Nutritional foods with low levels of allergens

Abstract

A method for processing oats is provided, comprising the steps of a) providing oat grains, b) heat-treating the oat grains at a temperature in the range of 95-100°C, c) processing the oat grains in a disc mill having discs to obtain ground oat grains, and d) separating the ground oat grains in terms of size to obtain at least one finer product fraction and at least one coarser fraction. Technical effects include the ability to provide oat flour with reduced levels of prolamins in specific compounds that cause food sensitivities and food disorders in patients diagnosed with celiac disease. This method is suitable for large-scale production because at least the separation is performed dry. Since all oat grains are recoverable and can be used for various applications, there is no need to discard any portion of the oat grains.

Description

Technical Field

[0001] The present invention relates to a method for preparing and separating various parts from oat grains in order to minimize the amount of specific proteins / peptides that may cause food allergies and food disorders. Further provided are several flours produced using the method, and nutritious foods such as bread made using raw materials produced according to this method.

Background Art

[0002] A gluten-free diet is currently the only effective means of treating patients with celiac disease (CD). Such a diet enables celiac disease patients to control their symptoms and avoid complications associated with this disease. However, in recent years, although the quality of gluten-free foods has improved, maintaining a gluten-free diet does not necessarily guarantee sufficient nutrient intake. Since oats are an important source of protein, lipids, vitamins, minerals, and dietary fiber, incorporating oats into a gluten-free diet may improve the nutritional status of celiac disease patients. Oats are included in the list of gluten-free raw materials approved by European regulations, but there is still room for discussion regarding their safety when consumed by celiac disease patients. Some studies claim that pure oats are safe for most people with celiac disease, but contamination with other grains such as wheat can be a major problem faced by people with celiac disease. However, oats include many varieties, and it is necessary to consider that they contain various amino acid sequences showing different immunoreactivities related to toxic prolamins. As a result, it has been clarified from several studies that the immunogenicity of oats varies depending on the variety consumed. Therefore, it is essential to carefully study the variety of oats used as a food raw material before including it in a gluten-free diet. See Isabel Comino et al., 21(41): 11825-11831, November 7, 2015.

[0003] Gluten-free diets for therapeutic purposes often have nutritional limitations. Oats are popular for use in gluten-free diets due to their nutritional properties, such as protein content, the presence of biologically active and beneficial substances (dietary fiber, beta-glucans, polyunsaturated fatty acids, essential amino acids, antioxidants, vitamins, and minerals), and their tolerance by the majority of celiac disease patients. The health risks of long-term oat consumption in celiac disease patients are debatable. Introducing oats into the diet is recommended only for celiac disease patients in remission. Furthermore, not all varieties of oats are suitable for gluten-free diets. The risk of sensitization and adverse immune-mediated reactions is a real threat to some celiac disease patients. Several unresolved issues remain, including: (1) determining susceptibility markers in a subgroup of celiac disease patients at risk due to dietary oat intolerance; (2) identifying appropriate oat varieties and estimating safe dietary intake of oats; and (3) optimizing methods for detecting gliadin contamination in raw oats used in gluten-free diets. See Iva Hoffman et al., Nutrients, 2019 Oct; 11(10): 2345.

[0004] Gluten is crucial in dough systems for retaining gas to achieve the desired volume and texture. It is essential for forming a strong protein network necessary to obtain the desired viscoelasticity. Prolamin and glutenin are the main fractions of gluten. Prolamin and glutenin impart viscosity and extensibility to the dough system, while glutenin is responsible for the dough's elasticity and stickiness. Gluten is important not only for appearance but also for the crumb structure of grain-based products. (Ilkem Demirkesen et al., Journal of Food Engineering Vol. 96 Jan. 2010, pp. 295-303.)

[0005] Prolamins are a group of plant storage proteins primarily found in cereals. They are a subgroup of proteins known as seed storage proteins and function as a nutrient source for developing plant embryos. Prolamins are characterized by high content of the amino acid residues proline and glutamine. Different types of cereals contain different prolamins; for example, oats contain avenin. These prolamins contribute to the unique properties of each cereal, such as the elasticity of wheat dough or the thickening properties of cornstarch.

[0006] Prolamins, including avenin and globulin, have historically also included gluten and have attracted attention due to their role in certain food sensitivities and dietary disorders. While oats are inherently gluten-free, they may be grown alongside wheat, barley, and rye, resulting in a risk of contamination by these other grains. This can cause problems for sensitive individuals, including those with celiac disease, irritable bowel syndrome (IBS), or similar gastrointestinal disorders. Some individuals may react to prolamins due to their lectin content, but this is less pronounced than the effects from gluten in wheat, barley, and rye; see Leisova-Svobodova et al., Sci Rep 12, p. 8660 (2022).

[0007] The major storage protein fraction in grains is defined as prolamins based on their solubility in a mixture of alcohol and water and their high content of glutamine and proline. These proteins make up up to 80% by mass in wheat, barley, and rye, but their proportion is lower in oats.

[0008] Wheat-derived proteins (gluten), when mixed with water, form a viscoelastic network, which enables the production of fermented bread and other bakery products. These properties are not shared by prolamins from barley or rye, and therefore wheat has gained increasing importance among bakers. Prolamins from various cereal species are called gliadin (wheat), hordein (barley), or secarin (rye). A further group found in oats is called avenin.

[0009] The safety of oats for people with celiac disease, which is caused by allergens such as gluten, remains unclear. Oats have attractive nutritional properties, which can improve their quality and palatability, but rigorous dietary studies are needed to address the safety of oats. Several key avenin peptides have been identified that stimulate pathogenic gluten-specific T cells in vivo in C.D. patients. One of these peptides is Avena sativa, an allergen belonging to the gliadin / glutenin family. Avenin is one of the most serious causes of celiac disease, also known as celiac plusp or gluten-irritated bowel syndrome. Q09114 is a known allergen in oats and has been selected as representative of allergens in oats because it is well-characterized. Q09114 consists of 182 amino acid residues. Q09114 is a notorious allergen in oats and has been well studied because it causes problems in many sensitive individuals.

[0010] The isolation of the prolamin protein (avenin) in oats, i.e., the allergen, or the analysis of the possibility of gluten contamination or other allergens causing nonspecific effects and symptoms, is essential and therefore forms the basis of this analysis. See Greg. Tanner et al., Front. Nutr. 2019 Oct 15:6:162; Rocher et al., FEBS Lett 310, (1) pp. 37-40 (1992); Michelle Lisa Colgrave et al., Frontiers in Nutrition 2021 May 06 vol B Article 6804 p. 13.

[0011] WO 2019 / 094585 discloses a method comprising the step of tempering whole grains containing a moisture content of 15-20% by mass. The grains are heated to a temperature of approximately 140°C to approximately 160°C for approximately 13-20 minutes, after which they are prepared and ground to form bran, germ components and breadcrumb components.

[0012] WO 2009 / 038938 describes a method for forming oat bran fraction and oat flour fraction. Claim 6 further describes a drying and heating step before grinding, wherein oat grains are heated at about 85-110°C for about 70-110 minutes to obtain roasted oat grains having a moisture content of about 9-14%.

[0013] WO 2008 / 096044 discloses a method for fractionating oats, wherein a lipid concentrate is obtained by extracting unheated oats with a supercritical fluid.

[0014] Moltenberg et al., in Cereal Chem. 73 (5): pp. 579-587, describe a heating procedure before grinding, which includes soaking the oats in water for 2 minutes, steaming them at 100°C for 10 minutes, and drying them in a paper bag at 100°C.

[0015] EP 0937411 discloses a method for producing an oat-containing grain product with improved stability. The claim is that the oat material is obtained by pre-oxidizing threshed, steam-treated, and roasted oat grains, flakes, or flour during roasting at a temperature of 120-135°C for about 2-45 minutes to obtain a pre-oxidized pre-gelatinized oat material having a pre-gelatinization degree of 25-50%. This is followed by heat treatment at 100-250°C for 2 seconds-60 minutes.

[0016] WO 2016 / 099557 describes a water- and energy-saving method for the continuous production of whole grain flour and whole grain gluten-free flour. This method involves pre-conditioning whole grains or seeds with water, followed by energy-efficient blanching using saturated steam. The method aims to reduce water input, energy demand, and carbon dioxide emissions while achieving high yields of the final product. The present invention provides flour having a bimodal particle size mixture, resulting in improved viscosity and biochemical properties. The main steps include washing the grains, mixing and pre-conditioning with water, blanching with saturated steam to partially gelatinize and modify the grains, preparing and cooling the grains, grinding into coarse and fine fractions, drying, and sorting the material. This method can be applied to various grains, including wheat, barley, rye, oats, sorghum, rice, amaranth, and quinoa, as well as legumes such as beans, lentils, and chickpeas. This invention claims to improve the nutritional and sensory properties of flour, making it suitable for baked foods and grain products. It is superior in reducing water and energy use compared to conventional methods and promotes sustainability in grain processing.

[0017] U.S. Patent Application Publication No. 20090078802 describes a method for producing oat products rich in β-glucan by dry grinding oats, particularly for the production of high-β-glucan oat bran and oat flour for use in food ingredients such as instant cereals. The method involves heating and adjusting hulled oats to enhance flavor and inactivate enzymes, followed by dry grinding and fractionation to separate coarser bran fractions from finer flour fractions, and then flaking and grinding steps to increase the β-glucan concentration. The resulting high-β-glucan oat bran contains at least 7-9% β-glucan, while the low-bran oat flour contains less than 3%, both providing improved flavor and partial gelatinization. These oat products can be used to nutritionally fortify foods, providing nutritional benefits such as lower cholesterol due to increased water-soluble dietary fiber, and the method is designed to be cost-effective and commercially viable using existing grinding equipment.

[0018] J. Ray Runyon et al., in the Journal of Cereal Science, volume 65, September 2015, pp. 119-124, investigated the effect of heat treatment on the soluble protein content in oat grains. The total amount of soluble protein (as a percentage of total protein) decreased in heat-treated oats. The ratio of monomers to globulin hexamers and aggregated proteins decreased with heat treatment. It was disclosed that heat treatment selectively removes protein bands associated with albumin and prolamin protein fractions. Globulin proteins were found to be less sensitive to heat treatment. The heat treatment of oats involved steaming at 102°C for 50 minutes, followed by drying at 110-120°C for 50 minutes. [Prior art documents] [Patent Documents]

[0019] [Patent Document 1] WO 2019 / 094585 [Patent Document 2] WO 2009 / 038938 [Patent Document 3] WO 2008 / 096044 [Patent Document 4] EP 0937411 [Non-patent literature]

[0020] [Non-licensed Document 1] Isabel Cominoら、2015 Nov 7; 21(41): 11825~11831 pages [Non-licensed Document 2] Iva Hoffman, Nutrients, 2019 Oct; 11(10): 2345 pages [Non-licensed Document 3] Ilkem Demirkesenら、Journal of Food Engineering Vol. 96 Jan. 2010, pages 295~303 [Non-licensed Document 4] Leisova-Svobodovaら, Sci Rep 12, 8660 pages (2022) [Non-licensed Document 5] Greg. Tanner, Front. Nutr. 2019 Oct 15:6:162 pages [Non-licensed Document 6] Rocher, FEBS Lett 310, (1) pages 37~40 (1992) [Non-licensed Document 7] Michelle Lisa Colgraveら、Frontiers in Nutrition 2021 May 06 vol B Article 680413 pages [Non-licensed Document 8] Moltenberg, Cereal Chem. 73 (5): pages 579~587 [Non-licensed Document 9] J. Ray Runyonら、Journal of Cereal Science, volume 65, September 2015, pages 119~124 [Non-licensed Document 10] E.Hvttnerら、J, of Cereal Science, Vol 52 July 2010, pages 65~71 [Non-licensed Document 11] I. Jokinen et al., LWT Vol 163 15 June 2022 [Non-Patent Document 12] M. Daly et al., Front Nutra. 2020 Jul 17:7:87. Doi: 10.3389 [Non-Patent Document 13] The Vegetable Proteins, 1909 [Non-Patent Document 14] Front. Nutr. 2019, Oct 15:6162 [Overview of the project] [Problems that the invention aims to solve]

[0021] One of the objectives of the present invention is to overcome at least some of the drawbacks of the prior art and to provide a novel dry method for extracting prolamins, specifically certain avenins, from oats, particularly avenins that cause allergic reactions in people diagnosed with celiac disease. [Means for solving the problem]

[0022] In the first embodiment, a method for processing oats, a. A process of providing oat grains, b. A process of heat-treating oat grains at a temperature in the range of 95-100°C, c. A process of processing oat grains in a disc mill with a disc, obtaining conjugates from the crushed oat grains, and obtaining a fraction from the conjugates, d. The process of separating the ground oat grains in terms of size to obtain at least one finer product fraction and at least one coarser fraction. The present invention provides a method that includes a series of steps.

[0023] In a second embodiment, oat flour is provided in which the amount of each protein having accession numbers Q09114, L0L4J1, L0L6J0, L0L5H3, Q2EPY2, L0L5I0, I4EP88, L0L5H5, L0L5G8, L0L6K1, Q09072, Q09071, L0L6J7, L0L837, L0L8A4, and L0L8A0 derived from Avena sativa is reduced by at least 50% by mass.

[0024] In a third embodiment, a nutritional food is provided, wherein the nutritional food is made from at least one component, and the component is made according to the method described above.

[0025] The advantage is that it provides a powder with extremely low levels of prolamin lectins such as avenin.

[0026] This method is suitable for large-scale production because the separation is carried out in a dry manner.

[0027] After separation, both the fine and coarse fractions can be used for various purposes, meaning that no part of the oat grain needs to be wasted.

[0028] Another advantage is that by removing the important components prolamin and glutenin, it becomes possible to produce bread containing a large amount of oats, and this bread is more porous compared to bread baked using oats according to the techniques of this art. Therefore, ordinary porous bread can be baked using oat flour according to the present invention.

[0029] Further embodiments of the present invention are defined in the appended dependent claims.

[0030] The aspects and embodiments will be described with reference to the following drawings. [Brief explanation of the drawing]

[0031] [Figure 1]A schematic diagram of one embodiment of the method according to the present invention is shown, which includes a) a step of providing oats, b) a step of removing the outer husk from the oats to obtain oat grains, c) a step of heat treating the oat grains at a temperature in the range of 95 to 100°C, d) a step of disc milling, and e) a step of size separation. [Figure 2] Two loaves of bread, cut in half lengthwise, are shown. Both are based on the same raw materials and the same recipe containing more than 50% by mass of oats. Bread A is based on hulled oat grains. Bread B is based on finely fractionated depleted prolamin meal according to the present invention. Both passed through a sieve with an opening diameter of 0.300 μm. For chemical analysis of breads A and B, see Table 1 and Table 2. See E. Hvttner et al., J, of Cereal Science, Vol 52 July 2010, pp. 65-71. [Figure 3] The results of Example 3, using a PCA plot that shows sample clustering based on proteome similarity, are shown. PC1 shows the largest variation, while PC2 shows the second largest variation. [Figure 4] The volcano plot obtained from Example 3 is shown. Points on the curve indicate proteins that have changed significantly. After multiple testing based on sorting, filters with p-value 0.05 and FDR 0.05 are set. Downregulation in depleted samples = higher amounts in zero samples. Points below the curve indicate peptides that were not detected in depleted samples. They were detected only in zero samples or were not significant. [Modes for carrying out the invention]

[0032] Before disclosing and describing the present invention in detail, it should be understood that the present invention is not limited to the specific configurations, process steps and materials disclosed herein, because such configurations, process steps and materials may vary mainly for seasonal and / or biological reasons.

[0033] It should be noted that, as used herein and in the appended claims, the singular forms "a," "an," and "the" include multiple references unless the context clearly indicates otherwise.

[0034] In the first embodiment, a method for processing oats, a. A process of providing oat grains, b. A process of heat-treating oat grains at a temperature in the range of 95-100°C, c. A process of processing oat grains in a disc mill equipped with a disc to obtain crushed oat grains, d. The process of separating the ground oat grains in terms of size to obtain at least one finer product fraction and at least one coarser fraction. A method is provided that includes a series of steps.

[0035] The hulling of oats is carried out by known standard methods. In one embodiment, oat grains are purchased. In another embodiment, oat grains are produced by removing the hulls from oats.

[0036] This method can be implemented using both batch processing and continuous processing methods.

[0037] In one embodiment, specific quality standards are applied to the oat grains provided in step a). In another embodiment, the volumetric mass must be at least 700 grams per liter of oat grains. In one embodiment, the amount of gluten in the oat grains for gluten-free food must be less than 20 ppm. In one embodiment, the amount of water should be less than 14% by mass. After heat treatment, the oat grains are hot-air dried, but not heated above 70°C.

[0038] [Table 1]

[0039] Water retention capacity (WHC) is an important coefficient that indicates the effectiveness of hydrothermal treatment applied to grains containing starch and protein, for example, after drying.

[0040] Regarding the water retention capacity (WHC) in the finer fractions, in one embodiment, 0.65 g of water is absorbed per 1 g of dry powder (in the range of 0.54 to 0.75).

[0041] Generally, the water retention capacity of at least one finer product fraction according to the present invention is lower compared to many other similar products. This is due to heat treatment and subsequent separation. This treatment removes certain components, including allergens, as well as oat components that contribute to water retention.

[0042] In one embodiment, the oat grains are heat-treated at approximately 100°C. In one embodiment, the heat treatment is carried out using steam. The oat grains are heat-treated at a temperature of 95-100°C. In one embodiment, the heat treatment is carried out under agitation.

[0043] Heat-treated oat grains are processed in a disc mill between discs that rotate opposite each other. Either one or both discs can rotate. It is important to adjust the distance between the discs according to the size of the oat grains, which in one embodiment is about 0.7 mm. This distance varies depending on the oat grains and can therefore fluctuate. Controlling the distance between the discs is important in determining how much of the outer portion is removed from the oat grains.

[0044] By gradually removing material from the outside of the oat grains during disc grinding, it becomes possible to separate material from the oat surface in any desired amount. This satisfies the requirement that specific proteins / peptides be removed from the remaining grains.

[0045] The long-standing challenges in oat milling have been found to be deeply related to the fat content, as fat tends to impart stickiness, significantly hindering conventional dry milling and sieving methods used over the past few years. As a result of extensive research, the inventors have found that the separation and milling challenges well known to everyone in the art can be solved by the preparation of oats and other grains according to the present invention.

[0046] While not wishing to be bound by any particular scientific theory, the inventors assert, through experience and testing, that careful heat treatment combined with the subsequent disc milling process alters the internal structure of the oat grain, which contributes to the organization of fats, starches, and proteins in the oats into complexes. These complexes can then be separated in a dry state using a special subsequent disc milling process. In a disc mill, the material is fed from the center of the mill, and the milled fraction is collected outside the peripheral part of the discs. In one embodiment, the discs rotate at high speed relative to each other. In another embodiment, the discs rotate at speeds ranging from 2000 to 6000 rpm relative to each other.

[0047] [Table 2]

[0048] Following the disc milling process, the milled oat fractions were separated from each other in terms of size and allergen levels, with the finer fraction (65%) containing low levels of allergens, while the coarser fraction (35%) contained high levels of allergens, β-glucans, proteins, and other beneficial nutrients. This is true for at least some known allergens in oats.

[0049] The advantage is that this grinding process can be carried out on dry grains, and then separation in a sieve is possible in a dry state.

[0050] The fine fraction is a safe food for people with celiac disease. The coarse fraction is useful because it has high content of β-glucan and protein. Both can be used in foods where the prolamin content, including avenin, is not important. Alternatively, β-glucan may be extracted in a further step, which may also be a drying step.

[0051] A qualified report presenting the materials, methods, and results is outlined below, where "N" represents four distinct samples serving as a control group and "D" represents four samples treated according to the present invention.

[0052] In one embodiment, the amount of at least certain proteins and / or peptides known to cause food sensitivities and food disorders in some individuals is reduced in at least one finer product fraction compared to the oat grains provided in step a). In one embodiment, the amount of at least certain allergens in at least one finer product fraction is reduced compared to the oat grains provided in step a). Such proteins / peptides and allergens may be diverse, but in one embodiment, the protein indicated as Q09114 is adopted as a representative protein of this group. In one embodiment, the level of prolamins in at least one finer product fraction is significantly reduced compared to the oat grains provided in step a). The oat grains from step a) constitute the control group, i.e., group "N", and will be the control group in the report described below. In particular, proteins and / or peptides that cause food sensitivities and food disorders in some individuals are reduced to levels that are tolerable for most individuals.

[0053] In one embodiment, the heat treatment in step b) is hydrothermal. The heat treatment in step b) is carried out at a temperature in the range of 95-100°C. In one embodiment, the heat treatment in step b) is carried out for 20-60 minutes. The heat treatment must be carried out at atmospheric pressure. In one embodiment, the heat treatment in step b) is carried out using steam at atmospheric pressure. Depending on the exact air pressure, the steam temperature may vary slightly up to 100°C. In one embodiment, the heat treatment is carried out with stirring, thereby preventing the oat grains from clumping together. This stirring also ensures a complete and uniform temperature rise. Clamping suggests high humidity and, inappropriately, indicates more severe partial gelatinization within certain grain groups. Rotating the stirrer in the process vessel at a low speed may be used for mixing during the heat treatment.

[0054] In one embodiment, the heat treatment in step b) is carried out under atmospheric pressure inside the process vessel by supplying steam until the temperature of the entire process vessel reaches 95-100°C, thereby continuing the treatment for a certain period of time at intervals of 20-60 minutes.

[0055] In one embodiment, a drying step is performed between step b) and step c), which includes supplying heated air to the processed oat grains from step b). The use of heated air is preferred because if steam is used for heat treatment, unexpected high humidity may occur within the grains. The dried grains facilitate subsequent dry separation during grinding and sieving. In another embodiment, the drying step is performed until the moisture content in the processed oat grains is less than 15% by mass, preferably less than 14% by mass, more preferably less than 13% by mass, and most preferably less than 12% by mass. In one embodiment, the drying step is performed by supplying air at a temperature in the range of 50-60°C. Temperatures exceeding 70°C should be avoided during the drying step. This minimizes the risk of undesirable starch changes that could interfere with the future dough manufacturing process. During disc grinding, the process should be monitored to ensure that the oat fraction meets the requirements of the desired properties. The distance between discs is very important and should be matched to the size of the oat grains. In one embodiment, the oat grains need to be separated according to their volume mass before starting step a). If the volume mass is less than 700 g / L, especially if the batch of oat grains is less than 700 g / L, controlled sieving can be an effective measure. It is also possible to use oat grains with a size in the range of 2.0 to 2.2 mm. For such oat grains, the appropriate spacing between discs is approximately 1.05 mm. It is also possible to use larger oat grains. Furthermore, if larger oat grains are used, the distance between discs needs to be adjusted accordingly.

[0056] In one embodiment, the disc mill in step c) has a disc distance in the range of 0.60 to 1.20 mm. In one embodiment, the disc mill in step c) has a disc distance in the range of 0.75 to 1.20 mm. In one embodiment, the disc mill in step c) has a disc distance in the range of 0.70 to 1.10 mm. In one embodiment, the disc mill in step c) had a disc distance of 1.05 to 1.15 mm, preferably 0.90 to 1.10 mm, more preferably 0.95 to 1.05 mm. In an alternative embodiment, the disc mill in step c) had a disc distance in the range of 0.6 to 0.8 mm, preferably 0.68 to 0.75 mm, more preferably 0.68 to 0.72 mm. All changes in spacing are performed manually, assisted in one embodiment by a fixed micrometer device, and frequently checked with a steel gap gauge. The disc needs to be adjusted to the size of the oat grains; a shorter distance is used for smaller oat grains, and a longer distance is used for larger oat grains.

[0057] To obtain a good distribution of various fractions, disc grinding needs to be monitored to ensure that the processing of oat grains follows current guidelines.

[0058] In one embodiment, the rotation direction of the disc mill in step c) can be switched. The discs rotate relative to each other. For example, one disc may rotate while the other remains stationary. Alternatively, both discs may rotate. One or both discs may have various groove patterns, thereby providing further possibilities for fine-tuning the process. The grooves provide further possibilities for fine-tuning the grinding. In one embodiment, a standard corrugated disc is used. In relation to grooved patterns, and especially in grooved discs, it is also possible to change the rotation direction. This provides further possibilities for fine-tuning the characteristics of the disc mill.

[0059] In one embodiment, size separation in step d) is performed by sieving. Sieving is suitable for large-scale separation. In one embodiment, separation in step d) is carried out using sieves with nominal aperture sizes in the range of 430 to 830 μm according to ASTM E11. In one embodiment, separation in step d) is carried out in multiple steps using at least two different sieves. In one embodiment, separation in step d) is first carried out with a first sieve with nominal aperture sizes in the range of 430 to 800 μm according to ASTM E11, and then with a second sieve with nominal aperture sizes in the range of 801 to 1200 μm according to ASTM E11.

[0060] In one embodiment, at least one finer product fraction is recovered and used in food or feed. This finer product fraction is also referred to as oat flour. This finer fraction is suitable for foods where low levels of allergens are desired. Furthermore, since certain animals may be hypersensitive to prolamins containing avenin, the finer fraction can also be used in animal feed.

[0061] In one embodiment, at least one coarser fraction is recovered and used in food or feed. This fraction may be used when the content of prolamins containing avenine is not important and when a high content of β-glucan is desired.

[0062] In one embodiment, at least one coarser fraction is recovered and served for at least one further separation step to concentrate at least β-glucan. β-glucan is a valuable nutrient and can, for example, be used as a food additive. For individuals not hypersensitive to specific components of oats, at least one coarse fraction is also suitable for consumption. A high amount of allergens in at least one coarse fraction is not a problem for individuals who are not hypersensitive or do not have allergies, and at least one coarse fraction contains many compounds useful in food.

[0063] In a second embodiment, oat flour is provided in which the amount of each protein having accession numbers Q09114, L0L4J1, L0L6J0, L0L5H3, Q2EPY2, L0L5I0, I4EP88, L0L5H5, L0L5G8, L0L6K1, Q09072, Q09071, L0L6J7, L0L837, L0L8A4, and L0L8A0 derived from Avena sativa is reduced by at least 50% by mass. The proteins are indicated by their accession numbers, and detailed information about the proteins can be obtained, for example, from the website https: / / www.ncbi.nlm.nih.gov / . All of the proteins mentioned are reduced by at least 50% by mass compared to oats before the reduction treatment. Various proteins can be reduced to varying degrees, but always more than 50% by mass.

[0064] Proteins Q09114, L0L4J1, L0L6J0, L0L5H3, Q2EPY2, L0L5I0, I4EP88, L0L5H5, L0L5G8, L0L6K1, Q09072, Q09071, L0L6J7, L0L837, L0L8A4, and L0L8A0 are present in oats, Avena sativa, and are known to cause problems in hypersensitive individuals. All of these proteins are reduced by at least 50% by mass according to the present invention, i.e., at least 50% by mass of the amount of each protein is removed according to the present invention. In alternative embodiments, at least 65% by mass of the amount of each protein is removed according to the present invention. In alternative embodiments, at least 75% by mass of the amount of each protein is removed according to the present invention. In alternative embodiments, at least 85% by mass of the amount of each protein is removed according to the present invention. The experimental section shows that the remaining amounts of these proteins vary in the range of 2–11 mass%, meaning that 89–98 mass of the protein is removed. The protein reduction is measured as described in the experimental section.

[0065] In one embodiment, oat flour has a water-holding capacity (WHC) of less than 0.6 ml / g product, as measured according to I. Jokinen et al., LWT Vol 163 15 June 2022. This measurement method is used throughout to measure water-holding capacity (WHC).

[0066] In one embodiment, the amount of protein having accession code Q09114 is reduced by at least 90% by mass, preferably at least 95% by mass, and more preferably at least 98% by mass, compared to the original oats. Protein having accession code Q09114 is a well-known and unpopular allergen that can cause problems for sensitive individuals.

[0067] In one embodiment, the oat flour is at least one finer product fraction produced according to the method described above.

[0068] In a second embodiment, oat flour produced using the above method is provided. This flour can be used in food for sensitive individuals, at least for most people of this type.

[0069] In a third embodiment, a nutritional food is provided which is made of at least one ingredient, the ingredient comprising the above-mentioned oat flour.

[0070] In one embodiment, the nutritional food is a food, and at least 52% by mass of the total components is at least one fine product fraction produced according to the method described above. In one embodiment, at least 55% by mass of the total components is at least one finer product fraction. In one embodiment, at least 60% by mass of the total components is at least one finer product fraction. In one embodiment, at least 70% by mass of the total components is at least one finer product fraction. In one embodiment, at least 80% by mass of the total components is at least one finer product fraction.

[0071] In one embodiment, the nutritional food is bread. The use of the finer fraction obtained by this method makes it possible to bake bread with normal porosity. If the bread is baked with oat flour that has not been treated according to the present invention, the bread will be much denser and will not have the desired porosity.

[0072] The porosity of bread refers to the volume fraction of air voids within the bread's structure. This is a measure of the bread's texture, indicating the lightness and breading that result from the fermentation and baking processes. Therefore, the porosity of bread is the ratio of the volume of air gaps (pores) within the bread to the total volume of the bread. Typical bread has a porosity of approximately 40-60%. In one embodiment, the bread has a porosity of at least 40%. In one embodiment, the bread has a porosity of at least 50%. In one embodiment, the bread has a porosity of at least 55%.

[0073] In a third embodiment, a nutritional food is provided, which is made from at least one component, the component being made according to the method described above. Examples of nutritional foods include, but are not limited to, bread and pancakes. Such nutritional foods are highly nutritious and tolerable even for sensitive individuals.

[0074] In one embodiment, bread dough is made using at least one component, and the dough is baked to obtain an excellent nutritional food with a porosity exceeding 52%.

[0075] Other features of the present invention and related advantages will become apparent to those skilled in the art upon reading this specification and the examples. The disclosed embodiments should be understood to be freely combined with all other embodiments, insofar as they do not obviously contradict each other.

[0076] It should be understood that the present invention is not limited to the specific embodiments shown herein. The following examples are provided for illustrative purposes only.

[0077] In the following, each method, apparatus, example, and embodiment described herein is not entirely consistent with the present invention as defined in the claims, and is therefore not part of the present invention, but is presented solely for illustrative purposes or to highlight specific aspects or features of the claims, as is the case with the entire description below. [Examples]

[0078] (Example 1) I purchased oat grains. I analyzed the oat grains and confirmed that they meet the following specifications: • Minimum volumetric weight per liter: 700 grams • Gluten: Less than 20 ppm by mass (to ensure that the oats are not contaminated by other crops). • Maximum moisture content: 14% by mass. Measured according to the official AOAC analytical method.

[0079] Two batches of oat grains, weighing 2000 kg and 500 kg respectively, were filled into a process vessel, and steam was supplied to the vessel. When the internal temperature of the entire vessel reached 99°C, steam was supplied for an additional 37 minutes. After that, the steam supply was cut off, and heated air in the range of 50-60°C was supplied to the processed oat grains to dry them. The oat grains were slowly stirred during steam treatment and drying. The oat grains were dried until the moisture content was 13% by mass.

[0080] The processed and dried oat grains were ground in an Engsko MHA600 disc mill. The discs had grooves running from the inside outwards. The distance between the discs was adjusted to 0.70 mm. This distance was measured using a steel feeler gauge. Therefore, the distance between the discs was measured from the outermost part of the grooved discs, resulting in the shortest distance between them.

[0081] After grinding, the material was sieved using an Engsko FS1000 sieve. The sieving was performed in two stages: the first stage used a sieve with a nominal aperture size of 630 μm in accordance with ASTM E11, and the second stage used a sieve with a nominal aperture size of 1000 μm in accordance with ASTM E11.

[0082] This resulted in one coarse fraction that did not pass through any of the sieves, a fine fraction that passed through the 630 μm sieve, and an intermediate fraction that passed through the 1000 μm sieve.

[0083] (Example 2) A nutritional food intended to use oat flour, free of gluten and prolamin allergens, as a substitute for wheat flour according to the present invention. The gluten- and prolamin-free nutritional food provides a delicious, soft, porous loaf of bread very similar to those sold in supermarkets. Recipe: Mix 50g potato flour, 10g salt, 15g sugar, and 6g psyllium to make the first mixture. Add 5 / 20g dried / live yeast to 430g water warmed to the touch and add it to the first mixture. Gradually add 434g of the fine fraction obtained in Example 1 to obtain the dough. Place the dough in a bread pan. The dough was fermented at 33°C for 45 minutes. The dough was baked in an oven at 200°C until the internal temperature of the loaf of bread reached 99°C. The loaf of bread was placed on a wire rack and covered with a cloth to cool. The amount was reduced by half and inspected (Figure 2).

[0084] (Example 3) Materials and Methods. Four control oat samples (n=4) and four depleted oat samples (n=4) were all produced from the Scandinavian oat 'Belinda' family by Maryhill AB in Helsingborg, Sweden. Prior to the initiation of proteomics analysis, total amino acids and Kjeldahl nitrogen were individually analyzed for both groups (8 samples) by the Eurofins / Steins Laboratory. The depleted oat samples were prepared according to the present invention. See Table 4 (Table 3) for amino acid and Kjeldahl nitrogen data.

[0085] [Table 3]

[0086] method Proteins were extracted from samples using lysis buffer [2% sodium dodecyl sulfate (SDS), 50 mM triethylammonium bicarbonate (TEAB)] and a FastPrep®-24 instrument (MP Biomedicals). Protein concentrations in the lysates were measured using the Pierce® BCA protein assay kit (Thermo Scientific) with bovine serum albumin (BSA) solution as the standard. Samples (30 μg) were processed using the Improved Filter-Assisted Sample Preparation Method (FASP) 17. Briefly, the samples were reduced in 100 mM dithiothreitol (DTT) at 56°C for 30 minutes, transferred to a Microcon-30 kDa centrifugal filter unit (Merck), washed several times with 8 M urea, and then alkylated in 375 mM iodoacetamide (IAA) at room temperature (RT) for 30 minutes. The samples were digested overnight at 37°C with chymotrypsin (Pierce MS-grade chymotrypsin; dilution 1:100; Thermo Fisher Scientific) in digestion buffer (0.5% sodium deoxycholate (SDC), 50 mM TEAB). The following day, additional samples were added and incubated for a further 3 hours. The peptides were recovered by centrifugation and labeled using TMTpro isobaric mass tag reagent according to the manufacturer's instructions. The samples were combined into a single TMT set, and the SDC was removed by acidification (10% trifluoroacetic acid). This set was desalted according to the manufacturer's instructions (Pierce peptide desalting spin column; Thermo Fischer Scientific) and pre-fractionated into 20 fractions using basic reversed-phase chromatography (XBridge BEH C18 column, 3.5 μm, 3.0 × 150 mm; Waters) on a Dionex Ultimate 3000 UPLC system (Thermo Fischer Scientific) with a gradient of 3% to 90% acetonitrile in 10 mM ammonium formate buffer (pH 10) for 25 minutes.

[0087] The analysis and database matching using nanoliquid chromatography-mass spectrometry (nLCMS) were replaced with conventional LC techniques.

[0088] Each fraction was analyzed using an Orbitrap Lumos® Tribrid® mass spectrometer with a FAIMS Pro ion mobility system interfaced to an nLC 1200 liquid chromatography system (all Thermo Fisher Scientific). Peptides were trapped on an Acclaim Pepmap 100 C18 trap column (100 μm × 2 cm, particle size 5 μm, Thermo Fischer Scientific) and separated over 90 minutes at a flow rate of 300 nL / min using a 3% to 80% acetonitrile gradient in 0.2% formic acid solution on a proprietary analytical column (350 × 0.075 mm inner diameter) packed with 3 μm Reprosil-Pur C18-AQ particles (Dr. Maisch, Germany). The FAIMS Pro was used with alternating compensation voltages (CV) between -50 and -70, essentially using the same data-dependent settings for both CVs. Precursor ion mass spectra were acquired at a resolution of 120,000. MS2 analysis was performed in data-dependent mode, in which an isolation window of 0.7 m / z and dynamic exclusion within 10 ppm were applied for 45 seconds to separate the most intense divalent or polyvalent precursor ions at the quadrupole. The separated precursors were fragmented by collision-induced dissociation (CID) at 30% collision energy ("maximum velocity" setting) for 3 seconds and detected by an ion trap. Subsequently, the top 10 MS2 fragment ions were subjected to MS3 multi-notch (simultaneous) separation by high-energy collision dissociation (HCD) at 55% collision energy and detected at Orbitrap at a resolution of 50,000 and in the m / z range of 100–500.

[0089] MS data were matched against the oat database Glurp v5.0 (see M. Daly et al., Front Nutra. 2020 Jul 17:7:87. Doi: 10.3389). Using quantification by isomass tandem mass tagging (TMT), the abundance of peptides and their corresponding proteins was compared at the overall level in parallel across several samples. In this study, 30 μg of pure protein samples were extracted from both proteins in nutrient-depleted oat samples and control oat samples, and then cleaved into peptides using chymotrypsin. Identical peptides from different samples were indistinguishable in their complete form during fractionation, separation, and analysis.

[0090] The classic text "The Vegetable Proteins 1909," reprinted in 1995 by the Cornell University Library Collection, investigated the solubility of plant proteins in alcohol and confirmed it to be 70-90% by mass. Later, Tanner G. et al. reported that the solubility was 85% by mass, and that soluble proteins contained 96% avenin by mass. See Front. Nutr. 2019, Oct 15:6162.

[0091] Table 6 (Table 4) shows the peptide values ​​confirmed in the control group: Mv 1.96025 (n=4). The peptide value confirmed in the depleted group was Mv 0.03975 (n=4). When the depleted peptide value (average 0.03975) is calculated as a ratio to the peptide value in the control group (Mv 1.96025), both cases are represented by the accession code Q09114 for the allergen Avena sativa. However, it is found that steps a to d of the process described on page 7 have an effectiveness rate of 98 percent.

[0092] [Table 4]

[0093] Table 7 (Table 5) confirms similar calculations regarding the proportion of all peptides investigated and their remaining peptides (peptides that have not yet been depleted). However, when searching for potentially pathogenic peptides that cause adverse immune-mediated responses in CD patients, the current top priority is to focus on accession number Q09114.1 of Avena sativa, a specific allergen organism officially classified as causing allergic reactions in humans (Figure 5).

[0094] A 2006 systematic review (project code T07048) by Coeliac UK, a UK-based organization supporting celiac patients, on tolerable levels of gluten in celiac disease patients showed that consuming more than 20 mg of gluten per day clearly caused abnormalities in the intestinal mucosa. Two studies showed that an average daily gluten intake of 34–36 mg did not cause histological changes or clinical symptoms, while another study showed that much lower amounts of gluten (1.5 mg per day) caused CD symptoms. The effects of consuming "gluten-free" products with varying levels of gluten contamination also showed inconsistency across studies. Some individuals tolerated "gluten-free" products according to current Codex standards (less than 20 mg per day), while others developed histological abnormalities when consuming the same products. The researchers concluded that the total amount of gluten consumed over time is likely more important than the concentration of gluten in food. The researchers concluded that there is some evidence suggesting that the current Codex standard of 20 mg of gluten in gluten-free foods does not adequately protect all individuals with celiac disease, and therefore, it may need to be lowered. This study was conducted on September 1, 2006, under project code: T07048 by a UK celiac patient support group.

[0095] In summary, the challenge for the food industry is how to systematize a well-tested set of measures to prevent pathogenic peptides from entering the food chain.

[0096] Therefore, new technologies for safely and effectively isolating prolamins are a crucial strategy. Thus, efforts to improve any technologies developed to be favorable for nutritional foods, leaving no trace of pathogenicity, are important.

[0097] Food allergens are food substances (often proteins) that commonly trigger allergic reactions or other hypersensitivity reactions.

[0098] Official analyses of nitrogen, specific amino acids, and peptides confirm a significant reduction in the suspected prolamin peptide (Avena sativa). Total protein and amino acid results confirm a 22% reduction in protein in the depleted group. Meanwhile, the proteomics laboratory has demonstrated a 98% reduction in the Avena sativa pathogen.

[0099] [Table 5]

[0100] Peptides identified in depleted oat samples and control oat samples were quantified, and the values ​​of variously expressed peptides and their corresponding proteins were compared based on data published by Greg Tanner et al. in Front Nutr. 2019 Oct 15:6162.

[0101] Protein identification and quantification were performed using Proteome Discoverer ver. 2.4 (Thermos Fisher Scientific) against the oat database Glurp v5.0 (see M. Daly et al., Front Nutra. 2020 Jul 17:7:87. Doi: 10.3389) with a peptide tolerance of 5 ppm and a fragment ion tolerance of 0.6 Da. Chymotrypsin was selected as the enzyme, and four cleavage errors were tolerated in the peptide. Oxidation of methionine and proline, as well as modification from N-terminal Gln to pyro-Glu, were set as variable modifications, while cysteine ​​carbamide methylation and tetro reagent modification of lysine and the peptide N-terminus were set as immobilized modifications. The Percolator algorithm was used to validate peptide spectral matching (PSM), with a strict false rejection rate (FDR) threshold of 1%. The TMT reporter ion was identified without normalization with a mass tolerance of 3 mum. Only peptide sequences with a minimum SPS matching rate of 65% and an average signal-to-noise ratio (S / N) greater than 10 were included in the quantification. For protein quantification, unique peptides and other peptides were used, and proteins were grouped by sharing identical sequences to minimize duplication. Protein abundance ratios were calculated using the average abundance of all samples. To estimate the percentage of depletion, the average abundance of depleted samples was verified using heatmap technology. Depletion is indicated by the remaining amount in mass %. The remaining amounts of potentially problematic Avena sativa proteins are shown in Table 7 (Table 5).

[0102] result Global quantitative proteomics analysis, when cross-referenced against the Oat GluProv5.1 database, identified a total of 312 peptides, of which 253 were subject to quantitative evaluation (Note 1). These peptides corresponded to 21 quantified proteins or protein groups, of which 17 were evaluable. Principal component analysis (PCA) was performed to comprehensively evaluate the similarities and differences in peptide profiles between depleted samples and control (zero) samples.

[0103] The results are shown in Figure 3.

[0104] The depleted samples and the control (zero) samples were clustered separately in the PCA plot. The first and second components separated the two groups, accounting for 93% and 4% variability, respectively. Three of the depleted samples were clustered closely together, and the fourth sample (sample 06D) was even further away from the control (zero) samples. The control (zero) samples were grouped in pairs, but were sufficiently far from the depleted samples in the PCA plot. The PCA plots for peptides and proteins showed good correlation as expected.

[0105] Statistical analysis of the quantified peptides revealed 237 different expressed peptides (red in the volcano plot, Figure 4). All of these peptides were significantly downregulated in the depleted samples compared to the control (zero) samples. Only four peptides were not statistically downregulated. However, these peptides belong to the same group of proteins / proteins in which other peptides were significantly downregulated. Therefore, these proteins / proteins are likely to be downregulated in the depleted samples. Twelve peptides were detected in the control (zero) sample group, but were only detected in very small amounts or not at all in the depleted samples. Statistical analysis of the proteins visualized in the volcano plot showed that 16 of the 21 quantified proteins were downregulated. To estimate the depletion of avenin protein, the average abundance in the depleted samples was divided by the average abundance in the control (zero) samples. Depletion of differentially expressed proteins was estimated to range from 2% to 11% by mass, with the exception of one protein whose depletion was estimated at 21% by mass. Depletion is expressed as the remaining mass percentage of the original content.

Claims

1. A method for processing oats, a. A process of providing oat grains, b. A process of heat-treating oat grains at a temperature in the range of 95 to 100°C, c. A process of processing oat grains in a disc mill equipped with a disc to obtain crushed oat grains, d. The process of separating the ground oat grains in terms of size to obtain at least one finer product fraction and at least one coarser fraction. A method comprising a series of steps.

2. The method according to claim 1, wherein the amount of at least certain proteins and / or peptides known to cause food sensitivities and food disorders in some individuals is reduced in at least one finer product fraction compared to the oat grains provided in step a).

3. The method according to claim 1 or 2, wherein the heat treatment in step b) is hydrothermal treatment.

4. The method according to any one of claims 1 to 3, wherein the heat treatment in step b) is carried out in a process vessel under atmospheric pressure by supplying steam until the temperature of the entire vessel reaches at least 95°C, preferably at least 99°C, and thereby the treatment is continued for a certain period of time at intervals of 20 to 60 minutes.

5. A drying step is performed between step b) and step c), the drying step includes supplying heated air to the processed oat grains from step b), and the drying step is performed at a temperature of less than 70°C. The method according to any one of claims 1 to 4.

6. The method according to claim 5, wherein the drying step is carried out until the moisture content of the treated oat grains is less than 15% by mass, preferably less than 14% by mass, more preferably less than 13% by mass, and most preferably less than 12% by mass.

7. The method according to any one of claims 1 to 6, wherein the disc mill in step c) has a distance between discs in the range of 0.60 to 1.20 mm, preferably in the range of 0.70 to 1.10 mm.

8. The method according to any one of claims 1 to 7, wherein the rotation direction of the disc mill in step c) can be switched.

9. The method according to any one of claims 1 to 8, wherein the separation in step d) is carried out by sieving.

10. The method according to any one of claims 1 to 9, wherein the separation in step d) is carried out using a sieve having a nominal aperture size in the range of 430 to 830 μm according to ASTM E11.

11. The method according to any one of claims 1 to 10, wherein the separation in step d) is carried out in multiple steps using at least two different sieves.

12. The method according to any one of claims 1 to 11, wherein the separation in step d) is first carried out with a first sieve having a nominal aperture size in the range of 430 to 800 μm according to ASTM E11, and then carried out with a second sieve having a nominal aperture size in the range of 801 to 1200 μm according to ASTM E11.

13. The method according to any one of claims 1 to 12, wherein at least one finer product fraction is recovered and used in food or feed.

14. The method according to any one of claims 1 to 13, wherein at least one coarser fraction is recovered and used in food or feed.

15. The method according to any one of claims 1 to 14, wherein at least one coarser fraction is recovered and provided to at least one further separation step in which at least β-glucan is concentrated.

16. Oat flour in which the amount of each protein having accession numbers Q09114, L0L4J1, L0L6J0, L0L5H3, Q2EPY2, L0L5I0, I4EP88, L0L5H5, L0L5G8, L0L6K1, Q09072, Q09071, L0L6J7, L0L837, L0L8A4, and L0L8A0 derived from Avena sativa is reduced by at least 50% by mass.

17. The oat flour according to claim 16, having a water retention capacity of less than 0.8 ml / g product, as measured according to I. Jokinen et al. LWT Vol 163, 15 June 2022.

18. The oat flour according to claim 16 or 17, wherein the amount of protein having accession code Q09114 is reduced by at least 90% by mass, preferably at least 95% by mass, and more preferably at least 98% by mass, compared to the original oats.

19. Oat flour according to any one of claims 16 to 18, which is at least one finer product fraction produced according to the manufacturing method described in any one of claims 1 to 15.

20. A nutritional food made of at least one ingredient, wherein at least one ingredient comprises oat flour as described in any one of claims 16 to 19.

21. The nutritional food according to claim 20, wherein at least 52% by mass of the total components is at least one finer product fraction produced according to the method of any one of claims 1 to 16.

22. The nutritional food according to claim 20 or 21, which is bread.

23. The nutritional food according to claim 22, wherein the bread has a porosity of more than 40%.

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