JP7404724B2 - Mochi-like food and method for producing mochi-like food - Google Patents

Description

The present invention relates to a rice cake-like food containing cellulose nanofibers and a method for producing a rice cake-like food containing cellulose nanofibers.

Mochi-like foods are prepared by steaming a mixture of glutinous rice or glutinous rice flour, optionally non-glutinous rice, various starches, wheat flour, etc., and then pounding or kneading the mixture.

After manufacturing, mochi-like foods may harden over time and deteriorate in texture. In order to solve these problems, it has been proposed to suppress hardening and improve texture by adding water-soluble hemicellulose (Patent Document 1).

Japanese Patent Application Publication No. 10-150938

However, in the method of Patent Document 1, it was insufficient to prevent the texture from deteriorating when the food was thawed after freezing. Furthermore, the method of adding sugar not only deteriorates the texture but also imparts unnecessary sweetness.

Therefore, an object of the present invention is to provide a rice cake that suppresses cracking when thawed after freezing and does not reduce texture.

As a result of intensive studies to achieve this objective, the present inventor found that it is effective to incorporate cellulose nanofibers (CNF), and completed the present invention.

The present invention provides the following.
(1) A rice cake-like food containing sticky rice and cellulose nanofibers.
(2) The rice cake-like food according to (1), wherein the cellulose nanofibers are anion-modified cellulose nanofibers.
(3) The rice cake-like food according to (1) or (2), wherein the anion-modified cellulose nanofiber is a cellulose nanofiber having a carboxy group or a cellulose nanofiber having a carboxyalkyl group.
(4) The rice cake-like food according to (3), wherein the anion-modified cellulose nanofiber is a carboxymethylated cellulose nanofiber having a degree of carboxymethyl substitution within the range of 0.01 to 0.50.
(5) The rice cake-like food according to any one of (1) to (4), further containing carboxymethylated cellulose.
(6) The mochi-shaped food according to any one of claims 1 to 5, wherein the mochi-shaped food is one selected from the group consisting of Daifuku mochi, Sakura mochi, Ankoro mochi, Bota mochi, Kusamochi, Gyuhi, Ohagi, and Dango. food.

According to the present invention, it is possible to provide a rice cake-like food product that is suppressed from cracking when frozen and thawed and has an excellent texture.

The present invention will be explained in detail below. In the present invention, "~" includes extreme values. That is, "X~Y" includes the values X and Y at both ends.

The sticky food of the present invention contains glutinous rice and cellulose nanofibers, and optionally contains nonglutinous rice, wheat flour, starches, and the like.

(glutinous rice)
The glutinous rice used in the rice cake-like food of the present invention is not particularly limited, and may be glutinous rice powder (glutinous rice flour, shiratama flour, Domyoji flour, etc.). In addition, if necessary, add non-glutinous rice, rice flour (joshin flour), wheat flour (strong flour, semi-strong flour, medium flour, soft flour, durum flour, whole wheat flour, etc.), buckwheat flour, corn flour, starches (potato starch, potato starch, Tapioca starch, wheat starch, lotus starch, sweet potato starch, corn starch, millet flour, arrowroot starch, bracken flour, and modified starch (starch that has been enzymatically, physically and/or chemically processed)) are mixed. Good too.

(auxiliary raw materials)
In the present invention, if necessary, auxiliary raw materials that are generally used in rice cake-like foods, or auxiliary raw materials that are used depending on the type of rice cake-like food, desired quality, etc., can be used. Specifically, sugars (monosaccharides such as glucose and fructose, disaccharides such as maltose, sucrose, and lactose, high fructose sugar, starch syrup, reduced starch syrup, and sugar alcohols), salt, leavening agents such as baking soda, fresh cream, Dairy products such as cheese and cream cheese, eggs (whole eggs, pasteurized liquid egg yolks, frozen egg yolks, dried egg yolks, sweetened egg yolks), milk ingredients (milk, skim milk, skim milk powder, whole milk powder, sweetened milk powder), honey, shortening , fats and oils (margarine, butter, liquid oil, emulsified fat, etc.), emulsifiers (glycerin fatty acid ester, sucrose fatty acid ester, calcium stearoyl lactate, etc.), polysaccharide thickeners (carboxymethylated cellulose, guar gum, xanthan gum, carrageenan, etc.) , spices (cinnamon, basil, etc.), Western liquors (brandy, rum, etc.), beans (soybeans, fava beans), sesame, dried fruits (raisins, dried cherries, etc.), nuts (almonds, peanuts, etc.), enzymes (α amylase, β-amylase, glucoamylase, protease, lipase, xylanase, hemicellulase, glucose oxidase, etc.), flavoring (e.g. vanilla essence), artificial sweetener (e.g. aspartame), dietary fiber (pectin, guar gum decomposition product, agarose, glucomannan) , polydextrose, sodium alginate, cellulose, hemicellulose, lignin, chitin, chitosan, indigestible dextrin, etc.), active gluten, soybean protein, matcha powder, chocolate, cocoa powder, etc.

(cellulose nanofiber)
In the present invention, cellulose nanofibers (hereinafter sometimes referred to as CNFs) are microfibers made from cellulosic raw materials such as pulp that have been refined to the nanometer level, and whose fiber width is approximately 1 to 500 nm. . The average fiber diameter and average fiber length of cellulose nanofibers are determined 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 Moreover, the average aspect ratio of cellulose nanofibers is usually 50 or more. The upper limit is not particularly limited, but is usually 1000 or less. The average aspect ratio can be calculated by the following formula:
Aspect ratio = average fiber length / average fiber diameter

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

(cellulose raw material)
Cellulose raw materials for producing cellulose nanofibers used in the present invention include, for example, plant materials (e.g., wood, bamboo, hemp, jute, kenaf, agricultural residues, cloth, pulp), animal materials (e.g., sea squirt), ), algae, and products of microorganisms (eg, acetic acid bacteria (acetobacter)). Pulps include softwood unbleached kraft pulp (NUKP), softwood bleached kraft pulp (NBKP), hardwood unbleached kraft pulp (LUKP), hardwood bleached kraft pulp (LBKP), softwood unbleached sulfite pulp (NUSP), and softwood bleached pulp. Examples include sulfite pulp (NBSP), thermomechanical pulp (TMP), recycled pulp, and waste paper. Although all of these can be used, cellulose fibers of plant or microbial origin are preferred, with cellulose fibers of plant origin being more preferred.

(carboxymethylation)
In the present invention, when using carboxymethylated cellulose nanofibers, the carboxymethylated cellulose may be obtained by carboxymethylating the above-mentioned cellulose raw material by a known method, or a commercially available product may be used. In either case, the degree of carboxymethyl substitution per anhydroglucose unit of cellulose is preferably 0.01 to 0.50. An example of a method for producing such carboxymethylated cellulose is the following method. Cellulose is used as the base material, and 3 to 20 times the weight of water or lower alcohol is used as the solvent. Specifically, water, methanol, ethanol, N-propyl alcohol, isopropyl alcohol, N-butanol, isobutanol, tertiary butanol, etc. can be used alone or in combination of two or more. When a mixed solvent of water and lower alcohol is used, the mixing ratio of the lower alcohol is 60 to 95% by mass. As the mercerization agent, alkali metal hydroxide, specifically sodium hydroxide or potassium hydroxide, is used in an amount of 0.5 to 20 times the mole per anhydroglucose residue in the bottom starting material. Mix the raw material for bottom formation, a solvent, and a mercerization agent, and perform mercerization treatment at a reaction temperature of 0 to 70°C, preferably 10 to 60°C, and a reaction time of 15 minutes to 8 hours, preferably 30 minutes to 7 hours. . Thereafter, a carboxymethylating agent is added in moles of 0.05 to 10.0 times per glucose residue, and 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 4 hours.

<Carboxymethylated cellulose nanofiber>
The carboxymethylated cellulose nanofibers of the present invention maintain at least a portion 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. Furthermore, when carboxymethylated cellulose nanofibers are measured by X-ray diffraction, the peak 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 40% or more for crystal type I, preferably 50% or more. When the degree of crystallinity of cellulose type I is as high as 40% or more, the proportion of cellulose that maintains a crystal structure without dissolving in solvents such as water is high, resulting in high thixotropy (thixotropy) and thickening agents, etc. This makes it suitable for viscosity adjustment applications. Further, for example, but not limited to this, when added to gel-like substances (for example, foods, 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, the temperature during treatment, and the degree of carboxymethylation. Since a high concentration of alkali is used in mercerization and carboxymethylation, type I crystals of cellulose are easily converted to type II, but modification can be prevented by adjusting the amount of alkali (mercerizing agent) used. By adjusting the degree, desired crystallinity can be maintained. The upper limit of the crystallinity of cellulose type I is not particularly limited. In reality, the upper limit is considered to be about 90%.

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

The proportion of type I crystals in carboxymethylated cellulose nanofibers is usually the same as that in carboxymethylated cellulose before it is made into nanofibers.

<Carboxymethyl substitution degree>
The carboxymethylated cellulose nanofibers used in the present invention have a degree of carboxymethyl substitution per anhydroglucose unit of cellulose of 0.50 or less. It is considered that if the degree of carboxymethyl substitution exceeds 0.50, it will dissolve in water and the fiber shape will not be maintained. In consideration of operability, the degree of substitution is preferably 0.01 to 0.50, more preferably 0.02 to 0.50, even more preferably 0.05 to 0.40, More preferably, it is 0.10 to 0.40. By introducing carboxymethyl groups into cellulose, the cellulose particles electrically repel each other, making it possible to defibrate them into nanofibers, but when the degree of carboxymethyl substitution per anhydroglucose unit is less than 0.01, If it is small, defibration may be insufficient and highly transparent cellulose nanofibers may not be obtained. In addition, 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, for example, by the method described below, obtained carboxymethylated cellulose in which the degree of carboxymethyl substitution is in the range of 0.20 to 0.40 and the degree of crystallinity of cellulose I type is 60% or more. We have discovered that cellulose nanofibers can be produced. The degree of carboxymethyl substitution can be adjusted by controlling the amount of carboxymethylating agent to be reacted, the amount of mercerizing agent, and the composition ratio of water and organic solvent.

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

The method for measuring the degree of carboxymethyl substitution is as follows:
Weigh approximately 2.0 g of the sample accurately and place it in a 300 mL Erlenmeyer flask with a stopper. Add 100 mL of a solution prepared by adding 100 mL of special grade concentrated nitric acid to 1000 mL of methanol nitric acid, and shake for 3 hours to convert carboxymethylated cellulose nanofiber salt (CMC) to H-CMC (hydrogen-type carboxymethylated cellulose nanofiber). . Accurately weigh 1.5 to 2.0 g of the bone-dried H-CMC and place it in a 300 mL Erlenmeyer flask with a stopper. Wet H-CMC with 15 mL of 80% methanol, add 100 mL of 0.1N 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 formula.
A=[(100×F'-0.1N-H ₂ SO ₄ (mL)×F)×0.1]/(H-CMC
(absolute dry mass (g))
Carboxymethyl substitution degree = 0.162 x A/(1-0.058 x A)
F': Factor of 0.1N-H ₂ SO ₄ F: Factor of 0.1N-NaOH.

The degree of carboxymethyl substitution in carboxymethylated cellulose nanofibers is usually the same as the degree of carboxymethyl substitution in carboxymethylated cellulose before it is made into 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, even more preferably 3 nm to 20 nm, even more preferably 5 nm to 19 nm, even 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, even more preferably 200 or less, and even more preferably 120 or less. , more preferably 100 or less, and even more preferably 80 or less. When the aspect ratio is 350 or less, the fibers are not excessively long, the entanglement of the fibers is reduced, and the generation of lumps of cellulose nanofibers can be reduced, making it suitable for use as an additive. Suitable. Moreover, since it has high fluidity, it is easy to use even at high concentrations, and has the advantage of being easy to use even in applications requiring a high solid content. The lower limit of the aspect ratio is not particularly limited, but is preferably 25 or more, more preferably 30 or more. When the aspect ratio is 25 or more, the effect of improved thixotropy can be obtained due to 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 manufacturing method described below. .

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

(defibration)
The cellulose raw material may be defibrated before or after the cellulose raw material is subjected to the modification treatment. Further, defibration may be performed at once or multiple times. In the case of multiple defibrations, each defibration can be performed at any time.

The device used for defibration is not particularly limited, but examples include high-speed rotation type, colloid mill type, high pressure type, roll mill type, and ultrasonic type devices. High pressure or ultra-high pressure homogenizers are preferred, and wet high pressure homogenizers are preferred. Or an ultra-high pressure homogenizer is more preferable. Preferably, the device is capable of applying a strong shear force to the cellulosic raw material or modified cellulose (usually a dispersion). The pressure that can be applied by the device is preferably 50 MPa or more, more preferably 100 MPa or more, and still more preferably 140 MPa or more. The device is preferably a wet high-pressure or ultra-high-pressure homogenizer that can apply the above pressure to the cellulose raw material or modified cellulose (usually a dispersion) and can also apply a strong shearing force. Thereby, defibration can be performed efficiently.

When defibrating a dispersion of cellulose raw materials, the solid content concentration of the cellulose raw materials in the dispersion is usually 0.1% by mass or more, preferably 0.2% by mass or more, and more preferably 0.3% by mass. % by mass or more. As a result, the amount of liquid is appropriate for the amount of cellulose fiber raw material, which is efficient. The upper limit is usually 10% by mass or less, preferably 6% by mass or less. This allows fluidity to be maintained.

Prior to defibration (preferably defibration using a high-pressure homogenizer) or dispersion treatment performed before defibration as necessary, a preliminary treatment may be performed as necessary. The pretreatment may be performed using a mixing, stirring, emulsifying, dispersing device such as a high-speed shear mixer.

(dry)
The cellulose nanofibers used in the present invention can be used in the form of a dispersion obtained after fibrillation, but if necessary, they can also be used after being dried and redispersed in water. The drying method is not limited at all, but includes, for example, freeze drying, spray drying, tray drying, drum drying, belt drying, drying by spreading thinly on a glass plate, fluidized bed drying, and microwave drying. Known methods such as drying method, exothermic fan vacuum drying method, etc. can be used. After drying, it may be pulverized using a cutter mill, hammer mill, pin mill, jet mill, etc., if necessary. Moreover, the method of redispersion into water is not particularly limited, and any known dispersion device can be used.

The form of cellulose nanofibers used in the present invention may be in the form of a dispersion or a powder, but from the viewpoint of excellent workability during confectionery production, it is preferable to use the cellulose nanofiber in the form of a dispersion. is preferred.

In the present invention, the blending amount of cellulose nanofibers is preferably 0.01 to 5% by mass, more preferably 0.05 to 3% by mass, and even more preferably It is 0.1 to 2% by mass.

The cellulose nanofiber of the present invention may contain other components as necessary. For example, when producing a powder, it is preferable to coexist a water-soluble polymer with a dispersion of cellulose nanofibers before drying, since this improves redispersibility.

<Water-soluble polymer>
Examples of water-soluble polymers include cellulose derivatives (carboxymethylcellulose, methylcellulose, hydroxypropylcellulose, ethylcellulose), xanthan gum, xyloglucan, dextrin, dextran, carrageenan, locust bean gum, alginic acid, alginate, pullulan, starch, starch powder, Examples include arrowroot flour, cornstarch, gum arabic, locust bean gum, gellan gum, polydextrose, pectin, chitin, water-soluble chitin, chitosan, casein, albumin, soybean protein solution, peptone, tamarind gum, guar gum, and the like. Among these, cellulose derivatives are preferred from the viewpoint of affinity with carboxymethylated cellulose nanofibers, and carboxymethyl cellulose and its salts are particularly preferred. Water-soluble polymers such as carboxymethylcellulose and its salts are thought to penetrate between carboxymethylated cellulose nanofibers and increase the distance between the nanofibers, thereby improving redispersibility.

When using carboxymethyl cellulose or a salt thereof as the water-soluble polymer, it is preferable to use carboxymethyl cellulose having a degree of substitution of carboxymethyl groups per anhydroglucose unit of 0.55 to 1.6, and preferably 0.55 to 1. 1 is more preferable, and 0.65 to 1.1 is even more preferable. Moreover, those with long molecules (high viscosity) are preferable because they are more effective in increasing the distance between nanofibers. Further, the B type viscosity of a 1% by mass aqueous solution of carboxymethylcellulose at 25°C and 60 rpm 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. In addition, "carboxymethylcellulose or its salt" as a water-soluble polymer here is completely soluble in water, so it is the carboxymethylated cellulose nano that can confirm the fiber shape in water. Distinguished from fiber.

The blending amount of the water-soluble polymer is preferably 5% to 300% by mass, more preferably 20% to 300% by mass, and more preferably 25% to 300% by mass, based on cellulose nanofibers (absolutely dry solid content). 200% by weight is more preferable, and even more preferably 25% by weight to 60% by weight.

(Method for producing rice cake-like food)
When adding cellulose nanofibers in the form of an aqueous dispersion to raw materials for a rice cake-like food, first, an aqueous dispersion of cellulose nanofibers is prepared. When preparing an aqueous dispersion from cellulose nanofiber powder, for example, the cellulose nanofiber powder and water may be stirred with a mixer. Next, the dough of the present invention is prepared by mixing glutinous rice, cellulose nanofiber aqueous dispersion, and auxiliary raw materials as necessary, and then steaming the obtained dough, followed by pounding or kneading. A rice cake-like food can be produced.

Since the rice cake-like food of the present invention contains cellulose nanofibers, it has uniform and fine air bubbles, so it has excellent texture. Specific examples of mochi-like foods include Daifuku mochi, Sakura mochi, Ankoro mochi, Bota mochi, Kusa mochi, Gyuhi, Ohagi, and Dango.

Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited thereto.

(Method for measuring degree of carboxymethyl substitution)
1) Accurately weigh about 2.0 g of carboxymethylated cellulose fiber (absolutely dry) and place it in a 300 mL Erlenmeyer flask with a stopper.
2) Add 100 mL of a solution obtained by adding 100 mL of special grade concentrated nitric acid to 1000 mL of methanol nitric acid, and shake for 3 hours to convert carboxymethylcellulose salt (CM-modified cellulose) into hydrogen-type CM-modified cellulose.
3) Accurately weigh 1.5 to 2.0 g of hydrogenated CM cellulose (absolutely dry) and place it in a 300 mL Erlenmeyer flask with a 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) Back titrate excess NaOH with 0.1N H ₂ SO ₄ using phenolphthalein as indicator.
6) Calculate the degree of carboxymethyl substitution (DS) by the following formula:
A = [(100 x F' - (0.1N H ₂ SO ₄ ) (mL) x F) x 0.1] / (absolute dry mass (g) of hydrogenated CM cellulose)
DS=0.162×A/(1-0.058×A)
A: Amount of 1N NaOH required to neutralize 1g of hydrogenated CM cellulose (mL)
F': 0.1N H ₂ SO ₄ factor F: 0.1N NaOH factor

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

[Example 1]
(Production of carboxymethylated cellulose nanofibers)
To a stirrer that can mix pulp, add 200 g dry weight of pulp (NBKP (softwood bleached kraft pulp), manufactured by Nippon Paper Industries Co., Ltd.) and 111 g dry weight of sodium hydroxide to obtain a pulp solid content of 20% (w). /v). Thereafter, after stirring at 30° C. for 30 minutes, 216 g (in terms of active ingredient) of sodium monochloroacetate was added. After stirring for 30 minutes, the temperature was raised to 70°C and stirred for 1 hour. Thereafter, the reactant was taken out, neutralized, and washed to obtain carboxymethylated pulp with a degree of carboxymethyl substitution per glucose unit of 0.25. Thereafter, the carboxymethylated pulp was adjusted to a solid content of 1% with water, and was defibrated by treatment with a high-pressure homogenizer at 20°C and a pressure of 150 MPa five times, resulting in an aqueous dispersion of carboxymethylated (CM) cellulose nanofibers. I got it. The obtained CM-modified cellulose nanofibers had an average fiber diameter of 5 nm and an aspect ratio of 500.
The obtained carboxymethylated cellulose nanofibers were made into a dispersion with a solid content of 0.7% by mass in water, and carboxymethylcellulose (trade name: F350HC-4, viscosity (1% by mass, 25°C, 60 rpm) of about 3000 mPa・s, carboxymethyl substitution degree of about 0.90) to 40% by mass of carboxymethylated cellulose nanofibers (that is, when the solid content of carboxymethylated cellulose nanofibers is 100 parts by mass, the solid content of carboxymethylcellulose is 40% by mass) parts by mass) and stirred for 60 minutes with a TK homomixer (12,000 rpm). The resulting aqueous dispersion of CM-modified cellulose nanofibers is dehydrated and dried using a drum dryer to obtain a dry solid, which is then pulverized. A powder was obtained.

(Manufacture of rice cakes)
100 parts of glutinous rice flour and 100 parts of water were mixed well and steamed in a steamer for 30 minutes. The steamed dough was kneaded for 5 minutes in the dough mode of a home bakery, and then 1 part of the CM-modified cellulose nanofiber powder obtained above was added and kneaded for another 5 minutes.
Next, 20 g of the kneaded dough was taken, and 12 g of red bean paste was wrapped in it to produce daifuku mochi, wrapped in plastic wrap, frozen for 48 hours, and then thawed.

[Comparative example 1]
Daifuku mochi was produced in the same manner as in Example 1 except that CM cellulose nanofibers were not added.

[Comparative example 2]
Daifuku mochi was produced in the same manner as in Example 1, except that 17 parts of caster sugar was added instead of the CM cellulose nanofibers.

Regarding the Daifuku mochi produced in Example 1 and Comparative Examples 1 and 2, the state after thawing was visually observed, and the texture was tasted and evaluated as follows. The results are shown in Table 1.
<Texture>
Ten panelists tasted the Daifuku mochi and rated the texture on a scale of 1 to 10, using the average value.
◎: 8-10 points, △: 4-7 points, ×: 1-3

As shown in Table 1, the daifuku mochi containing CM-modified cellulose nanofibers of Example 1 had better texture and did not crack after thawing compared to the daifuku mochi of comparative example 1, which did not contain cellulose nanofibers. There was no oxidation, and curing was suppressed. The Daifuku mochi of Comparative Example 2 in which caster sugar was added had excellent texture, but was excessively sweet.

Claims (5)

A rice cake-like food containing sticky rice and cellulose nanofibers ,
A rice cake-like food product, wherein the cellulose nanofibers contain carboxymethylcellulose or a salt thereof having a degree of carboxymethyl substitution of 0.55 to 1.6 in a range of 5 to 300% by mass based on the cellulose nanofibers. The rice cake-like food according to claim 1, wherein the cellulose nanofibers are anion-modified cellulose nanofibers. 3. The rice cake-like food according to claim 1, wherein the anion-modified cellulose nanofiber is a cellulose nanofiber having a carboxy group or a cellulose nanofiber having a carboxyalkyl group. The rice cake-like food according to claim 3, wherein the anion-modified cellulose nanofiber is a carboxymethylated cellulose nanofiber having a degree of carboxymethyl substitution within the range of 0.01 to 0.50. The mochi-like food according to any one of claims 1 to 4 , wherein the mochi-like food is one type selected from the group consisting of Daifuku mochi, Sakuramochi, Ankoromochi, Botamochi, Kusamochi, Gyuhi, Ohagi, and Dango.