Cereal flakes

Abstract

The present invention relates to a method for producing a whole grain cereal flake product containing at least 4.0% (w / w) maltose and 1.0% (w / w) maltotriose on a dry matter basis, comprising the steps of: a) providing a germinated or malted (pseudo-) cereal of an unhulled cereal; b) optionally adding sugar; c) incubating the composition of step a) or b) under moist conditions for a time, temperature and duration to allow enzymatic release of maltose and maltotriose from the starch; d) further heating the incubated composition; e) flaking the heated composition; and f) drying the flaked composition.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates to the production of cereal flakes.The present invention relates to the use of malted cereals, typically whole grain malted cereals, in the production of cereal flakes. [Background technology]

[0002] Breakfast cereals are prepared by a variety of methods described in Fast & Caldwell (1990) American Association of Cereal Chemists, St. Paul, MN, USA, p. 372 and Delcour & Hoseney (2010) Principles of Cereal Science and Technology, 3rd ed. AACC International, St. Paul, MN, USA, p. 270. Wheat flour is a common raw material for the production of cereal flakes [Oliveira et al. (2015) Int. J. Food Sci. Technol. 50, 1504-1514].

[0003] The problem is that commercially available cereal flakes often have a high content of added sugars [Woods & Walker (2007) Nutrition & Dietetics 64, 226-233] and, as a result, contain less desirable minerals and vitamins, on a serving weight basis, than if they had less or no added sugars.

[0004] Additionally, consumers desire wholemeal that is high in nutrients such as dietary fiber and minerals and vitamins that are beneficial to health. However, peeling or pearling of grains (a process in which the outer layer of the kernels is (partially) removed as part of the cereal flaking process prior to cooking) results in the product not being able to be sold as a whole grain product. Unfortunately, the presence of the outer layer can be problematic because it results in the unpleasant, straw-like mouthfeel of processed cereal. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] American Association of Cereal Chemists, St.Paul, MN, USA, 372p, 1990 [Non-patent document 2] AACC International, St. Paul, MN, USA, 270p, 2010 [Non-patent document 3] Int. J. Food Sci. Technol. 50,1504-1514, 2015 [Non-patent document 4] Nutrition & Dietetics 64,226-233, 2007 Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention relates to the production of flakes having high levels of sweet intrinsic sugars from whole wheat grains or from such grains or ground fractions thereof by hydrothermal treatment, either alone or as part of an ingredient bill.

[0007] The method of the present invention allows for the production of cereal flakes with improved nutritional value, a unique flavor profile, and a cleaner label because less or no added sugars are required.

[0008] The method of the present invention provides whole grain cereals with a pleasant mouthfeel by using non-peeled whole grain wheat malts.

[0009] The use of sprouted grains allows for proper processing into well-structured cereal flakes, a whole grain product without a straw-like texture.

[0010] The presence of sugars produced by the enzymes in the germinated grains, combined with compounds produced during kilning, gives a sweet taste without the need for added sugars.

[0011] The use of sprouted grains results in a delicious whole grain cereal product that contains no added sugars.

[0012] This is important as health benefits are ascribed to whole grain products.

[0013] An embodiment of the present invention uses moistened sprouted cereal as the starting material, thereby avoiding the unnecessary step of moistening dried malted cereal. Aside from saving energy to dry the sprouted cereal and saving water for subsequent wetting, the absence of a drying step reduces the formation of acrylamide.

[0014] The process of the present invention makes it possible to produce a flake product with an EBC < 10 (European Brewery convention colour unit). [Means for solving the problem]

[0015] The present invention is summarized in the following: Aspect 1 1. A cereal flake product containing, on a dry matter basis, at least 0.9% (w / w), at least 1.5% (w / w), at least 2% (w / w), at least 3% (w / w) or at least 4% (w / w) maltose and at least 0.3% (w / w), at least 0.4% (w / w), at least 0.5% (w / w), at least 0.7% (w / w), at least 0.9% (w / w) or at least 1.0% (w / w) maltotriose. A manufacturing method comprising the steps of: a) Providing malted or germinated (pseudo-) cereals or mixtures of malted or germinated (pseudo-) cereals with (pseudo-) cereals (pseudo-cereals or pseudo-cereals), Typically, providing moist (15-25 g water per 100 g composition) unpeeled and sprouted (pseudo-) cereals, b) optionally adding sugar (alternatively, sugar can be added before or after step b); c) incubating the composition of step a) or b) under humid conditions for a time and at a temperature that allows the enzymatic release of maltose and maltotriose from the starch and, optionally, simultaneously or subsequently reduces the moisture content, typically to less than 25% (w / w), less than 20% (w / w), less than 15% (w / w), down to 10% (w / w) or down to 8% (w / w); d) further heating the incubated composition; e) flaking the heated composition; and f) Drying the flaked composition. In the method of the present invention, step d) inactivates the enzymes, kills microorganisms and softens the cereal. Aspect 2 2. The method of claim 1, wherein the (pseudo-)cereals or the malted or germinated (pseudo-)cereals in step a) are grains or peeled grains, kernels or peeled kernels. Aspect 3 2. The method of claim 1, wherein the (pseudo-)cereal or malted or germinated (pseudo-)cereal grains in step a) are ground grain fragments or ground kernels, such as whole meal, flour or grits. Aspect 4 4. The method according to any one of aspects 1 to 3, wherein the composition in step a) has an α-amylase activity of more than 100 U, 125 U, 150 U or 200 U / g dry matter / hr. Aspect 5 5. The method according to any one of aspects 1 to 4, wherein the composition in step a) has an α-amylase activity of more than 400 U, 500 U / g dry matter / hr. Aspect 6 Aspect 6. The method of any one of aspects 1 to 5, wherein in step a) the malted or germinated cereal or the mixture of malted or germinated cereal and cereal is provided in a wet state. Aspect 7 7. The method according to any one of aspects 1 to 6, wherein the germinated or malted cereal and / or the cereal is barley and / or wheat, preferably the malted or germinated cereal is wheat. Aspect 8 Aspect 8. The method according to any one of aspects 1 to 7, wherein the malted or germinated cereal is wheat, and the cereal is wheat. Aspect 9 Aspect 9. The method according to any one of aspects 1 to 8, wherein in step a) non-dried malted (i.e. germinated) (pseudo-) cereal is provided. Aspect 10 Aspect 9. The method according to any one of aspects 1 to 8, wherein in step a) malted (pseudo-) cereal is provided. Aspect 11 11. The method according to any one of aspects 1 to 10, wherein in step b) sugar is added in an amount of up to 15 g, up to 10 g, or up to 6 g / 100 g dry matter. Aspect 12 12. The method of embodiment 11, wherein the sugar is sucrose. Aspect 13 13. The method of any one of aspects 1 to 12, wherein in step c) the moisture content is 12 to 50 grams or 20 to 50 grams per 100 grams of composition (hence 100 grams of composition will contain 12 to 50 grams of water or 20 to 50 grams of water, the remainder being (pseudo-)cereal, typically malted or germinated (pseudo-)cereal). Aspect 14 Aspect 14. The method of any one of aspects 1-13, wherein the composition in step c) has a pH between 3.5 and 7.0. Aspect 15 15. The method of claim 14, wherein the pH is established with a food-grade acid. Aspect 16 16. The method of embodiment 15, wherein the food-grade acid is citric acid or lactic acid. Aspect 17 17. The method of any one of aspects 1 to 16, wherein the temperature in step c) is between 10 and 70, 80, or 90°C. Aspect 18 Aspect 18. The method according to any one of aspects 1 to 17, wherein the temperature in step c) is between 60 and 80°C, or between 40 and 65°C. Aspect 19 19. The method of any one of aspects 1 to 18, wherein the time period in step c) is between 10 and 180 minutes, or between 3 and 180 minutes. Aspect 20 20. The method of any one of aspects 1 to 19, wherein step b) is carried out for a period of time between 30 and 90 minutes or between 10 and 90 minutes. Aspect 21 21. The method according to any one of aspects 1 to 20, wherein steps c) and d) are carried out using a stepwise increase in temperature to a temperature above 70, 80 or 90°C, whereby during said increase the composition is for a period of time long enough to allow enzymatic release of maltose and maltotriose from the starch. Aspect 22 22. The method of claim 21, wherein the stepwise increase in temperature is accomplished prior to or as part of a pressure cooking or extrusion cooking process. Aspect 23 22. The method of claim 21, wherein the stepwise increase in temperature is accomplished prior to or as part of a pressure cooking process. Aspect 24 22. The method according to any one of the preceding aspects, wherein the weight ratio between malted or germinated (pseudo-) cereal and (pseudo-) cereal dry matter varies between 3 / 1 and 1 / 3. Aspect 25 25. The method according to any one of aspects 1 to 24, wherein the weight ratio between malted or germinated (pseudo-) cereal and (pseudo-) cereal dry matter varies between 3 / 1 and 1 / 10. Aspect 26 26. The method according to any one of aspects 1 to 25, wherein in step a) malted or germinated (pseudo-) cereal is provided without further addition of non-malted (pseudo-) cereal. . Aspect 27 27. The method of any one of aspects 1-26, further comprising adding one or more of an emulsifier, a vitamin, or a mineral. Aspect 28 A wheat cereal flake product comprising malted or germinated wheat and one or more of grains, peeled grains, kernels, peeled kernel grits, whole meal or wheat flour, characterized in that the total soluble maltose and maltotriose content of the wheat cereal flake product is at least 1.2% (w / w), 2% (w / w), 3% (w / w), 4% (w / w) or 5% (w / w) on a dry matter basis. Aspect 29 29. The cereal flake product according to claim 28, wherein the weight ratio of maltose to maltotriose is between 15 and 3. Aspect 30 30. The cereal flake product according to aspect 28 or 29, having a sucrose content of up to 10% (w / w), 9% (w / w), 8% (w / w) or 7.0% (w / w) on a dry matter basis. Aspect 31 30. The cereal flake product of claim 28 or 29, having a sucrose content of up to 5.0% on a dry matter basis. A cereal product containing at least 95% (w / w) of malted or germinated cereal. Aspect 32 32. The cereal flake product according to any one of aspects 28 to 31, having a relative sweetness intensity of between 3 and 20, wherein relative sweetness intensity is defined as follows: (Glucose content * 74 + Fructose content * 110 + sucrose content * 100+ Maltose Content * 50+ Maltotriose Content * 30) / 100. Aspect 33 1. A method for producing a whole grain cereal flake product containing at least 4.0% (w / w) maltose and 1.0% (w / w) maltotriose on a dry matter basis, comprising the steps of: a) Providing unhulled, germinated or malted (pseudo-) cereals; b) optionally adding sugar; c) incubating the composition of step a) or b) in moist conditions for a time and at a temperature to allow the enzymatic release of maltose and maltotriose from the starch; d) further heating the incubated composition; e) flaking the heated composition; and f) drying the flaked composition. Aspect 34 34. The method of embodiment 33, wherein non-hulled sprouted (pseudo-) cereals are provided. Aspect 35 34. The method according to embodiment 33, wherein in step c), the incubation is carried out under conditions that allow a reduction in the water content. Aspect 36 36. The method of embodiment 35, wherein the moisture content is reduced to a composition of 25 g or less. Aspect 37 34. The method of embodiment 33, wherein a malted (pseudo-) cereal is provided and then moistened. Aspect 38 38. The method of claim 33 or 37, wherein the malted (pseudo-) cereal in step a) is a ground kernel fragment, such as grit. Aspect 39 Aspect 39. The method according to any one of aspects 33 to 38, wherein the unhulled cereal is barley and / or wheat. Aspect 40 40. The method according to any one of aspects 33 to 39, wherein in step b), glucose and / or fructose and / or sucrose are added in an amount of up to 6 g per 100 g dry matter (6 g / 100 g dry matter). Aspect 41 Aspect 41. The method of any one of aspects 33 to 40, wherein in step a), c) or d), the moisture content is between 20 and 50 g of water per 100 g of composition. Aspect 42 Aspect 42. The method of any one of aspects 33-41, wherein the composition in step c), d), e) or f) has a pH between 3.5 and 7.0. Aspect 43 A method according to any one of aspects 33 to 42, wherein the temperature in step c) is between 10 and 130°C. Aspect 44 A method according to any one of aspects 33 to 43, wherein the temperature in step c) is between 50 and 80°C. Aspect 45 A method according to any one of aspects 33 to 44, wherein the time period in step c) is between 10 and 180 minutes. Aspect 46 A method according to any one of aspects 33 to 45, wherein the time period in step c) is between 20 and 60 minutes. Aspect 47 Aspect 47. The method according to any one of aspects 33 to 46, wherein steps c) and / or d) are carried out using a stepwise increase in temperature to a temperature above 90°C, whereby during the increase the composition is allowed a period long enough to allow enzymatic release of maltose and maltotriose from the starch. Aspect 48 48. The method of embodiment 47, wherein the stepwise increase in temperature is achieved as part of a pressure cooking process. Aspect 49 A (pseudo-) cereal flake product prepared from germinated or malted unhulled (pseudo-) cereal, characterized in that the sum of soluble maltose and maltotriose content is at least 5.0% on a dry matter basis. Aspect 50 50. The flake product of embodiment 49, wherein the cereal is wheat. Aspect 51 51. The cereal flake product of aspect 49 or 50, having a sucrose content of up to 5.0% on a dry matter basis. Aspect 52 52. The cereal flake product according to any one of aspects 49 to 51, having a relative sweetness intensity of 3, 5, or between 8 and 15 or 20, wherein relative sweetness intensity is defined as: [Glucose content (g / 100g DS (dry solids, the same below)] * 74 + Fructose content (g / 100g DS) * 110 + sucrose content (g / 100g DS) * 100 + Maltose content (g / 100g DS) * 50+ Maltotriose content (g / 100gDS) * 30) / 100). [Brief explanation of the drawings]

[0016] [Figure 1] Figure 1 is a scheme of the raw materials used in the cereal flake manufacturing process. [Figure 2] FIG. 2 shows a typical cereal flake manufacturing scheme where hydration was performed with water and settling was performed at room temperature (RT) for 30 minutes. [Figure 3] FIG. 3 shows a scheme for producing modified cereal flakes (referred to as the modified process) in which hydration was performed with a buffer solution and incubation was performed at 50° C. for 60 minutes. [Figure 4] Figure 4 shows the sugar content [% dry matter (dm)] in whole meals derived from the ingredients shown in Figure 1. Mean sugar contents are significantly different (p < 0.05) if they do not share the same letter. [Figure 5] Figure 5 shows the sugar content [% dry matter (dm)] in cereal flakes produced from the ingredients shown in Figure 1 using the standard method shown in Figure 2. Mean sugar contents are significantly different (p<0.05) if they do not share the same letter. [Figure 6] Figure 6 shows the sugar content [% (dm)] in cereal flakes produced from the raw materials shown in Figure 1 using the standard steps shown in Figure 2 or the modified process shown in Figure 3. Mean sugar contents that do not share the same letter are significantly different (p<0.05). [Figure 7]Figure 7 shows the sugar content [% dry matter (dm)] of whole meals derived from the ingredients shown in Figure 1; mean sugar contents are significantly different (p<0.05) if they do not share the same letter. [Figure 8] Figure 8 shows the sugar content [% of dry matter (dm)] in cereal flakes produced from the ingredients shown in Figure 1 using the standard method shown in Figure 2. Mean sugar contents are significantly different (p<0.05) if they do not share the same letter. [Figure 9] Figure 9 shows the sugar content [% of dry matter (dm)] in wheat malt and industrially produced cereal flakes. [Figure 10] FIG. 10 shows the maltose and maltotriose contents [% of dry matter (dm)] in wheat malts incubated at 70° C. for 60 minutes at different moisture contents. [Figure 11] FIG. 11 shows the maltose and maltotriose contents [% of dry matter (dm)] in wheat malt incubated at moisture contents of 28% and 70° C. for different incubation times. [Figure 12] FIG. 12 shows the maltose and maltotriose contents [% of dry matter (dm)] in wheat malt incubated at different incubation temperatures for 60 minutes at a moisture content of 28%. [Figure 13] FIG. 13 shows the sugar content [% of dry matter (dm)] in wheat malt that can be used to make cereal flakes. DETAILED DESCRIPTION OF THE INVENTION

[0017] Cereal refers to the food grains of cultivated grasses (Poaceae or Gramineae). Examples are wheat, barley, rye, sorghum, maize, and rice. In the context of the present invention, typical grains for producing flake products are wheat and barley.

[0018] Pseudocereals refer to food grains from the families Amaranthaceae, Polygonaceae, or Chenopodiaceae, examples of which are amaranth, buckwheat, and quinoa, respectively.

[0019] In the context of the present invention, (a) (pseudo-)cereal(s) refers to "cereals or pseudo-cereals". The terms peeling or pearling refer to a process in which the outer layer of a (pseudo-)cereal (usually 4-8% of the total grain mass) is removed.

[0020] The complete process of malting, used industrially to produce diastatic malts, consists of steeping (pseudo-) cereal grains, germinating them, and the subsequent step of kilning. In the context of the present invention, kilning is not necessary, depending on the process used. The term malted (pseudo-) cereal is used here for any (pseudo-) cereal that has been steeped, germinated, and dried at a temperature that retains most of the enzymatic activity of the germinated (pseudo-) cereal and allows substantial enzymatic release of maltose and maltotriose from the starch.

[0021] Drying allows for longer storage times and allows for the step of germinating the cereal to be separated from the process of producing cereal flakes, whereby water must be added to the malted cereal.

[0022] The term germinated (pseudo-) cereal is used herein to refer to any (pseudo-) cereal that has been soaked and germinated but not subsequently dried. Not drying the germinated (pseudo-) cereal equally preserves most of the enzyme activity of the germinated (pseudo-) cereal and allows for substantial enzymatic release of maltose and maltotriose from the starch.

[0023] In certain instances in this application, sprouted cereals are also referred to as non-dried malts.

[0024] Sprouted material without drying to a malted material allows for immediate production of cereal flakes. This results in significant energy savings for drying and water savings for subsequent wetting compared to the use of malted cereal. The omitted drying step also typically results in acrylamide formation, reduced enzyme activity, and increased color.

[0025] In addition to the above, on a gram dry matter basis, such malted (pseudo-) cereal contains a minimum α-amylase activity of 100 or 200 U / g dry matter / hr. This material can be used in the methods of the invention with or without further grinding or milling.

[0026] "(Pseudo-)cereal", without the prefixes germinated or malted, refers to the starting material before steeping or that has not undergone the steeping and germination steps.

[0027] "Cereal flake product" refers to the heat-flaked and dried material obtained by the claimed process, regardless of whether cereal, malted cereal, or germinated material (or a mixture of two or three of these) was used as the starting material.

[0028] The sugar added in the production of (pseudo-)cereal flakes can be sucrose or a mixture of glucose, fructose and / or sucrose.

[0029] The food grade acid is citric acid, acetic acid, fumaric acid, lactic acid, phosphoric acid, malic acid or tartaric acid.

[0030] Two techniques are primarily used to produce cereal flakes. The first is pressure cooking, in which grains or grain particles are steamed at high temperature and pressure for about 1 to 2 hours. The steamed mass is generally broken into small segments and dried under controlled conditions. The grit pieces are then either tempered for about 24 hours or flaked directly between steel rolls. The resulting flakes are then dried and toasted at high temperature to obtain the appropriate flavor and color (Fast and Caldwell, 1990, supra; Tribelhorn (1995) Breakfast Cereals, Handbook of Cereal Science and Technology, in: Lorenz & Kulp (Eds.) Dekker, M., New York, USA, 762 p.).

[0031] The second is extrusion cooking, a versatile, low-cost, and highly efficient food processing technology [Oliveira et al. (2015) Int. J. Food Sci. Technol. 5, 1504-1514]. The extruder consists of a preconditioning system, a feeding system, a screw, a barrel, and a die with a cutter [Navale et al. (2015) J. Ready to Eat Food 2, 66-80]. For cereal flake production, extruded pellets can be flaked between steel rollers, and the resulting flakes are typically toasted to achieve a specific crisp texture, flavor, and color [Ding et al. (2006) J. of Food Eng. 73, 142-148; Le Corre (2006) Cereal Foods World 51, 302-305].

[0032] Wheat, spelt, rice, and barley grains are commonly peeled (i.e., pearled, polished); in such processes, 4-8% of the outer layer is removed prior to cereal flake production to ensure good sensory quality (Fast and Caldwell, 1990, cited above). Unfortunately, the resulting flakes do not meet the requirements of a whole grain product.

[0033] The definition is as follows: "A whole grain consists of the intact, ground, cracked, or flaked kernel after removal of inedible parts such as the hull and husk. The main structural and morphological components: starchy endosperm, germ, and bran, are present in the same relative proportions as they are in the intact kernel. Minor losses of components, i.e., less than 2% of grain / 10% of bran, caused by processing methods consistent with safety and quality are acceptable" [van der Kamp et al. (2014) Food & Nutrition Res. 58, 1-8].

[0034] In one aspect of the invention, the methods described herein do not require dehulling of the grain prior to pressure cooking in order to obtain good sensory quality for the resulting flakes.

[0035] Whole grain-based products deserve to be an important part of a healthy diet, as their consumption can reduce the risk of developing diet-related disorders such as obesity (Anderson et al. (1994) Am. J. Clin. Nutr. 59, 1242-1247.), type II diabetes (de Munter et al. (2007) PLOS Med. 4, 1385-1395), cardiovascular disease (Liu et al. (1999) Am. J. Clin. Nutr. 70, 412-149), and cancer (Slavin et al. (2000) J. Am. Coll. Nutrition 19, 300-307).

[0036] Their health benefits are primarily due to the presence of high concentrations of dietary fiber and bioactive compounds such as B-vitamins, minerals, polyphenols and methyl donors (Shewry and Hey (2015) Food and Energy Security 4, 178-202).

[0037] The sweetness of cereal flakes can be enhanced by using sprouted grain as a source of intrinsic sugars released by amylolytic enzymes. In fact, the relative sweetness increased 7-9 times with malted wheat compared to the control whole meal (see Figure 13 and 5.5 times with germinated and hydrothermally treated whole meal (sprouted wheat 1A)). Therefore, this ingredient can be added to breakfast flakes to reduce sugar levels.

[0038] In conclusion, the use of these novel ingredients with high levels of hydrolytic enzymes in a rationally modified manufacturing process (e.g., the use of malted cereals) can result in cereal flakes with an inherent sugar content that contributes to the sweet taste of the product and serves as a flavor precursor in the Maillard reaction (caramel and toasty aromas). Furthermore, by fully utilizing the nutritional profile of wheat grains, cereal flakes with a cleaner label (no added sugars) can be obtained that meets consumer needs. [Example]

[0039] Example 1 1.1 Materials Winter wheat (Cellule winter wheat, moisture content: 12.6%, protein content: 9.7% of dry matter (dm)) was kindly provided by Limagrain (Avelgem, Belgium). Salt, sucrose, and glucose were food grade. Kellogg's All-Bran flakes were obtained from a local supermarket. They are made from 66% whole wheat flour, 21% wheat bran, and 6% oat flour, and are fortified with vitamins and iron, and were prepared for comparison.

[0040] 1.2 Method 1.2.1 Steeping, germination and hydrothermal treatment of wheat To study their functionality in cereal flake production, control wheat grain was processed using three regimes shown in Figure 1.

[0041] (i) Germinated wheat 1 was obtained under standard germination conditions (soaking at 15°C for 29 hours and germinating at 15°C for 48 hours); (ii) Control wheat and germinated wheat 1 were hydrothermally treated under optimal conditions for phytate hydrolysis (50°C, pH 3.8 for 8 hours), and then cooked in an autoclave (Systec VX-55, Systec, Linden, Germany) (121°C, 10 minutes) to obtain control wheat A and germinated wheat 1A, respectively. (iii) Germinated wheat 2 is obtained under optimal germination conditions for the hydrolysis of both phytate and AX (soaking at 15°C for 36 hours and germinating at 26°C for 48 hours).

[0042] The treated wheat grains were flash-frozen using liquid nitrogen (N2) and freeze-dried (to 5% moisture content). These four treated wheat grains and the control wheat were then milled (FOSS Tecator cyclotec 1093 sample mill, Hillard, Denmark) to whole meal (<500 μm) before producing cereal flakes. In addition, we also prepared whole meal blends using 75% control wheat and either 25% germinated wheat 1 (Blend 1) or 25% germinated wheat 2 (Blend 2) (Figure 1).

[0043] 1.2.2 Cereal flakes production 1.2.2.1 Standard Cereal Flakes Production Cereal flakes were produced on a pilot scale from a formulation consisting of 358 g dm whole wheat flour, 30 g sucrose, 10.0 g glucose, and 2.0 g salt, essentially as described in Joye et al. (2011) Food Chem. 129, 395-401; De Brier et al. (2015) LWT-Food Sci Technol. 62, 668-674; De Brier et al. (2015) J. Cereal Sci. 62, 66-72. The sucrose, glucose, and salt were dissolved in 160 ml of water to achieve a moisture content of 30% (Figure 2). All ingredients were then blended in a Stephan UMS 5 electronic mixer (Hameln, Germany) for 2 minutes, mixed by hand, and then mixed again for 30 seconds to ensure proper homogenization. After standing for 30 min at room temperature (RT), the mixture was extruded in a Brabender (Duisburg, Germany) single-screw extruder (65–100 °C, 1–4 bar, screw speed 100 rpm, nozzle diameter 6 mm) to form pellets with moisture levels of 25–28% (Sartorius Moisture Analyser MA30, Göttingen, Germany).

[0044] They were then flaked at room temperature using a roller mill (Shule, Hamburg, Germany) with a gap setting of 0.25 mm and air-dried overnight. If necessary, the resulting flakes were conditioned to a moisture content of 12–15% in a climate chamber (HC0057, Heraeus Votsch, Hanau, Germany) at 30°C and 80% relative humidity for 4 hours. Finally, they were toasted at 248°C for 3 minutes in a drum roaster (PROBAT-WERKE von Gimborn Maschinenfabrik, Emmerich am Rhein, Germany) to obtain a moisture level of 3–5%. Samples were taken immediately after mixing, before the start of extrusion (i.e., after settling), after extrusion, after flaking, and after roasting.

[0045] All samples except the roasted flakes were stored at −20° C. After freeze-drying, these samples and a portion of the roasted flakes were ground in an IKA mill (Staufen, Germany).

[0046] 1.2.2.2 Modified Cereal Flakes Production In the modified process, 160 ml of 100 mM sodium acetate buffer (pH 3.8) was added to the components instead of water (160 ml), and the component mixture was allowed to stand at 50°C for 60 min instead of RT for 30 min (Figure 3). Samples were removed, stored, lyophilized, and ground as above.

[0047] 1.2.3 Flake analysis Soluble sugars formed during germination, hydrothermal treatment, and (modified) cereal flake manufacturing were quantified in triplicate using high-performance anion-exchange chromatography (HPAEC) with pulsed amperometric detection (PAD) on a Dionex ICS5000 system (Dionex, Sunnyvale, CA, USA). Aqueous extracts were obtained by adding 10.0 ml of deionized water to 80–100 mg samples, extracting (30 min, 150 rpm, 7°C), and centrifuging (10 min, 1,500 g, 7°C).

[0048] An aliquot (50 μl) of the supernatant was then added to 950 μl of deionized water, and after filtration (0.22 μm), an aliquot (12.5 μl) was injected onto a Carbopac PA-100 guard and PA-100 anion-exchange (250 × 4 mm) column. The mobile phase (1.0 ml / min) during equilibration and the first 5 min of the experiment was 100 mM NaOH. The sodium acetate concentration in 100 mM NaOH was then increased at 3.6 mM / min over 25 min. Sugars were identified and quantified (% w / w of dm) using glucose, fructose, sucrose, maltose, maltotriose, and rhamnose (internal standards added to the sample before extraction and 0.125 μg in 12.5 μL final injection). The total soluble sugar content (% of dm) in the different samples was calculated here as the sum of the measured glucose, fructose, sucrose, maltose and maltotriose contents.

[0049] The soluble sugar content (g / 100g) of the obtained sample (raw material or cereal flakes) was used to calculate the relative sweetness value using the following formula [Lavic (2011) Relative sweetness value of various sweeteners. XP055434432]:

[0050] Relative sweetness = [(Glucose content) * 74+ (fructose content) * 110+ (sucrose content) * 100+ (maltose content)* 50+ (maltotriose content) * 30) / 100

[0051] The relative sweetness factors of glucose, fructose, maltose, and maltotriose were 74, 110, 50, and 30, respectively, compared to sucrose, which has a relative sweetness value of 100.

[0052] Alpha-amylase activity in the raw materials (Figure 1) and / or flakes was measured in triplicate using the Amylazyme method (Megazyme, Bray, Ireland) as described in De Brier et al. (2015) LWT-Food Sci. Technol. 62, 668-674 and De Brier et al. (2015) J. Cereal Sci. 62, 66-72, with minor modifications.

[0053] A substrate tablet was added to 1.0 ml of pre-incubated extract diluted 5- to 50-fold at 40°C, and the reaction was stopped after 5 to 120 minutes of incubation. The extract dilution and incubation time depended on the germination time and were chosen so that the Beer-Lambert law was applicable. One α-amylase unit was defined as the enzyme activity per gram of dry matter, with an increase in absorbance (590 nm) of 1.00 per hour of incubation at 40°C.

[0054] 1.3 Results and discussion 1.3.1 Cereal flakes from control wheat and sprouted wheat grains or mixtures thereof 1.3.1.1 Soluble sugar content in cereal flakes Figure 4 shows the sugar composition of whole meal from control wheat, germinated wheat 1, and germinated wheat 2. Germination resulted in a significant increase in glucose, maltose, and maltotriose content as a result of starch hydrolysis. Furthermore, there was a significant increase in sucrose levels, which is the most important energy source during early germination [Aoki et al. (2006) Plant Physiol. 141, 1255-1263; Benincasa et al. (2019) Nutrients 11, 1-29].

[0055] Furthermore, germination at 26°C (Germinated Wheat 2) instead of 15°C (Germinated Wheat 1) results in a substantially higher sugar content, which can give the cereal flakes their inherent sweetness.

[0056] FIG. 5 shows the sugar content of cereal flakes produced by the standard method identified in FIG. 2 from an ingredient bill containing 7.5% sucrose and 2.5% glucose.

[0057] The sucrose content of the commercial flakes reached approximately 15% of the dm, consistent with the amount stated on the label. The use of germinated wheat 1, blend 1, and blend 2 resulted in increased levels of maltose and maltotriose, apparently as a result of α-amylase action.

[0058] Kruma et al. (2018) Agronomy Res. 16, 1405-1416 showed that in cereal flakes produced without extrusion, roasting, or added sugars, the sugar content (mainly sucrose and maltose) was 1.5% of the dm when 40% germinated cereals (trichomes, oats, and barley) were used, and 2.2% of the dm when 50% germinated cereals (rye, oats, and barley) were used.

[0059] They attributed the increase in sugar content to enzymatic hydrolysis of starch.

[0060] 1.3.2 Modified Cereal Flakes Production In this section, the properties of cereal flakes produced from the ingredients in Figure 1 are examined using the modified manufacturing procedure in Figure 3 and compared, where applicable, with the results of processing using the standard method shown in Figure 2.

[0061] 1.3.2.1 Soluble sugar content in cereal flakes As mentioned earlier, maltotriose levels were higher in flakes derived from germinated wheat (containing blends) than from control wheat (Figure 6).

[0062] 1.3.3 Effect of Hydrothermally Treated (Germinated) Wheat Grains on Cereal Flake Properties In this section, the properties of cereal flakes prepared from hydrothermally treated (germinated) wheat grains were investigated using the standard method shown in Figure 2. Where applicable, the results were compared with those of other raw material treatments shown in Figure 1.

[0063] 1.3.3.1 Soluble sugar content in cereal flakes The sweetness of cereal flakes can be enhanced by using sprouted grains as a source of intrinsic sugars released by amylolytic enzymes. Figure 7 shows the sugar composition of wholemeal from control (A) and sprouted wheat 1 (A).

[0064] Hydrothermal treatment of control wheat significantly reduced sucrose content but increased glucose and fructose contents, indicating invertase activity [Kashem et al. (1995) J. Ntl. Sci. Found. Sri Lanka 23, 55-61]. The processing conditions used here may have favored wheat invertase activity, since the enzyme has optimal activity in the pH range of 4.5 to 5.5 [Krishnanet et al. (1985) Plant Physiol. 78, 241-245]. Furthermore, both neutral and acid invertases in wheat have optimal activity temperatures in the range of 35 to 50°C. As previously mentioned, significant increases in glucose and sucrose levels occurred during wheat germination (cfr. section 1.3.1.1).

[0065] Next, when germinated grains were hydrothermally treated (germinated wheat 1A), a 16-fold and 18-fold increase in maltose and maltotriose levels, respectively, was obtained as a result of α-amylase action under conditions closer to its optimum (pH 5.0, 68°C) [Singh & Kayastha (2014) Food Chem. 162, 1-9].

[0066] Consistent with what was observed for control wheat A, a decrease in sucrose levels and an increase in fructose and glucose levels was found as a result of invertase action in germinated wheat 1A.

[0067] The 14-fold increase in glucose levels was the result of the action of other enzymes such as α-glucose [Kruger & Reed (1988) Enzymes and color, Wheat: Chemistry and Technology. American Association of Cereal Chemists, St. Paul, MN, USA, pp. 441-500].

[0068] The use of germinated wheat 1A in a cereal flake recipe is interesting because the relative sweetness value of this ingredient was calculated to be 4.4, while that of the control wholemeal was assessed to be 0.8. This inherent sweetness allows manufacturers to reduce the level of added sugars in the cereal flakes [Pagand et al. (2017) Cereal Foods World 62, 221-226]. For example, a breakfast flake recipe containing 90 g of control wholemeal and 10 g of sucrose has a relative sweetness value of 10.7.

[0069] To obtain the same relative sweetness value in breakfast flakes from germinated wheat 1A, the recipe would consist of 93.4 g of wholemeal from germinated wheat 1A and only 6.6 g of sucrose, thus reducing the sucrose addition by 34%.

[0070] In a next step, the sugar composition in cereal flakes produced from hydrothermally treated (germinated) wheat was evaluated (Figure 8). When the recipe contained 7.5% sucrose and 2.5% glucose, no clear differences in sugar composition and sugar content were observed between control wheat and control wheat A. The significantly lower maltose content after hydrothermal treatment was unexpected. Hydrothermal treatment of germinated wheat 1 (germinated wheat 1A) significantly increased glucose levels as a result of α-glucosidase action.

[0071] Example 2 2.1 Method 2.1.1 Production of wheat flakes from malted grains Whole wheat flakes were produced on an industrial scale. The wheat malt had the following specifications: moisture content 5.6%, protein content 11.2% of dm, EBC color 3.5, and α-amylase activity approximately 6,900 U / h / g dm. Malted whole wheat grains were first washed to remove foreign matter. All ingredients were added to a pressure cooker. The cooked mass was then dried / tempered before being broken into pieces. The broken cooked mass was then flaked between rolls, and the flakes were hot-air toasted. Finally, the resulting flakes were milled in an IKA mill, after which the soluble sugar content was determined (cfr. 1.2.3).

[0072] α-Amylase activity in malted wheat grains (Figure 13) was measured in triplicate using the Amylazyme method (Megazyme, Bray, Ireland) as described by De Brier et al. (2015) LWT- Food Sci. Techn. 62, 668-674, with minor modifications. Substrate tablets were added to 1.0 ml of 5- to 50-fold diluted preincubated extract at 40°C, and the reaction was stopped after 5 to 120 min of incubation. The extract dilution and incubation time depended on the germination time and were chosen so that the Lambert-Beer Law was applicable. One α-amylase unit was defined as enzyme activity per gram of dry matter, corresponding to a 1.00 increase in absorbance (590 nm) per hour of incubation at 40°C.

[0073] 2.1.2 Incubation of malted wheat grains Malted wheat grains (50.0 g) were incubated in sealed Schott glass bottles for 10 to 120 min at moisture contents ranging from 22 to 41% and temperatures ranging from 40 to 80°C. After incubation, the grains were flash-frozen in liquid N2, freeze-dried, and milled (IKA mill) to wholemeal before the maltose and maltotriose content (cfr. 1.2.3) was determined.

[0074] 2.2 Results and discussion 2.2.1 Soluble sugar content in cereal flakes Figure 9 shows the sugar composition of industrially produced cereal flakes. When wheat malt with high α-amylase activity levels was used in the cereal flake production process, a soluble sugar content of 5.7% of dm was found in the resulting flakes, which is comparable to that in the raw material used (5.9% of dm). Although the sucrose content was low, the glucose and fructose contents were higher than in the raw material, indicating invertase action during cereal flake production. The increase in maltotriose content from 0.03% of dm in the raw material to 0.33% of dm in the flakes is attributed to α-amylase action during cereal flake production. Therefore, the sweetness of whole grain flakes can be enhanced by using malted grains as a source of amylolytic enzymes that release intrinsic sugars. In fact, the soluble sugar content in commercially available wheat flakes derived from regular wheat was only 1.6% of the dm.

[0075] Furthermore, the present invention does not require grain dehulling prior to pressure cooking to obtain good sensory qualities in the resulting flakes. Indeed, malting induces structural changes in the cereal cell walls [Autio et al. (2001) J. Institute Brewing 107, 19-25; DeBacker et al. (2010) Plant Physiol. Biochem. 48, 90-97], imparting a natural sweetness to the grain, so that retaining the bran does not compromise the quality of the final product. As a result, our technology makes it possible to produce tasty whole grain flakes.

[0076] 2.2.2 Soluble sugar content in incubated malted wheat grains To further increase the soluble sugar content in malted grains, a hot and humid incubation step was performed, the results of which are discussed in this section. Of note, the incubation step may also be part of the cereal flake manufacturing process.

[0077] 2.2.2.1 Effect of moisture content on maltose and maltotriose content The maltose and maltotriose contents increased with increasing moisture content in wheat malt incubated at 70°C for 60 minutes (Figure 10). This is logical, as amylase is more active in wet conditions. For example, Roder et al. (2009) Food Chem. 113, 471-478 found that α-amylase activity on wheat starch was relatively low until the moisture content reached 30%, then increased sharply.

[0078] 2.2.2.2 Effect of incubation time on maltose and maltotriose content Maltose and maltotriose contents increased with increasing incubation time of wheat malt at 70°C and 28% moisture (Figure 11). This was expected because amylases can be activated at temperatures close to their optimum (55-68°C) [Daba et al. (2012) Enz. Microbial Technol. 51, 245-251; Singh & Kayastha (2014) Food Chem. 162, 1-9].

[0079] 2.2.2.3 Effect of incubation temperature on maltose and maltotriose content In general, the maltose and maltotriose contents increased when the temperature was increased during the 60-minute incubation of wheat malt at 28% moisture content (Figure 12). However, the highest maltose content (2.6% of dm) was found in wheat malt (also called wheat malt) incubated at 75°C, whereas the highest maltotriose content (0.8% of dm) was found in wheat malt incubated at 80°C.

[0080] In conclusion, to maximize the soluble sugar content, and therefore the inherent relative sweetness, in flakes derived from saccharifying malted wheat, it is interesting to carry out an incubation step under humidity conditions (>28%) at temperatures in the range of 60-80°C for more than 60 minutes, allowing the enzymatic release of maltose and maltotriose from the starch.

[0081] Example 3 3.1. Method 3.1.1. Wheat malt The wheat malt used had the following specifications: moisture content 6–12%, protein content 10–12% dm, EBC (European Brewery Convention unit) color <10, α-amylase activity 20–400 U / h / g dm, and total soluble sugar content 9–13% of dm.

[0082] 3.1.2. Production of wheat flakes from malted grain Whole wheat flakes are produced on an industrial scale (cfr. 2.1.1). Malted whole wheat kernels (also called wheat grains) are first washed to remove any foreign matter. All ingredients are added to a pressure cooker. The cooked mass is then dried / tempered before breaking the mass. The broken cooked mass is then flaked between rolls and the flakes are toasted with hot air. Finally, the resulting flakes are milled in an IKA mill before the soluble sugar content is determined (cfr. 1.1.3).

[0083] 3.1.3. Texture analysis of wheat flakes The texture of the flakes was examined using an Instron 5943 (Norwood, MA, USA) materials testing machine equipped with a 1 kN load cell, as described by De Brier et al. LWT- Food Sci Techn. 62, 668-674.

[0084] The test was performed in bulk (15.0 g) at 10x magnification using a five-blade Kramer shear cell. The blades of the cell forced the breakfast flakes through the open space at the bottom of the cell. The sample was compressed at 120 mm / min at room temperature. The maximum force (Fmax, [N]) was a measure of the hardness of the sample.

[0085] Spatial frequency of fracture (Nsr, [mm -1 ]), mean crushing force (Fcr, [N]) and crispness work (Wc [N.mm]) are calculated from the force-displacement curves using the following equations (Agbisit et al. (2007) J. Texture Studies 38, 199-219):

[0086] Nsr = n / d Fcr = s / d Wc = Fcr / Nsr where s is the area under the curve, n is the number of peaks, and d is the distance traveled by the probe.

[0087] The most important quality parameter for cereal flakes is how well their texture withstands immersion in milk (De Brier et al. (2015) LWT- Food Sci Techn. 62, 668-674). Approximately 15.0 g of breakfast flakes are immersed six times for 30 seconds in 300 ml of semi-skimmed milk in a tea sieve at 23±1°C under continuous stirring (200 rpm), essentially as in Sachetti et al. (2003) and De Brier et al. (2015 LWT-Food Sci. Techn. 62, 668-674). The immersed flakes are drained for 30 seconds to remove excess milk from the surface, and texture analysis is performed as described above. [Explanation of symbols]

[0088] Control wheat: Control wheat Hydrothermal processing: Hydrothermal processing Autoclave cooking: Pressure cooker cooking Steeping: Soaking Sprouting Sprouted wheat Blend: Blend (mixed preparation) Mixing of ingredients: Hydration with water Resting:Standing RT: room temperature Extrusion Flaking: Flaking Drum roasting Modified process: Modified process Hydration with buffer: Hydration with buffer Saccharide content: Sucrose content Wheat malt (raw material): Wheat malt (raw material) Flakes derived from wheat malt Commercial wheat flakes

Claims

1. 1. A method for producing a whole grain cereal flake product made from germinated, unhulled wheat, comprising the steps of: a) providing germinated, unhulled wheat; b) incubating the composition of step a) in the absence of added sugars, in a moist state with a moisture content of 20-50% by weight, at a temperature of 50-80°C for a time period allowing the enzymatic release of maltose and maltotriose from the starch; c) further heating the incubated composition; d) flaking the heated composition; and e) drying the flaked composition.

2. 2. The method of claim 1, wherein in step b) the incubation is carried out under conditions that allow the water content to be reduced to less than 25% (w / w).

3. 3. The method of claim 1 or 2, wherein the composition in step b) or c) has a pH between 3.5 and 7.

0.

4. 4. The method according to claim 1, wherein the time in step b) is between 10 and 180 minutes.

5. 5. The method according to claim 1, wherein the time in step b) is between 20 and 60 minutes.

6. A cereal flake product obtainable by the method according to any one of claims 1 to 5, characterized in that the sum of the soluble maltose and maltotriose content is at least 1.2% (w / w) on a dry matter basis.

7. 7. The cereal flake product of claim 6, wherein the sucrose content is up to 5.0% on a dry matter basis.

8. 8. The cereal flake product according to claim 6 or 7, having a relative sweetness between 3 and 20, wherein the relative sweetness is defined as follows: [Glucose content (g / 100g DS (dry solids) ＊ 74 + Fructose Content (g / 100g DS) ＊ 110 + sucrose content (g / 100g DS) ＊ 100 + Maltose content (g / 100g DS) ＊ 50 + Maltotriose content (g / 100g DS) ＊ 30) / 100).

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