JP2023056628A - Breads - Google Patents

Abstract

To provide breads containing soya flour with improved texture such as voluminous feel, excellent elasticity, additional moist feel, good crispness and good solubility in the mouth.SOLUTION: Breads containing soya bean flour of the invention contain 0.05% by mass or more and 5% by mass or less of cellulose nanofibers (preferably carboxymethylated cellulose nanofibers) relative to the absolute dry mass of cereal flour.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to breads containing cellulose nanofibers and soybean flour.

In general, breads (bread, pancakes, etc.) are mainly made of wheat flour (including starch, gluten) and other cereal flours, with water, foaming agents (yeast, baking soda, etc.), salt, eggs, oils and fats, etc. Produced by mixing, fermentation, molding, final fermentation and heating in time. The properties required for these breads are voluminous, uniform appearance, fine and uniform air bubbles in the inner phase (the cut surface when bread is cut), as well as texture, It is important that it is moist, crisp, and melts in the mouth. As a method to improve this, it is known to use wheat flour containing a lot of gluten to increase the amount of water absorption, and to use a lot of sugars, fats and oils, eggs, emulsifiers, etc. In Patent Document 1, anhydroglucose units are known. Disclosed is a process containing carboxymethyl cellulose or a salt thereof having a specific range of carboxymethyl substitution per unit.

JP 2010-226983 A

However, when part of the wheat flour is replaced with soybean flour, the amount of gluten decreases and the spreadability of the bread dough decreases, so the retention of carbon dioxide generated during yeast fermentation becomes insufficient, resulting in the formation of air bubbles in the bread. The smaller the amount, the less the texture. Therefore, the present invention provides bread containing soybean flour that has a voluminous feel, excellent resilience, and improved texture in terms of moistness, crispness, and melting in the mouth. for the purpose.

As a result of intensive studies in order to achieve this object, the present inventors have found that blending cellulose nanofibers (CNF) is effective, and completed the present invention.

The present invention provides the following.
(1) Breads containing cellulose nanofibers and soybean flour, the breads containing 0.05% by mass or more and 5% by mass or less of the cellulose nanofibers relative to the absolute dry mass of the cereal flour.
(2) The bread according to (1), wherein the cellulose nanofibers are anion-modified cellulose nanofibers.
(3) The breads according to (1) or (2), wherein the anion-modified cellulose nanofibers are cellulose nanofibers having carboxyl groups or cellulose nanofibers having carboxyalkyl groups.
(4) The breads according to (3), which are carboxymethylated cellulose nanofibers having a degree of carboxymethyl substitution of the anion-modified cellulose nanofibers in the range of 0.01 to 0.50.
(5) The bread according to any one of (1) to (4), further containing carboxymethylated cellulose.
(6) The bread according to any one of (1) to (5), containing 10% by mass or more and 50% by mass or less of soybean flour relative to the absolute dry mass of the whole cereal flour.
(7) Any one of (1) to (6) in which a dough composition containing 80 to 150% by weight of water component and 0.05 to 5% by weight of cellulose nanofiber is baked with respect to 100% by weight of whole flour. Bread described in Crab.

According to the present invention, it is possible to provide breads containing soybean flour that have a voluminous feel, are excellent in resilience, and are improved in terms of moistness, crispness, and melting in the mouth.

The bread of the present invention will be described below. In the present invention, "-" includes end values. That is, "X through Y" includes the values X and Y at both ends.

The bread of the present invention contains soybean flour and cellulose nanofibers, and contains 0.05% by mass or more and 5% by mass or less of the cellulose nanofibers relative to the absolute dry mass of the cereal flour.

(cellulose nanofiber)
In the present invention, cellulose nanofibers (hereinafter sometimes referred to as CNF) are fine fibers made of pulp, which is a cellulose-based raw material, to the nanometer level, and have a fiber width of about 1 to 500 nm. . The average fiber diameter and average fiber length of cellulose nanofibers are obtained by averaging the fiber diameter and fiber length obtained from the results of observing each fiber using an atomic force microscope (AFM) or a transmission electron microscope (TEM). can be obtained by Well, the average aspect ratio of cellulose nanofibers is usually 50 or more. Although the upper limit is not particularly limited, it is usually 1000 or less. Average aspect ratio can be calculated by the following formula:
Aspect ratio = average fiber length/average fiber diameter

Cellulose nanofibers are obtained by applying a mechanical force to pulp to make it finer, and are composed of unmodified cellulose, carboxylated cellulose (also called oxidized cellulose), carboxymethylated cellulose, and phosphate ester groups. It can be obtained by defibrating anion-modified cellulose such as the introduced cellulose and modified cellulose such as cationized cellulose. The average fiber length and average fiber diameter of fine fibers can be adjusted by oxidation treatment and fibrillation treatment. In the present invention, it is preferable to use carboxymethylated (CM) cellulose nanofibers obtained by defibrating carboxymethylated cellulose obtained by performing carboxymethylation treatment.

(raw material for cellulose)
Cellulose raw materials for producing cellulose nanofibers used in the present invention include, for example, plant materials (for example, wood, bamboo, hemp, jute, kenaf, agricultural waste, cloth, pulp), animal materials (for example, sea squirt species), algae, microorganisms (eg, Acetobacter) products, and the like. As pulp, unbleached softwood kraft pulp (NUKP), bleached softwood kraft pulp (NBKP), unbleached hardwood kraft pulp (LUKP), bleached hardwood kraft pulp (LBKP), unbleached softwood sulfite pulp (NUSP), bleached softwood Sulfite pulp (NBSP), thermomechanical pulp (TMP), recycled pulp, used paper, and the like. Although all of these can be used, cellulose fibers derived from plants or microorganisms are preferred, and cellulose fibers derived from plants are more preferred.

(Carboxymethylation)
In the present invention, when carboxymethylated cellulose nanofibers are used, the carboxymethylated cellulose may be obtained by carboxymethylating the above cellulose raw material by a known method, or a commercially available product may be used. In any case, the degree of carboxymethyl substitution per anhydroglucose unit of the cellulose is preferably between 0.01 and 0.50. As an example of the method for producing such carboxymethylated cellulose, the following method can be mentioned. Cellulose is used as a starting material, and water or a lower alcohol in an amount of 3 to 20 times the mass is used as a solvent. Specifically, water, methanol, ethanol, N-propyl alcohol, isopropyl alcohol, N-butanol, isobutanol, tertiary butanol and the like can be used alone or in combination of two or more. When using a mixed solvent of water and a lower alcohol, the mixing ratio of the lower alcohol is 60 to 95% by mass. As the mercerizing agent, an alkali metal hydroxide, specifically sodium hydroxide or potassium hydroxide, is used in an amount of 0.5 to 20 times the moles of the anhydroglucose residue of the starting material. A bottom raw material, a solvent, and a mercerizing agent are mixed and mercerized at a reaction temperature of 0 to 70° C., preferably 10 to 60° C., for a reaction time of 15 minutes to 8 hours, preferably 30 minutes to 7 hours. . Thereafter, a carboxymethylating agent is added at 0.05 to 10.0 mol per glucose residue, the reaction temperature is 30 to 90° C., preferably 40 to 80° C., and the reaction time is 30 minutes to 10 hours, preferably 1 The etherification reaction is carried out for 1 hour to 4 hours.

<Carboxymethylated cellulose nanofiber>
The carboxymethylated cellulose nanofibers of the present invention maintain at least part of their fibrous shape even when dispersed in water. That is, when an aqueous dispersion of carboxymethylated cellulose nanofibers is observed with an electron microscope, a fibrous substance can be observed. Also, when carboxymethylated cellulose nanofibers are measured by X-ray diffraction, peaks of cellulose type I crystals can be observed.

<Crystallinity of cellulose type I>
The crystallinity of cellulose in the carboxymethylated cellulose nanofibers used in the present invention is preferably 40% or more, and more preferably 50% or more, for crystalline type I. When the crystallinity of cellulose type I is as high as 40% or more, the proportion of cellulose that maintains the crystal structure without dissolving in a solvent such as water is high, resulting in high thixotropy (thixotropy), thickeners, etc. become suitable for viscosity adjustment applications. In addition, for example, but not limited to, when added to a gel-like substance (for example, food, cosmetics, etc.), there is an advantage that excellent shape retention can be imparted. The crystallinity of cellulose can be controlled by the concentration of the mercerizing agent and temperature during treatment, as well as the degree of carboxymethylation. Since high concentrations of alkali are used in mercerization and carboxymethylation, type I crystals of cellulose tend to be converted to type II crystals. Desired crystallinity can be maintained by adjusting the degree. The upper limit of the crystallinity of cellulose type I is not particularly limited. Realistically, it is considered that the upper limit is about 90%.

The method for measuring the cellulose type I crystallinity of carboxymethylated cellulose nanofibers is as follows:
A sample is placed in a glass cell and measured using an X-ray diffraction measurement device (LabX XRD-6000, manufactured by Shimadzu Corporation). The crystallinity is calculated using the method of Segal et al., and the diffraction intensity at 2θ = 10 ° to 30 ° in the X-ray diffraction diagram is used as a baseline, and the diffraction intensity at 2θ = 22.6 ° 002 plane and 2θ = It is calculated by the following formula from the diffraction intensity of the amorphous portion at 18.5°.
Xc = (I002c - Ia)/I002c x 100
Xc = crystallinity of cellulose type I (%)
I002c: 2θ=22.6°, diffraction intensity of 002 plane Ia: 2θ=18.5°, diffraction intensity of amorphous portion.

The proportion of type I crystals in the carboxymethylated cellulose nanofibers is generally the same as in the carboxymethylated cellulose before nanofibers.

<Carboxymethyl substitution degree>
The carboxymethylated cellulose nanofibers used in the present invention preferably have a degree of carboxymethyl substitution of 0.50 or less per anhydroglucose unit of cellulose. If the degree of carboxymethyl substitution exceeds 0.50, it is considered that the fiber dissolves in water and the fiber shape cannot be maintained. Considering the workability, the degree of substitution is preferably 0.01 to 0.50, more preferably 0.02 to 0.50, further preferably 0.05 to 0.40, More preferably 0.10 to 0.40. By introducing carboxymethyl groups into cellulose, the celluloses electrically repel each other, making it possible to defibrate into nanofibers. If it is too small, defibration will be insufficient, and cellulose nanofibers with high transparency may not be obtained. In the conventional aqueous method, it is difficult to obtain carboxymethylated cellulose nanofibers with a cellulose type I crystallinity of 60% or more when the degree of carboxymethyl substitution is in the range of 0.20 to 0.40. However, the present inventors have found, for example, by the method described later, that the degree of carboxymethyl substitution is in the range of 0.20 to 0.40 and the crystallinity of cellulose type I is 60% or more. We have found that cellulose nanofibers can be produced. The degree of carboxymethyl substitution can be adjusted by controlling the added amount of the carboxymethylating agent to be reacted, the amount of the mercerizing agent, the composition ratio of water and the organic solvent, and the like.

Anhydroglucose units in the present invention mean individual anhydroglucose (glucose residues) constituting cellulose. In addition, the degree of carboxymethyl substitution (also referred to as the degree of etherification) refers to the ratio of hydroxyl groups in glucose residues that constitute cellulose that are substituted with carboxymethyl ether groups (carboxymethyl ether per glucose residue). number of ether groups). The degree of carboxymethyl substitution may be abbreviated as DS.

The method for measuring the degree of carboxymethyl substitution is as follows:
About 2.0 g of the sample is precisely weighed and placed in a 300 mL Erlenmeyer flask with a common stopper. Add 100 mL of a liquid obtained by adding 100 mL of special grade concentrated nitric acid to 1000 mL of methanol nitrate and shake for 3 hours to convert the salt of carboxymethylated cellulose nanofibers (CMC) to H-CMC (hydrogenated carboxymethylated cellulose nanofibers). . Accurately weigh 1.5 to 2.0 g of the absolute dry H-CMC and put it in a 300 mL Erlenmeyer flask with a common stopper. Wet the H-CMC with 15 mL of 80% methanol, add 100 mL of 0.1 N NaOH, and shake at room temperature for 3 hours. Excess NaOH is back-titrated with 0.1N—H ₂ SO ₄ using phenolphthalein as an indicator, and the degree of carboxymethyl substitution (DS value) is calculated by the following equation.
A = [(100 x F'- _0.1N - _H2SO4 (mL) x F) x 0.1]/(H-CMC
Absolute dry mass (g))
Carboxymethyl substitution degree = 0.162 × A / (1-0.058 × A)
F′: factor of 0.1N—H ₂ SO ₄ F: factor of 0.1N—NaOH.

The degree of carboxymethyl substitution in the nanofibers of carboxymethylated cellulose is generally the same as the degree of carboxymethyl substitution in the carboxymethylated cellulose before nanofibers.

<Fiber diameter, aspect ratio>
The carboxymethylated cellulose nanofibers used in the present invention have a nanoscale fiber diameter. The average fiber diameter is preferably 3 nm to 500 nm, more preferably 3 nm to 150 nm, still more preferably 3 nm to 20 nm, still more preferably 5 nm to 19 nm, still more preferably 5 nm to 15 nm.

The aspect ratio of the carboxymethylated cellulose nanofibers is not particularly limited, but is preferably 350 or less, more preferably 300 or less, further preferably 200 or less, further preferably 120 or less. , is more preferably 100 or less, and more preferably 80 or less. When the aspect ratio is 350 or less, the fibers are not excessively long, the entanglement between the fibers is reduced, and the generation of clumps (lumps) of cellulose nanofibers can be reduced. Suitable. In addition, since it has high fluidity, it is easy to use even at a high concentration, and there is an advantage that it is easy to use even in applications where a high solid content is required. Although the lower limit of the aspect ratio is not particularly limited, it is preferably 25 or more, more preferably 30 or more. When the aspect ratio is 25 or more, the effect of improving thixotropy can be obtained from the fibrous shape. The aspect ratio of carboxymethylated cellulose nanofibers can be controlled by the mixing ratio of solvent and water during carboxymethylation, the amount of chemicals added, and the degree of carboxymethylation, and can be produced, for example, by the method described below. .

The average fiber diameter and average fiber length of nanofibers of carboxymethylated cellulose are measured using an atomic force microscope (AFM) when the diameter is 20 nm or less, and a field emission scanning electron microscope (FE-SEM) when the diameter is 20 nm or more. It can be measured by analyzing 200 randomly selected fibers and calculating the average. Also, the aspect ratio can be calculated by the following formula:
Aspect ratio = average fiber length/average fiber diameter.

(Method for producing carboxymethylated cellulose nanofibers)
The carboxymethylated cellulose nanofibers used in the present invention are not particularly limited, but can be produced by defibrating carboxymethylated cellulose produced by the following method.

Carboxymethylated cellulose is generally produced by treating (mercerizing) cellulose with an alkali, and then reacting the resulting mercerized cellulose (also referred to as alkali cellulose) with a carboxymethylating agent (also referred to as an etherifying agent). It can be manufactured by Carboxymethylated cellulose capable of forming nanofibers having the above characteristics of the present invention is subjected to mercerization (alkali treatment of cellulose) in a solvent mainly containing water, followed by carboxymethylation (also called etherification). ) in a mixed solvent of water and an organic solvent.

(cellulose)
In the present invention, cellulose means a polysaccharide having a structure in which D-glucopyranose (also referred to simply as "glucose residue" or "anhydroglucose") is linked by β-1,4 bonds. Cellulose is generally classified into natural cellulose, regenerated cellulose, fine cellulose, microcrystalline cellulose excluding non-crystalline regions, etc., according to its origin, production method, and the like. In the present invention, any of these celluloses can be used as a raw material for mercerized cellulose. It is preferable to use cellulose having a high degree of crystallinity of type I cellulose as a raw material. The crystallinity of cellulose type I of the raw material cellulose is preferably 70% or more, more preferably 80% or more. The method for measuring the crystallinity of cellulose type I is as described above.

Examples of natural cellulose include bleached or unbleached pulp (bleached wood pulp or unbleached wood pulp); linters, purified linters; cellulose produced by microorganisms such as acetic acid bacteria. Raw materials for bleached or unbleached pulp are not particularly limited, and examples thereof include wood, cotton, straw, bamboo, hemp, jute, and kenaf. Also, the method for producing the bleached pulp or the unbleached pulp is not particularly limited, and may be a mechanical method, a chemical method, or a combination of the two. Examples of bleached pulp or unbleached pulp classified by manufacturing method include mechanical pulp (thermomechanical pulp (TMP), groundwood pulp), chemical pulp (softwood unbleached sulfite pulp (NUSP), softwood bleached sulfite pulp (NBSP) ), softwood unbleached kraft pulp (NUKP), softwood bleached kraft pulp (NBKP), hardwood unbleached kraft pulp (LUKP), hardwood bleached kraft pulp (LBKP) and other kraft pulps). Further, dissolving pulp may be used in addition to paper pulp. Dissolving pulp is pulp that has been chemically refined, and is mainly used by dissolving it in chemicals, and serves as a main raw material for artificial fibers, cellophane, and the like.

Examples of regenerated cellulose include those obtained by dissolving cellulose in some solvent such as cuprammonium solution, cellulose xanthate solution, morpholine derivative, and spinning again.

The fine cellulose is obtained by subjecting cellulosic materials such as the natural cellulose and regenerated cellulose to depolymerization (for example, acid hydrolysis, alkaline hydrolysis, enzymatic decomposition, explosion treatment, vibration ball mill treatment, etc.). and those obtained by mechanically processing the above cellulosic materials.

(mercerized)
Mercerized cellulose (also referred to as alkali cellulose) is obtained by using the aforementioned cellulose as a raw material and adding a mercerizing agent (alkali).

A solvent mainly containing water (solvent mainly containing water) refers to a solvent containing water in a proportion higher than 50% by mass. Water in the solvent containing water as a main component is preferably 55% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, It is more preferably 90% by mass or more, and still more preferably 95% by mass or more. Particularly preferably, the water-based solvent is 100 mass % water (ie, water).

Examples of the solvent other than water (used in a mixture with water) in the solvent mainly containing water include the organic solvent used as the solvent for the subsequent carboxymethylation. For example, alcohols such as methanol, ethanol, N-propyl alcohol, isopropyl alcohol, N-butanol, isobutanol, tertiary butanol; ketones such as acetone, diethyl ketone, methyl ethyl ketone; and dioxane, diethyl ether, benzene, dichloromethane. and the like, and a mixture of these alone or two or more thereof can be added to water in an amount of less than 50% by mass and used as a solvent for mercerization. The organic solvent in the solvent mainly containing water is preferably 45% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, and still more preferably 20% by mass or less. , more preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 0% by mass.

The mercerizing agent includes, for example, alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide, and any one of these or a combination of two or more thereof can be used. The mercerizing agent is, but is not limited to, these alkali metal hydroxides, for example, 1 to 60% by weight, preferably 2 to 45% by weight, more preferably 3 to 25% by weight of aqueous solution in the reactor. can be added.

The amount of the mercerizing agent to be used is not particularly limited, but in one embodiment, it is preferably 0.1 mol or more and 2.5 mol or less, and 0.3 mol or more and 2.0 mol with respect to 100 g of cellulose (bone dry). It is more preferably mol or less, and further preferably 0.4 mol or more and 1.5 mol or less.

The amount of the solvent mainly composed of water during mercerization is preferably 1.5 to 20 times the weight of the cellulose raw material, more preferably 2 to 10 times the weight. Such an amount facilitates stirring and mixing of the raw materials, and allows the raw materials to react uniformly.

In the mercerization treatment, the bottom raw material (cellulose) and a solvent mainly composed of water are mixed, and the temperature of the reactor is adjusted to 0 to 70°C, preferably 10 to 60°C, more preferably 10 to 40°C. Then, an aqueous solution of a mercerizing agent is added and stirred for 15 minutes to 8 hours, preferably 30 minutes to 7 hours, more preferably 30 minutes to 3 hours. This gives mercerized cellulose (alkali cellulose).

The pH during mercerization is preferably 9 or higher, which allows the mercerization reaction to proceed. The pH is more preferably 11 or higher, still more preferably 12 or higher, and may be 13 or higher. The upper limit of pH is not particularly limited.

Mercerization can be performed using a reactor capable of mixing and stirring the above components while controlling the temperature, and various reactors conventionally used for mercerization reactions can be used. For example, a batch-type agitator in which two shafts agitate and mix the components described above is preferable from the viewpoint of both uniform mixing and productivity.

(Carboxymethylation)
Carboxymethylated cellulose is obtained by adding a carboxymethylating agent (also referred to as an etherifying agent) to mercerized cellulose.

Carboxymethylating agents include monochloroacetic acid, sodium monochloroacetate, methyl monochloroacetate, ethyl monochloroacetate, isopropyl monochloroacetate and the like. Of these, monochloroacetic acid or sodium monochloroacetate is preferred in terms of availability of raw materials.

The amount of the carboxymethylating agent used is not particularly limited, but in one embodiment, it is preferably added in the range of 0.5 to 1.5 mol per anhydroglucose unit of cellulose. The lower limit of the above range is more preferably 0.6 mol or more, more preferably 0.7 mol or more, and the upper limit is more preferably 1.3 mol or less, still more preferably 1.1 mol or less. The carboxymethylating agent can be added to the reactor as, but not limited to, an aqueous solution of 5 to 80% by weight, more preferably 30 to 60% by weight, or in powder form without dissolving. can also

The molar ratio of the mercerizing agent to the carboxymethylating agent (mercerizing agent/carboxymethylating agent) is generally 0.9 to 2.45 when monochloroacetic acid or sodium monochloroacetate is used as the carboxymethylating agent. adopted by The reason is that if it is less than 0.9, the carboxymethylation reaction may be insufficient, and unreacted monochloroacetic acid or sodium monochloroacetate may remain and waste may occur, and 2.45 If it exceeds , there is a possibility that a side reaction with excessive mercerizing agent and monochloroacetic acid or sodium monochloroacetate will proceed to form an alkali metal glycolate, which may be uneconomical.

Although the concentration of the cellulose raw material in the carboxymethylation reaction is not particularly limited, it is preferably 1 to 40% (w/v).

Simultaneously with the addition of the carboxymethylating agent, or before or immediately after the addition of the carboxymethylating agent, an organic solvent or an aqueous solution of an organic solvent is appropriately added to the reactor, or the pressure is reduced to remove water other than water during mercerization. is appropriately reduced to form a mixed solvent of water and an organic solvent, and the carboxymethylation reaction proceeds in this mixed solvent of water and an organic solvent. The timing of the addition or reduction of the organic solvent is not particularly limited as long as it is from the end of the mercerization reaction to immediately after the addition of the carboxymethylating agent. For example, 30 minutes before and after adding the carboxymethylating agent. Within is preferred.

Examples of organic solvents include alcohols such as methanol, ethanol, N-propyl alcohol, isopropyl alcohol, N-butanol, isobutanol and tertiary butanol; ketones such as acetone, diethyl ketone and methyl ethyl ketone; and dioxane, diethyl ether, Benzene, dichloromethane and the like can be mentioned, and these can be used alone or as a mixture of two or more of them added to water as a solvent for carboxymethylation. Among these, monohydric alcohols having 1 to 4 carbon atoms are preferred, and monohydric alcohols having 1 to 3 carbon atoms are more preferred, because of their excellent compatibility with water.

The ratio of the organic solvent in the mixed solvent during carboxymethylation is preferably 20% by mass or more, more preferably 30% by mass or more, relative to the total sum of water and the organic solvent. It is more preferably 40% by mass or more, further preferably 45% by mass or more, and particularly preferably 50% by mass or more. The upper limit of the proportion of the organic solvent is not limited, and may be, for example, 99% by mass or less. Considering the cost of the organic solvent to be added, it is preferably 90% by mass or less, more preferably 85% by mass or less, still more preferably 80% by mass or less, and even more preferably 70% by mass or less.

The reaction medium for carboxymethylation (a mixed solvent of water, an organic solvent, etc. that does not contain cellulose) has a lower proportion of water than the reaction medium for mercerization (in other words, the proportion of the organic solvent is more) is preferred. By satisfying this range, it becomes easier to increase the degree of carboxymethyl substitution while maintaining the crystallinity of the obtained carboxymethylated cellulose. Further, when the reaction medium for carboxymethylation has a lower proportion of water than the reaction medium for mercerization (the proportion of organic solvent is higher), when transitioning from the mercerization reaction to the carboxymethylation reaction, There is also the advantage that the mixed solvent for the carboxymethylation reaction can be formed by a simple means of adding a desired amount of organic solvent to the reaction system after the mercerization reaction is completed.

After forming a mixed solvent of water and an organic solvent and adding the carboxymethylating agent to the mercerized cellulose, the temperature is preferably kept constant in the range of 10 to 40°C for 15 minutes to 4 hours, preferably 15 minutes. Stir for about 1 minute to 1 hour. The liquid containing mercerized cellulose and the carboxymethylating agent are preferably mixed in multiple batches or by dropwise addition in order to prevent the reaction mixture from becoming hot. After adding the carboxymethylating agent and stirring for a certain period of time, if necessary, the temperature is raised to raise the reaction temperature to 30 to 90° C., preferably 40 to 90° C., more preferably 60 to 80° C., for 30 minutes or more. An etherification (carboxymethylation) reaction is carried out for 10 hours, preferably 1 to 4 hours to obtain carboxymethylated cellulose.

In the carboxymethylation, the reactor used in the mercerization may be used as it is, or another reactor capable of mixing and stirring the above components while controlling the temperature may be used. .

After completion of the reaction, residual alkali metal salts may be neutralized with a mineral acid or an organic acid. If necessary, by-produced inorganic salts, organic acid salts, etc. may be removed by washing with water-containing methanol, dried, pulverized, and classified to obtain carboxymethylated cellulose or salts thereof. When washing to remove by-products, it may be first washed in an acid form and then returned to a salt form after washing. Examples of devices used for dry pulverization include impact mills such as hammer mills and pin mills, medium mills such as ball mills and tower mills, and jet mills. Devices such as homogenizers, mass colloiders, and pearl mills are examples of devices used for wet pulverization.

(Fibrillation into nanofibers)
By defibrating the carboxymethylated cellulose obtained by the above method, it can be converted into cellulose nanofibers having a nanoscale fiber diameter.

For defibration, a dispersion of carboxymethylated cellulose obtained by the above method is prepared. The dispersion medium is preferably water for ease of handling. The concentration of carboxymethylated cellulose in the dispersion during fibrillation is preferably 0.01 to 10% (w/v) in consideration of the efficiency of fibrillation and dispersion.

The device used for defibrating carboxymethylated cellulose is not particularly limited, and devices such as high-speed rotation type, colloid mill type, high pressure type, roll mill type, and ultrasonic type can be used. It is preferable to apply a strong shearing force to the carboxymethylated cellulose dispersion during defibration. In particular, for efficient fibrillation, it is preferable to use a wet high-pressure or ultrahigh-pressure homogenizer capable of applying a pressure of 50 MPa or more to the dispersion and applying a strong shearing force. The pressure is more preferably 100 MPa or higher, still more preferably 140 MPa or higher. In addition, prior to fibrillation and dispersion treatment with a high-pressure homogenizer, the dispersion may be pretreated, if necessary, using a known mixing, stirring, emulsifying, and dispersing device such as a high-speed shear mixer. .

A high-pressure homogenizer pressurizes (high pressure) a fluid with a pump and ejects it from very fine gaps provided in the flow path, emulsifying and dispersing by total energy such as shear force due to collision between particles and pressure difference. , shredding, pulverizing, and micronizing.

In the present invention, the carboxymethylated cellulose nanofibers may be used in the form of a dispersion, or may be used as a powder after drying (removing the dispersion medium), pulverizing and classifying.

When the carboxymethylated cellulose nanofibers used in the present invention are used as powder, they may contain other components as necessary. For example, when producing a powder, it is preferable to allow a water-soluble polymer to coexist with a dispersion of carboxymethylated cellulose nanofibers before drying, because redispersibility is improved. The reason why the redispersibility is improved by the water-soluble polymer is not clear, but the water-soluble polymer covers the areas with low charge density on the surface of the carboxymethylated cellulose nanofibers, suppressing the formation of hydrogen bonds and drying. It is presumed that this is to prevent the aggregation of nanofibers at the time.

(water-soluble polymer)
When carboxymethylated cellulose nanofibers are used as a powder, examples of water-soluble polymers that can coexist during powder production include cellulose derivatives (carboxymethylcellulose, methylcellulose, hydroxypropylcellulose, ethylcellulose), xanthan gum, and xyloglucan. , dextrin, dextran, carrageenan, locust bean gum, alginic acid, alginate, pullulan, starch, potato starch, arrowroot powder, modified starch (cationized starch, phosphated starch, phosphate crosslinked starch, phosphate monoesterified phosphate crosslinked starch, hydroxypropyl Starch, hydroxypropylated phosphate cross-linked starch, acetylated adipic acid cross-linked starch, acetylated phosphate cross-linked starch, acetylated oxidized starch, sodium octenyl succinate, starch acetate, oxidized starch), corn starch, gum arabic, locust bean gum, gellan gum, Polydextrose, pectin, chitin, water-soluble chitin, chitosan, casein, albumin, soybean protein lysate, peptone, polyvinyl alcohol, polyacrylamide, polysodium acrylate, polyvinylpyrrolidone, polyvinyl acetate, polyamino acid, polylactic acid, polymalic acid , polyglycerin, latex, rosin-based sizing agent, petroleum resin-based sizing agent, urea resin, melamine resin, epoxy resin, polyamide resin, polyamide/polyamine resin, polyethyleneimine, polyamine, vegetable gum, polyethylene oxide, hydrophilic crosslinked polymer, Polyacrylates, starch polyacrylic acid copolymers, tamarind gum, guar gum and colloidal silica and mixtures of one or more thereof. Among these, cellulose derivatives are preferable from the viewpoint of affinity with carboxymethylated cellulose nanofibers, and carboxymethylcellulose and salts thereof are particularly preferable. A water-soluble polymer such as carboxymethylcellulose and its salt is considered to enter between carboxymethylated cellulose nanofibers and increase the distance between the nanofibers, thereby improving the redispersibility.

When carboxymethylcellulose or a salt thereof is used as the water-soluble polymer, it is preferable to use carboxymethylcellulose having a degree of carboxymethyl group substitution per anhydroglucose unit of 0.55 to 1.6, more preferably 0.55 to 1.6. 1 is more preferred, and 0.65 to 1.1 is even more preferred. In addition, longer molecules (higher viscosity) are preferable because they are more effective in widening the distance between nanofibers. In addition, the B-type viscosity at 25 ° C. and 60 rpm in a 1% by mass aqueous solution of carboxymethyl cellulose is preferably 3 mPa s to 14000 mPa s, more preferably 7 mPa s to 14000 mPa s, and 1000 mPa s to 8000 mPa s. More preferred. The term "carboxymethyl cellulose or a salt thereof" as a water-soluble polymer used herein is completely soluble in water. Distinguished from fibers.

The blending amount of the water-soluble polymer is preferably 5% by mass to 300% by mass, more preferably 20% by mass to 300% by mass, based on the carboxymethylated cellulose nanofiber (absolute dry solid content). % to 200% by mass is more preferred, and 25% to 60% by mass is even more preferred. When the water-soluble polymer is blended in an amount of 5% by mass or more, an effect of improving the redispersibility can be obtained. On the other hand, when the amount of the water-soluble polymer exceeds 300% by mass, problems such as viscosity characteristics such as thixotropy characteristic of carboxymethylated cellulose nanofibers and deterioration of dispersion stability may occur. It is preferable that the amount of the water-soluble polymer is 25% by mass or more because particularly excellent redispersibility can be obtained. In addition, considering the thixotropy, the content is preferably 200% by mass or less, and particularly preferably 60% by mass or less.

(dry)
A dispersion of carboxymethylated cellulose nanofibers, or a dispersion of carboxymethylated cellulose nanofibers optionally mixed with a water-soluble polymer is dried (removal of the dispersion medium) to obtain carboxymethylated cellulose nanofibers. A dry solid is obtained. In this case, it is preferable to adjust the pH of the dispersion to 9 to 11 and then dry it, because the redispersibility is further improved.

As a drying method, a known method can be used and is not particularly limited. Examples include spray drying, pressing, air drying, hot air drying, and vacuum drying. The drying device is not particularly limited, but may be a continuous tunnel drying device, a band drying device, a vertical drying device, a vertical turbo drying device, a multi-stage disk drying device, a ventilation drying device, a rotary drying device, a flash drying device, or a spray drying device. Dryer dryer, spray dryer, cylindrical dryer, drum dryer, belt dryer, screw conveyor dryer, rotary dryer with heating tube, vibration transport dryer, batch type box dryer, ventilation dryer, vacuum A box-type drying device, a stirring drying device, and the like can be used alone or in combination of two or more.

Among these, the use of a device that forms a thin film and dries it can uniformly supply heat energy directly to the material to be dried, and the drying process can be performed more efficiently in a short time, so it is energy efficient. It is preferable from the point of view. In addition, an apparatus for forming a thin film and drying it is preferable from the viewpoint that the dried product can be immediately recovered by a simple means such as scraping off the thin film. Furthermore, it was found that the redispersibility is further improved when the thin film is formed and then dried. As an apparatus for forming and drying a thin film, there are, for example, a drum drying apparatus and a belt drying apparatus for forming and drying a thin film on a drum or belt using a blade, a die, or the like. The film thickness of the thin film formed and dried is preferably 50 μm to 1000 μm, more preferably 100 μm to 300 μm. When it is 50 μm or more, it is easy to scrape off after drying, and when it is 1000 μm or less, the redispersibility is further improved.

The residual moisture content after drying is preferably 2% by mass to 15% by mass with respect to the entire dried product.

(crushing)
The pulverization method is not particularly limited, and a known method can be used, and examples include a dry pulverization method in which the powder is processed and a wet pulverization method in which the powder is dispersed or dissolved in a liquid. When wet pulverization is performed, it may be performed before the above drying.

Examples of equipment used in the dry pulverization method include, but are not limited to, cutting mills, impact mills, airflow mills, and media mills. These can be used singly or in combination, and can be processed in several stages with the same model. Among these, airflow mills are preferred. Cutting type mills include mesh mill (manufactured by Horai Co., Ltd.), Atoms (manufactured by Yamamoto Hyakuma Seisakusho Co., Ltd.), knife mill (manufactured by Palman), granulator (manufactured by Herbolt), rotary cutter mill (manufactured by Nara Co., Ltd.). manufactured by Kikai Seisakusho), etc. are exemplified. Impact mills include Pulperizer (manufactured by Hosokawa Micron Corporation), Fine Impact Mill (manufactured by Hosokawa Micron Corporation), Super Micron Mill (manufactured by Hosokawa Micron Corporation), Sample Mill (manufactured by Seishin Co., Ltd.), Bantam Mill ( Seishin Co., Ltd.), atomizer (Seishin Co., Ltd.), tornado mill (Nikkiso Co., Ltd.), turbo mill (Turbo Kogyo Co., Ltd.), bevel impactor (Aikawa Iron Works Co., Ltd.), and the like. Air flow mills include CGS type jet mill (manufactured by Mitsui Mining Co., Ltd.), jet mill (manufactured by Sansho Industry Co., Ltd.), Ebara Jet Micronizer (manufactured by Ebara Corporation), Selen Miller (Masuko Sangyo Co., Ltd.) Co., Ltd.), supersonic jet mill (manufactured by Nippon Pneumatic Industry Co., Ltd.), and the like. A vibrating ball mill or the like is exemplified as the medium mill. Apparatus used in the wet pulverization method includes a mass colloider (manufactured by Masuko Sangyo Co., Ltd.), a high pressure homogenizer (manufactured by Sanmaru Kikai Kogyo Co., Ltd.), and a media mill. As the medium mill, a bead mill (manufactured by Imex Co., Ltd.) and the like can be exemplified.

(Classification)
After the carboxymethylated cellulose nanofibers are pulverized, they are classified and adjusted to have a specific particle size. Although the method of classification is not particularly limited, for example, it can be carried out by passing through a mesh (sieve) having a predetermined mesh size. As the mesh, preferably 20 to 400 mesh, more preferably 40 to 300 mesh, and even more preferably 60 to 200 mesh can be used, and these may be used in multiple stages. The median diameter of the finally obtained powder is 10.0 μm to 150.0 μm, preferably 30.0 μm to 130.0 μm, more preferably 50.0 μm to 120.0 μm.

In the present invention, the content of cellulose nanofibers is 0.05% by mass or more with respect to the absolute dry mass of cereal flour used as the main raw material of bread, from the viewpoint of being able to exhibit a sufficient effect of improving texture. From the viewpoint of fluidity when kneading, it is 5% by mass or less, preferably 0.1% by mass or more and 3% by mass or less, and more preferably 0.2% by mass or more and 2% by mass or less.

In the present invention, breads are mainly made of cereal flours such as wheat flour (including starch and gluten), but must contain soybean flour. In addition, water, foaming agents (yeast, baking soda, etc.), salt, sugars, dairy products, egg products, edible oils and fats, etc. are used as auxiliary raw materials, and the dough is fermented, molded, baked, steamed, fried, etc. Bread such as Pullman, French bread such as baguettes and batards, bread rolls such as sweet rolls and table rolls, sweet bread such as croissants, Danish pastries, yeast donuts, pancakes and pancakes. exemplified.

In the present invention, as the grain flour (main raw material), any wheat flour that is usually used for bread making or the like can be used. Examples of such wheat flour include hard flour, semi-strong flour, all-purpose flour, soft flour, and durum wheat flour. Among them, strong flour, semi-strong flour and durum wheat flour are preferable. Furthermore, grain flours other than wheat flour, such as rye flour, rye flour, corn flour, starches, rice flour, buckwheat flour, various starches, and mixed flours thereof, may be appropriately selected and used according to the type of bread desired. can be done. These can be used singly or in combination.

In the present invention, it is essential to contain soybean flour as cereal flour, and it is preferable to contain 10% by mass or more and 50% by mass or less of soybean flour relative to the absolute dry mass of the whole cereal flour.

(Secondary raw material)
The breads of the present invention may contain auxiliary materials other than the raw material components described above, if necessary. Examples of such auxiliary materials include yeast foods; sugars such as sugar, glucose, fructose, invert sugar, starch syrup, maltose, lactose, and oligosaccharides; eggs or egg powder; skim milk powder, whole milk powder, cheese powder, yogurt powder , dairy products such as whey powder; oils and fats such as shortening, butter, margarine and other animal and vegetable oils; emulsifiers; swelling agents; thickeners; sweeteners; , glucose oxidase, amylase, lipase, and hemicellulase; and dietary fiber.

The bread of the present invention is produced by baking a dough composition containing the flour, water component, auxiliary raw materials, and cellulose nanofibers. Dough compositions also typically include fermented ingredients.

(fermented ingredients)
Fermented ingredients are not particularly limited as long as they are commonly used in dough compositions. Examples of fermented ingredients include various fermented seeds such as sourdough and ruban, and yeasts (fresh yeast, dry yeast, etc.).

The fermented component is preferably contained in an amount of 0.1 to 10% by weight, more preferably 0.5 to 5% by weight, even more preferably 1 to 5% by weight, relative to 100% by weight of flour.

(Water component)
The water component refers to the total amount of water and water components contained in eggs and the like. It is important that such a water component is contained in the range of 80 to 150% by weight, preferably 80 to 120% by weight, and more preferably 80 to 100% by weight, based on 100% by weight of flour. When the water content is 80% by weight or more, the bread obtained by heating such a dough composition is soft and stale. Moreover, when the water component is 150% by weight or less, excessive stickiness can be suppressed and workability can be ensured.

The bread of the present invention contains 0.05% by mass or more and 5% by mass or less of cellulose nanofiber relative to the absolute dry mass of the cereal flour, so it has a voluminous feel even though it contains soybean flour. It has excellent resilience, and is improved in terms of moistness, crispness, and melt-in-your-mouth texture. Although the reason why the bread of the present invention achieves these effects is not clear, in the present invention, the viscosity of the cellulose nanofibers contained in the bread at a low shear rate (<0.1 s ⁻¹ ) is, for example, carboxy It is speculated that this is because it is higher than general water-soluble polymers such as methyl cellulose, preventing coalescence of bubbles after foaming due to fermentation, etc., preventing collapse of bubbles, and generating fine-textured bubbles. be.

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these.

(Method for measuring degree of carboxymethyl substitution)
1) About 2.0 g of carboxymethylated cellulose fiber (absolute dry) is precisely weighed and placed in a 300 mL Erlenmeyer flask with a common stopper.
2) Add 100 mL of a solution obtained by adding 100 mL of special grade concentrated nitric acid to 1000 mL of nitric acid methanol, and shake for 3 hours to convert carboxymethyl cellulose salt (CM cellulose) into hydrogen-type CM cellulose.
3) Accurately weigh 1.5 to 2.0 g of hydrogenated CM cellulose (absolutely dry) and put it in a 300 mL conical flask equipped with a common stopper.
4) Wet the hydrogenated CM-cellulose with 15 mL of 80% methanol, add 100 mL of 0.1N NaOH, and shake at room temperature for 3 hours.
5) Backtitrate excess NaOH with 0.1N _H2SO4 using phenolphthalein as indicator _.
6) Calculate the degree of carboxymethyl substitution (DS) by the formula:
A=[(100×F′−(0.1N H ₂ SO ₄ ) (mL)×F)×0.1]/(absolute dry mass of hydrogen-type CM cellulose (g))
DS = 0.162 x A/(1 - 0.058 x A)
A: Amount of 1N NaOH (mL) required to neutralize 1 g of hydrogenated CM-cellulose
F': Factor of 0.1N _H2SO4 F: Factor of 0.1N _NaOH

(Measuring method of average fiber diameter and aspect ratio)
The average fiber diameter and average fiber length of CNF were analyzed for 200 randomly selected fibers using an atomic force microscope (AFM). The aspect ratio was calculated by the following formula.
Aspect ratio = average fiber length/average fiber diameter

[Example 1]
(Production of carboxymethylated cellulose nanofibers)
1089 parts of isopropanol (IPA) and 31 parts of sodium hydroxide dissolved in 121 parts of water were added to a 5 L twin-screw kneader whose rotation speed was adjusted to 100 rpm, and hardwood pulp (manufactured by Nippon Paper Industries Co., Ltd., LBKP) was charged at 200 parts by dry mass when dried at 100° C. for 60 minutes. The mixture was stirred and mixed at 30°C for 60 minutes to prepare mercerized cellulose. Further, 117 parts of sodium monochloroacetate was added with stirring, and after stirring at 30°C for 30 minutes, the temperature was raised to 70°C over 30 minutes, and carboxymethylation reaction was carried out at 70°C for 60 minutes. The proportion of water in the reaction medium during the mercerization reaction and the carboxymethylation reaction was 10% by mass. After completion of the reaction, the sodium salt of carboxymethylated cellulose having a carboxymethyl substitution degree of 0.27 and a cellulose type I crystallinity of 64% was neutralized, washed with 65% aqueous methanol, deliquored, dried, and pulverized. got The methods for measuring the degree of carboxymethyl substitution and the crystallinity of cellulose type I are as described above.
The resulting sodium salt of carboxymethylated cellulose was dispersed in water to form a 1% (w/v) aqueous dispersion. This was treated with a high-pressure homogenizer at 150 MPa three times to obtain a dispersion of carboxymethylated cellulose nanofibers. The obtained carboxymethylated cellulose nanofibers had an average fiber diameter of 3.2 nm and an aspect ratio of 40.

(Production of CNF powder 1)
The obtained carboxymethylated cellulose nanofibers were made into a dispersion with a solid content of 0.7% by mass with water, and carboxymethylcellulose (manufactured by Nippon Paper Industries Co., Ltd., trade name: F350HC-4, viscosity (1% by mass, 25°C, 60 rpm) about 3000 mPa s, carboxymethyl substitution degree about 0.90) is 40% by mass with respect to carboxymethylated cellulose nanofibers (that is, when the solid content of carboxymethylated cellulose nanofibers is 100 parts by mass The solid content of carboxymethyl cellulose was 40 parts by mass), and the mixture was stirred with a TK homomixer (12,000 rpm) for 60 minutes.
After adjusting the pH to 9 by adding 0.5% by mass of an aqueous sodium hydroxide solution to the dispersion, the dispersion was applied to the surface of a drum of a drum dryer D0405 (manufactured by Katsuragi Industry Co., Ltd.) and dried at 140° C. for 1 minute. The resulting dried material was scraped off and then pulverized using an impact mill at a rate of 10 kg per hour to obtain a dry pulverized material having a water content of 5% by mass. The resulting pulverized material was classified using a 30 mesh to obtain a powder (CNF powder 1) containing carboxymethylated cellulose nanofibers and carboxymethyl cellulose.

(Manufacturing of bread)
Next, a loaf of bread was produced by the method shown below (straight method).
(1) Raw materials were weighed as shown in Table 1. In addition, the numerical value of the raw material of Table 1 represents a mass part.
(2) 1/2 of the weighed and temperature-controlled water was separately weighed, and yeast was added.
(3) The rest of the water was added to the mixer and all ingredients except the yeast were added to the mixer. The dissolved yeast was then added to the mixer.
(4) The raw materials put into the mixer were mixed at a temperature of 27°C.
(5) The obtained dough was subjected to primary fermentation for 90 minutes in a fermentation chamber at a temperature of 27°C and a humidity of 75%.
(6) The dough was simply rounded, placed in a tray, and benched for 30 minutes.
(7) The dough was degassed, and the rolled dough was placed in a mold.
(8) Final fermentation was carried out in a fermentation room at a temperature of 35°C and a humidity of 85% for 80 minutes.
(9) Bake in an oven for 35 minutes under conditions of 185° C. top heat and 195° C. bottom heat.

[Examples 2-3]
A loaf of bread was produced in the same manner as in Example 1, except that the raw materials were blended as shown in Table 1.

[Comparative Example 1]
Bread was produced in the same manner as in Example 1 except that CNF powder 1 was not added to the raw material.

The breads produced in Examples 1 to 3 and Comparative Example 1 were evaluated for volume and appearance. In addition, as evaluation of texture, 8 panelists evaluated the moist feeling, crispness, and melting in the mouth after 4 hours from the production according to the following 5-grade evaluation. Table 2 shows the results.

As is clear from the results in Table 2, the bread containing carboxymethylated cellulose nanofibers of Examples 1 to 3 and containing soybean flour is the bread containing soybean flour that does not contain carboxymethylated cellulose nanofibers of Comparative Example 1. Compared to , it is clearly superior in voluminousness and appearance, and it can be seen that the texture is improved. In particular, the effect is remarkable in a loaf of bread made from dough with a lot of water as in Example 3.

Claims (7)

Breads containing cellulose nanofibers and soybean flour, the breads containing 0.05% by mass or more and 5% by mass or less of the cellulose nanofibers relative to the absolute dry mass of the cereal flour. The bread according to claim 1, wherein the cellulose nanofibers are anion-modified cellulose nanofibers. 3. The breads according to claim 1, wherein the anion-modified cellulose nanofibers are cellulose nanofibers having carboxyl groups or cellulose nanofibers having carboxyalkyl groups. 4. The bread according to claim 3, wherein the anion-modified cellulose nanofibers are carboxymethylated cellulose nanofibers having a degree of carboxymethyl substitution in the range of 0.01 to 0.50. The bread according to any one of claims 1 to 4, further comprising carboxymethylated cellulose. The bread according to any one of claims 1 to 5, comprising 10% by mass or more and 50% by mass or less of soybean flour relative to the absolute dry mass of the whole cereal flour. The bread according to any one of claims 1 to 6, wherein a dough composition containing 80 to 150% by weight of water component and 0.05 to 5% by weight of cellulose nanofiber is baked with respect to 100% by weight of whole grain flour. kind.