com fiber composition.BACKGROUND OF THE INVENTION

[0003] Consumer demand for healthy superfoods is driving the market for insoluble fibers. This market has also benefited from a growing body of research linking regular intake of insoluble fibers to lower risk of gastrointestinal diseases, such as irritable bowel syndrome (IBS). In addition, increasing consumer awareness on the role of insoluble fibers in lowering the risk of diverticulitis, constipation, and managing weight loss are all driving market growth. Food manufacturers are thus looking to include insoluble fibers in their products in order to appeal to the ever more health-driven consumer.

[0004] Thus, there is a growing need in the food industry for more sources of natural plantbased insoluble fibers.

[0005] One type of insoluble fiber with commercial potential is insoluble corn fiber (also referred to as corn hull fiber or com bran fiber), which can be extracted from com, mainly from the tough fibrous outer layer or hull of the corn kernel or corn bran. Insoluble corn fiber is high in lignocellulosic components with cellulose and hemicellulose making up the majority of the composition. Insoluble corn fiber refers herein to both low and high molecular weight insoluble dietary fibers found in corn. Insoluble corn fiber comprises at least 30 wt.% on a dry weight basis of hemicellulose, at least 10 wt.% on a dry weight basis of cellulose and at least 1 wt.% on a dry weight basis of lignin.

[0006] Compositions rich in com bran / fiber are normally obtained as a by-product from the production of com starch. These are generally referred to as corn gluten feed and are currentlywidely used in animal feed. This is sold either wet to animal farms in the proximity of the plant, or first dried for easier transportation over longer distances.

[0007] To date, com fibers / bran ingredients suitable for human consumption have limited availability on the market. Those corn fiber materials that have made it to the market have limited properties due to the way they have been extracted, which make it unsuitable for several different types of applications. Valorization of the by-products from wet-milled corn starch production to prepare a food-grade composition rich in insoluble corn fibers is one of the challenges the industry is facing. Several aspects render insoluble corn fibers obtained from the wet-milling process difficult to use for human consumption and in various food products.

[0008] The wet-milling process in corn starch extraction involves the use of an aqueous sulfur dioxide solution. The com is steeped in this solution to soften the kernel so that the protein matrix is weakened allowing the starch granules to separate out cleanly. The sulfur dioxide also serves as an anti -microbial agent. According to European regulations in order to be safe for human consumption the sulphur dioxide content should be less than 40 ppm in the final insoluble com fiber ingredient. Sulphur dioxide is however also a known allergen. In order to avoid labelling with an allergen warning, the ingredient is required to have less than 10 ppm of sulphur dioxide. A frequently used method to remove the sulphur dioxide is treatment of the insoluble corn fiber with hydrogen peroxide (H2O2) solutions.

[0009] W02022 / 060992 Al discloses an insoluble com fiber composition having good water absorption capacity, which can be used in processed meats and plant-based meat alternatives.

[0010] WO2017 / 165748 Al discloses a corn protein product having a free sulfite concentration of less than 150 ppm.

[0011] However, there remains a need to find an effective process that can remove the high sulphur dioxide content from insoluble fiber-rich side-streams coming from the wet-milling processing of com thereby affording an insoluble corn fiber composition having a low sulphur dioxide content.

[0012] Hence, in a first object of the invention a process for preparing an insoluble com fiber composition with a reducing agent having a reduced sulphur dioxide content is provided.

[0013] In a further object of the invention a use of ozone to reduce the sulphur dioxide content in an insoluble fiber composition is provided.

[0014] In a further object of the invention an insoluble corn fiber composition obtainable from said process having reduced sulphur dioxide levels is provided.SUMMARY OF THE INVENTION

[0015] The present invention provides in a first aspect a process for preparing an insoluble corn fiber composition comprising the following steps: i) Providing a fibrous composition comprising insoluble com fiber, wherein the fibrous composition has a water content of at least 40 wt.% relative to the fibrous composition; ii) Treating the fibrous composition with ozone; iii) Drying the fibrous composition to obtain an insoluble corn fiber composition comprising insoluble com fiber having a water content of less than 15 wt.%.

[0016] The present inventors have demonstrated that by treating a fibrous composition comprising insoluble corn fiber with ozone up to 100% of the present sulphur dioxide in the insoluble corn fiber is reduced whilst retaining the nutritional content, as shown in the appended examples.

[0017] Without wishing to be bound by any theory the present inventors believe that the ozone oxidizes the sulphur dioxide to sulphite and ultimately to sulphate anions. Furthermore, the present inventors suggest that the chemical structure of com bran exhibits remarkable resistance to the oxidative effects of ozone and they believe that this resilience arises from the intricate and highly branched fiber structures that virtually encapsulate the nutritional components within the bran. Consequently, these complex fibers serve as a protective barrier, preventing ozone-induced deterioration of the com bran’s nutritional constituents. Additionally, there is no chemical pathway identified for the oxidation of sulphur dioxide with ozone resulting in the production of toxic compounds.

[0018] In a further aspect the present invention provides an insoluble com fiber composition obtainable from said process having reduced sulphur dioxide levels.

[0019] In a further aspect the present invention provides a use of ozone to reduce the sulphur dioxide content in an insoluble fiber composition.DETAILED DESCRIPTION

[0020] The term "comprising", as used herein and in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It needs to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression "a composition comprising components A and B" should not be limited to compositions consisting only of components A and B. It means that with respect to the present invention, the only relevantcomponents of the composition are A and B. Accordingly, the terms "comprising" and "including encompass the more restrictive terms "consisting essentially of and "consisting of .Process

[0021] In a first aspect the invention provides a process for preparing an insoluble corn fiber composition comprising the following steps: i) Providing a fibrous composition comprising insoluble corn fiber, wherein the fibrous composition has a water content of at least 40 wt.% relative to the fibrous composition, preferably at least 50 wt.%, more preferably at least 55 wt.%; ii) Treating the fibrous composition with ozone; iii) Drying the fibrous composition to obtain an insoluble corn fiber composition comprising insoluble com fiber having a water content of less than 15 wt.%, preferably less than 12 wt.%, more preferably less than 10 wt.%, most preferably less than 8 wt.%.Step i)

[0022] Preferably, the fibrous composition comprising insoluble corn fiber provided in step i) is obtainable as a side-stream from the wet-milling processing of corn. This side-stream is usually the side-stream richest in the insoluble fibres from corn. This is usually the side-stream used to prepare corn gluten feed for animals. However, these side-streams are also rich in sulphur dioxide originating from the steeping solution in the wet-milling process. The fibrous composition before step ii) may have a sulphur dioxide content of at least 100 ppm, or at least 150 ppm or at least 200 ppm relative to the fibrous composition. The fibrous composition before step (ii) may have a sulphur dioxide content of at most 500 ppm, or at most 400 ppm, or at most 300 ppm relative to the fibrous composition. The fibrous composition before step (ii) may have a sulphur dioxide content between 100 and 500 ppm, or between 150 and 400 ppm, or between 200 and 300 ppm relative to the fibrous composition.

[0023] Sulphur dioxide content of the fibrous composition comprising insoluble corn fiber or the insoluble com fiber composition comprising insoluble corn fiber can be measured according to AOAC 962.16.Step ii)

[0024] Preferably, the fibrous composition is treated with gaseous ozone, wherein the gaseous ozone comprises ozone in amount of at least 5 ppm relative to the gaseous ozone, more preferably at least 8 ppm, most preferably at least 10 ppm. Preferably the gaseous ozone comprisesozone in amount of at most 200 ppm relative to the gaseous ozone, more preferably at most 100 ppm, most preferably at most 50 ppm. Preferably, the gaseous ozone comprises ozone in an amount between 5 and to 200 ppm relative to the gaseous ozone, preferably between 8 and 100 ppm, more preferably between 10 and 50 ppm.

[0025] Preferably, the fibrous composition is treated with an aqueous ozone solution comprising ozone in an amount between 0.80 and 1.30 ppm, preferably between 0.85 and 1.20 ppm, more preferably between 0.90 and 1.15 ppm, relative to the aqueous ozone solution.

[0026] The process according to the invention does not require an enzymatic treatment step. The process to obtain the composition from step (iii) does not comprise an enzymatic treatment step starting from step (i) through to step (iii).

[0027] In step (ii) the fibrous composition is treated in order to remove sulphur dioxide down to levels acceptable for human consumption z.e., below 40 ppm. Below 40 ppm sulphur dioxide is generally considered to be safe. However, some people are sensitive to it and may develop allergic reactions, such as asthma. Thus, sulphur dioxide levels below 10 ppm are preferred by many food manufacturers.

[0028] It was surprisingly found that treatment of the fibrous composition comprising insoluble fiber with ozone, preferably the gaseous ozone as defined herein or the aqueous ozone solution as defined herein, more preferably the gaseous ozone, results in reducing the sulphur dioxide content of the insoluble corn fiber composition down to acceptable levels less than 40 ppm, preferably less than 30 ppm, more preferably less than 20 ppm, even more preferably less than 15 ppm, most preferably less than 10 ppm relative to the insoluble com fiber composition. The sulphur dioxide content of the insoluble com fiber composition may even be less than 5 ppm relative to the insoluble corn fiber composition, preferably less than 3 ppm, more preferably less than 1 ppm. Most preferably the insoluble corn fiber composition is substantially free of sulphur dioxide. By "substantially free" it is meant herein that sulphur dioxide is below the detection limits of the measurement method.

[0029] As appreciated by the skilled person at least 75% of the amount of sulphur dioxide present in the fibrous composition comprising insoluble com fiber is removed, or worded differently oxidized to e.g. sulphite or sulphate, preferably at least 80%, more preferably at least 85%, even more preferably at least 90%, even more preferably at least 95%, most preferably substantially all or 100% of the sulphur dioxide is removed. By "substantially all" it is meant herein that sulphur dioxide is below the detection limits of the measurement method.

[0030] The fibrous composition comprising insoluble corn fiber may be treated with the gaseous ozone as defined herein. The fibrous composition comprising insoluble corn fiber may beplaced in a chamber, preferably an ozone chamber, wherein the gaseous ozone can be supplied to. The gaseous ozone is generated with a gaseous ozone production equipment. The present invention is not limited to a specific gaseous ozone production equipment and any commercially available gaseous ozone production equipment can be used. The concentration of the ozone in the gaseous ozone can be adjusted with gaseous ozone production equipment.

[0031] Preferably, the fibrous composition comprising insoluble com fiber is treated with the gaseous ozone for at least 5 minutes, preferably at least 15 minutes, more preferably at least 20 minutes, even more preferably at least 25 minutes, most preferably at least 30 minutes. Preferably, the fibrous composition comprising insoluble corn fiber is treated with the gaseous ozone for at most 2 hours, preferably at most 1.5 hour, more preferably at most 1 hour. Preferably, the fibrous composition comprising insoluble corn fiber is treated with the gaseous ozone for between 5 minutes and 2 hours, preferably between 15 minutes and 1.5 hour, more preferably between 30 minutes and 1 hour.

[0032] More preferably, the fibrous composition in step ii) is treated with the gaseous ozone, wherein- the gaseous ozone comprises ozone in an amount between 5 and to 200 ppm relative to the gaseous ozone, preferably between 8 and 100 ppm, more preferably between 10 and 50 ppm; and- the fibrous composition comprising insoluble corn fiber is treated with the gaseous ozone for between 5 minutes and 2 hours, preferably between 15 minutes and 1.5 hour, more preferably between 30 minutes and 1 hour.

[0033] Alternatively, the fibrous composition comprising insoluble corn fiber may be treated with the aqueous ozone solution as defined herein. The aqueous ozone solution is prepared by treating an aqueous solution with ozone gas generated with an aqueous ozone production equipment. The present invention is not limited to a specific aqueous ozone production equipment and any commercially available aqueous ozone production equipment can be used. As appreciated by the skilled person the aqueous ozone solution is prepared by treating an aqueous solution with gaseous ozone thereby affording the aqueous ozone solution as defined herein. The fibrous composition comprising the insoluble corn fiber is mixed with the aqueous ozone solution, wherein between 100 and 200 g of the insoluble fiber composition, preferably between 125 and 175 g, more preferably about 150 g, is placed in 1 to 10 liters of the aqueous ozone solution, preferably 3 to 6 liters, more preferably about 5 liters, wherein preferably the treatment time is between 1 second and 1 minute, preferably between 5 seconds and 30 seconds. Alternatively, the fibrous composition is washed with the aqueous ozone solution between 10 seconds and 10minutes, preferably between 20 seconds and 8 minutes, more preferably between 2 minutes and 6 minutes, and with a flow between 1 and 10 liters between 1 second and 1 minute, preferably between 2 and 8 liters between 1 second and 30 seconds, more preferably about 5 liters per 15 seconds of the aqueous ozone solution.

[0034] Preferably, the fibrous composition is treated with the gaseous ozone as described herein. Advantageously, this eliminates the need for additional water to treat the fibrous composition.

[0035] The treatment of the fibrous composition with ozone in step ii) may occur at a temperature between 10 and 40 °C, preferably between 15 and 35 °C, more preferably between 20 and 30 °C. As appreciated by the skilled person no additional heating step is needed to remove the sulphur dioxide with the gaseous ozone or the aqueous ozone solution from the fibrous composition comprising insoluble corn fiber.

[0036] Moreover, after treatment with the gaseous ozone or the aqueous ozone solution the ozone does not remain in the composition, but the gaseous ozone is safely removed from the fibrous composition or the aqueous ozone solution is volatilized. Hence, the insoluble corn fiber composition according to the composition comprises less than 5 ppm ozone on a dry weight basis, preferably less than 3 ppm ozone, more preferably less than 2 ppm ozone, most preferably less than 1 ppm ozone. Preferably, the insoluble corn fiber composition according to the composition comprises between 0 and 5 ppm ozone on a dry weight basis, preferably between 0 and 3 ppm ozone, most preferably between 0 and 1 ppm ozone. The insoluble corn fiber composition may also be substantially free of ozone. By "“substantially free"” it is meant herein below the detection limits of the measurement methods.Step iii)

[0037] After drying the insoluble corn fiber composition comprising insoluble corn fiber has a water content of less than 15 wt.%, preferably less than 12 wt.%, more preferably less than 10 wt.%, most preferably less than 8wt.% relative to the insoluble corn fiber composition. Preferably, the insoluble corn fiber composition has a water content of at least 1 wt.%, more preferably at least 1.5 wt.%. most preferably at least 2 wt.%, relative to the insoluble corn fiber composition. Preferably, the insoluble corn fiber composition has a water content between 1 wt.% and 15 wt.%, more preferably between 1.5 and 10 wt.%. most preferably between 2 and 8 wt.%, relative to the insoluble corn fiber composition. The water content can be measured by heating to evaporate all residual water until no water is detected in the IR spectrum and weighing the composition before and after the evaporation The difference in weight equals the amount of waterthat was in the sample. From this the wt.% of water can be calculated.

[0038] Preferably, the drying in step (iii) takes place in a vacuum dryer, tunnel dryer, fluidized bed dryer, or flash dryer.

[0039] When the dryer is a vacuum dryer, tunnel dryer, flash dryer or fluidized bed dryer, the temperature in the dryer is preferably from 100 to 125 °C, more preferably from 105 to 125 °C, and the residence time of the fibrous composition in the dryer is from 5 seconds to 10 minutes, preferably from 5 seconds to 5 minutes, more preferably from 7 seconds to 600 seconds, even more preferably from 10 seconds to 45 seconds, preferably 12 to 20 seconds. The shorter the residence time, the higher the capacity at which the drying can be run.

[0040] When the dryer is a vacuum dryer, tunnel dryer or fluidized bed dryer, the temperature in the dryer can also be between 50 to 99 °C. However, at these lower temperatures, the residence time of the fibrous composition in the dryer is much longer, preferably from 30 minutes to 4 hours, more preferably from 45 minutes to 3 hours, even more preferably from 1 to 2 hours, most preferably from 1 to 1.5 hours.Step iv) and v)

[0041] After the drying step iii) the insoluble corn fiber composition may be subjected to the following steps: iv) milling the insoluble com fiber composition; and v) sieving the milled insoluble com fiber composition to obtain a sieved insoluble corn fiber composition having a D50 particle size of less than or equal to 290 pm, preferably less than or equal to 180 pm.

[0042] Preferably, the D50 particle size is less than or equal to 250 pm, or less than or equal to 220 pm, or less than or equal to 200 pm, or less than or equal to 180 pm, or less than or equal to 150 pm, or less than or equal to 120 pm, or less than or equal to 110 pm. More preferably, the D50 particle size is less than or equal to 250 pm, and most preferably less than or equal to 220 pm. The D50 particle size may be from 50 pm to 250 pm, or from 50 pm to 220 pm, or from 50 pm to 200 pm, or from 50 pm to 180 pm, or from 50 pm to 150 pm, or from 80 pm to 120 pm, or from 90 pm to 110 pm, or around 100 pm. By D50 is meant the median particle size whereby 50% of the particles by volume have a particle size smaller than that value and 50% of the particles by volume have a particle size greater than that value. Particle size and particle size distribution D50 can be measured using laser diffraction, for instance a laser diffraction analyzer such as a Mastersizer 3000.

[0043] Moreover, the process to obtain the composition from step (v) does not comprisean enzymatic treatment step starting from step (iv) through to step (v).

[0044] This fractionation may be performed by any suitable method known in the art, such as milling / grinding followed by sieving. As the dried composition obtained in step iii) is elastic in nature, preferably the milling / grinding to reduce the particle size is done using a hammer mill. Other milling / grinding equipment equivalent to hammer mills capable of handling and milling such types of elastic compositions can also be used. The milled composition can then be sieved in order to obtain a composition having a D50 particle size as defined above.Nutritional value

[0045] The present invention relates to a process for preparing an insoluble corn fiber composition. Preferably, the insoluble com fiber composition has a content of at least 50 wt.% insoluble corn fiber, more preferably the composition comprises at least 55 wt.%, even more preferably at least 60 wt.%, most preferably at least 65 wt.% of insoluble corn fiber on a dry weight basis.

[0046] Insoluble com fiber refers to both low and high molecular weight insoluble dietary fibers found in corn. Insoluble corn fiber may comprise at least 30 wt.%, preferably at least 50 wt.%, more preferably at least 60 wt.%, most preferably at least 70 wt.%, on a dry weight basis of hemicellulose. Insoluble com fiber may comprise between 10 and 90 wt.%, preferably between 20 and 80 wt.%, more preferably between 30 and 60 wt.%, on a dry weight basis of hemicellulose.

[0047] Furthermore, insoluble corn fiber may comprise at least 10 wt.%, preferably at least 20 wt.%, preferably at least 25 wt.%, more preferably at least 28 wt.% on a dry weight basis of cellulose. Insoluble corn fiber may comprise between 1 and 50 wt.%, preferably between 5 and 30 wt.%, more preferably between 10 and 30 wt.%, on a dry weight basis of cellulose.

[0048] Furthermore, insoluble com fiber may comprise at least 1 wt.%, preferably at least 1.5 wt.%, preferably at least 2 wt.%, more preferably at least 2.5 wt.% on a dry weight basis of lignin. Insoluble corn fiber may comprise between 1 and 20 wt.%, preferably between 1.5 and 15 wt.%, more preferably between 2 and 10 wt.%, on a dry weight basis of lignin.

[0049] The amount of insoluble corn fiber can be measured according to method AO AC 2011.25.

[0050] The insoluble com fiber composition prepared by the process according to the invention consists of or essentially consists of components extracted or derived from corn, preferably extracted or derived from the wet-milling processing of corn.

[0051] The insoluble com fiber composition prepared by the process according to the invention may comprise not only insoluble corn fiber, but may also comprise, for instance,moisture (e.g. water), soluble fiber, starch, protein, and / or lipids.

[0052] The insoluble corn fiber composition may comprise from 0.01 wt.% to 80 wt.%, preferably from 0.1 wt.% to 70 wt.%, or from 1 wt.% to 60 wt.% as the total amount of total dietary fiber on a dry weight basis. The amount of total dietary fiber is measured according to method AO AC 991.43.

[0053] The insoluble corn fiber composition may comprise of from 0.01 wt.% to 50 wt.%, or from 0.1 wt.% to 45 wt.%, or from 1 wt.% to 40 wt.% as the total amount of starch, protein and fat on a dry weight basis.

[0054] The insoluble corn fiber composition may comprise of from 0.01 wt.% to 30 wt.%, or from 0.05 wt.% to 25 wt.%, or from 0.1 wt.% to 20 wt.% of starch on a dry weight basis. The amount of starch is measured according to method TS EN ISO 10520.

[0055] The insoluble corn fiber composition may comprise of from 0.01 wt.% to 25 wt.%, or from 0.05 wt.% to 20 wt.%, or from 0.1 wt.% to 16 wt.% of protein on a dry weight basis. The amount of protein is measured according to method AOAC 960.52. Alternatively, the protein content may be measured according to the Kjeldahl method. The Kjeldahl method is a well-known method to analyze protein content, such as com protein content.

[0056] The insoluble corn fiber composition may comprise of from 0.01 wt.% to 15 wt.%, or from 0.05 wt.% to 10 wt.%, or from 0.1 wt.% to 5 wt.% of lipids on a dry weight basis. The amount of lipids is measured according to method TS EN ISO 659.

[0057] The insoluble corn fiber composition may comprise of from 0.01 wt.% to 15 wt.% moisture, or from 0.05 wt.% to 15 wt.%, or from 0.1 wt.% to 10 wt.% of moisture on a dry weight basis. The moisture content is measured according to method TS EN 150 712.

[0058] The content of each component described herein z.e., cellulose, hemicellulose, lignin, moisture, starch, protein and fat, can be measured as discussed herein or according to standard methods known in the art.

[0059] The composition according to the invention may have an ash content of from 0.01 wt.% to 5 wt.%, or from 0.05 wt.% to 0.3 wt.%, or from 0.1 wt.% to 2 wt.% on a dry weight basis. Ash content may be measured according to standard methods known in the art.

[0060] The present inventors have demonstrated that by treating the fibrous composition comprising insoluble fiber with ozone, preferably the gaseous ozone as defined herein or the aqueous ozone solution as defined herein, more preferably the gaseous ozone, the nutritional value content of the insoluble com fiber composition is not changed substantially. In particular, the protein content, the total dietary fiber content and / or the total lipid content is not changed substantially. Worded differently, the nutritional value content of the fibrous compositioncomprising insoluble corn fiber provided in step i) of the process of the invention is not changed substantially after treatment of the fibrous composition comprising insoluble com fiber with the gaseous ozone or the aqueous ozone solution as defined herein. “Not changed substantially” means that that difference in nutritional content, preferably the protein content, the total dietary fiber content and / or the total lipid content, between the fibrous composition comprising insoluble corn fiber provided in step i) and the insoluble com fiber composition obtained after treatment with the gaseous ozone or the aqueous ozone solution is less than 10 wt.%, preferably less than 5 wt.%, more preferably less than 4 wt.%, even more preferably less than 3 wt.%, even more preferably less than 2 wt.%, even more preferably less than 1 wt.%, even more preferably less 0.5 wt.%, even more preferably less than 0.1 wt.%, most preferably less than 0.01 wt.%.Use

[0061] The present invention provides in a second aspect a use of gaseous ozone to reduce the sulphur dioxide content in an insoluble corn fiber composition, wherein the amount of ozone is at least 5 ppm, relative to the gaseous ozone. As appreciated by the skilled person all features related to the process for preparing the insoluble corn fiber composition as explained under the first aspect of the invention apply mutatis mutandis to the use of the gaseous ozone as defined in the second aspect of the invention. For example, all features related to the amount and identity of the insoluble corn fiber composition, the gaseous ozone, the sulphur dioxide amounts and the nutritional components such as proteins, lipids or fiber content, explained in the context of process for preparing the insoluble corn fiber composition are equally applicable to the use of the gaseous ozone.

[0062] The present invention provides in a third aspect a use of an aqueous ozone solution to reduce the sulphur dioxide content in an insoluble corn fiber composition, wherein the aqueous ozone solution comprises ozone in an amount between 0.80 and 1.30 ppm, preferably between 0.85 and 1.20 ppm, more preferably between 0.90 and 1.15 ppm, relative to the aqueous ozone solution. As appreciated by the skilled person all features related to the process for preparing the insoluble corn fiber composition as explained under the first aspect of the invention apply mutatis mutandis to the use of the gaseous ozone as defined in the second aspect of the invention. For example, all features related to the amount and identity of the insoluble com fiber composition, the aqueous ozone solution, the sulphur dioxide amounts and the nutritional components such as proteins, lipids or fiber content, explained in the context of process for preparing the insoluble corn fiber composition are equally applicable to the use of the aqueous ozone solution.Product-by-process

[0063] The present invention provides in a fourth aspect the insoluble corn fiber composition obtainable by the process for preparing the insoluble com fiber composition as defined in the first aspect of the invention. As appreciated by the skilled person all features related to the process for preparing the insoluble corn fiber composition as explained under the first aspect of the invention apply mutatis mutandis to the insoluble corn fiber composition obtainable by the process for preparing the insoluble corn fiber composition as defined in the first aspect of the invention. For example, all features related to the amount and identity of the insoluble corn fiber composition, the gaseous ozone, the sulphur dioxide amounts and the nutritional components such as proteins, lipids or fiber content, explained in the context of process for preparing the insoluble corn fiber composition are equally applicable to the_insoluble corn fiber composition obtainable from the process for preparing the insoluble corn fiber composition as defined in the first aspect of the invention.

[0064] Although certain aspects of the invention have been described, the scope of the appended claims is not intended to be limited solely to these specific aspects. The claims are to be constmed literally, purposively, and / or to encompass equivalents. The scope of the present invention is defined by the appended claims. One or more of the objects of the invention are achieved by the appended claims.EXAMPLESMethods

[0065] Statistical significance was analyzed using one-way ANOVA (analysis of variance) to determine differences between different exposure time of ozone and different initial amount of SO2. JMP 5.0.1 (SAS Institute) was used to conduct statistical analysis, and the Tukey, multiple comparison test, was used to compare means (p < 0.05). Exposure time experiments were conducted in parallel as given in table of experimental design.Materials

[0066] Untreated wet corn bran (control) has been provided from Cargill Orhangazi Plant. A commercially available gas ozone device was used to generated gaseous ozone. Alternatively, a commercially available aqueous ozone device was used to see the effect of liquid ozone form on sulphur dioxide in corn bran. Untreated corn bran obtained in the natural bran production process has sulphur dioxide levels between 30 and 200 ppm. Sulphur dioxide levels are measured according to method AO AC 962.16. A sulphur dioxide enriched corn bran has been prepared byinjecting sulphur dioxide to an untreated com bran sample. The sulphur dioxide enriched com bran sample has 334 ppm sulphur dioxide. It is noted that such high sulphur dioxide levels are not observed in untreated corn bran obtained in the conventional bran production process.Experimental setup of gaseous ozone, aqueous ozone and aqueous H2O2Gaseous ozone

[0067] The untreated corn bran (100-150 g) was placed in an ozone cabine and treated with gaseous ozone generated with the gas ozone device with different exposures times. The concentration of the gaseous ozone was 40 ppm. The amount of sulphur dioxide was measured again after treatment with ozone. Results are shown in Table 1.Aqueous ozone

[0068] 150 g of the untreated corn bran was added to 5 liters of an aqueous ozone solution having an ozone concentration between 0.94 ppm and 1.13 ppm, relative to the aqueous solution. The bran was filtered after 15 seconds and the sulphur dioxide concentration was measured. Results are shown in Table 1.ResultsTable 1 : treatment of com fiber with gaseous ozone and aqueous ozone

[0069] Table 2 shows the protein content, total dietary fiber content, the starch content and the lipid content for EX2. There is no significant difference in nutritional value content between the untreated com barn and the ozone treated corn bran.Table 2: the protein content, total dietary fiber content, starch and lipid content for untreated corn bran and EX2.

Claims

CLAIMS1. A process for preparing an insoluble corn fiber composition comprising the following steps: i) Providing a fibrous composition comprising insoluble corn fiber, preferably wherein the fibrous composition is obtainable as a side-stream from the wet-milling processing of corn, wherein the fibrous composition has a water content of at least 40 wt.% relative to the fibrous composition, preferably at least 50 wt.%, more preferably at least 55 wt.%; ii) Treating the fibrous composition with gaseous ozone, wherein the gaseous ozone comprises ozone in amount of at least 5 ppm relative to the gaseous ozone, or an aqueous ozone solution, wherein the aqueous ozone solution comprises ozone in an amount of at least 0.80 ppm, relative to the aqueous ozone solution; iii) Drying the fibrous composition to obtain an insoluble corn fiber composition comprising insoluble corn fiber having a water content of less than 15 wt.%, preferably less than 12 wt.%, more preferably less than 10 wt.%, most preferably less than 8 wt.%.

2. The process according to claim 1, wherein the fibrous composition in step i) has a sulphur dioxide content of at least 100 ppm or at least 150 ppm or at least 200 ppm, relative to the fibrous composition.

3. The process according to claim 1 or 2, wherein the amount of ozone in the gaseous ozone is between 5 and 200 ppm, preferably between 8 and 100 ppm, more preferably between 10 and 50 ppm relative to the gaseous ozone.

4. The process according to claim 1 or 2, wherein the amount of ozone in the aqueous ozone solution is between 0.80 and 1.30 ppm, preferably between 0.85 and 1.20 ppm, more preferably between 0.90 and 1.15 ppm.

5. The process according to any one of claims 1-4, wherein treating the composition with ozone in step ii) is between 5 minutes and 2 hours, preferably between 15 minutes and 1.5 hour, more preferably between 30 minutes and 1 hour.

6. The process according to any one of claims 1-5, wherein the insoluble com fiber composition obtained in step iii) has a sulphur dioxide content of less than 40 ppm, preferably less than 20 ppm, more preferably less than 10 ppm, relative to the insoluble corn fiber composition.

7. The process according to any one of claims 1-6, wherein at least 75% of the amount of sulphur dioxide present in the fibrous composition is removed after step ii), preferably at least 80%, more preferably at least 90%.

8. The process according to any one of claims 1-7, wherein the insoluble com fiber composition comprises at least 30 wt.% on a dry weight basis of hemicellulose and, at least 10 wt.% on a dry weight basis of cellulose, and at least 1 wt.% on a dry weight basis of lignin.

9. The process according to any one of claims 1-8, wherein the insoluble com fiber composition comprises• between 10 and 90 wt.%, preferably between 20 and 80 wt.%, more preferably between 30 and 60 wt.%, on a dry weight basis of hemicellulose; and / or• between 1 and 50 wt.%, preferably between 5 and 30 wt.%, more preferably between 10 and 30 wt.%, on a dry weight basis of cellulose; and / or• between 1 and 20 wt.%, preferably between 1.5 and 15 wt.%, more preferably between 2 and 10 wt.%, on a dry weight basis of lignin.

10. The process according to any one of claims 1-9, wherein the insoluble com fiber composition obtained in step iii) is further subjected to the following steps: iv) milling the insoluble com fiber composition; and v) sieving the milled insoluble corn fiber composition to obtain a sieved insoluble corn fiber composition having a D50 particle size of less than or equal to 290 pm, preferably less than or equal to 180 pm.

11. The process according to any one of claims 1-10, wherein the nutritional value content on a dry basis of the insoluble corn fiber composition is not changed substantially.

12. The process according to any one of claims 1-11, wherein the temperature in the dryer is between 100 to 125 °C and the residence time of the fibrous composition in the dryer isfrom 5 seconds to 10 minutes, preferably 5 seconds to 5 minutes, more preferably 7 seconds to 60 seconds, even more preferably from 10 to 45 seconds, most preferably 12 to 20 seconds.

13. The process according to any one of claims 1-12, wherein the temperature in the dryer is between 50 and 99 °C and the residence time of the fibrous composition in the dryer is from 30 minutes to 4 hours, preferably from 45 minutes to 3 hours, more preferably from 1 to 2 hours, most preferably from 1 to 1.5 hours.

14. The insoluble corn fiber composition obtainable from the process according to any one of claims 1-13.

15. Use of gaseous ozone ozone to reduce the sulphur dioxide content in an insoluble com fiber composition, wherein the amount of ozone is at least 5 ppm relative to the gaseous ozone.

16. Use of an aqueous ozone solution to reduce the sulphur dioxide content in an insoluble corn fiber composition, wherein the aqueous ozone solution comprises ozone in an amount of at least 0.80 ppm, relative to the aqueous ozone solution.

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