Confectionery sponge dough

Abstract

To provide confectionery sponge dough using rice flour with good texture and having sufficient softness even after time lapse as a result of using cellulose fine particle fibers.SOLUTION: Confectionery sponge dough containing rice flour and cellulose fine particle fibers. The confectionery sponge dough is characterized in that the cellulose fine particle fibers are carboxymethylated, and further the cellulose fine particle fibers are cellulose nanofibers.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a sponge dough for confectionery. [Background technology]

[0002] In recent years, the demand for desserts such as roll cakes made with sponge cake dough has grown dramatically due to the development of convenience store sweets. Such desserts require industrially intensive mass production, and if the sponge cake does not have a certain level of flexibility, it can crack or break when rolled up in the factory, resulting in a large number of defective products. Furthermore, sponge cake doughs used in roll cakes and other desserts tend to be moist and fluffy, and therefore tend to be made by whipping eggs and mixing them with flour and milk to create a fluffy texture. Therefore, wheat flour, eggs, milk, and other ingredients traditionally used as ingredients in sponge cake doughs have been difficult to replace, and in many cases, they have been used as is.

[0003] However, foods designed to combat food allergies are beginning to attract significant attention. A food allergy is a condition that causes adverse symptoms in the body through immunological mechanisms after ingesting a certain food. Wheat, eggs, and milk are particularly common food allergies, and many allergy sufferers cannot eat these foods. However, as mentioned above, traditional roll cakes have the problem that it is difficult to substitute the wheat flour, eggs, milk, and other ingredients used, making them inedible for people with these allergies.

[0004] On the other hand, rice has traditionally been a staple food in Japan and other Southeast Asian countries, but rice consumption in Japan has been declining year by year. Rice has a higher yield per unit area than wheat and is a nutritionally excellent, balanced food, so there is a need to expand its uses and increase consumption. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-199497 [Patent Document 2] However, even if the sponge dough is made using rice flour, if it is in contact with something with a high moisture content, such as fresh cream, for a long period of time, the water retention capacity of the dough is insufficient from the viewpoint of moisture balance, and the dough becomes hard or cracks. There was a problem that the texture deteriorated. Summary of the Invention [Problem to be solved by the invention]

[0006] In the present invention, it was discovered that by using cellulose fine fibers, it is possible to obtain a sponge dough for confectionery using rice flour that remains sufficiently soft even over time and has a good texture, and this led to the completion of the present invention.

[0007] That is, the present invention provides the following (1) to (4). (1) A sponge dough for confectionery, characterized by containing rice flour and cellulose microfibers. (2) The sponge dough for confectionery described in (1), characterized in that the cellulose fine fibers are carboxymethylated. (3) The sponge dough for confectionery according to any one of (1) to (2), wherein the cellulose fine fibers are cellulose nanofibers. (4) A sponge dough for confectionery according to any one of (1) to (2), characterized in that it does not contain gluten. (5) A Western-style confectionery using the sponge dough for confectionery described in any one of (1) to (4). (6) A roll cake made using the sponge dough for confectionery described in any one of (1) to (4). [Effects of the Invention]

[0008] According to the present invention, by using cellulose fine fibers, it is possible to obtain a sponge dough for confectionery using rice flour that remains sufficiently soft even after the passage of time and has a good texture. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a photograph of the roll cakes obtained in the examples and comparative examples, visually observed from the top after weight treatment. [Figure 2] 3A and 3B are photographs showing cross sections of roll cakes obtained in Examples and Comparative Examples before and after refrigerated storage. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in detail below. In the present invention, "to" includes the extreme values. That is, "X to Y" includes the values ​​X and Y at both ends.

[0011] The present invention relates to a sponge dough for confectionery, characterized by containing rice flour and cellulose fine fibers.

[0012] <Rice flour> In the present invention, it is essential that rice flour be included as the main raw material cereal flour. The rice flour content is preferably 50 to 95% by mass of the total bone dry mass of all cereal flours and starch. Rice flour is typically produced by polishing and grinding raw non-glutinous rice. Examples of non-glutinous rice include Japonica rice, Indica rice, and Javanica rice. Examples of rice to be ground include polished rice, brown rice, broken rice, and old rice. There are no particular limitations on the particle size after grinding, and it is typically about the same as the particle size of commonly available joshinko rice flour.

[0013] In the present invention, in addition to rice flour as the cereal flour (main ingredient), cereal flours such as wheat flour may be contained as needed. Examples of cereal flours other than rice flour include wheat flour (hard flour, semi-hard flour, medium-strength flour, soft flour, durum wheat flour, whole wheat flour, etc.), buckwheat flour, soy flour, and, if necessary, unprocessed starches such as potato starch, sweet potato starch, tapioca starch, corn starch, waxy corn starch, rice starch, and mung bean starch, as well as processed starches produced by etherifying, esterifying, oxidizing, bleaching, crosslinking, pregelatinizing, or a combination of these processes. However, the presence of cereal flours other than rice flour raises concerns about the onset of allergies. Because the use of fine cellulose in the pancake batter of the present invention allows rice flour alone to achieve excellent leavening and texture, it is preferable that no cereal flours other than rice flour are present, and it is particularly preferable that the batter does not contain gluten.

[0014] <Other materials> In addition, salt and brine may be blended as additives. In addition to these, thickening and stabilizing agents such as phosphates, alginates (alginates and alginate esters), caprobean gum, guar gum, tamarind seed gum, pectin, xanthan gum, carrageenan, and curdlan, sweeteners such as sugar and trehalose, emulsifiers, oils and fats, butters, egg yolks, egg whites, milk proteins, coloring agents, antioxidants, wheat proteins, and other physiologically active ingredients such as vitamins, calcium, iron, and other seasonings may also be used as desired.

[0015] On the other hand, since alginic acids have a thermo-irreversible gelling property without the involvement of heat in their gelling action, there is a concern that workability may be impaired depending on the formulation. In the present invention, the fine cellulose fibers provide a moderate thickening effect, so workability is good, and it is desirable that no alginic acids are included.

[0016] <Cellulose microfibers> The cellulose fine fibers used in the present invention are fine fibers made from cellulose. The average fiber diameter of the cellulose fine fibers is not particularly limited, but is about 2 nm to 10 μm. The cellulose fine fibers may be, for example, microfibril cellulose (also referred to as MFC) that has been defibrated to an average fiber diameter of about 1 μm to 10 μm, preferably about 3 μm to 7 μm, or cellulose nanofibers (also referred to as CNF) that have been finely defibrated to an average fiber diameter of about 2 nm to 1 μm, preferably 3 nm to 500 nm, more preferably 3 nm to 100 nm, and even more preferably 3 nm to 50 nm. The average fiber diameter and average fiber length of the cellulose fine fibers can be determined by averaging the fiber diameters and fiber lengths obtained from observations of each fiber using a fiber tester manufactured by ABB Corporation, a fractionator manufactured by Valmet, a scanning electron microscope (SEM), an atomic force microscope (AFM), or a transmission electron microscope (TEM), appropriately selected depending on the fiber diameter. Cellulose fine fibers can be produced by defibrating a cellulose raw material.

[0017] The aspect ratio of the cellulose fine fibers used in the present invention is preferably 10 or more, more preferably 15 or more, and even more preferably 20 or more. There is no particular upper limit to the aspect ratio, but it is preferably 1000 or less, more preferably 500 or less, and even more preferably 300 or less. The aspect ratio can be calculated by the following formula: Aspect ratio = average fiber length / average fiber diameter

[0018] (cellulose raw material) The cellulose raw material used to produce the cellulose fine fibers is not particularly limited as long as it contains cellulose. Examples of such cellulose raw materials include plant-derived cellulose raw materials (e.g., wood, bamboo, hemp, jute, kenaf, agricultural waste, cloth, pulp (softwood unbleached kraft pulp (NUKP), softwood bleached kraft pulp (NBKP), hardwood unbleached kraft pulp (LUKP), hardwood bleached kraft pulp (LBKP), bleached kraft pulp (BKP), softwood unbleached sulfite pulp (NUSP), softwood bleached sulfite pulp (NBSP), thermomechanical pulp (TMP), recycled pulp, and waste paper)), animal-derived cellulose raw materials (e.g., ascidians), algae-derived cellulose raw materials, microorganism-derived cellulose raw materials (e.g., acetic acid bacteria (Acetobacter)), and microbial-derived cellulose raw materials. The cellulose raw material may be any one of these or a combination of two or more of them, but is preferably a cellulose raw material derived from a plant or microorganism, and more preferably a cellulose raw material derived from a plant.

[0019] (chemical modification) Cellulose has three hydroxyl groups per glucose unit and can be chemically modified in various ways. From the viewpoint of promoting the progress of defibration, it is preferable to use chemically modified cellulose fine fibers produced by defibrating a cellulose raw material obtained by chemical modification (chemically modified cellulose).

[0020] A preferred chemical modification is anionic modification, which introduces anionic groups into cellulose. Specifically, anionic modification refers to the introduction of anionic groups into the pyranose ring by oxidation or substitution. In the present invention, the oxidation reaction refers to a reaction in which the C6 position of the pyranose ring is oxidized to a carboxy group. Furthermore, in the present invention, the substitution reaction refers to a reaction in which anionic groups are introduced into the pyranose ring by a substitution reaction other than the oxidation. Examples of anionic modifications include oxidation (carboxylation), carboxyalkylation (e.g., carboxymethylation), and esterification. Among these, oxidation (carboxylation) and carboxymethylation are more preferred.

[0021] Examples of chemically modified cellulose microfibers include TEMPO-oxidized cellulose microfibers, ozone-oxidized cellulose microfibers, carboxyalkylated cellulose microfibers, carboxymethylated cellulose microfibers, phosphate-esterified cellulose microfibers, phosphite-esterified cellulose microfibers, cationized cellulose microfibers, sulfonated cellulose microfibers, and xanthated cellulose microfibers, with carboxymethylated cellulose microfibers being particularly preferred.

[0022] Carboxyalkylated cellulose fine fibers, preferably carboxymethylated cellulose fine fibers, which are an example of chemically modified cellulose fine fibers, may be obtained by known methods, or commercially available products may be used. The degree of carboxyalkyl substitution per anhydroglucose unit of cellulose is preferably less than 0.60. Furthermore, when the anionic group is a carboxymethyl group, the degree of carboxymethyl substitution is preferably less than 0.60. If the degree of substitution is 0.60 or more, crystallinity decreases and the proportion of soluble components increases, which may result in loss of function as fine fibers. Furthermore, the lower limit of the degree of carboxyalkyl substitution is preferably 0.01 or more. Considering operability, the degree of substitution is particularly preferably 0.02 to 0.50, and even more preferably 0.10 to 0.40. An example of a method for producing carboxyalkylated cellulose fibers, which are the raw material for such carboxyalkylated cellulose fine fibers, includes the following steps: The modification is a modification by substitution reaction. The following describes carboxymethylated cellulose fibers as an example.

[0023] i) mixing a cellulose raw material with a solvent and a mercerizing agent, and subjecting the mixture to mercerization 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; and ii) Subsequently, a step of adding a carboxymethylating agent in an amount of 0.05 to 10.0 times the moles per glucose residue, and carrying out an etherification reaction at a reaction temperature of 30 to 90°C, preferably 40 to 80°C, for a reaction time of 30 minutes to 10 hours, preferably 1 hour to 4 hours.

[0024] As the solvent for the mercerization and etherification reactions, 3 to 20 times by mass of water or a lower alcohol, specifically water, methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, isobutanol, tertiary butanol, etc., can be used alone or in combination. When a lower alcohol is mixed, the mixing ratio is 60 to 95% by mass. As the mercerizing agent, 0.5 to 20 times by mole of an alkali metal hydroxide, specifically sodium hydroxide or potassium hydroxide, can be used per anhydrous glucose residue of the cellulose raw material.

[0025] As mentioned above, the degree of carboxymethyl substitution per glucose unit of cellulose is less than 0.60, and preferably 0.01 or more but less than 0.60. Introducing carboxymethyl substituents into cellulose causes electrical repulsion between cellulose molecules. Therefore, cellulose fibers with carboxymethyl substituents introduced can be easily defibrated. Note that if the degree of carboxymethyl substitution per glucose unit is less than 0.01, sufficient defibration may not be achieved.

[0026] The degree of carboxymethyl substitution of carboxymethylated cellulose fibers can be measured by the following procedure: Weigh out approximately 2.0 g of bone-dry carboxymethylated cellulose fiber and place it in a 300 mL Erlenmeyer flask with a stopper. Add 100 mL of a solution of 100 mL of concentrated nitric acid in 1000 mL of methanol and shake for 3 hours to convert the salt-form carboxymethylated (CM) cellulose fiber into hydrogen-form carboxymethylated cellulose fiber. Weigh out 1.5-2.0 g of hydrogen-form carboxymethylated cellulose fiber (bone-dry) and place it in a 300 mL Erlenmeyer flask with a stopper. Wet the hydrogen-form carboxymethylated cellulose fiber with 15 mL of 80% methanol, add 100 mL of 0.1 N NaOH, and shake for 3 hours at room temperature. Back-titrate the excess NaOH with 0.1 N H2SO4 using phenolphthalein as an indicator. Calculate the degree of carboxymethyl substitution (DS) using the following formula: A = [(100 × F' - (0.1N H2SO4) (mL) × F) × 0.1] / (bone-dry mass of hydrogenated carboxymethyl cellulose fiber (g)) DS=0.162×A / (1-0.058×A) A: The amount of 1N NaOH (mL) required to neutralize 1 g of hydrogenated carboxymethylcellulose fiber F': Factor of 0.1N H2SO4 F: Factor of 0.1N NaOH

[0027] The degree of substitution in the carboxymethylated cellulose fibers is usually the same as the degree of substitution in the carboxymethylated cellulose fine fibers.

[0028] In the carboxyalkylated cellulose fibers obtained by the above process, the carboxyalkyl groups introduced into the cellulose raw material are usually in the form of alkali metal salts such as sodium salts (this is called the "salt form"). Before the defibration process, the alkali metal salts of the carboxyalkylated cellulose fibers may be substituted with other cationic salts such as phosphonium salts, imidazolinium salts, ammonium salts, and sulfonium salts. The substitution can be carried out by known methods.

[0029] Oxidized cellulose microfibers (also called "carboxylated cellulose microfibers"), an example of chemically modified cellulose microfibers, are obtained by oxidizing (carboxylating) the above-mentioned cellulose raw material using a known method to produce oxidized cellulose fibers, which are then defibrated. One example of the oxidation (carboxylation) method is a method in which the cellulose raw material is oxidized in water using an oxidizing agent in the presence of an N-oxyl compound and a compound selected from the group consisting of bromides, iodides, and mixtures thereof. This oxidation reaction selectively oxidizes the C6 position of the glucopyranose ring on the cellulose surface, resulting in cellulose fibers (TEMPO-oxidized cellulose fibers) bearing aldehyde groups and carboxyl (-COOH) or carboxylate (-COO-) groups on the surface. TEMPO-oxidized cellulose microfibers can be obtained by defibrating these TEMPO-oxidized cellulose fibers using the method described below.

[0030] An N-oxyl compound refers to a compound capable of generating a nitroxy radical. Any compound that promotes the target oxidation reaction can be used as the N-oxyl compound. Examples include 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) and its derivatives (e.g., 4-hydroxyTEMPO). The amount of the N-oxyl compound used is not particularly limited, as long as it is a catalytic amount capable of oxidizing the cellulose raw material. For example, 0.01 to 10 mmol is preferred, 0.01 to 1 mmol is more preferred, and 0.01 to 0.5 mmol is even more preferred, per 1 g of bone-dry cellulose raw material. The concentration of the N-oxyl compound in the reaction system is preferably about 0.1 to 4 mmol / L.

[0031] Bromides are compounds containing bromine, examples of which include alkali metal bromides that can dissociate and ionize in water. Iodides are compounds containing iodine, examples of which include alkali metal iodides. The amount of bromide or iodide used can be selected within a range that can promote the oxidation reaction. The total amount of bromide and iodide is, for example, preferably 0.1 to 100 mmol, more preferably 0.1 to 10 mmol, and even more preferably 0.5 to 5 mmol, per 1 g of bone-dry cellulose raw material.

[0032] Known oxidizing agents can be used, such as halogens, hypohalous acids, halous acids, perhalogen acids or their salts, halogen oxides, and peroxides. Among these, sodium hypochlorite is preferred because it is inexpensive and environmentally friendly. The appropriate amount of oxidizing agent used is, for example, preferably 0.5 to 500 mmol, more preferably 0.5 to 50 mmol, and even more preferably 2.5 to 25 mmol, per 1 g of bone-dry cellulose raw material. Furthermore, for example, 1 to 40 mol is preferred per 1 mol of the N-oxyl compound.

[0033] The oxidation process of cellulose raw materials can proceed efficiently even under relatively mild conditions. Therefore, the reaction temperature is preferably 4 to 40°C, or may be room temperature, about 15 to 30°C. As the reaction proceeds, carboxyl groups are generated in the cellulose, causing the pH of the reaction solution to decrease. To efficiently proceed with the oxidation reaction, it is preferable to add an alkaline solution such as an aqueous sodium hydroxide solution to the reaction system as needed to maintain the pH of the reaction solution at about 9 to 12, preferably about 10 to 11. Water is preferred as the reaction medium because of its ease of handling and the low occurrence of side reactions. The reaction time for the oxidation reaction can be appropriately set depending on the degree of oxidation progress and is usually 0.5 to 6 hours, for example, about 0.5 to 4 hours. The concentration of the cellulose raw material during the oxidation reaction is not particularly limited, but is preferably 5% by mass or less.

[0034] Alternatively, the oxidation reaction may be carried out in two stages. For example, the oxidized cellulose obtained by filtration after the first stage of the reaction can be oxidized again under the same or different reaction conditions, thereby efficiently introducing carboxyl groups into the cellulose raw material without reaction inhibition by salts produced as by-products in the first stage of the reaction.

[0035] Another example of the oxidation (carboxylation) method is a method in which oxidation is performed by ozone treatment, which produces ozone-oxidized cellulose fibers. The ozone-oxidized cellulose fibers can be defibrated using the method described below to produce ozone-oxidized cellulose fine fibers. Between ozone-oxidized cellulose fine fibers and TEMPO-oxidized cellulose fine fibers, it is preferable to use TEMPO-oxidized cellulose fine fibers.

[0036] The amount of carboxy groups contained in oxidized cellulose fine fibers obtained by defibrating oxidized cellulose fibers, relative to the bone dry mass of the cellulose fine fibers, is preferably 0.6 mmol / g or more, more preferably 0.8 mmol / g or more, and even more preferably 1.0 mmol / g or more. The upper limit is preferably 2.2 mmol / g or less, more preferably 2.0 mmol / g or less, and even more preferably 1.8 mmol / g or less. Therefore, it is preferably 0.6 mmol / g to 2.2 mmol / g, more preferably 0.8 mmol / g to 2.0 mmol / g, and even more preferably 1.0 mmol / g to 1.8 mmol / g.

[0037] The amount of carboxyl groups in oxidized cellulose fibers can be measured by the following procedure: 60 mL of a 0.5% by mass slurry (aqueous dispersion) of oxidized cellulose fiber is prepared, and after adding 0.1 M aqueous hydrochloric acid to adjust the pH to 2.5, 0.05 N aqueous sodium hydroxide is added dropwise and the electrical conductivity is measured until the pH reaches 11. The amount of carboxyl groups is calculated using the following formula from the amount of sodium hydroxide (a) consumed in the neutralization stage of the weak acid, where the change in electrical conductivity is gradual. Amount of carboxyl groups [mmol / g oxidized cellulose fiber] = a [mL] x 0.05 / mass of oxidized cellulose fiber [g]

[0038] The amount of carboxy groups in the oxidized cellulose fibers can be adjusted by controlling the reaction conditions, such as the amount of oxidizing agent added, reaction time, etc. The amount of carboxy groups in the oxidized cellulose fibers is usually the same as the amount of carboxy groups when the oxidized cellulose fibers are defibrated to form oxidized cellulose fine fibers.

[0039] In the oxidized cellulose fibers obtained by the above process, the carboxyl groups introduced into the cellulose raw material are usually in the form of alkali metal salts such as sodium salts (this is called the "salt form"). Prior to the defibration process, the alkali metal salts of the oxidized cellulose fibers may be substituted with other cationic salts such as phosphonium salts, imidazolinium salts, ammonium salts, and sulfonium salts. Substitution can be carried out by known methods.

[0040] Examples of methods for producing esterified cellulose fibers (e.g., phosphated cellulose fibers, phosphite cellulose fibers, etc.) that serve as raw materials for esterified cellulose fine fibers (e.g., phosphated cellulose fine fibers, phosphite cellulose fine fibers, etc.), which are examples of chemically modified cellulose fine fibers, include a method of mixing a powder or aqueous solution of a phosphoric acid compound with a cellulose raw material, and a method of adding an aqueous solution of a phosphoric acid compound to a slurry of the cellulose raw material. Examples of phosphoric acid compounds include phosphoric acid, polyphosphoric acid, phosphorous acid, hypophosphorous acid, phosphonic acid, polyphosphonic acid, and esters of these acids. These may be in the form of salts. Among the above, compounds having phosphoric acid groups are preferred because they are low cost, easy to handle, and can be used to introduce phosphoric acid groups into the cellulose of pulp fibers, thereby improving defibration efficiency. Examples of compounds having a phosphate group include phosphoric acid, sodium dihydrogen phosphate, disodium hydrogen phosphate, trisodium phosphate, sodium phosphite, potassium phosphite, sodium hypophosphite, potassium hypophosphite, sodium pyrophosphate, sodium metaphosphate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, tripotassium phosphate, potassium pyrophosphate, potassium metaphosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, ammonium pyrophosphate, and ammonium metaphosphate. These compounds can be used alone or in combination to introduce phosphate groups. Among these compounds, phosphoric acid, sodium salts of phosphoric acid, potassium salts of phosphoric acid, and ammonium salts of phosphoric acid are preferred from the viewpoints of high efficiency of phosphate group introduction, ease of defibration in the defibration step described below, and ease of industrial application. Sodium dihydrogen phosphate and disodium hydrogen phosphate are particularly preferred. Furthermore, the phosphoric acid compound is preferably used as an aqueous solution, as this allows the reaction to proceed uniformly and increases the efficiency of phosphate group introduction. The pH of the aqueous solution of the phosphoric acid compound is preferably 7 or less to increase the efficiency of phosphate group introduction, but a pH of 3 to 7 is preferred to suppress hydrolysis of cellulose fibers.

[0041] The following method can be given as a specific example of a method for producing phosphated cellulose fibers. A phosphoric acid compound is added to a suspension of a cellulose raw material having a solids concentration of 0.1 to 10% by mass while stirring, to introduce phosphate groups into the cellulose. When the cellulose raw material is taken as 100 parts by mass, the amount of the phosphoric acid compound added is preferably 0.2 to 500 parts by mass, and more preferably 1 to 400 parts by mass, in terms of the amount of phosphorus element. If the proportion of the phosphoric acid compound is equal to or greater than the lower limit, the yield of cellulose fine fibers can be further improved. However, if the proportion exceeds the upper limit, the effect of improving the yield will plateau, which is not preferable from a cost perspective.

[0042] In addition to the phosphoric acid compound, powders or aqueous solutions of other compounds may be mixed. The other compounds are not particularly limited, but nitrogen-containing compounds exhibiting basicity are preferred. "Basicity" here is defined as the aqueous solution exhibiting a pink to red color in the presence of a phenolphthalein indicator, or the aqueous solution having a pH greater than 7. The nitrogen-containing compounds exhibiting basicity are not particularly limited as long as they do not impair the effects of the present invention, but compounds having an amino group are preferred. Examples include urea, methylamine, ethylamine, trimethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, pyridine, ethylenediamine, and hexamethylenediamine. Among these, urea is preferred because of its low cost and ease of handling. The amount of the other compounds added is preferably 2 to 1,000 parts by mass, more preferably 100 to 700 parts by mass, per 100 parts by mass of the solid content of the cellulose raw material. The reaction temperature is preferably 0 to 95°C, more preferably 30 to 90°C. The reaction time is not particularly limited, but is approximately 1 to 600 minutes, more preferably 30 to 480 minutes. When the esterification reaction conditions are within these ranges, it is possible to prevent the cellulose from being excessively esterified and becoming more soluble, resulting in a good yield of phosphated cellulose. After dehydrating the resulting phosphated cellulose suspension, it is preferable to heat-treat it at 100 to 170°C in order to suppress hydrolysis of the cellulose. Furthermore, it is preferable to heat the suspension at 130°C or lower, preferably 110°C or lower, while it contains water, and then, after removing the water, heat-treat it at 100 to 170°C.

[0043] The degree of phosphate substitution per glucose unit of the phosphated cellulose fiber is preferably 0.001 or more and less than 0.40. Introducing phosphate group substituents into cellulose causes electrical repulsion between cellulose molecules. Therefore, cellulose with phosphate groups introduced can be easily defibrated. If the degree of phosphate substitution per glucose unit is less than 0.001, it cannot be sufficiently defibrated. On the other hand, if the degree of phosphate substitution per glucose unit is greater than 0.40, it may swell or dissolve, making it impossible to obtain fine fibers. To efficiently defibrate, the phosphated cellulose raw material obtained above is preferably subjected to a washing treatment, such as boiling and washing with cold water. The modification by esterification is a modification by substitution reaction. The degree of substitution in phosphated cellulose fiber and the degree of substitution when the phosphated cellulose fine fiber is obtained are usually the same.

[0044] In the phosphated cellulose fibers obtained by the above process, the phosphate groups introduced into the cellulose raw material are usually in the form of an alkali metal salt such as a sodium salt (this is called the "salt form"). Before the defibration process, the alkali metal salt of the phosphated cellulose fibers may be substituted with other cationic salts such as phosphonium salts, imidazolinium salts, ammonium salts, and sulfonium salts. The substitution can be carried out by a known method.

[0045] (defibration) The device for defibrating cellulose raw materials or chemically modified cellulose raw materials (chemically modified cellulose fibers) is not particularly limited. For example, it is preferable to apply shear force to the raw material (usually an aqueous dispersion of the raw material) using a defibration device such as a high-speed rotary type, colloid mill type, high-pressure type, roll mill type, or ultrasonic type, or a refiner or cavitation jet device. In particular, it is preferable to use a cavitation jet device that can efficiently defibrate at a pressure of about 7 MPa, or a wet high-pressure or ultra-high-pressure homogenizer that can apply a pressure of 50 MPa or more to the raw material (usually an aqueous dispersion) and apply a strong shear force. Furthermore, prior to the defibration and dispersion treatment, a pretreatment can be performed as necessary. The pretreatment can be performed using a known mixing, stirring, emulsifying, or dispersing device such as a high-speed shear mixer. The number of treatments (passes) in the defibration device may be one or two or more times, with two or more being preferred.

[0046] When defibrating, a dispersion is usually prepared by first dispersing the cellulose raw material or chemically modified cellulose fibers in a dispersion medium. The dispersion medium is not particularly limited as long as it can disperse the cellulose raw material or chemically modified cellulose fibers, and examples thereof include water, an organic solvent, and a mixture thereof.

[0047] The solids concentration of the cellulose raw material or chemically modified cellulose fiber 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 or more. This ensures an appropriate liquid volume relative to the amount of solids, 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.

[0048] Prior to defibration, a pretreatment may be carried out as necessary, which may be carried out using a mixing, stirring, emulsifying, or dispersing device such as a high-speed shear mixer.

[0049] In the present invention, it is preferable to defibrate the cellulose fine fibers to the CNF level. Defibration to the nanofiber level makes it easier to mix uniformly when added to the sponge dough, and the effects of the present invention can be more effectively achieved.

[0050] (Dry) The cellulose fine fibers used in the present invention can be used in the form of a dispersion obtained after defibration, or can be dried and redispersed in water as needed. The drying method is not particularly limited, and known methods such as freeze drying, spray drying, tray drying, drum drying, belt drying, a method of thinly spreading the cellulose fine fibers on a glass plate or the like and drying, fluidized bed drying, microwave drying, and heated fan-type reduced pressure drying can be used. After drying, the cellulose fine fibers may be pulverized using a cutter mill, hammer mill, pin mill, jet mill, or the like as needed. The method for redispersing the cellulose fine fibers in water is also not particularly limited, and known dispersing devices can be used.

[0051] The cellulose fine fibers used in the present invention may be in the form of a dispersion or powder, but it is preferable to use them in powder form, as this has excellent workability as they can be used as a mix powder for sponge dough as is.

[0052] In the present invention, the blending amount of the cellulose fine fibers is preferably 0.01 to 5 mass %, more preferably 0.05 to 5 mass %, and even more preferably 0.1 to 3 mass %, calculated as solid content, relative to the cereal flour.

[0053] The cellulose fine fibers of the present invention may contain other components as needed. For example, when producing a powder, it is preferable to add a water-soluble polymer to the cellulose fine fiber dispersion before drying, as this improves redispersibility.

[0054] (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, alginates, pullulan, starch, potato starch, arrowroot flour, corn starch, gum arabic, locust bean gum, gellan gum, polydextrose, pectin, chitin, water-soluble chitin, chitosan, casein, albumin, soy protein lysate, peptone, tamarind gum, and guar gum. Among these, cellulose derivatives are preferred in terms of their affinity with carboxymethylated cellulose fine fibers, and carboxymethylcellulose and its salts are particularly preferred. It is believed that water-soluble polymers such as carboxymethylcellulose and its salts penetrate between carboxymethylated cellulose fine fibers, increasing the distance between the fine fibers and thereby improving redispersibility.

[0055] When carboxymethyl cellulose or a salt thereof is used as the water-soluble polymer, it is preferable to use a carboxymethyl cellulose having a degree of carboxymethyl group substitution per anhydroglucose unit of 0.55 to 1.6, more preferably 0.55 to 1.1, and even more preferably 0.65 to 1.1. Furthermore, carboxymethyl cellulose with longer molecules (higher viscosity) is preferred because it is more effective in increasing the distance between fine fibers. Furthermore, the Brookfield viscosity of a 1% by mass aqueous solution of carboxymethyl cellulose at 25°C and 60 rpm is preferably 3 mPa·s to 14,000 mPa·s, more preferably 7 mPa·s to 14,000 mPa·s, and even more preferably 1,000 mPa·s to 8,000 mPa·s. Note that the "carboxymethyl cellulose or a salt thereof" referred to here as the water-soluble polymer is completely soluble in water, and is therefore distinct from the carboxymethyl cellulose fibers described above, the fiber shape of which can be confirmed in water.

[0056] 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, even more preferably 25% by mass to 200% by mass, and even more preferably 25% by mass to 60% by mass, relative to the cellulose fine fibers (bone dry solid content).

[0057] The confectionery sponge dough of the present invention can be prepared without any problems by known methods, for example, by preparing a mixed flour containing rice flour and powdered cellulose fine fibers, dissolving the mixed flour in milk, soy milk, water, melted butter or oil as appropriate, and stirring well until it becomes whipped.

[0058] Furthermore, when the cellulose fine fibers are preliminarily made into a dispersion, they can be similarly obtained by adding them to milk, soy milk, water, melted butter, oils, etc. instead of the mixed powder.

[0059] The sponge dough for confectionery of the present invention thus obtained can be used for Western confectionery, etc. As Western confectionery, if the sponge dough and fresh cream are in contact with each other, the effects of the present invention can be more effectively exhibited, so roll cakes, cakes, castella, etc. are preferred, and roll cakes are particularly preferred. [Example]

[0060] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0061] (Method for measuring degree of carboxymethyl substitution) 1) Weigh out approximately 2.0 g of carboxymethylated cellulose fiber (bone dry) and add it to a 300 mL container. Place in a stoppered Erlenmeyer flask. 2) Add 100 mL of a solution of 100 mL of special-grade concentrated nitric acid to 1000 mL of methanol, shake for 3 hours, and convert the carboxymethyl cellulose salt (carboxymethyl cellulose) into hydrogen-type carboxymethyl cellulose. 3) Accurately weigh out 1.5 to 2.0 g of hydrogenated carboxymethyl cellulose (bone dry) and add it to a 300 mL container with a stopper. Place in an Erlenmeyer flask. 4) Wet the hydrogenated carboxymethyl cellulose with 15 mL of 80% methanol, add 100 mL of 0.1 N NaOH, and shake at room temperature for 3 hours. 5) Back-titrate excess NaOH with 0.1N H2SO4 using phenolphthalein as an indicator. 6) The degree of carboxymethyl substitution (DS) is calculated by the following formula: A = [(100 × F' - (0.1N H2SO4) (mL) × F) × 0.1] / (bone-dry mass of hydrogenated carboxymethyl cellulose (g)) DS=0.162×A / (1-0.058×A) A: Amount of 1N NaOH (mL) required to neutralize 1 g of hydrogenated carboxymethyl cellulose F': Factor of 0.1N H2SO4 F: Factor of 0.1N NaOH

[0062] (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

[0063] [Example 1] (Preparation of carboxymethylated cellulose nanofibers) A 5-L twin-screw kneader with the rotation speed adjusted to 100 rpm was charged with 1,089 parts of isopropanol (IPA) and a solution of 31 parts of sodium hydroxide in 121 parts of water. 200 parts of hardwood pulp (LBKP, manufactured by Nippon Paper Industries Co., Ltd.) (dry mass after drying at 100°C for 60 minutes) was then added. The mixture was stirred and mixed at 30°C for 60 minutes to prepare mercerized cellulose. Further stirring was continued, and 117 parts of sodium monochloroacetate was added. After stirring at 30°C for 30 minutes, the mixture was heated to 70°C over 30 minutes and allowed to undergo a carboxymethylation reaction at 70°C for 60 minutes. The proportion of water in the reaction medium during the mercerization and carboxymethylation reactions was 10% by mass. After completion of the reaction, the mixture was neutralized, washed with 65% aqueous methanol, deliquored, dried, and pulverized to obtain a sodium salt of carboxymethylated cellulose with a carboxymethyl substitution degree of 0.27 and a crystallinity of cellulose type I of 64%. The methods for measuring the degree of carboxymethyl substitution and the crystallinity of cellulose type I are as described above.

[0064] The resulting sodium salt of carboxymethyl cellulose was dispersed in water to form a 1% (w / v) aqueous dispersion. This was then processed three times in a high-pressure homogenizer at 150 MPa to obtain a dispersion of carboxymethyl cellulose nanofibers. The resulting carboxymethyl cellulose nanofibers had an average fiber diameter of 3.2 nm and an aspect ratio of 40.

[0065] The obtained carboxymethylated cellulose nanofibers were dispersed in water to a solid content of 0.7% by mass, and carboxymethyl cellulose (manufactured by Nippon Paper Industries Co., Ltd., product name: F350HC-4, viscosity (1% by mass, 25°C, 60 rpm) approximately 3000 mPa·s, degree of carboxymethyl substitution approximately 0.90) was added in an amount of 40% by mass relative to the carboxymethyl cellulose nanofibers (i.e., so that the solid content of carboxymethyl cellulose was 40 parts by mass per 100 parts by mass of the solid content of the carboxymethyl cellulose nanofibers), and the mixture was stirred for 60 minutes using a TK homomixer (12,000 rpm).

[0066] To this dispersion, 0.5% by mass of aqueous sodium hydroxide was added to adjust the pH to 9, and then the dispersion was applied to the drum surface of a drum dryer D0405 (manufactured by Katsuragi Kogyo Co., Ltd.) and dried at 140°C for 1 minute. The resulting dried product was scraped off and then pulverized using an impact mill at a rate of 10 kg per hour to obtain a dried pulverized product with a moisture content of 5% by mass. The pulverized product was classified using a 30 mesh to obtain a powder containing carboxymethylated cellulose nanofibers and carboxymethyl cellulose (CNF powder).

[0067] (Adjusting the sponge dough) 145 parts by weight of sweetened egg yolk, 9 parts by weight of sugar, and 1 part by weight of CNF powder were thoroughly mixed in a stainless steel bowl, to which 23 parts by weight of light sesame oil and 20 parts by weight of unsalted butter that had been heated and melted were added, and the mixture was thoroughly stirred and mixed until emulsified. 100 parts by weight of rice flour was then added and thoroughly mixed to obtain Mixture 1. Separately, 240 parts by weight of frozen egg white and 60 parts by weight of sugar were mixed and stirred thoroughly until a meringue-like consistency was obtained. Mixture 1 was then added and mixed slowly so as not to crush the air bubbles, to obtain mixture 2. Mixture 2 was poured into a roll cake mold and baked in a deck oven (top heat: 180°C, bottom heat: 180°C, 12 minutes).

[0068] After baking, the cake was allowed to cool, then covered with a cooking sheet so that the browned surface was facing up, and then turned upside down to remove it from the mold, thereby obtaining sponge cake A.

[0069] (Cream adjustment) 15 parts by weight of sugar was added to 200 parts by weight of commercially available vegetable whipped cream (Sujata Whip) in a stainless steel bowl and stirred thoroughly until it became whipped, to obtain Cream A.

[0070] (Roll cake adjustment) Cream A was evenly spread on the top surface of the inverted sponge cake A obtained, and the cake was rolled up so that the beginning of the roll formed the core. The end of the roll was placed downwards and wrapped in plastic wrap on a cooking sheet, and stored in the refrigerator for 1 hour to allow the dough and cream to blend. After that, the plastic wrap and cooking sheet were removed, and roll cake A using a sponge cake containing CNF was obtained.

[0071] [Comparative Example 1] To prepare the sponge cake, 145 parts by weight of sweetened egg yolk and 17 parts by weight of trehalose were mixed thoroughly in a stainless steel bowl, to which 23 parts by weight of light sesame oil and 20 parts by weight of unsalted butter that had been heated and melted were added, and the mixture was thoroughly stirred and mixed until emulsified. Then, 100 parts by weight of rice flour was added and thoroughly mixed to obtain Mixture 3. Separately, 240 parts by weight of frozen egg whites and 52 parts by weight of sugar were mixed and thoroughly stirred until a meringue-like consistency was obtained. Mixture 3 was then added and slowly mixed in, taking care not to crush the air bubbles, to obtain Mixture 4. A roll cake was prepared in the same manner as in Example 1, and Roll Cake B was obtained using a sponge dough that did not contain CNF.

[0072] <Roll cake evaluation> (Texture over time) The obtained roll cake was placed in a container without covering it with plastic wrap and stored in the refrigerator. After 0 days (immediately after production / not stored in the refrigerator), 1 day, 2 days, 3 days, and 4 days, three panelists tasted and evaluated the cakes according to the following criteria, and the average values ​​are shown in Table 1. Texture criteria: The dryness of the dough (outside and inside), roughness, hardness, and moistness due to moisture transfer from the cream were all comprehensively judged and rated on a scale of 1 to 10 (the better the closer to 10).

[0073] [Table 1]

[0074] (Softness after 4 days in the refrigerator) After storing in the refrigerator for 4 days, a 200g weight was placed on top of the roll cake for 30 seconds as shown in Figure 1. Immediately after removing the weight, the condition of the dough where the weight was placed was visually inspected from the top and evaluated according to the following criteria. The results are shown in Table 2. ○: The area where the weight was placed is indented, and the softness of the dough is maintained. ×: The area where the weight was placed is not deeply indented and the fabric is hard.

[0075] [Table 2]

[0076] (Observation of the cross section of a roll cake) The roll cakes were cut after 0 days (immediately after production) and after 4 days of storage in the refrigerator, and the cross sections were visually observed as shown in Figure 2 and evaluated according to the following criteria. The results are shown in Table 3. Good: No bubbles or tears, the fabric is in good condition. △: The dough has some bubbles. ×: The fabric has tears or other damage and is in poor condition.

[0077] [Table 3]

[0078] Roll cake A made using the sponge dough for confectionery of the present invention retains moisture in the dough even when stored for a long period of time, resulting in excellent results in terms of texture, appearance, and softness. It is particularly suitable for applications where it comes into contact with fresh cream and where moisture balance is important, making it suitable for Western confectionery applications, particularly cakes and roll cakes.

Claims

1. A sponge dough for confectionery, characterized by containing rice flour and fine cellulose fibers.

2. 2. The sponge dough for confectionery according to claim 1, wherein the cellulose fine fibers are carboxymethylated.

3. The sponge dough for confectionery according to any one of claims 1 to 2, characterized in that the cellulose fine fibers are cellulose nanofibers.

4. 3. The sponge dough for confectionery according to claim 1, which is gluten-free.

5. A Western-style confectionery using the sponge dough for confectionery according to any one of claims 1 to 4.

6. A roll cake made using the sponge dough for confectionery according to any one of claims 1 to 4.

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