Method for producing rice flour-containing composition and gel-like food material

Abstract

To provide a rice flour-containing composition easily usable as a gelatinous food such as a deglutition food raw material, and to provide a production method of a gelatinous food such as a deglutition food raw material.SOLUTION: A rice flour-containing composition contains: (A) a rice flour of high amylose rice having a Wxa gene and an alkali hard-degradable gene; and (B) a rice flour having a gelatinization initiation temperature of less than 75°C. A production method of a deglutition food raw material includes: a step 1) of adding water to the composition so as to obtain a dispersion; and a step 2) of heat-treating the dispersion so as to gelatinize. The step 1 preferably includes a step 1-1) of primarily adding water to the composition, and a step 1-2) of secondarily adding water and performing preliminary heat treatment at 70°C or more and 80°C or less so as to obtain the dispersion.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a method for producing a rice flour-containing composition and a gel-like food material. [Background technology]

[0002] Recent consumer demands for food include high quality, ease of preparation, high safety, low price, and low calorie content. Rice flour-based foods that meet these consumer needs are in demand.

[0003] Rice flour-containing foods are expected to be used in dysphagia-friendly foods. Dysphagia-friendly foods are meals for people with dysphagia who have difficulty eating or swallowing due to aging, illness, surgery, etc. In Japan, the population is aging, and the need for dysphagia-friendly foods is increasing. To make rice, a staple food, into a dysphagia-friendly food, it is necessary to cook it as porridge, add starch-degrading enzymes to reduce stickiness, blend it in a mixer, and then solidify it with a gelling agent to make a porridge jelly. Amidst labor shortages, there is a need to develop simpler cooking methods for dysphagia-friendly food ingredients.

[0004] Non-patent document 1 describes that a gel conforming to the Consumer Affairs Agency's dysphagia dietary standards II can be prepared by adding 10 times the amount of water to rice flour made from high-amylose rice with an amylose content of 25% or more, heating the mixture, and then cooling the resulting paste. Patent document 1 describes that partially pregelatinized rice flour, in which the degree of gelatinization of high-amylose rice flour is controlled to 60-95%, becomes a viscoelastic gel when mixed with water, satisfying the physical properties of various foods such as dysphagia dietary foods and also improving texture. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2017-212971 [Non-patent literature]

[0006] [Non-Patent Document 1] Ashida et al., (2019) Journal of the Japanese Society for Food Science and Technology 66(8) 290-298. [Overview of the project] [Problems that the invention aims to solve]

[0007] However, the technology described in Non-Patent Document 1 has the drawback that when preparing the paste by adding water to rice flour and heating it, lumps can form if not constantly stirred, making it difficult to obtain a uniform paste. Furthermore, the partially pregelatinized rice flour described in Patent Document 1 has the problem of requiring special equipment to control the degree of pregelatinization.

[0008] The present invention has been made in view of the above, and aims to provide a rice flour-containing composition that can be easily used as a gel-like food such as a dysphagia food ingredient, and a method for producing a gel-like food such as a dysphagia food ingredient. [Means for solving the problem]

[0009] The present invention provides the following [1] to

[12] . [1] Wx encoding (A)(a1) or (a2) a Rice flour from high-amylose rice possessing genes and alkali-disintegration-resistant genes, (B) Rice flour with a gelatinization onset temperature of less than 75°C including, Composition containing rice flour. (a1) Protein containing the amino acid sequence of Sequence ID No. 1 (a2) A protein having an amino acid sequence that is 90% identical to the amino acid sequence of SEQ ID NO: 1, with the 415th proline conserved, and possessing the same starch granule-bound starch synthase I activity as the protein containing the amino acid sequence of SEQ ID NO: 1. The composition according to [1], wherein [2] (B) is high-amylose rice. The composition according to [1] or [2], wherein [3] (B) is rice flour of readily alkali-disintegrating rice. [4] The composition according to any one of items [1] to [3], wherein (A) and / or (B) are ungelatinized rice flour. The rice flour-containing composition according to any one of [1] to [4], wherein the weight ratio of [5] (A) and (B) is (A):(B) = 1:5 to 5:1. [6] Step 1) adding water to the composition according to any one of [1] to [5] to obtain a dispersion, Step 2) heat-treating the dispersion to gelatinize it, A method for producing a gelled food material, comprising the above steps. [7] Step 1 is Step 1-1) adding water to the composition according to any one of [1] to [5] once, and Step 1-2) further adding water and pre-heat-treating at 70°C or higher and 80°C or lower to obtain a dispersion The production method according to [6], comprising the above steps. The production method according to [6] or [7], wherein the total amount of water added is 8 times or more the total amount of rice flours (A) and (B). The production method according to [7] or [8], wherein the amount of water added in the first water addition is 1.5 times or more the total amount of rice flours (A) and (B). The production method according to any one of [7] to [9], wherein the temperature of the water added in the first water addition is not higher than the gelatinization start temperature of rice flour (B). The production method according to any one of [7] to

[10] , wherein the temperature of the water added in the second water addition is 80°C or higher. The production method according to any one of [7] to

[11] , wherein the amount of water added in the second water addition is 3 times or more the amount of water added in the first water addition.

Advantages of the Invention

[0010] According to the present invention, there are provided a rice flour-containing composition that can exhibit physical properties as a gelled food material such as a swallowing food material, and a method for producing a gelled food material using the same, which enables simple cooking into a gelled food such as a swallowing food using a general cooking utensil.

Brief Description of the Drawings

[0011] [Figure 1] Figure 1 is a graph showing the change over time in hardness of each sample of Reference Examples 1 to 3. [Figure 2] Figure 2 is a graph showing the change in cohesiveness over time for each sample from Reference Examples 1 to 3. [Figure 3] Figure 3 is a graph showing the change in adhesion over time for each sample from Reference Examples 1 to 3. [Modes for carrying out the invention]

[0012] [Rice flour-containing composition] The rice flour-containing composition includes the following rice flours (A) and (B).

[0013] (Rice flour (A)) Rice flour (A) has a specified Wx a This is rice flour made from high-amylose rice that possesses genes for alkali disintegration resistance.

[0014] -High-amylose rice- Rice flour (A) is rice flour made from high-amylose rice. In this specification, high-amylose rice is rice that is rich in amylose. The amylose content of high-amylose rice is usually 24% or more. There is no particular upper limit, and it may exceed 30%. The amylose content can be determined by the iodine colorimetric method.

[0015] -Waxy gene- The rice used as raw material for rice flour (A) is specified in Wx a It possesses a gene. In this specification, Wx a The gene in question is the Waxy gene (GBSSI), specifically the Wx a This refers to a type and is generally found in high-amylose rice (e.g., indica rice). a The gene encodes a protein with starch-binding starch synthase I (GBSSI) activity involved in amylose synthesis, and the first base (5' end) of the 5' splicing site of intron 1 (In1) is guanine (G: In1_G). This base is an SNP marker, while the allele Wx b The waxy gene (Wx) of a type (for example, found in Japonica rice such as Koshihikari)b It is distinguished in that it is thymine in the (gene). Wx a In the gene, when the SNP marker is G, splicing occurs, transcription is activated, high starch granule-bound starch synthase I activity is exhibited, and the amylose content is high. However, in Wx b splicing does not occur, so transcription becomes insufficient and enzyme activity is also insufficient. The amylose content of rice flour with the Wx b type is usually lower than that of rice with the Wx a type (Hirano et al (1998) Mol. Biol. Evol. 15(8) p978 - 987). The promoter region of the Wx a gene containing intron 1 is registered in GenBank (https: / / www.ncbi.nlm.nih.gov / nuccore / AB008795), and the SNP marker of In1 corresponds to the 1606th guanine base of the registered sequence.

[0016] The Wx a gene possessed by the raw rice of rice flour (A) can express the following proteins (a1) and (a2): (a1) A protein containing the amino acid sequence of SEQ ID NO: 1 (a2) A protein having an amino acid sequence with 90% identity to the amino acid sequence of SEQ ID NO: 1, in which the 415th proline is conserved, and having starch granule-bound starch synthase I activity equivalent to that of a protein containing the amino acid sequence of SEQ ID NO: 1

[0017] The 415th amino acid residue in the amino acid sequence of SEQ ID NO: 1 is a SNP marker in exon 10 of the rice Wx a gene. It is known that when it is proline (Ex10_C), the content of long amylopectin chains is medium or less (Crofts et al (2019) J. Appl. Glycosci., 66, p37 - 46). In (a2), the amino acid sequence identity may be 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% or higher. Identity can be determined using, for example, NCBI's BLAST (see http: / / www.ncbi.nlm.nih.gov) under default conditions. "Having similar activity" means having, for example, 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, 95% or more, or 100% or more of the activity that the protein would have if measured under the same conditions.

[0018] The modification site in the amino acid sequence may be either a site within the catalytic domain or a site outside the catalytic domain. The location of an amino acid residue in a protein that can be mutated while maintaining the desired activity can be identified by a person skilled in the art. For example, a person skilled in the art can 1) compare the amino acid sequences of several proteins having the same activity (e.g., the amino acid sequence of SEQ ID NO: 1), 2) identify relatively conserved or unconserved regions, and then 3) predict from the relatively conserved and unconserved regions which regions may and may not play an important role in the function, thereby recognizing the correlation between structure and / or function and identifying sites where mutations may be introduced.

[0019] The mutations introduced into proteins may be substitutions of amino acid residues with other amino acid residues, with substitutions with amino acid residues having similar side chains being preferred. Examples of amino acid classifications based on amino acid residues having similar side chains include: amino acids with basic side chains such as lysine, arginine, and histidine; amino acids with acidic side chains such as aspartic acid and glutamic acid; amino acids with uncharged polar side chains such as asparagine, glutamine, serine, threonine, tyrosine, and cysteine; amino acids with nonpolar side chains such as glycine, alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine, and tryptophan; amino acids with β-branched side chains such as leucine, valine, and isoleucine; amino acids with aromatic side chains such as tyrosine, phenylalanine, tryptophan, and histidine; amino acids with hydroxyl group-containing side chains (e.g., alcohol and phenoxy group-containing side chains) such as serine, threonine, and tyrosine; and amino acids with sulfur-containing side chains such as cysteine ​​and methionine.

[0020] Wx of rice flour (A) a The gene may be (In1_G-Ex10_C) as a haplotype, or it may be a genetically modified organism into which (In1_G) and / or (Ex10_C) have been introduced, but the former is preferred.

[0021] - Alkali-degradation-resistant genes - The rice used as raw material for rice flour (A) contains the alkali-disintegration-resistant gene (ALK, starch synthase IIa (SSIIa)). In this specification, the alkali-disintegration-resistant gene (ALK) is a functional gene containing a protein that includes the amino acid sequence of SEQ ID NO: 2, or a nucleotide sequence that has an amino acid sequence with 90% or more identity with the amino acid sequence of SEQ ID NO: 2 and has starch synthase IIa activity equivalent to that of the protein containing the amino acid sequence of SEQ ID NO: 2. The amino acid sequence of SEQ ID NO: 2 and the nucleotide sequence encoding it are registered in GenBank, and the Accession number is AY423717 (https: / / www.ncbi.nlm.nih.gov / nuccore / AY423717).

[0022] In this specification, alkali disintegration can be determined by the presence or absence of starch leaching after soaking rice grains in an alkaline solution for several hours. For example, if broken brown rice is soaked in a 1.5% potassium hydroxide aqueous solution and left to stand at room temperature, if starch leaching is observed from the grains, it can be evaluated as easily alkali disintegrating; if no starch leaching is observed, it can be evaluated as poorly alkali disintegrating. Rice flour (A) usually has a high amount of amylopectin long chains due to the presence of the alkali disintegration poor gene (ALK), and therefore has a high gelatinization onset temperature. The gelatinization onset temperature of rice with the alkali disintegration poor gene is usually higher than that of rice flour (B), for example, 5 to 10°C higher (usually 6 to 9°C, preferably around 7 to 8°C). The gelatinization onset temperature of rice in rice flour (A) is preferably 75°C or higher.

[0023] Examples of rice varieties used as raw materials for rice flour (A) include "Ajia no Kaori," "Koshi no Kaori," "Beniroman," their offspring varieties, and combinations of two or more of these. Of these, "Ajia no Kaori" and its offspring varieties are preferred. Rice flour (A) may also be a combination of two or more varieties that differ in harvest year, cultivation method, rice flour manufacturing method, and physical properties (e.g., particle size).

[0024] (Rice flour (B)) Rice flour (B) is rice flour whose gelatinization onset temperature is less than 75°C, and is rice flour other than rice flour (A).

[0025] -Gelinization start temperature- In this specification, the gelatinization initiation temperature is the temperature at which α-gelatinization (gelatinization) begins. The gelatinization initiation temperature can be determined by adding room temperature water to rice flour (water amount: 25 mL of water for 2.5 g of rice flour), holding it at 50°C for 1 minute, and then raising the temperature to 99°C, at which point the viscosity begins to increase. The gelatinization initiation temperature of rice flour (B) is less than 75°C, preferably 70°C or lower, and more preferably 65°C or lower.

[0026] - Alkali-degradation-resistant genes - The rice used as raw material for rice flour (B) may contain naturally occurring mutants (functionally impaired) of alkali-disintegration-resistant genes. Examples of such naturally occurring mutants include those in which SNP3 (located at base number 2209 from the translation start site) changes from G to A, or SNP4 (located at base number 2341 from the translation start site) changes from C to T (References: NARO 2005 Research Results Information (https: / / www.naro.go.jp / project / results / laboratory / nics / 2005 / nics05-07.html), Umemoto and Aoki (2005) Funct. Plant Biol. 32:763-768).

[0027] -Easily alkali-disintegrates- The rice used as the raw material for rice flour (B) is preferably readily alkali-disintegrating. This makes it easier for the composition to thicken when water is added. Alkali disintegration can be determined by whether or not starch dissolves after soaking rice grains in an alkaline solution for several hours. For example, if broken brown rice is soaked in a 1.5% potassium hydroxide aqueous solution and left to stand at room temperature, if starch dissolution is observed from the grains, it can be evaluated as readily alkali-disintegrating; if no starch dissolution is observed, it can be evaluated as not readily alkali-disintegrating. Rice containing a naturally occurring variant of the alkali-disintegrating gene is usually readily alkali-disintegrating.

[0028] The rice used as the raw material for rice flour (B) can be either non-glutinous rice or glutinous rice, but non-glutinous rice is usually used. Japonica, Japanica, or Indica varieties are all acceptable. In addition, high-amylose rice, medium-amylose rice (e.g., amylose content of 15% or more but less than 20%), or low-amylose rice (e.g., amylose content of less than 15%) are all acceptable, but high-amylose rice (e.g., amylose content of 24% or more) is preferred.

[0029] -Waxy gene- The rice used as raw material for rice flour (B) is Wx a Gene (In1_G-Ex10_T) or Wx a It is preferable to have the gene (In1_G-Ex10_C). Wx aThe gene (In1_G-Ex10_C) is as explained in the section on rice flour (A). Wx a The gene (In1_G-Ex10_T) is a Wx gene where the SNP marker of intron 1 (In1) is guanine (G) and the SNP marker of exon 10 (Ex10) is thymine (T). a It is a gene.

[0030] Examples of rice varieties used as raw materials for rice flour (B) include "Fukunoko," "Momiroman," "Hoshinishiki," "Hoshiyutaka," "Nihonbare," "Koshihikari," "Kita Mizuho," "Yumejushoku," their offspring varieties, and combinations of two or more of these, with "Fukunoko" and its offspring varieties being preferred. Rice flour (B) may also be a combination of two or more varieties that differ in harvest year, cultivation method, rice flour manufacturing method, and physical properties (e.g., particle size).

[0031] (Presence or absence of alpha-enhancement) Rice flours (A) and (B) may be gelatinized, partially gelatinized, or ungelatinized, with ungelatinized (ungelatinized rice flour) being preferred.

[0032] (Origin of rice) The origin of the rice used as the raw material for rice flour (A) and (B) is not particularly limited, and any of the Japonica, Indica, or Javanica varieties may be used.

[0033] ((A):(B) ratio) The preferred ratio (mass ratio) of (A) to (B) in the composition is 1:5 to 5:1, more preferably 1:4 to 4:1, and more preferably 1:3 to 3:1. This makes it easier for the mixture to thicken after preheating, prevents lumps from forming after gelatinization, and achieves physical properties suitable for swallowing.

[0034] (Rice flour manufacturing method, particle size) The method for producing rice flour (A) and (B) can be any conventional method, such as milling the raw rice (already polished), and a wet milling method such as wet air-jet milling is preferred. This suppresses stickiness caused by damage to the rice flour during milling, and allows for the production of fine-grained, smooth rice flour. The degree of starch damage and particle size of the rice flour are not particularly limited, but as an example, the degree of starch damage is preferably less than 10%, more preferably 7% or less, and even more preferably 5% or less. The average particle size is preferably less than 100 μm, more preferably 70 μm or less, and even more preferably 50 μm or less. The degree of starch damage can be measured by quantifying the glucose produced by acting with an enzyme (mold α-amylase) that specifically decomposes damaged starch. The particle size can be measured by a laser diffraction particle size distribution analyzer. The values ​​in the examples below were also measured according to this measurement method.

[0035] (Ingredients other than rice flour) The composition may also use ingredients other than rice flour (A) and (B). Examples of other ingredients include salt, pepper, oils and fats, animal cream (fresh cream, whipped cream, etc.), skim milk, vegetable cream (e.g., soy milk, coconut, almonds, etc.), vegetable protein (legumes, etc.), vegetable starch (corn starch, tapioca starch, etc.), grains, vegetables, fruits, eggs, cocoa, fruit juice (lemon juice, etc.), protein (meat, fish, processed products thereof, processed plant products such as soybeans), alcohol, flavorings, spices, sweeteners (sugar, granulated sugar, honey, etc.), soy milk, additives (acidulants, colorings, preservatives, leavening agents (foaming agents), etc.), and combinations of two or more selected from these. The purpose of adding other ingredients may include, for example, flavoring food ingredients and improving shelf life, but is not particularly limited.

[0036] The composition may contain rice flour other than rice flour (A) and (B). When using the composition as a gel-like food material, it is preferable to select rice flour and the amount added that have little effect on the physical properties of the gel-like food material.

[0037] (Use of the copyrighted material) The composition can be made into a uniform gel when hydrated and gelatinized, so it can be used as a gel-like food material and is useful as a raw material for gel-like food materials such as dysphagia food materials (so-called gel-like food material mixes such as dysphagia food material mixes).

[0038] [Method for manufacturing gel-like food material] When the above composition is used as a raw material for a gel-like food material, the gel-like food material can be manufactured by, for example, a method comprising the following steps 1 and 2.

[0039] (Step 1: Add water) In step 1, water is added to the rice flour-containing composition to obtain a dispersion.

[0040] -Water-based raw materials in the addition of water- Hydration can be achieved by adding an aqueous raw material. The aqueous raw material can be any raw material that is liquid at room temperature, such as water. The water can be tap water, natural water, mineral water, purified water (e.g., ion-exchanged water, distilled water), or any other water used for food. The aqueous raw material can also be something other than water, such as liquid food or food ingredients, specifically milk, soy milk, fruit juice, dairy beverages, tea, coffee, broth, soup, and aqueous solutions thereof.

[0041] -Water temperature when adding water- The upper limit of the temperature of the aqueous raw material added during hydration is preferably 4 to 6°C higher than the gelatinization start temperature of the rice flour (A), and is usually 80°C or lower, but may also be 79°C or 78°C or lower. This allows the rice flour to be completely dispersed without clumps. The lower limit is any temperature at which the aqueous raw material is liquid, and is usually 4°C or higher. This makes temperature adjustment during preheating easier. Therefore, the temperature of the aqueous raw material added during hydration is usually 4 to 80°C, but may also be 4 to 79°C or 4 to 78°C. Methods for adjusting the water temperature include, for example, adjusting the temperature of the aqueous raw material before adding it to the system, adjusting it by heating after adding it to the system, adjusting it by adding a high-temperature aqueous raw material to the aqueous raw material, and combinations of these methods may also be used.

[0042] When adding water, it is preferable to stir (so-called mixing). Stirring can be done by hand or using a machine, and can be continued, for example, until the clumps of rice flour are broken up and there are no small clumps left, resulting in a uniform state (mixing).

[0043] -Amount of water added- The amount of water added (the total amount of water added to the rice flour-containing composition) is preferably 8 times or more, more preferably 9 times or more, and even more preferably 10 times or more, relative to the weight of the rice flour (the total amount of rice flour (A) and (B) in the composition, and any other rice flour used as needed, the same applies hereinafter). This makes it possible to obtain a gel-like food material that is free of lumps and has a thick consistency. Furthermore, since the gel-like food material is suitable for dysphagia dietary food category II, it is useful as a dysphagia dietary food material. The upper limit is preferably 13 times or less, more preferably 12 times or less, and even more preferably 11 times or less. This allows for thickening after preheating and suppresses the formation of lumps. Therefore, the total amount of water added is preferably 8 to 13 times, more preferably 9 to 12 times, and even more preferably 10 to 11 times, relative to the weight of the rice flour.

[0044] The hydration in step 1 may be divided into two steps: a first hydration step to completely disperse the rice flour without lumps (step 1-1), and a second hydration step to preheat the sample obtained in step 1 (step 1-2).

[0045] (Step 1-1: Primary water addition) In step 1-1, the above composition is subjected to primary hydration.

[0046] -Water temperature during primary hydration- The temperature of the aqueous raw material added during primary hydration is preferably lower than the gelatinization start temperature of rice flour (B) (for example, 2 to 10°C, or 4 to 6°C lower). Typically, it is 70°C or lower, preferably 65°C or lower, and more preferably 60°C or lower. This helps to suppress the formation of lumps. The lower limit is any temperature at which the aqueous raw material is liquid, typically 4°C or higher. This facilitates temperature control during preheating. Therefore, the temperature of the aqueous raw material added during primary hydration is typically 4 to 70°C, preferably 4 to 65°C, and more preferably 4 to 60°C.

[0047] -Primary water addition amount- The amount of water added in the first stage is 1.5 times or more, preferably 1.6 times or more, and more preferably 1.7 times or more, relative to the total amount of rice flour (A) and (B) in the composition. This allows the rice flour to be completely dispersed without clumping. The upper limit is preferably 3 times or less, more preferably 2.8 times or less, and even more preferably 2.5 times or less. This makes temperature control during preheating easier. Therefore, the amount of water added in the first stage is usually 1.5 to 3 times, preferably 1.6 to 2.8 times, and more preferably 1.7 to 2.5 times.

[0048] When adding water for the first time (before step 2), it is preferable to stir (so-called mixing). Stirring can be done by hand or using a machine, and can be continued, for example, until the clumps of rice flour are broken up and there are no small clumps left, resulting in a uniform state (mixing).

[0049] (Steps 1-2: Secondary hydration and preheating) In step 2, the sample obtained in step 1 is subjected to secondary hydration and preheating treatment.

[0050] -Water-based raw materials in secondary hydration- For the aqueous raw materials used in the secondary hydration, the aqueous raw materials exemplified in the section on primary hydration can be used. The aqueous raw materials used in the secondary hydration may be the same as or different from those used in the primary hydration.

[0051] -Secondary water addition amount- The amount of water added in the second stage is preferably such that the total amount of water added in the first and second stages is within the range of the above-mentioned water amounts. For example, the lower limit is preferably 5 times or more, more preferably 6 times or more, relative to the total amount of rice flour (A) and (B) in the composition. The upper limit is preferably 11 times or less, more preferably 10 times or less, and even more preferably 9 times or less. This allows the gel-like food material to thicken and suppresses the formation of lumps. Therefore, the amount of water added is usually 5 to 11 times, preferably 5 to 10 times, and more preferably 6 to 9 times.

[0052] -Preheating temperature- Preheating is performed at a temperature of 70°C or higher, preferably 71°C or higher. This allows for the development of an appropriate thickness. The upper limit is preferably 4 to 6°C higher than the gelatinization start temperature of rice flour (A), usually 80°C or lower, preferably 79°C or lower, and more preferably 78°C or lower. This makes it easier for the mixture to thicken after preheating, suppresses the formation of lumps after gelatinization, and enables the creation of physical properties suitable for gel-like foods or dysphagia foods. Therefore, the temperature of the mixture after preheating is usually 70 to 80°C, preferably 70 to 79°C, and more preferably 71 to 78°C.

[0053] -Water temperature during secondary water addition- The temperature of the aqueous raw material added during secondary hydration is preferably higher than the temperature of the aqueous raw material added during primary hydration, usually 90°C or higher, preferably 95°C or higher. This allows for preheating through secondary hydration. The upper limit of the water temperature is not particularly limited and may be the boiling point (100°C). Preheating can be performed simultaneously with secondary hydration by raising the temperature within the system, or the system may be heated using appropriate heating means after secondary hydration to adjust the temperature. An example of adjustment is heating for a short time (e.g., 10 to 60 seconds, preferably 20 to 30 seconds) using an electromagnetic cooking device such as a microwave oven.

[0054] -Ratio of secondary water addition to primary water addition- The amount of water added in the second step is preferably four times or more the amount of water added in the first step, more preferably 4.1 times or more, and even more preferably 4.2 times or more. The upper limit is preferably 4.7 times or less, more preferably 4.6 times or less, and even more preferably 4.5 times or less. This makes it easier to control the temperature during the preheating process, allows for thickening, and suppresses the formation of lumps. Therefore, the amount of water added in step 2 is preferably 4 to 4.7 times the amount of water added in step 1, more preferably 4.1 to 4.6 times, and even more preferably 4.2 to 4.5 times.

[0055] - Distributed Processing - In step 1, a dispersion is obtained after secondary hydration and preheating. To obtain the dispersion, a dispersion treatment such as stirring is usually performed. The dispersion treatment can be carried out by conventional methods such as stirring.

[0056] (Step 2: Gelatinization) In step 2, the dispersion obtained in step 1 is heat-treated to gelatinize it.

[0057] - Heat treatment - The heat treatment conditions should be such that rice flour (A) and (B) gelatinize after treatment. Equipment such as a constant temperature bath, pot, or induction cooker (e.g., microwave oven) may be used for the heat treatment. The sample may also be stirred during the heat treatment (e.g., manually or mechanically).

[0058] An example of the heat treatment is as follows: The heating temperature should be above the gelatinization temperature, for example, usually 90°C or higher, preferably 95°C or higher, and more preferably 100°C. The upper limit is usually 120°C or lower. Therefore, the heating temperature is usually 90-120°C, preferably 95-120°C, and more preferably 100°C. This causes the dispersion to boil, and a gel-like rice flour-containing composition can be obtained. When processing 250-350g of the dispersion using a microwave oven, the heating time is usually 1 minute 30 seconds to 2 minutes 50 seconds, preferably 1 minute 40 seconds to 2 minutes 40 seconds, and more preferably 2 minutes to 2 minutes 30 seconds at 500W.

[0059] (Optional action) Other ingredients may be added when manufacturing gel-like food materials. The timing of adding other ingredients can be at any stage of steps 1 or 2. For example, they may be added before hydration in step 1, after hydration in step 1, or, if steps 1-1 and 1-2 are performed, before primary hydration in step 1-1, before secondary hydration (before preheating) in step 1-2, before heat treatment, or in combination of two or more of these. After addition, stirring may be performed as needed.

[0060] The gelatinized sample obtained through step 2 can be used directly as a gel-like food material. The gel-like food material can be used as is, or after processing such as seasoning or the addition of other ingredients, as a dysphagia food. When seasoning, ingredients other than the rice flour mentioned above can be selected and used as needed. If necessary, it may be stored by refrigeration or freezing until it is used for cooking or processing. Alternatively, it may be filled into airtight packaging and used as a retort pouch food. Or, it may be frozen and used as a frozen food. When freezing, pre-treatment (for example, adding sugars after heating) may be performed to suppress quality deterioration due to freezing.

[0061] [Uses of gel-like food materials] Gel-like food materials can be used as ingredients in various foods such as confectionery (e.g., jelly, pudding), bread, noodles, mochi, baked goods, creams, and prepared foods (e.g., pizza, okonomiyaki, chawanmushi).

[0062] [Physical properties of dysphagia-friendly food ingredients] The gel-like food material obtained by the above method can be used as a food material for dysphagia. The food material for dysphagia preferably meets the Consumer Affairs Agency's "Approval Standards for Foods for Persons with Swallowing Difficulties" (August 8, 2018, Consumer Affairs Agency Food Labeling No. 403) (https: / / www.caa.go.jp / policies / policy / food_labeling / health_promotion / pdf / health_promotion_180808_0005.pdf), specifically meeting any of the approval standards I to III, preferably meeting approval standard II or III, and more preferably meeting approval standard II. Specifically, it should be homogeneous at room temperature and have a hardness (resistance when compressed at a constant speed, the same applies hereinafter) of 3 × 10⁻⁶. 2 ~2×10 4 Adhesion is 1.5 × 10 3 If the following conditions are met, the permit criterion III is satisfied and the hardness is 1 × 10 3 ~1.5×10 4 N / m 2 Adhesion is 1 × 10 3 J / m 3 Below, if the cohesiveness is between 0.2 and 0.9, the permit criterion II is met. [Examples]

[0063] The present invention will be described in detail below with reference to examples. The following examples are not intended to limit the present invention.

[0064] [Measurement conditions for physical properties] The measurement conditions for the physical properties in the following examples were as follows.

[0065] -Adhesion, hardness, cohesiveness, and approval standards- Measurements were taken under the following conditions, in accordance with the Consumer Affairs Agency's "Approval Standards for Foods for Persons with Swallowing Difficulties" (August 8, 2018, Consumer Affairs Agency Food Labeling No. 403) (https: / / www.caa.go.jp / policies / policy / food_labeling / health_promotion / pdf / health_promotion_180808_0005.pdf). The sample was filled into a stainless steel petri dish and compressed twice using a creep meter with a resin plunger at the specified compression speed and clearance. It was also evaluated whether each measured value conformed to Approval Standard 2 of the standards specified in the above approval standards. Measuring instrument: CREEP METER RE2-33005C (manufactured by Yamaden Co., Ltd.) Plunger: Diameter 20mm, Height 8mm Stainless steel petri dish, 40mm diameter, 15mm height Compression speed: 10 mm / sec Number of compressions: 2 Clearance: 5mm

[0066] -Evaluation of thickness- After adding hot water to the sample, it was stirred with a spoon and then scooped up with the spoon. The degree of viscosity was observed by observing how it fell when the spoon was tilted, and classified into one of the following categories. +++: Very thick (when you tilt the spoon, it flows out like a thick potage soup) ++: Medium consistency (when you tilt the spoon, it flows like a thin curry sauce) +: Slightly thickened (When the spoon is tilted, it flows down in a slightly thick consistency like a medium-thick sauce. No lumps formed after heating.) -: It lacks thickness (it flows like water when you tilt the spoon. Lumps form after heating).

[0067] Reference examples 1~3 30g of rice flour was mixed with 45ml of water using a polypropylene spoon, then 275ml of boiling water was added and stirred with the same spoon to thicken the mixture. The mixture was then heated in a 500W microwave oven for 2.5 minutes to prepare the sample. The following rice flours were used: "Kita Mizuho" (amylose content: 25%, gelatinization onset temperature: 63℃, easily alkali-disintegrating: Reference Example 1), "Ajia no Kaori" (amylose content: 28%, gelatinization onset temperature: 75℃, poor alkali-disintegrating: Reference Example 2), and "Fukunoko" (amylose content: 27%, gelatinization onset temperature: 70℃, easily alkali-disintegrating: Reference Example 3) (all with starch damage degree of 2-5% and average particle size of approximately 50μm). The obtained samples were paste-like. After cooling the samples at 4℃ for 2 hours, they were taken out at 24℃, and their hardness, cohesiveness, and adhesiveness were measured after 0-3 hours (Figures 1-3).

[0068] In all of the reference examples 1-3, the hardness of the samples tended to decrease as the temperature rose after cooling (Figure 1). Reference example 3 (Fukunoko) had high adhesiveness and sometimes fell outside of standard II (Figure 3). Cohesiveness did not change much over time (Figure 2). Regarding the hardness of the paste, reference example 1 (Kita Mizuho) had excessively hard paste, causing it to solidify and making it difficult to transfer to other containers after cooking, whereas reference example 2 (Ajia no Kaori) did not have excessively hard paste, resulting in good workability for portioning into other containers after cooking. The results from the reference examples suggest that pre-mixing the rice flour with water and then adding hot water to thicken it suppresses the occurrence of precipitation due to subsequent heating. However, it was also suggested that lumps were difficult to dissolve during mixing, and that adding a little more water during mixing would make the process easier.

[0069] Examples 1 and 2, Comparative Examples 1-3 (Investigation of the effect of the presence or absence of rice flour blend on the physical properties of the composition) The procedure was the same as in Reference Example 1, except that the amount and temperature of the water added, the amount of hot water added afterward were as shown in Table 1, and the temperature was measured immediately after lightly stirring following the second addition of water. After thickening, the paste was prepared by heating in a 500W microwave oven for 2.5 minutes. The thickness of the sample obtained after the second addition of water was evaluated (Table 1). The gelatinization onset temperature for Asia Fragrance was 75°C.

[0070] [Table 1]

[0071] In Comparative Examples 1 and 2, which used rice flour from "Fukunoko" alone, a thickening effect was achieved, and subsequent heating resulted in a smooth, lump-free gel. In Comparative Example 3, which used rice flour from "Ajia no Kaori" alone, no thickening occurred, and subsequent heating resulted in lumps that could not be resolved. In contrast, in Examples 1 and 2, which used rice flour mixed with "Fukunoko" and "Ajia no Kaori," a moderate thickness was achieved that prevented lumps from forming even after subsequent heating (Table 2).

[0072] Reference Examples 4-9 (Consideration of water temperature and water addition amount) Except for not using rice flour, and using the amounts of water, temperature, and the amount of hot water added afterward as shown in Table 2, and maintaining a room temperature of 23°C, the procedure was the same as in Example 1.

[0073] [Table 2]

[0074] The temperature of tap water and the temperature when water and hot water were mixed were investigated. In all of the reference examples, the water temperature immediately after mixing was able to be raised to 70°C or higher. In reference examples 7-9, even when the temperature of the added water was 4°C, the temperature after mixing was 70°C or higher, suggesting that it is possible to thicken the mixture even when using cold water in winter. Furthermore, from each reference example, it was found that the amount of added water and hot water can be adjusted to amounts that are easy to measure with a measuring cup (usually in 50mL units) or tablespoon (usually in 15mL units), thereby improving work efficiency.

[0075] Examples 3-18 (Microwave cooking using cold water and confirmation of physical properties as a dysphagia-friendly food) 23g of rice flour from each rice variety shown in Table 3 was mixed with 50ml of cold water (water temperature 4°C) and dissolved using a polypropylene spoon (water temperature after adding water: 72.8°C (from Reference Example 8)). 200ml of hot water was then added and mixed, and the mixture was thickened with the same spoon. After thickening, the mixture was heated in a 500W microwave oven for the time shown in Table 3 to prepare the sample (paste-like). The sample was cooled at 4°C for 20 hours, and the following day, it was stored in a constant temperature incubator set to the temperature shown in Table 3 for 1 hour. The hardness, cohesiveness, and adhesiveness of the sample were then measured. In addition, it was evaluated whether the sample conformed to the dysphagia dietary food permission category II, and the ratio of the adhesiveness measurement to the hardness measurement (adhesion / hardness) was calculated (Table 3: average value of 3 measurements).

[0076] [Table 3]

[0077] In all of the examples, a consistency slightly thinner than Worcestershire sauce was achieved, and a smooth gel was prepared without settling or clumping during microwave heating. All of the examples exhibited physical properties corresponding to dysphagia dietary food category II.

[0078] Examples 19-21 and Comparative Examples 4 and 5 (Microwave cooking using tap water) 23g of rice flour from each rice variety shown in Table 4 and 50mL of tap water (water temperature 20℃) were placed in a microwave-safe bowl and mixed with a whisk for 30 seconds. Then, 200mL of boiling water was added and mixed with a whisk for 15 seconds to thicken, and the temperature was measured immediately after mixing. After thickening, the mixture was heated in a 500W microwave for 1 minute and 50 seconds (Table 4: average value of 5 measurements).

[0079] [Table 4]

[0080] Compared to Comparative Example 4, which used 100% Fukunoko, and Comparative Example 5, which used 100% Asia no Kaori, Examples 19-21, which used both in a predetermined ratio, showed appropriate hardness, cohesiveness, and adhesiveness when cooked in a microwave oven. Furthermore, the samples from the examples could be easily cooked into dysphagia-friendly food material exhibiting physical properties suitable for dysphagia-friendly food category II by heating them in a microwave oven (Table 4).

[0081] Examples 22-24 and Comparative Examples 6 and 7 (Cooking in a pot using tap water) 40g of rice flour from each rice variety shown in Table 5 and 400ml of tap water (water temperature 20°C, 10 times the amount of rice flour) were placed in a pot and mixed with a whisk for 30 seconds. The pot was placed over medium heat and heated while stirring until it boiled. After confirming boiling, the heat was reduced to low and heated for an additional 2 minutes while stirring. The samples obtained from each were dispensed into petri dishes for measurement, allowed to cool to room temperature, and then refrigerated for 1 hour. After cooling, the samples were heated to 20°C using an incubator, and their hardness, cohesiveness, and adhesiveness were measured (Table 5: average values ​​of 5 measurements).

[0082] [Table 5]

[0083] Compared to Comparative Example 6, which used 100% fukunoko, and Comparative Example 7, which used 100% Asia no Kaori, Examples 22-24, which used both in a predetermined ratio, showed appropriate hardness, cohesiveness, and adhesiveness even when cooked in a pot. Furthermore, the samples from the examples could be easily cooked in a pot starting with water to produce dysphagia-friendly food material exhibiting physical properties suitable for dysphagia-friendly food category II (Table 5).

Claims

1. (A) Rice flour of high-amylose rice having the Wxa gene encoding (a1) or (a2), and the alkali-disintegration-resistant gene, (B) Rice flour made from high-amylose rice with a gelatinization onset temperature of less than 75°C and readily alkali-disintegrating properties. Includes, The weight ratio of (A) and (B) is (A):(B) = 1:5 to 5:

1. A rice flour-containing composition for gel-like food products. (a1) Protein containing the amino acid sequence of Sequence ID No. 1 (a2) A protein having an amino acid sequence that is 90% identical to the amino acid sequence of SEQ ID NO: 1, with the 415th proline conserved, and possessing starch granule-bound starch synthase I activity equivalent to that of the protein containing the amino acid sequence of SEQ ID NO:

1.

2. The composition according to claim 1, wherein (A) is rice flour of high-amylose rice, one or more varieties from the group consisting of Asia Kaori, Koshi Kaori, Beni Roman, and their offspring varieties.

3. The composition according to claim 1 or 2, wherein (B) is rice flour of high-amylose rice, one or more of the group consisting of Fukunoko, Momiroman, Hoshinishiki, Hoshiyutaka, Kitamizuho, ​​Yumejushoku, and their offspring varieties.

4. The composition according to any one of claims 1 to 3, wherein (A) and / or (B) is ungelatinized rice flour.

5. The composition according to any one of claims 1 to 4, wherein the weight ratio of (A) and (B) is (A):(B) = 1:3 to 3:

1.

6. Step 1) Add water to the composition according to any one of claims 1 to 5 to obtain a dispersion, Step 2) Heat-treat the dispersion to gelatinize it. including, A method for manufacturing gel-like food materials.

7. Step 1 is, Step 1-1) Adding primary water to the composition according to any one of claims 1 to 5, and Steps 1-2) Further hydration is performed, followed by preheating to 70°C to 80°C to obtain a dispersion. The manufacturing method according to claim 6, including

8. The manufacturing method according to claim 6 or 7, wherein the total amount of water added is 8 times or more the total amount of rice flour (A) and (B).

9. The manufacturing method according to claim 7 or 8, wherein the amount of water added in the primary watering is 1.5 times or more the total amount of rice flour (A) and (B).

10. The manufacturing method according to any one of claims 7 to 9, wherein the temperature of the water added in the primary hydration is below the gelatinization start temperature of the rice flour (B).

11. The manufacturing method according to any one of claims 7 to 10, wherein the temperature of the water added in the secondary hydration is 80°C or higher.

12. The manufacturing method according to any one of claims 7 to 11, wherein the amount of water added in the secondary hydration is three times or more the amount of water added in the primary hydration.

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