Method for producing processed grain-containing composition, and application thereof

Abstract

A problem addressed by this invention is to provide a method for improving the aroma of grain raw material. The present invention provides a method for producing a processed grain-containing composition, the method including a step for causing lipase to act on grain raw material and a step for thermally sterilizing same. The present invention also relates to a processed grain-containing composition obtained by said method for producing a processed grain-containing composition.

Description

Method for producing a processed grain-containing composition and its application

[0001] The present invention relates to a method for producing a processed grain-containing composition, a processed grain-containing composition, a method for improving the aroma of a grain material, and an enzyme preparation.

[0002] In recent years, the number of people with dairy allergies or intolerances has been increasing, leading to a growing demand for dairy alternatives. Furthermore, growing environmental awareness and health consciousness have led to an increased demand for plant-based foods, and plant-derived alternatives are gaining attention. While dairy production requires large amounts of water and feed and is considered to have a significant environmental impact, grains such as oats use relatively little water and land and are attracting attention as a sustainable food.

[0003] Since plant-derived raw materials that replace dairy products lack a milky smell and flavor, studies have been conducted to improve the flavor by treating vegetable oils with lipase to enhance the milky smell and flavor. For example, Patent Document 1 discloses a technology for improving the flavor (making it closer to a milky flavor) by adding various oils and fats that have been oxidized and lipase-treated to vegetable milk. Furthermore, Patent Document 2 discloses a technology for imparting a milky flavor by treating vegetable oils with lipase.

[0004] International Publication No. WO 2023 / 053792 International Publication No. WO 2023 / 106224

[0005] Grain-containing foods and beverages have a unique aroma that may be undesirable to consumers. In addition, the sterilization process during the production of grain-containing foods and beverages can produce a unique aroma that is undesirable to consumers, which has been a problem.

[0006] Therefore, in order to solve the problems of the conventional technology, the present inventors have conducted research with the aim of providing a method for improving the aroma of grain raw materials.

[0007] Examples of specific embodiments of the present invention are given below.

[0008] [1] A method for producing a processed grain-containing composition, comprising the steps of treating a grain raw material with lipase and thermal sterilization. [2] A method for producing a processed grain-containing composition according to [1], wherein the grain raw material is at least one selected from the group consisting of barley, wheat, oats, rice, buckwheat, barnyard millet, and foxtail millet. [3] A method for producing a processed grain-containing composition according to [1] or [2], wherein the grain raw material has a moisture content of 50% by mass or more. [4] A method for producing a processed grain-containing composition according to any of [1] to [3], wherein the lipase is at least one selected from the group consisting of lipases derived from the genus Aspergillus and lipases derived from the genus Mucor. [5] A method for producing a processed grain-containing composition according to any of [1] to [4], wherein the thermal sterilization step is at least one selected from the group consisting of pressurized heat sterilization, low-temperature sterilization, ultra-high-temperature short-time sterilization, and ultra-high-temperature short-time sterilization. [6] A processed grain-containing composition obtained by the production method according to any of [1] to [5]. [7] A method for improving the aroma of a grain raw material, comprising a step of treating the grain raw material with a lipase and a step of thermal sterilization. [8] The method for improving the aroma of a grain raw material according to [7], wherein the grain raw material is at least one species selected from the group consisting of barley, wheat, oats, rice, buckwheat, barnyard millet, and foxtail millet. [9] The method for improving the aroma of a grain raw material according to [7] or [8], wherein the grain raw material has a moisture content of 50% by mass or more.

[10] The method for improving the aroma of a grain raw material according to any of [7] to [9], wherein the lipase is at least one species selected from the group consisting of lipases derived from the genus Aspergillus and lipases derived from the genus Mucor.

[11] The method for improving the aroma of a grain raw material according to any of [7] to

[10] , wherein the thermal sterilization step is at least one method selected from the group consisting of pressurized heat sterilization, low-temperature sterilization, ultra-high-temperature short-time sterilization, and ultra-high-temperature short-time sterilization.

[12] An enzyme agent containing lipase for improving the aroma of a grain raw material via a thermal sterilization step.

[13] The enzyme preparation according to

[12] , wherein the lipase is at least one selected from the group consisting of lipases derived from the genus Aspergillus and lipases derived from the genus Mucor.

[0009] [A] Use of an enzyme preparation containing a lipase for improving the aroma of a grain raw material after a heat sterilization process. [B] Use of the enzyme preparation containing a lipase according to [A], wherein the lipase is at least one selected from the group consisting of lipases derived from the genus Aspergillus and lipases derived from the genus Mucor.

[0010] According to the production method of the present invention, a processed grain-containing composition with reduced grain odor can be obtained.

[0011] The present invention will be described in detail below. The following description may be based on representative embodiments or specific examples, but the present invention is not limited to such embodiments. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits.

[0012] (Method for producing a processed grain-containing composition) This embodiment relates to a method for producing a processed grain-containing composition, which includes a step of treating a grain raw material with lipase and a step of thermal sterilization. In the method for producing a processed grain-containing composition of this embodiment, a grain raw material is treated with lipase and then subjected to thermal sterilization, thereby obtaining a processed grain-containing composition with a reduced grain odor.

[0013] <Grain raw material> The grain raw material is a food material obtained from a plant and contains starch. The grain raw material used in the present embodiment may further contain fats and oils, proteins, etc. in addition to starch.

[0014] The plant from which the grain is derived is not particularly limited, and examples thereof include rye, barley, wheat, oats, rice, buckwheat, barnyard millet, and foxtail millet. One of these plant-derived vegetable proteins may be used alone, or two or more of them from different origins may be used in combination. Among these, it is preferable to use at least one selected from the group consisting of barley, wheat, oats, rice, buckwheat, barnyard millet, and foxtail millet, more preferably at least one selected from barley and oats, and even more preferably oats.

[0015] The grain raw material includes a slurry in which the grain raw material is dispersed, a solution in which the grain raw material has settled, and a dried solid grain raw material. Of these, the grain raw material is preferably in the form of a slurry.

[0016] In this embodiment, the grain raw material may be a saccharified liquid of the grain raw material. Specifically, it is preferable to use a saccharified liquid obtained by enzymatically saccharifying starch contained in the grain raw material. When obtaining the saccharified liquid, α-amylase and / or β-amylase, as described below, can be used. The grain raw material used in this embodiment may be an unsaccharified liquid, or a saccharified liquid that has already been enzymatically saccharified.

[0017] The moisture content of the grain raw material is preferably 40% by mass or more, more preferably 45% by mass or more, 50% by mass or more, 55% by mass or more, 60% by mass or more, 65% by mass or more, 70% by mass or more, 75% by mass or more, 80% by mass or more, 85% by mass or more, or 90% by mass or more.

[0018] The content of vegetable oil contained in the grain raw material (based on the mass of the grain raw material in a dried state) is not particularly limited, but is preferably, for example, 0.1% by mass or more. From the viewpoint of further enhancing the effect of reducing grain odor, the content of vegetable oil is preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 5% by mass or more. The upper limit of the vegetable oil content is not particularly limited, but is, for example, preferably 30% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less, and particularly preferably 10% by mass or less.

[0019] Lipase is an enzyme that hydrolyzes the ester bonds that make up lipids. Specifically, it acts on triacylglycerol (triglyceride) and, depending on the specificity of the enzyme, catalyzes the reaction that liberates fatty acids to produce diacylglycerol (DAG) or monoacylglycerol (MAG), or the reverse reaction.

[0020] Examples of lipases include those from the genus Rhizopus (e.g., Rhizopus delemar, Rhizopus oryzae, Rhizopus arrhizus, Rhizopus niveus, Rhizopus javanicus, etc.); the genus Aspergillus (e.g., Aspergillus niger, etc.); the genus Mucor (e.g., Mucor javanicus, Mucor miehei, etc.); Examples of lipases include lipases derived from the genus Rhizomucor (e.g., Rhizomucor miehei), the genus Thermomyces (e.g., Thermomyces lanuginosus), the genus Pseudomonas, the genus Geotrichum, the genus Penicillium, and the genus Candida. These lipases may be used singly or in combination of two or more.

[0021] Among these, it is preferable to use at least one lipase selected from, for example, lipases derived from the genus Aspergillus and lipases derived from the genus Mucor. It is particularly preferable to use at least one lipase selected from lipases derived from Aspergillus niger and lipases derived from Mucor javanicus. By using these lipases, a processed grain-containing composition with a more effectively reduced grain odor can be obtained. The lipase can be appropriately prepared from a culture solution of the microorganism from which the lipase is derived.

[0022] Commercially available lipases can also be used. Preferred examples of commercially available lipases include Aspergillus niger-derived lipase and Mucor javanicus-derived lipase, both manufactured by Amano Enzyme Inc.

[0023] The amount of lipase used is not particularly limited, but the amount used per 1 g of fat or oil can be, for example, 0.1 U or more. From the viewpoint of further enhancing the aroma improving effect of the processed grain-containing composition, the amount of lipase used per 1 g of fat or oil is preferably 0.5 U or more, more preferably 1 U or more, even more preferably 5 U or more, even more preferably 10 U or more, even more preferably 30 U or more, even more preferably 50 U or more, and even more preferably 70 U or more. The upper limit of the range of the amount of lipase used per 1 g of fat or oil is not particularly limited, but is preferably 10,000 U or less, more preferably 5,000 U or less, even more preferably 3,000 U or less, even more preferably 1,000 U or less, even more preferably 500 U or less, even more preferably 300 U or less, and even more preferably 200 U or less. In addition, the amount of lipase used is not particularly limited, but the amount used per 1 g of grain raw material can be, for example, 0.01 U or more. From the viewpoint of further enhancing the aroma-improving effect of the processed grain-containing composition, the amount of lipase used per 1 g of grain raw material is preferably 0.05 U or more, more preferably 0.1 U or more, even more preferably 0.5 U or more, even more preferably 1 U or more, even more preferably 3 U or more, even more preferably 5 U or more, and even more preferably 6 U or more. The upper limit of the range of the amount of lipase used per 1 g of grain raw material is not particularly limited, but is preferably 1000 U or less, more preferably 500 U or less, even more preferably 100 U or less, even more preferably 50 U or less, even more preferably 30 U or less, even more preferably 20 U or less, and even more preferably 10 U or less.

[0024] The enzymatic activity of Aspergillus niger-derived lipase can be measured using the following method. 75 mL of olive oil and 225 mL of an emulsion (20 g / L of polyvinyl alcohol I (saponification 98.0-99.0 mol%)) are mixed and emulsified using a homogenizer to prepare a substrate solution. 1 mL of lipase solution is added to 5 mL of substrate solution and 4 mL of 0.1 mol / L phosphate buffer (pH 6.0), and the reaction is carried out at 37°C. After 30 minutes, 10 mL of an ethanol-acetone mixture is added to stop the enzymatic reaction. Next, 10 mL of 0.05 mol / L sodium hydroxide solution and 10 mL of an ethanol-acetone mixture are added, and the mixture is titrated with 0.05 mol / L hydrochloric acid to a pH of 10. The amount of enzyme that increases fatty acids by 1 μmol per minute is defined as 1 unit (U).

[0025] The enzymatic activity of the Mucor javanicus lipase can be measured by the following method. Lipase powder is dissolved or uniformly dispersed in a sample diluent (cold water, chilled pH 7.0 phosphate buffer (0.02 mol / L), or sodium dodecyl sulfate-bovine serum albumin test solution) to a volume of 5 mL. This is further diluted 10-fold, 100-fold, 1000-fold, or 10,000-fold with the same diluent to prepare a sample solution. Next, 70 mL of a 0.6 g / dL gum arabic solution, 22.3 mL of tributyrin (glyceryl tributyrate, manufactured by SIGMA), and 329 mL of water are stirred in an emulsifier at 11,000 to 13,000 rpm for approximately 150 seconds, and the resulting emulsified solution is used as the substrate solution. The gum arabic solution was prepared by dissolving 17.9 g of sodium chloride and 0.41 g of potassium dihydrogen phosphate in 400 mL of water and 540 mL of glycerin, then gradually adding 6.0 g of gum arabic while stirring, and diluting the solution to 1000 mL with water. 30 mL of the substrate solution was measured and heated at 30°C for 15 minutes. A 0.05 mol / L sodium hydroxide solution was added while stirring, adjusting the pH to 7.00±0.05 at 30°C, and 2 mL of the sample solution was added to prepare the test solution. A comparison solution was prepared by repeating the procedure described above, except that the sample solution was replaced with the water used to prepare the sample solution, 2 mL of a pH 7.0 phosphate buffer (0.02 mol / L), or 2 mL of sodium dodecyl sulfate-bovine serum albumin test solution. To the test solution and the control solution, 0.05 mol / L sodium hydroxide solution is continuously added dropwise for 5 minutes at 30° C. to maintain the pH at 7.00±0.05. The activity of the Mucor javanicus-derived lipase is calculated using the following formula, where 1 unit (1 U) is the amount of enzyme that increases butyric acid by 1.0 μmol per minute when treated with a tributyrin substrate solution at pH 7.0 and 30° C.Lipase activity = (V5 - V1) / 4 x 0.05 x f x 1000 / 2 V1: Titration volume 1 minute after the start of measurement (mL) V5: Titration volume 5 minutes after the start of measurement (mL) 0.05: Normality of 0.05 mol / L sodium hydroxide solution f: Factor of 0.05 mol / L sodium hydroxide solution 1000: Unit conversion coefficient (mmol → μmol) D: Dilution factor (mL / g) 2: Amount of sample solution added (mL).

[0026] This embodiment may relate to an enzyme preparation containing lipase used in the above-described production method. The enzyme preparation of this embodiment contains lipase and is used to improve the aroma of a grain raw material after a thermal sterilization process. The enzyme preparation of this embodiment preferably contains at least one lipase selected from the group consisting of a lipase derived from the genus Aspergillus and a lipase derived from the genus Mucor. Furthermore, the enzyme preparation of this embodiment may be in any form, such as a powder, solid, gel, or liquid.

[0027] <Production process> By using the production method of this embodiment, a processed grain-containing composition with reduced grain odor can be produced. One aspect of the production method of the processed grain-containing composition of this embodiment includes the following steps (1), (2), and (3). Note that an enzyme deactivation step may be provided after step (2): (1) A step of preparing a grain raw material; (2) A step of treating the prepared grain raw material with lipase; and (3) A step of heat sterilizing the lipase-treated processed grain raw material.

[0028] In the step of preparing a grain raw material, it is preferable to prepare a grain raw material (solid content) and add a sufficient amount of a drinkable liquid such as water to the grain raw material. In this case, the solid content of the grain raw material obtained by adding water or the like is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more. Furthermore, the solid content of the grain raw material is preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less.

[0029] The reaction time, temperature, and pH of the reaction solution for allowing lipase to act on the grain raw material are not particularly limited. The reaction temperature is, for example, 0 to 80°C, preferably 10 to 70°C, and more preferably 20 to 65°C. The pH of the reaction solution is, for example, 3 to 9, preferably 4 to 8, and more preferably 5 to 7. The reaction time is, for example, 30 seconds to 48 hours, preferably 1 minute to 24 hours, and more preferably 10 minutes to 12 hours. By adopting the above reaction conditions, the effect of reducing grain odor can be more effectively achieved. These reaction conditions are selected appropriately depending on the grain raw material of interest. The optimal reaction conditions can be determined through preliminary experiments.

[0030] In the step of thermally sterilizing the lipase-treated processed grain raw material, a heat sterilization treatment is performed. In the heat sterilization step (heat sterilization step) herein, heat treatment is performed at a temperature capable of sterilizing at least a portion of the bacteria contained in the lipase-treated processed grain raw material. Examples of heat sterilization methods include pressurized heat sterilization (retort heating, retort sterilization), boil sterilization, batch sterilization, microwave sterilization, low-temperature sterilization (LTLT method), high-temperature short-time (HIST) sterilization, high-temperature short-time (HTST) sterilization, ultra-high-temperature (UHT) sterilization, and ultra-high-temperature short-time (UHT) sterilization. Among these, the heat sterilization method is preferably at least one selected from the group consisting of pressurized heat sterilization, low-temperature sterilization, ultra-high-temperature sterilization, high-temperature short-time sterilization, and ultra-high-temperature short-time sterilization, more preferably at least one selected from the group consisting of high-temperature short-time sterilization, ultra-high-temperature sterilization, and ultra-high-temperature short-time sterilization, and ultra-high-temperature sterilization is particularly preferred. When ultra-high-temperature sterilization is performed as the heat sterilization method, it is preferable to perform heat sterilization at 120 to 150 ° C for 1 to 60 seconds, for example.

[0031] The temperature and processing time of the thermal sterilization step vary depending on the sterilization method used, but sterilization is preferably performed under conditions where the F value is preferably 0.00000001 or more, 0.0000001 or more, 0.000001 or more, 0.00001 or more, 0.0001 or more, or 0.001 or more. More preferably, sterilization is performed under conditions where the F value is 0.01 or more, even more preferably 0.05 or more, even more preferably 0.1 or more, and even more preferably 1 or more. In addition, the upper limit of the F value is not particularly limited, but when considering the flavor of the resulting processed grain-containing composition, sterilization is preferably performed under conditions where the F value is 500 or less, more preferably 200 or less, even more preferably 100 or less, even more preferably 50 or less, and even more preferably 25 or less. Here, the F value is an index used in retort foods, and is a value obtained by converting the sterilization effect when a food or beverage is treated at a certain temperature for a certain time into the time (unit: minutes) when heated at 121 ° C.

[0032] The lower limit of the temperature of the heat sterilization step in the present invention is not particularly limited, and may be, for example, 60 ° C. or higher, 70 ° C. or higher, 80 ° C. or higher, or 90 ° C. or higher. The lower limit of the temperature of the heat sterilization step is preferably 100 ° C. or higher, more preferably 110 ° C. or higher, even more preferably 120 ° C. or higher, even more preferably 125 ° C. or higher, and even more preferably 130 ° C. or higher. The upper limit of the temperature of the heat sterilization step is also not particularly limited, and is, for example, preferably 200 ° C. or lower, more preferably 180 ° C. or lower, even more preferably 170 ° C. or lower, even more preferably 160 ° C. or lower, even more preferably 150 ° C. or lower, even more preferably 145 ° C. or lower, and even more preferably 140 ° C. or lower.

[0033] The temperature and time of the heat sterilization step in the present invention are not particularly limited, but examples thereof include the following conditions: (1) When the temperature is 70 to 100°C, 5 minutes or more and 120 minutes or less (2) When the temperature is 100 to 130°C, 1 second or more and 50 minutes or less (3) When the temperature is 130 to 150°C, 1 second or more and 10 minutes or less

[0034] In this embodiment, a step of deactivating the enzyme may be provided after the step of treating the grain raw material with lipase. In this case, the step of deactivating the enzyme may also serve as the above-mentioned heat sterilization step, or a heat sterilization step may be provided separately from the step of deactivating the enzyme. In a preferred embodiment, the above-mentioned heat sterilization step is further provided after the step of treating the grain raw material with lipase and the step of deactivating the enzyme.

[0035] In this embodiment, the aroma (grain odor) of grain raw materials, which is generally considered undesirable to consumers, can be reduced by combining lipase treatment and heat sterilization treatment on grain raw materials. In the heat sterilization treatment, enzyme treatment products of some components of the grain raw materials, which are produced by lipase treatment, are heated at a predetermined temperature or higher, which is thought to produce substances that can mask the grain odor.

[0036] The production method of this embodiment may include a step of treating the grain raw material with an enzyme other than lipase. For example, in a preferred embodiment, a step of treating the grain raw material with α-amylase and / or β-amylase can be provided before or after the step of treating the grain raw material with lipase. In such a case, the saccharified liquid obtained by treating the α-amylase and / or β-amylase can be used as the grain raw material.

[0037] When a step of reacting with α-amylase and / or β-amylase is provided, the order in which the enzymes are reacted (i.e., the order of treatment with lipase, α-amylase, and β-amylase) is not particularly limited, but α-amylase may be reacted first, and then lipase and β-amylase may be reacted simultaneously, or α-amylase, β-amylase, and lipase may be reacted in this order, or α-amylase, lipase, and β-amylase may be reacted in this order. Of these, it is preferable to react with α-amylase first, and then lipase and β-amylase may be reacted simultaneously, from the viewpoint of improving work efficiency, etc.

[0038] <<α-Amylase>> The α-amylase used in this embodiment is not particularly limited in type, origin, etc., as long as it is an enzyme that produces dextrin by hydrolyzing α-1,4 glycosidic bonds.

[0039] The origin of the α-amylase is not particularly limited, and examples thereof include α-amylases derived from plants such as wheat, barley, and soybean, and α-amylases derived from microorganisms such as the genus Bacillus (e.g., Bacillus flexus, Bacillus megaterium, Bacillus polymyxa, and Bacillus circulans), Streptomyces sp., and Pseudomonas sp. These α-amylases may be used alone or in combination.

[0040] <<β-amylase>> The β-amylase used in this embodiment is not particularly limited in type, origin, etc., as long as it is an exo-type enzyme that sequentially degrades α-1,4 glycosidic bonds in maltose (malt sugar) units from the non-reducing end of starch.

[0041] The origin of the β-amylase is not particularly limited, and examples thereof include β-amylases derived from plants such as wheat, barley, and soybean, and β-amylases derived from microorganisms such as the genus Bacillus (e.g., Bacillus flexus, Bacillus megaterium, Bacillus polymyxa, and Bacillus circulans), Streptomyces sp., and Pseudomonas sp. These β-amylases may be used alone or in combination.

[0042] Among these β-amylases, from the viewpoint of further enhancing the effect of reducing grain odor, β-amylase derived from a microorganism is preferred, β-amylase derived from the genus Bacillus is more preferred, and β-amylase derived from Bacillus flexus is even more preferred.

[0043] The amount of β-amylase used is not particularly limited, but is preferably 0.01 U or more per 1 g of grain raw material used in the production of the processed grain-containing composition. From the viewpoint of further enhancing the effect of reducing grain odor, it is more preferably 0.05 U or more, even more preferably 0.1 U or more, even more preferably 0.5 U or more, and particularly preferably 1 U or more. The upper limit of the range of the amount of β-amylase used per 1 g of vegetable protein raw material is not particularly limited, but is preferably, for example, 100 U or less, 70 U or less, 50 U or less, or 10 U or less. The activity of β-amylase is defined as the amount of enzyme that, using potato starch as a substrate, causes an increase in reducing power equivalent to 1 mg of glucose per minute, where 1 unit (1 U) is the amount of enzyme that causes an increase in reducing power equivalent to 1 mg of glucose per minute.

[0044] <<Optional Components>> The production method of this embodiment may further include a step of mixing other components in addition to the step of treating the grain raw material with an enzyme other than lipase and the step of heat-sterilizing the lipase-treated processed grain raw material. Examples of the other components include optional components that may be contained in the processed grain-containing composition.

[0045] The step of mixing other ingredients may be carried out, for example, between the step of lipase-treating the grain raw material and the step of heat-sterilizing the lipase-treated processed grain raw material, or may be carried out before the step of lipase-treating the grain raw material, or may be carried out after the step of heat-sterilizing the processed grain-containing composition.

[0046] Examples of optional components include fats and oils, flavorings, sweeteners, acidulants, bittering agents, coloring agents, antioxidants, pH adjusters, vitamins, amino acids, minerals, antifoaming agents, emulsifiers (glycerin fatty acid esters, sucrose fatty acid esters, lecithin, saponin, etc.), thickening polysaccharides (pectin, carboxymethylcellulose, etc.), salts (table salt, calcium salts, phosphates, etc.), etc. Among these, it is preferable to mix fats and oils as other components.

[0047] The type of oil or fat is not particularly limited, but includes animal oil or vegetable oil, and vegetable oil is preferred.Vegetable oil or fat is not particularly limited, but includes, for example, canola oil (rapeseed oil), coconut oil, corn oil, olive oil, soybean oil, peanut oil, walnut oil, almond oil, sesame oil, cottonseed oil, sunflower seed oil, sunflower oil, flaxseed oil, palm oil, palm kernel oil, palm fruit oil, babassu oil, shea butter, mango butter, cocoa butter, wheat germ oil, rice bran oil, etc.These vegetable oils may be used alone or in combination of two or more.Among these vegetable oils, from the viewpoint of reducing the grain odor of the grain raw material, canola oil (rapeseed oil), coconut oil, and sunflower oil are preferred, and sunflower oil is more preferred.

[0048] The amount of oil or fat used is not particularly limited, but is, for example, 0.05 to 30 parts by mass per 100 parts by mass of grain raw material, and from the viewpoint of further improving the effect, is preferably 0.1 to 15 parts by mass, more preferably 1 to 10 parts by mass. The amount of oil or fat used is, for example, 0.05 to 50 mg per 1 U of lipase, and from the viewpoint of further improving the effect, is preferably 0.1 to 30 mg, more preferably 1 to 10 mg.

[0049] When fats and oils are added, they may be emulsified using, for example, a high-speed mixer, a homogenizer, a pressure homogenizer, or a high-pressure homogenizer.

[0050] (Processed grain-containing composition) This embodiment relates to a processed grain-containing composition obtained by the above-mentioned method for producing a processed grain-containing composition. The processed grain-containing composition contains an enzyme-treated product of a portion of the grain raw material, and in this embodiment, it is preferable that the enzyme-treated product contains, for example, a fatty acid. The processed grain-containing composition of this embodiment has a reduced grain odor, resulting in an improved aroma.

[0051] Specific examples of the processed grain-containing composition include grain food and drink ingredients and grain food and drink, and specific examples thereof include grain milk and grain yogurt.

[0052] The processed grain-containing composition of this embodiment is obtained by subjecting a grain raw material to a combination of lipase treatment and heat sterilization treatment. The processed grain-containing composition of this embodiment includes not only final products such as grain milk and grain yogurt, but also intermediate grain food and beverage ingredients (grain food and beverage raw materials) such as saccharified liquid.

[0053] In this specification, the processed grain-containing composition also includes a slurry in which the grain material is dispersed, a solution in which the grain material has settled, and a solid product in which the processed grain-containing material has been dried.

[0054] (Method for improving the aroma of grain raw materials) This embodiment relates to a method for improving the aroma of grain raw materials, which includes a step of treating the grain raw materials with lipase and a step of thermal sterilization. In the aroma improving method of this embodiment, the grain odor is reduced by treating the grain raw materials with the above-mentioned lipase in combination with a thermal sterilization treatment, and as a result, the aroma can be improved.

[0055] The grain raw material used in the aroma improving method of this embodiment is the same as the grain raw material described above, and the preferred ranges are also the same.Furthermore, the lipase used in the aroma improving method of this embodiment is the same as the lipase described above, and the preferred ranges are also the same.

[0056] The specific and preferred conditions for the step of treating the grain raw material with lipase and the step of thermal sterilization in the aroma improving method of this embodiment are the same as those described above. Furthermore, it is preferable to combine a step of treating the grain raw material with an enzyme other than lipase or a step of mixing other ingredients, if necessary.

[0057] This embodiment may relate to an aroma improving agent containing lipase for use in the aroma improving method described above. The aroma improving agent of this embodiment contains lipase and is an agent for improving the aroma of a grain raw material after a thermal sterilization process. The aroma improving agent of this embodiment preferably contains at least one lipase selected from the group consisting of an Aspergillus-derived lipase and a Mucor-derived lipase. Furthermore, the aroma improving agent of this embodiment may be in any form, such as a powder, solid, gel, or liquid.

[0058] The features of the present invention will be explained in more detail below with reference to examples and comparative examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

[0059] (Materials used)

[0060] (Method for measuring enzyme activity) The activity value of the Aspergillus niger-derived lipase was calculated by the method described in the following activity measurement (1), and the activity value of the Mucor javanicus-derived lipase was calculated by the method described in the following activity measurement (2).

[0061] Activity measurement (1) 75 mL of olive oil and 225 mL of emulsion (20 g / L polyvinyl alcohol I (saponification 98.0-99.0 mol%)) were mixed and emulsified using a homogenizer to prepare a substrate solution. 1 mL of lipase solution was added to 5 mL of substrate solution and 4 mL of 0.1 mol / L phosphate buffer (pH 6.0), and the reaction was carried out at 37°C. After 30 minutes, 10 mL of an ethanol-acetone mixture was added to stop the enzyme reaction. Next, 10 mL of 0.05 mol / L sodium hydroxide solution and 10 mL of an ethanol-acetone mixture were added, and the mixture was titrated with 0.05 mol / L hydrochloric acid to a pH of 10. The amount of enzyme that causes an increase of 1 μmol of fatty acids per minute was defined as 1 unit (U).

[0062] Activity Measurement (2) Lipase powder was dissolved or uniformly dispersed in a sample diluent (cold water, chilled pH 7.0 phosphate buffer (0.02 mol / L), or sodium dodecyl sulfate-bovine serum albumin test solution) to a volume of 5 mL. This was further diluted 10-fold, 100-fold, 1000-fold, or 10,000-fold with the same diluent to prepare a sample solution. 70 mL of 0.6 g / dL gum arabic solution, 22.3 mL of tributyrin (glyceryl tributyrate: manufactured by SIGMA), and 329 mL of water were stirred in an emulsifier at 11,000 to 13,000 rpm for approximately 150 seconds, and the resulting emulsified solution was used as the substrate solution. The gum arabic solution was prepared by dissolving 17.9 g of sodium chloride and 0.41 g of potassium dihydrogen phosphate in 400 mL of water and 540 mL of glycerin, then gradually adding 6.0 g of gum arabic while stirring, and diluting the solution to 1000 mL with water. 30 mL of the substrate solution was measured and heated at 30°C for 15 minutes. A 0.05 mol / L sodium hydroxide solution was added with stirring to adjust the pH to 7.00±0.05 at 30°C, and 2 mL of the sample solution was added to prepare the test solution. The same procedures were repeated to prepare the test solutions, except that the sample solution was replaced with the water used to prepare the sample solution, 2 mL of a pH 7.0 phosphate buffer (0.02 mol / L), or 2 mL of sodium dodecyl sulfate-bovine serum albumin test solution. To the test solution and the control solution, 0.05 mol / L sodium hydroxide solution was continuously added dropwise for 5 minutes at 30° C. to maintain the pH at 7.00±0.05. The activity of the Mucor javanicus-derived lipase was calculated using the following formula, where 1 unit (1 U) is the amount of enzyme that increases butyric acid by 1.0 μmol per minute when treated with a tributyrin substrate solution at pH 7.0 and 30° C. Lipase activity = (V5 - V1) / 4 x 0.05 x f x 1000 / 2 V1: Titration volume 1 minute after the start of measurement (mL) V5: Titration volume 5 minutes after the start of measurement (mL) 0.05: Normality of 0.05 mol / L sodium hydroxide solution f: Factor of 0.05 mol / L sodium hydroxide solution 1000: Unit conversion coefficient (mmol → μmol) D: Dilution factor (mL / g) 2: Amount of sample solution added (mL)

[0063] (Test Example 1) An oat flour suspension with an oat flour concentration of 30% by mass was treated with α-amylase to obtain a saccharified oat flour solution. The oat flour saccharified solution was incubated at 53°C for 90 minutes with or without the addition of enzymes to obtain the composition shown in Table 2. The solution was then heat-treated at 90°C for 5 minutes (enzymes were inactivated when added), and filtered through a filter cloth. Twice the amount of water was added to the filtrate to obtain processed oat milk (processed grain-containing composition).

[0064] The resulting processed oat milk was subjected to a sensory test by two panelists to evaluate its aroma (Table 2). The rating scale was as follows, and the average scores are shown in Table 2. 5: Strong grain smell 4: Slightly strong grain smell 3: Slightly strong grain smell 2: Slightly weak grain smell 1: Weak grain smell

[0065]

[0066] In test plots 1 and 2 where the enzyme was added, the effect of reducing grain odor was confirmed.

[0067] (Test Example 2) An oat flour suspension with an oat flour concentration of 30% by mass was treated with α-amylase to obtain an oat flour saccharified solution. β-amylase was added to the oat flour saccharified solution to a concentration of 1.3 U / g-oat, and various lipases were added or not added to achieve the compositions shown in Table 3. The pH of the resulting oat flour saccharified solution was measured and found to be 6.0. The solution was then incubated at 53°C for 90 minutes. It was then heat-treated at 90°C for 5 minutes (enzymes were inactivated if added), and filtered through a filter cloth. Two volumes of water were added to the filtrate, and salt (0.1% by mass) and sunflower oil (1.75% by mass) were added. Dipotassium phosphate was added to adjust the pH to 7.0. The solution was then thoroughly emulsified using a homogenizer (Laboratory Homogenizers, SPXFLOW). Next, the mixture was subjected to HTST / UHT sterilization under the following conditions to obtain processed oat milk (processed grain-containing composition). (UHT conditions) Equipment used: HT122 Bench-Top Heat Treatment System (manufactured by OMVE) Heating section temperature: 135°C Flow rate: 10 L / hr Holding time: 30 seconds F value: 12

[0068] The resulting processed oat milk was subjected to a sensory test to evaluate its aroma by two panelists (Table 3). The rating scale was as follows, and the average scores are shown in Table 3. 5: Strong grain smell 4: Slightly strong grain smell 3: Grain smell is noticeable 2: Slightly weak grain smell 1: Weak grain smell

[0069]

[0070] In test plots 1 and 2 where the enzyme was added, the effect of reducing the grain odor was confirmed, and by further performing UHT treatment, the effect of reducing the grain odor was confirmed to be even greater.

Claims

1. A method for producing a processed grain-containing composition, comprising the steps of treating a grain raw material with lipase and heat sterilizing the raw material.

2. The method for producing a processed grain-containing composition according to claim 1, wherein the grain raw material is at least one selected from the group consisting of barley, wheat, oats, rice, buckwheat, barnyard millet and foxtail millet.

3. A method for producing a processed grain-containing composition according to claim 1, wherein the moisture content of the grain raw material is 50% by mass or more.

4. The method for producing a processed grain-containing composition according to claim 1, wherein the lipase is at least one selected from the group consisting of lipases derived from the genus Aspergillus and lipases derived from the genus Mucor.

5. The method for producing a processed grain-containing composition according to claim 1, wherein the heat sterilization step is at least one selected from the group consisting of pressure-heat sterilization, low-temperature sterilization, ultra-high-temperature sterilization, high-temperature short-time sterilization, and ultra-high-temperature short-time sterilization.

6. A processed grain-containing composition obtained by the manufacturing method according to any one of claims 1 to 5.

7. A method for improving the aroma of a grain material, comprising the steps of treating the grain material with lipase and sterilizing the grain material by heat.

8. The method for improving the aroma of a grain material according to claim 7, wherein the grain material is at least one selected from the group consisting of barley, wheat, oats, rice, buckwheat, barnyard millet, and foxtail millet.

9. The method for improving the aroma of a grain material according to claim 7, wherein the moisture content of the grain material is 50% by mass or more.

10. The method for improving the aroma of grain raw materials according to claim 7, wherein the lipase is at least one selected from the group consisting of lipases derived from the genus Aspergillus and lipases derived from the genus Mucor.

11. The method for improving the aroma of grain raw materials according to claim 7, wherein the heat sterilization step is at least one selected from the group consisting of pressurized heat sterilization, low-temperature sterilization, ultra-high-temperature sterilization, high-temperature short-time sterilization, and ultra-high-temperature short-time sterilization.

12. An enzyme preparation containing lipase for improving the aroma of grain raw materials through a heat sterilization process.

13. The enzyme preparation according to claim 12, wherein the lipase is at least one selected from the group consisting of lipases derived from the genus Aspergillus and lipases derived from the genus Mucor.

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