Syneresis inhibitor and its uses

Abstract

The objective of the present invention is to provide a syneresis inhibitor that can be safely and advantageously used in fields such as food, cosmetics, quasi-drugs, pharmaceuticals, and industrial products, and uses thereof. The objective of the present invention is to provide a syneresis inhibitor containing, as an active ingredient, a branched α-glucan mixture, which has glucose as its constituent sugar, a branched structure with a glucose polymerization degree of 1 or higher, linked via a bond other than an α-1,4 bond to a non-reducing terminal glucose residue at one end of a linear glucan with a glucose polymerization degree of 3 or higher and linked via an α-1,4 bond, and which produces isomaltose in an amount of 25% by mass to 50% by mass per solid of the digestion product upon isomaltodextranase digestion, and in which the ratio of α-1,4-linked glucose residues to α-1,6-linked glucose residues is in the range of 1:0.6 to 1:4, and the total of these two types of residues accounts for 60% or more of all glucose residues, and uses thereof.

Description

[Technical Field]

[0001] The present invention relates to a syneresis inhibitor and various uses thereof, and more particularly to a syneresis inhibitor that can prevent syneresis without impairing the inherent quality of products in the fields of food, cosmetics, pharmaceuticals, etc., and uses thereof. [Background technology]

[0002] Gel compositions are obtained by mixing a gelling agent such as a thickening polysaccharide or gelatin with water. Therefore, they contain a larger amount of water than typical solid compositions, and maintaining this water content in the composition is important for maintaining the functionality of the product. For example, when foods, cosmetics, pharmaceuticals, etc. are in the form of gel compositions, it is known that the behavior of water has a significant impact on storage stability. Examples of functions that can be maintained by maintaining water content include texture, flavor, and color (e.g., "feel on the tongue," "melt in the mouth," and "goes down the throat") in the case of foods; feel, aroma, and color (e.g., "spread," "stickiness," and "comfort") in use in the case of cosmetics; and ease of administration and stability of active ingredients in the case of pharmaceuticals.

[0003] For example, processed jelly foods are often filled and sealed in containers such as plastic cups, sterilized, and then distributed and supplied to the market, and over time, they lose moisture during refrigeration or room temperature storage, resulting in "syringe," which causes the processed food to lose its original texture, flavor, color, and other aspects of its appearance, and can also lead to problems such as reduced commercial value when consumers open the container or remove the seal or lid.

[0004] Furthermore, in recent years, due to the aging of the population and growing health consciousness, the market for jelly-like beverages, in which soft jelly filled in a flexible package with a drinking spout is manually squeezed out and consumed directly, has expanded in the fields of nursing care food, sports nutrition food, etc. Such gel compositions, which are softer and more easily crumbled than conventional jelly-like foods, generally have a low concentration of gelling agent, which makes it even more difficult to suppress syneresis.

[0005] Usually, free water in a gel composition is held between gaps in the network structure formed by substances other than water. On the other hand, the structure collapses and tightens over time for stabilization, and it is believed that this change causes the free water that was merely physically held between the structural gaps to overflow from the structure, resulting in syneresis. As described above, since gel compositions hold a large amount of liquid within them, syneresis occurs over time immediately after production. In order to prevent quality deterioration of gel compositions due to syneresis, gel compositions characterized by components useful for syneresis suppression and methods for producing the same have been reported.

[0006] Specifically, reports have included a gel composition in which syneresis is suppressed by including native gellan gum (Patent Document 1); an aqueous gel composition in which carrageenan is used as a gelling agent, and which contains xanthan gum and locust bean gum as gelling aids and a modified polyalkylene oxide as a syneresis suppressant (Patent Document 2); and an aqueous gel composition in which N-vinylacetamide polymer is also used as a syneresis suppressant (Patent Document 3). In the food field, there have also been disclosed a method of improving gel physical properties by using a dried konjac processed product prepared by combining konjac flour, sugars, and starch as a physical property improver for gel foods (Patent Document 4); a method of suppressing syneresis by reducing water activity by including trehalose as a moisture regulator for gel composition foods (Patent Document 5); and a method of suppressing syneresis in gel foods by incorporating starch whose gel-forming ability has been improved by enzyme treatment (Patent Document 6).

[0007] None of the syneresis inhibition methods of the above-mentioned prior art have yet achieved long-term syneresis inhibition without affecting texture or flavor. For example, the techniques disclosed in Patent Documents 1 and 4 increase structural strength but impart a highly elastic texture, which significantly alters the original texture of gel compositions with a high water content. Furthermore, the chemically synthesized products disclosed in Patent Documents 2 and 3 have the disadvantage of being limited in their use in food. On the other hand, the technique disclosed in Patent Document 5 can be applied in a wide range of fields, including food, and has little effect on the original flavor, color, and texture, but imparts a slight sweetness, which limits its use and dosage. Furthermore, the technique disclosed in Patent Document 6 involves enzyme treatment, but has the problem of the possibility of the starch's characteristic pasty odor remaining. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 10-150933 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-268156 [Patent Document 3] Japanese Patent Application Laid-Open No. 2003-277253 [Patent Document 4] Japanese Patent Application Laid-Open No. 2004-166580 [Patent Document 5] Japanese Patent Application Publication No. 9-56342 [Patent Document 6] Japanese Patent Application Laid-Open No. 2016-103992 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0009] The present invention has been made to solve the problems with the conventional syneresis suppression technology described above, and aims to provide a syneresis suppressor, which is a branched α-glucan mixture prepared from starch, which, when blended with processed foods and the like, exhibits an excellent syneresis suppression effect without impairing the original texture, flavor, or color of the food, and can therefore be advantageously used for quality improvement purposes, and which can be safely and advantageously used not only in the fields of food but also in cosmetics, quasi-drugs, pharmaceuticals, industrial products, and the like, as well as uses thereof. [Means for solving the problem]

[0010] In the course of intensive research to solve the above-mentioned problems, the inventors unexpectedly discovered that a branched α-glucan mixture (hereinafter referred to as "this branched α-glucan mixture"), which can be obtained, for example, by the manufacturing method disclosed in International Publication No. WO2008 / 136331 by the same applicant as the present application and is typically characterized by (A) to (E) described below, exhibits an excellent syneresis suppression effect when incorporated into a gel composition.

[0011] It has long been known that high molecular weight polysaccharides, such as starch, cellulose, and agar, retain water within their molecules. This property is due to the ability of the intertwined polysaccharide molecular backbone to retain free water, and the ability of the hydroxyl groups of the monosaccharide structural units to form hydrogen-bonded networks with surrounding water molecules to retain bound water. The density and strength of the latter hydrogen-bonded networks are thought to depend on the conformation of the hydrophilic groups in the constituent monosaccharides, the configuration of the polysaccharide molecular chain, and the degree and type of branching of the molecular chain. However, the ability to retain bound water has not yet been fully understood or predicted. Furthermore, it is particularly difficult to predict the performance, physical properties, and processing characteristics of polysaccharides when they are blended into various compositions that are molded using complex compositions and processes.

[0012] As mentioned above, the strong water-holding capacity of this branched α-glucan mixture is thought to be due to the unique molecular structure, although the details of its mechanism are unknown. This coexists in a good balance with the functions and properties of water-soluble dietary fiber. The present invention is the result of further investigation based on these compound properties and has advanced this knowledge.

[0013] The scope of use of the syneresis inhibitor characterized by containing this branched α-glucan mixture is not limited to the inhibition of syneresis in gel compositions. Surprisingly, when incorporated into frozen desserts, it has been revealed that it exerts a significant effect of improving quality by imparting a desirable texture by influencing the growth and stability of ice crystals.

[0014] That is, the present invention solves the above-mentioned problems by providing a versatile and multifunctional syneresis inhibitor containing the branched α-glucan mixture as an active ingredient, and uses thereof. [Effects of the Invention]

[0015] The syneresis inhibitor of the present invention can impart a syneresis inhibitory effect to a gel composition that cannot be achieved by conventional gelling aids or compounding ingredients, without changing the original taste or texture of the gel composition. This effect is particularly pronounced when agar and / or carrageenan is used as the gelling agent.

[0016] When the syneresis inhibitor of the present invention is incorporated into frozen desserts including ice cream, it can improve the melting properties and smoothness of the frozen desserts containing milk and dairy products without the need for special equipment, processes, or additives. It can also improve the loosening properties in the mouth and provide a crispy, smooth texture for frozen desserts that do not contain milk or dairy products.

[0017] Furthermore, the syneresis inhibitor of the present invention, which contains the branched α-glucan mixture as an active ingredient, is highly soluble in water, and its aqueous solution is colorless and transparent. Furthermore, it does not have the sticky smell that is characteristic of starch, so it does not suffer from the problems of the prior art that use processed starch or roasted dextrin, such as the loss of flavor and color due to unpleasant tastes or coloring. In addition, it has a lower retrogradation tendency than general high molecular weight dextrins, so it is possible to provide a syneresis inhibitor with good storage stability that could not be achieved with prior art.

[0018] The reasons why branched α-glucan mixtures have the above-mentioned properties are not fully understood, but it is presumed that the mixture as a whole contains a high proportion of glucose residues in the constituent α-glucan molecules that are bonded to other glucose residues at the 1st and 6th positions (hereinafter abbreviated as "α-1,6 bonds" and the same notation will be applied hereinafter), and that the proportion of branched structures formed by α-1,3,6 bonds and α-1,4,6 bonds has an effect.

[0019] The syneresis inhibitor of the present invention is produced using starch as a raw material and is substantially colorless, tasteless, and odorless, and therefore does not impair the original color, luster, flavor, texture, etc. of foods, etc. The properties of this branched α-glucan mixture enable it to capture free water and effectively reduce water activity, thereby improving shelf life. At the same time, in gel-like compositions that retain a large amount of water, surface syneresis can be suppressed, without affecting flavor or color, and good texture such as mouthfeel and spreadability can be maintained. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 10 is a diagram comparing the cross-sectional appearance of gel compositions containing a high concentration of the branched α-glucan mixture, depending on the gelling agent used. [Figure 2] FIG. 1 is a graph showing the relationship between the concentration of a water-soluble polysaccharide in an aqueous solution and the ratio of short components in the T2 relaxation time measured by pulsed NMR. DETAILED DESCRIPTION OF THE INVENTION

[0021] 1. Definitions As used herein, the following terms have the following meanings:

[0022] <Frozen dessert> "Frozen desserts" as used in this specification refers to frozen desserts or beverages made by freezing milk, dairy products, fruit juice, a liquid flavored with flavors and sugars, or unflavored water, including ice cream (milk solids 15.0% or more, milk fat 8.0% or more), ice milk (milk solids 10.0% or more, milk fat 3.0% or more), lacto ice cream (milk solids 3.0% or more) and other frozen desserts as defined by the Dairy and Milk Products Ordinance.

[0023] <Isomaltodextranase digestion> As used herein, "isomaltodextranase digestion" refers to the hydrolysis of liquefied starch, dextrin, high molecular weight polysaccharides, and other target substances by the action of isomaltodextranase. Isomaltodextranase is an enzyme designated by the enzyme code (EC) 3.2.1.94, and is an enzyme that has the ability to hydrolyze any of the α-1,2, α-1,3, α-1,4, and α-1,6 bonds adjacent to the reducing end of the isomaltose structure in α-glucan. Preferably, isomaltodextranase derived from Arthrobacter globiformis is used.

[0024] <Water-soluble dietary fiber content> As used herein, "water-soluble dietary fiber content" refers to a value determined by the "high-performance liquid chromatography (enzyme-HPLC) method" described in Section 8, "Dietary Fiber," of the Nutrition Labeling Standards, "Methods for Analyzing Nutritional Components, etc. (Methods listed in Column 3 of Appendix 1 of the Nutrition Labeling Standards)" of the Ministry of Health, Labour and Welfare Notification No. 146 of May 1996. The method is outlined below: A sample is hydrolyzed using a series of enzyme treatments with thermostable α-amylase, protease, and amyloglucosidase (glucoamylase). Proteins, organic acids, and inorganic salts are removed from the treated solution using an ion exchange resin to prepare a sample solution for size exclusion chromatography. The sample is then subjected to size exclusion chromatography, and the peak areas of undigested glucan and glucose in the chromatogram are determined. The water-soluble dietary fiber content of the sample is calculated using these peak areas and the amount of glucose in the sample solution, which has been determined separately by a standard glucose oxidase method. Unless otherwise specified, the term "water-soluble dietary fiber content" used throughout this specification refers to the water-soluble dietary fiber content determined by the "high performance liquid chromatography method (enzyme-HPLC method)" described above.

[0025] <Methylation analysis> As used herein, "methylation analysis" refers to a chemical method for determining the bonding patterns of monosaccharides that make up a polysaccharide or oligosaccharide. When applying "methylation analysis" to the analysis of the bonding patterns of glucose in glucan, first, all free hydroxyl groups in the glucose residues that make up the glucan are methylated, and then the completely methylated glucan is hydrolyzed. Next, the methylated glucose obtained by hydrolysis is reduced to give methylated glucitol with the anomeric form eliminated, and further, the free hydroxyl groups in this methylated glucitol are acetylated to obtain partially methylated glucitol acetate (in some cases, the notation of the acetylated site in "partially methylated glucitol acetate" and "glucitol acetate" may be omitted and abbreviated as "partially methylated product"). By analyzing the resulting partially methylated product by gas chromatography, the percentage (%) of the peak area of each type of partially methylated product derived from glucose residues with different bonding patterns in glucan in the total peak area of all partially methylated products in the gas chromatogram can be represented. And from this peak area %, the abundance ratio of glucose residues with different bonding patterns in the glucan, that is, the abundance ratio of each glucoside bond, can be determined. Note that the "ratio" for the partially methylated product means the "ratio" of the peak areas in the gas chromatogram of the methylation analysis, and the "%" for the partially methylated product means the "area %" in the gas chromatogram of the methylation analysis.

[0026] <Mw / Mn (weight-average molecular weight / number-average molecular weight)> As used herein, "Mw / Mn" refers to the value obtained by dividing the mass-average molecular weight (Mw) by the number-average molecular weight (Mn). Mw / Mn is an index that represents the spread (dispersity) of the molecular weight distribution; the larger the value, the wider the molecular weight range of the molecular species, and the closer the value is to 1, the more uniform the molecular weight of the molecular species. Mw / Mn can be calculated by subjecting a sample to gel filtration high-performance liquid chromatography (gel filtration HPLC), analyzing the chromatogram using molecular weight distribution analysis software, and determining the mass-average molecular weight (Mw) and number-average molecular weight (Mn).

[0027] <Bound water, intermediate water and free water> As used herein, "bound water" refers to water molecules that are bound to specific molecules via hydrogen bonds, and is also called "unfreezable water" because it does not freeze even at 0°C. On the other hand, water molecules that can freely change state depending on environmental conditions such as temperature and humidity and exhibit molecular behavior different from that of bound water are called "free water." "Intermediate water" refers to water molecules that have properties intermediate between "bound water" and "free water."

[0028] 2. Aspects and structural characteristics of this branched α-glucan mixture The branched α-glucan mixture contained as an active ingredient in the syneresis inhibitor of the present invention is a branched α-glucan mixture having the following characteristics (A) to (E): (A) Glucose is the constituent sugar. (B) A branched structure with a glucose polymerization degree of 1 or more linked via a bond other than an α-1,4 bond to a non-reducing terminal glucose residue located at one end of a linear glucan with a glucose polymerization degree of 3 or more linked via an α-1,4 bond. (C) Isomaltodextranase digestion to produce isomaltose. (D) The ratio of α-1,4-linked glucose residues to α-1,6-linked glucose residues is in the range of 1:0.6 to 1:4. (E) The sum of α-1,4-linked glucose residues and α-1,6-linked glucose residues accounts for 60% or more of the total glucose residues.

[0029] That is, this branched α-glucan mixture is an α-glucan whose sole constituent sugar is glucose (Characteristic (A)), and has a branched structure with a glucose polymerization degree of 1 or higher, which is linked via a bond other than an α-1,4 bond to a non-reducing terminal glucose residue located at one end of a linear glucan with a glucose polymerization degree of 3 or higher linked via an α-1,4 bond (Characteristic (B)). Note that "non-reducing terminal glucose residue" refers to a glucose residue located at the non-reducing end of a glucan chain linked via an α-1,4 bond. In addition, this branched α-glucan mixture has the characteristic of producing isomaltose upon isomaltodextranase digestion (Characteristic (C)).

[0030] The proportion of isomaltose produced by isomaltodextranase digestion per solid indicates the proportion of isomaltose structures in the branched α-glucan structure that can be hydrolyzed by isomaltodextranase, and this branched α-glucan mixture as a whole can be used as one of the indicators for characterizing the structure by enzymatic techniques.

[0031] Furthermore, this branched α-glucan mixture has the following characteristics, which can be determined by methylation analysis: the ratio of α-1,4-linked glucose residues to α-1,6-linked glucose residues is in the range of 1:0.6 to 1:4 (characteristic D), and the sum of α-1,4-linked glucose residues and α-1,6-linked glucose residues accounts for 60% or more of the total glucose residues (characteristic E).

[0032] The ratio of α-1,4-linked glucose residues to α-1,6-linked glucose residues (characteristic (D)) and the ratio of α-1,4-linked glucose residues to α-1,6-linked glucose residues to the total glucose residues (characteristic (E)) obtained by methylation analysis can be used as one of the indices for characterizing the structure of this branched α-glucan mixture as a whole by chemical methods.

[0033] The "α-1,4-linked glucose residue" in (D) and (E) above refers to a glucose residue that is linked to another glucose residue only through the hydroxyl groups bonded to the carbon atoms at positions 1 and 4, and is detected as 2,3,6-trimethyl-1,4,5-triacetylglucitol in methylation analysis. The "α-1,6-linked glucose residue" in (1) and (2) above refers to a glucose residue that is linked to another glucose residue only through the hydroxyl groups bonded to the carbon atoms at positions 1 and 6, and is detected as 2,3,4-trimethyl-1,5,6-triacetylglucitol in methylation analysis.

[0034] The above-mentioned (D) stipulates that "the ratio of α-1,4-linked glucose residues to α-1,6-linked glucose residues is in the range of 1:0.6 to 1:4" means that in the methylation analysis of the branched α-glucan mixture, the ratio of 2,3,6-trimethyl-1,4,5-triacetylglucitol to 2,3,4-trimethyl-1,5,6-triacetylglucitol is in the range of 1:0.6 to 1:4. Furthermore, the above-mentioned (E) stipulates that "the sum of α-1,4-linked glucose residues and α-1,6-linked glucose residues accounts for 60% or more of the total glucose residues" means that in the methylation analysis of the branched α-glucan mixture, the sum of 2,3,6-trimethyl-1,4,5-triacetylglucitol and 2,3,4-trimethyl-1,5,6-triacetylglucitol accounts for 60% or more of the partially methylated glucitol acetate.

[0035] The branched α-glucan mixture may be produced by any method as long as it has the above characteristics (A) to (E), and a suitable example is the branched α-glucan mixture obtained by the production method disclosed in International Publication No. WO 2008 / 136331. The branched α-glucan mixture may also be an enzymatic digest obtained by treating the branched α-glucan mixture with an enzyme such as amyloglucosidase (glucoamylase), a fraction obtained by fractionating the branched α-glucan mixture by size exclusion chromatography, or a reduced product obtained by reducing the glucose residues at the reducing ends of the branched α-glucan mixture by hydrogenation or the like.

[0036] A more preferred embodiment of the present branched α-glucan mixture is one characterized by a water-soluble dietary fiber content of 40% by mass or more as determined by the high-performance liquid chromatography (enzyme-HPLC) method described herein. The water-soluble dietary fiber content indicates the content of α-glucan that is not degraded by α-amylase and amyloglucosidase (glucoamylase). The present branched α-glucan mixture as a whole can be used as an index for characterizing the structure by enzymatic methods.

[0037] The degree of glucose polymerization of the branched α-glucan mixture is usually 6 to 430, and the value (Mw / Mn) obtained by dividing the mass average molecular weight (Mw) of the branched α-glucan mixture by the number average molecular weight (Mn) is usually 20 or less. The mass average molecular weight (Mw) and number average molecular weight (Mn) can be determined, for example, using size exclusion chromatography. The degree of glucose polymerization can be determined by subtracting 18 from the mass average molecular weight (Mw) and dividing the result by 162.

[0038] The degree of glucose polymerization refers to the number of glucose residues that make up a glucan molecule, and can be used as an index to characterize the structure of the branched α-glucan mixture as a whole by physical methods.

[0039] Among the branched α-glucan mixtures, the one that can be most suitably used as a syneresis inhibitor is the product "Fibrixa (registered trademark)" manufactured and sold by Hayashibara Co., Ltd. In this mixture, the proportions of glucose residues with different bond types are, on average, approximately 50% for α-1,6 bond, and approximately 10% for α-1,3,6 bond and α-1,4,6 bond combined, and the mixture satisfies all of the above characteristics (A) to (E).

[0040] 3. Use and dosage of the syneresis inhibitor of the present invention The syneresis inhibitor of the present invention can be advantageously used in foods, cosmetics, pharmaceuticals, quasi-drugs, industrial products, and the like, where it is desirable to reduce free water while maintaining the moisture content of the entire composition. Furthermore, the amount of the branched α-glucan mixture contained as an active ingredient in the syneresis inhibitor of the present invention is not particularly limited, and the content of the branched α-glucan mixture may be in the range of 1 to 100% by mass, for example. The lower limit of 1% by mass is set because, although the effect is not necessarily lost if the content of the branched α-glucan mixture is lower than this, the syneresis inhibitory effect is less likely to be achieved.

[0041] The amount of the syneresis inhibitor of the present invention can be set freely without particular restrictions in foods, cosmetics, pharmaceuticals, quasi-drugs, and industrial products depending on the intended use and the strength of the expected effect. Typically, the amount of the branched α-glucan mixture is blended in the target product in the range of 0.01 to 35% by mass, preferably 0.05 to 25% by mass, and more preferably 0.1 to 10% by mass.

[0042] When the syneresis inhibitor of the present invention is incorporated into a gel composition for the purpose of syneresis inhibition, the branched α-glucan mixture is typically incorporated into the product in an amount of 0.2 to 30% by mass, preferably 0.5 to 20% by mass, and more preferably 1 to 5% by mass, although the preferred range varies depending on the type and concentration of the gelling agent incorporated.

[0043] When the syneresis inhibitor of the present invention is incorporated into frozen desserts for the purposes of improving spoonability, disintegration in the mouth, and melt-in-the-mouth texture, the branched α-glucan mixture is typically incorporated into the product in an amount of 0.01 to 20% by mass, preferably 0.05 to 8% by mass, and more preferably 0.1 to 5% by mass. When smooth spoonability is particularly important, the preferred amount of the syneresis inhibitor of the present invention at which its effectiveness is achieved varies depending on the composition of the frozen dessert. For frozen desserts containing milk and dairy products, a concentration of 0.2 to 20% by mass, more preferably 0.5 to 10% by mass, is selected. On the other hand, for frozen desserts that do not contain milk or dairy products and are primarily composed of ice, a concentration of 0.01 to 0.5% by mass, more preferably 0.05 to 0.25% by mass is selected.

[0044] Furthermore, the syneresis inhibitor of the present invention may naturally consist solely of the branched α-glucan mixture as the active ingredient, but depending on the intended use, it may also contain one or more ingredients used in the fields of food, cosmetics, pharmaceuticals, and industrial products, such as water, starch, modified starch, polysaccharides, gelling agents, gelling aids, sweeteners, proteins, enzymes, peptides, amino acids, minerals, thickeners, stabilizers, extenders, excipients, fillers, thickeners, surfactants, foaming agents, antifoaming agents, pH adjusters, stabilizers, flame retardants, release agents, antibacterial agents, colorants, flavoring agents, nutrients, favorite foods, flavoring substances, medicinal substances, and physiologically active substances.

[0045] The gelling agent and gelling aid used in combination with the syneresis inhibitor of the present invention are not particularly limited, and gel strength and syneresis rate of the gel composition can be adjusted by using gelling agents and gelling aids commonly used in the fields of food, cosmetics, pharmaceuticals, and industrial products, specifically, gelatin, collagen, pectin, agar, carrageenan, xanthan gum, locust bean gum, gellan gum, gum arabic, guar gum, tara gum, tamarind seed gum, curdlan, psyllium seed gum, alginic acid, hyaluronic acid, starch, modified starch, dextrin, dextran, carboxyvinyl polymer, cross-linked polyacrylic acid, hydroxyethyl cellulose, carboxymethyl cellulose, sodium acrylate, etc., in combination, but agar, carrageenan, and locust bean gum are particularly advantageously used. Any carrageenan having gelling ability may be used, and κ-carrageenan is preferably used.

[0046] As described above, in a preferred embodiment, the branched α-glucan mixture used as an active ingredient in the syneresis inhibitor of the present invention has a water-soluble dietary fiber content of 40% by mass or more. Therefore, it is particularly suitable for use, for example, in designing gel foods with a high dietary fiber content. However, when the syneresis inhibitor of the present invention is incorporated into a gel composition at a high concentration, the gel surface may become rough and the texture (feel on the tongue) may be impaired. In such cases, the syneresis inhibitor of the present invention can be combined with two gelling agents, carrageenan and locust bean gum, to inhibit syneresis without causing the gel surface to become rough or the texture to be impaired, resulting in a smooth gel food with a pleasant texture. Furthermore, as a result of testing various gelling agents, when the branched α-glucan mixture is incorporated at a concentration of more than 15% by mass relative to the mass of the composition, the gel obtained is firm and chewy when carrageenan and locust bean gum are used as gelling agents, whereas the gel obtained is soft and loose when carrageenan and agar are used. Therefore, when the present branched α-glucan mixture is incorporated at a high concentration, a wide range of gel hardness, texture, or mouthfeel can be achieved by combining carrageenan with roasted bean gum and / or agar as gelling agents and appropriately setting the concentration and blending ratio of each gelling agent.

[0047] 4. Experimental Examples and Examples of the Present Invention The present invention will be described in more detail below based on experiments. In Experiments 1 to 5, a branched α-glucan mixture (corresponding to the present branched α-glucan mixture) prepared by the method described in Example 3 below was used.

[0048] <Experiment 1: Effect of branched α-glucan mixture on the syneresis rate of gel composition> Since the addition of sugars to a gel composition is known to have the effect of suppressing syneresis, the syneresis suppression effect of adding a branched α-glucan mixture to a gel composition was compared with that of sucrose.

[0049] <Experiment 1-1> The gelling agents used were agar and κ-carrageenan, which are generally known to synergize more than other gelling agents. Gel compositions prepared using these gelling agents were mixed with sucrose or a branched α-glucan mixture, and the syneresis rate was measured after 14 days.

[0050] Agar (trade name "ZL," manufactured by Ina Food Industry Co., Ltd.) or κ-carrageenan (trade name "CSK-1," manufactured by San-Ei Gen F.F.I. Co., Ltd.) was added to water at a concentration of 2.0% by mass, and the mixture was heated with stirring to complete dissolution. Sucrose or a branched α-glucan mixture was then added at concentrations of 15, 25, and 35% by mass, respectively, and dissolved. Water was then added to adjust the total volume. Approximately 60 g of each gel solution was filled into truncated conical plastic jelly cups and refrigerated at 4°C for 14 days to prepare the samples. A sugar-free gel was prepared for both agar and κ-carrageenan using the same procedure, except that no sugar was added. This gel was used as a control sample.

[0051] On the 14th day after sample preparation, the surface syneresis rate was measured as follows. First, the sample was left to stand at room temperature for 2 hours, and then the sample weight (A) including the jelly cup (tare weight: C) was measured. The gel was then removed from the jelly cup, the moisture on the gel surface was wiped off with a paper towel, and the gel weight (B) was measured. The amount of syneresis (ABC) was calculated, and this was divided by the original gel weight (AC) to calculate the amount of syneresis per gel mass, i.e., the surface syneresis rate. The results of measuring three samples for each sample are shown in Table 1. Statistical analysis of the surface syneresis rates of the control sample and the samples containing added sugars was performed using a t-test. A significance level of p<0.05 was considered significant, and p<0.05 and p<0.01 are indicated in the table by * and **, respectively. The surface syneresis rates of gels containing the same concentrations of sucrose and branched α-glucan mixture were also tested for significance, and p<0.05 and p<0.01 are indicated in the table by # and ##.

[0052] [Table 1]

[0053] As shown in Table 1, sucrose, known for its syneresis-inhibiting effect, showed significant syneresis-inhibiting effects in 2.0% agar gel at 25 and 35% by weight compared to a control gel containing no sucrose. Similarly, in 2.0% κ-carrageenan gels, sucrose additions in the range of 15 to 35% by weight significantly inhibited syneresis compared to the control gel. In contrast, when a branched α-glucan mixture was added instead of sucrose, the syneresis rate significantly decreased compared to the control gel at 15 and 25% by weight. The degree of decrease, i.e., the syneresis-inhibiting effect of the branched α-glucan mixture, was significantly greater than that of sucrose. At 35% by weight, the effect was slightly weakened, but still maintained sufficient syneresis-inhibiting effect compared to the control. In the case of κ-carrageenan gels, the branched α-glucan mixture also exhibited significantly greater syneresis-inhibiting effects than sucrose, demonstrating a dose-dependent syneresis-inhibiting effect in the range of 15 to 35% by weight.

[0054] These results indicate that the branched α-glucan mixture inhibited surface water syneresis from the gel composition more effectively than sucrose in the concentration range of 15 to 35% by mass in agar and κ-carrageenan gels.

[0055] <Experiment 1-2> The gel strength and syneresis rate were measured when the blending concentrations of the gelling agent and branched α-glucan mixture were lower than in Experiment 1-1 above.

[0056] Agar (trade name "ZL", manufactured by Ina Food Industry Co., Ltd.) was added to water to a concentration of 1.0% by mass relative to the final mass, and the mixture was heated with stirring using a heater until completely dissolved. Next, a branched α-glucan mixture was added to the mixture to a concentration of 5, 10, 15, and 20% by mass relative to the final mass, respectively, and dissolved. Water was then added to adjust the total volume. Each gel solution was treated in the same manner as in Experiment 1-1 to prepare test samples. A control sample was prepared in the same manner, except that the branched α-glucan mixture was not added. Approximately 60 g of each gel solution was filled into a truncated conical plastic jelly cup and stored refrigerated at 4°C to prepare the sample. Gel strength was measured the next day, and surface syneresis was measured after 14 days.

[0057] The surface water separation rate was measured in accordance with Experiment 1-1. A creep meter (RE2-33005C, manufactured by Yamaden Co., Ltd.) was used to measure the gel strength. A cylindrical plunger with a diameter of 16 mm was pressed vertically against the gel removed from the jelly cup at a speed of 1 mm per second, and the maximum load at the breaking point when compressed to 90% was recorded as the breaking load.

[0058] The surface syneresis rate was measured on three specimens for each sample, and the breaking load was measured on one specimen for each sample, and the results are shown in Table 2. The surface syneresis rate was analyzed using a t-test to determine whether it was significantly different from the control sample to which the branched α-glucan mixture had not been added, with a significance level of p<0.05 being considered significant, and p<0.05 and p<0.01 being indicated with * and **, respectively, in the table.

[0059] [Table 2]

[0060] As shown in Table 2, even in 1.0% by mass agar gels, gels containing the branched α-glucan mixture exhibited a significant syneresis suppression effect, with the syneresis rate decreasing dose-dependently up to 15% by mass. On the other hand, although the gel strength increased when the branched α-glucan mixture was added at 5% by mass, a dose-dependent decrease in strength was observed as the concentration increased. However, this fluctuation was small and did not have a significant effect on the actual gel strength.

[0061] These results indicate that the branched α-glucan mixture, in a dosage range of 5 to 20% by mass, exhibited a syneresis-inhibiting effect without affecting the gel strength, even in soft gel compositions prepared with low concentrations of gelling agent.

[0062] <Experiment 2: Effect of water-soluble polysaccharides on the syneresis rate of gel compositions> Next, we investigated the syneresis inhibitory effect of adding a branched α-glucan mixture or various water-soluble polysaccharides to a gel composition at low doses. As in Experiment 1, agar and κ-carrageenan were used as gelling agents, and gels were prepared with a polysaccharide concentration of 2.5% by mass. The syneresis rate was measured after 14 days. The branched α-glucan mixture used was the same as that used in Experiment 1.

[0063] In addition to the branched α-glucan mixture (mass-average molecular weight 4,860), the experiments used resistant dextrin (trade name "Fibersol 2", sold by Matsutani Chemical Industry Co., Ltd., mass-average molecular weight 2,910), resistant dextrin (trade name "Nutriose FB06", sold by Rocket Japan Co., Ltd., mass-average molecular weight 4,610), inulin (trade name "Orafti GR", sold by DKSH Japan Co., Ltd., mass-average molecular weight 2,950), and polydextrose (trade name "Lites II", manufactured by Danisco Japan, mass-average molecular weight 1,560). All five of these polysaccharides are classified as water-soluble dietary fiber.

[0064] To prepare the agar gels, agar was added to each polysaccharide aqueous solution at a concentration of 0.5% by mass relative to the final mass, heated with stirring in a heater, and boiled for 15 minutes. Water was then added to adjust the mass to a polysaccharide concentration of 2.5% by mass. When a branched α-glucan mixture was used as the polysaccharide, a solution containing 1.0% by mass of polysaccharide (branched α-glucan mixture) was also prepared in the same manner as above, in addition to a solution containing 2.5% by mass of polysaccharide. When each gel solution reached 50°C, 60 g of each solution was packed into a zipper bag (Lamizip ZL-9) and stored refrigerated for 14 days to prepare the samples. Various gel solutions were prepared in the same manner using κ-carrageenan instead of agar. When κ-carrageenan gel was used, κ-carrageenan was added to each polysaccharide aqueous solution so that the concentration was 0.8% by mass of the final mass, and the solution was stirred in a water bath. Once the solution reached 85°C, it was heated for 15 minutes to dissolve. As with the agar gel, water was added to adjust the mass so that the polysaccharide concentration was 2.5% by mass. The samples were filled in 60g zip-lock bags and stored refrigerated at 4°C for 14 days to prepare the samples. For both gelling agents, a polysaccharide-free gel was prepared in the same manner except that no polysaccharide was added, and used as a control sample.

[0065] On the 14th day after sample preparation, the surface water release rate was measured as follows. The sample was removed from the zipper bag, and the water on the gel surface was wiped off for 30 seconds with a paper towel whose tare weight had been measured in advance. Any remaining water in the bag was then absorbed by the paper towel, and the increase in mass of the paper towel was measured using an electronic balance. This increase in mass was taken as the mass of water released from the gel, and the mass percentage of released water per gel mass was calculated to give the water release rate. Five agar gel samples and three κ-carrageenan gel samples were measured, and the results are shown in Table 3. Statistical analysis of the results was performed using a t-test. A significance level of p<0.05 was considered significant, and p<0.05 and p<0.01 were indicated in the table with * and **, respectively.

[0066] [Table 3]

[0067] As shown in Table 3, in the 0.5% by mass agar gel, only the gel containing the branched α-glucan mixture showed a significant decrease in synergy rate, and synergy was inhibited in a dose-dependent manner with the branched α-glucan mixture. On the other hand, the synergy rate significantly increased in the gel containing 2.5% by mass inulin. In the κ-carrageenan gel, the synergy rate significantly decreased in the gel containing 2.5% by mass of the branched α-glucan mixture and the gel containing 2.5% by mass of resistant dextrin (Fibersol 2), but the branched α-glucan mixture had a higher synergy-inhibiting ability. Nutriose FB06, another type of resistant dextrin, also showed a tendency to inhibit synergy, but the inhibitory effect was not significant.

[0068] These results indicate that the branched α-glucan mixture inhibited syneresis from the agar and κ-carrageenan gel compositions more effectively than other water-soluble dietary fibers.

[0069] <Experiment 3: Effect of branched α-glucan mixture on syneresis rate of sucrose-added gel> Jelly foods with fruit juice flavors are generally formulated with sweeteners such as sucrose, glucose, or isomerized sugar, and their concentration affects the shape retention and syneresis of the gel composition. Therefore, an experiment was conducted to investigate whether a branched α-glucan mixture exerts a syneresis-inhibiting effect in κ-carrageenan gels containing added sucrose. The branched α-glucan mixture used was the same as that used in Experiment 1.

[0070] <Experiment 3-1> The samples were prepared as follows: 8 parts by weight of κ-carrageenan and 25 parts by weight of a branched α-glucan mixture were pre-powdered, 967 parts by weight of water was added, and the mixture was heated to 85°C with stirring for 15 minutes to dissolve. The mixture was then cooled to 60°C, poured into plastic cups in 50 ml portions, solidified at room temperature, and stored at 4°C for 14 days to prepare samples, and the surface synergy was measured. This sample served as a control (sucrose concentration 0% by weight). Three samples with different sucrose concentrations (sucrose concentrations of 2.5%, 10%, and 40% by weight) were prepared in the same manner, except that 25, 100, and 400 parts by weight of the 967 parts by weight of water were replaced with sucrose, respectively. The surface synergy was measured in the same manner as in Experiment 1. The results of measuring five specimens of each sample are shown in Table 4. The results were statistically analyzed using a t-test, with a significance level of p<0.05 being considered significant. Significant differences between gel compositions with the same sucrose concentration that contained a branched α-glucan mixture were indicated by ** and *** at p<0.01 and p<0.001, respectively, and significant differences between gel compositions without branched α-glucan that contained sucrose at p<0.001 were indicated by #.

[0071] [Table 4]

[0072] As shown in Table 4, the κ-carrageenan gel containing sucrose showed reduced syneresis compared to the κ-carrageenan gel without sucrose, but the syneresis rate was further significantly reduced by adding 2.5% by mass of the branched α-glucan mixture.

[0073] <Experiment 3-2> In Experiment 3-1, the branched α-glucan mixture was found to have a significant syneresis-inhibiting effect in κ-carrageenan gels containing sucrose. Meanwhile, in Experiment 2, the syneresis-inhibiting effects of both the branched α-glucan mixture and the indigestible dextrin (Fibersol 2) were confirmed in κ-carrageenan gels. To compare the effects of both, the syneresis-inhibiting effect was then measured in a gel composition containing orange juice and sucrose.

[0074] Specifically, 25 parts by mass of sucrose, 25 parts by mass of the same branched α-glucan mixture used in Experiment 1, and 8 parts by mass of κ-carrageenan were pre-powdered and mixed, followed by 942 parts by mass of orange juice (trade name "Pon Juice" sold by Ehime Beverage Co., Ltd.). A gel sample was prepared in the same manner as in Experiment 3-1. Another gel sample was prepared in the same manner, except that the branched α-glucan mixture was replaced with indigestible dextrin (Fibersol 2). As a control, an orange jelly was prepared without these two polysaccharides, but with 50 parts by mass of sucrose. These samples were stored at 4°C for 5 days, and the surface syneresis rate was measured in the same manner as in Experiment 1. Samples stored at 4°C for 14 days were also measured. The results are shown in Table 5. Statistical analysis of the results was performed using a t-test. A significance level of p<0.05 was considered significant. Significant differences between the polysaccharide-containing orange jelly and the control orange jelly containing 5% sucrose are indicated by an * at p<0.05.

[0075] [Table 5]

[0076] As shown in Table 5, when half of the sucrose in κ-carrageenan gel prepared from orange juice containing 5% sucrose was replaced with a branched α-glucan mixture, the syneresis rate tended to decrease after 5 days of storage at 4°C, and was significantly reduced after 14 days of storage. However, no inhibition of syneresis was observed after 5 or 14 days of storage in orange jelly in which half of the sucrose was replaced with resistant dextrin (Fibersol 2).

[0077] Resistant dextrin (Fibersol 2) and branched α-glucan are known to share common structures, physical properties, and even some physiological functions. However, methylation analysis revealed differences in the type and ratio of multi-branched bonds, suggesting that these structural differences may be responsible for the differences in their syneresis-inhibiting effects. Thus, even though they are similar water-soluble dietary fiber materials, this branched α-glucan mixture has been shown to function more advantageously as a syneresis inhibitor than other water-soluble dietary fibers. It also exhibited significant syneresis-inhibiting properties in gel compositions containing a high carbohydrate content and gel compositions made with pure fruit juice rich in vitamins and minerals.

[0078] <Experiment 4: Improving the texture of gels containing a high proportion of branched α-glucan mixture> In Experiment 1, it was revealed that the branched α-glucan mixture can be incorporated into a gel composition at a high concentration of 35% by mass while maintaining its syneresis-inhibiting effect. On the other hand, because the branched α-glucan mixture functions as a water-soluble dietary fiber, it is quite conceivable that it will be incorporated into gel foods at high concentrations for the purpose of nutritional enrichment. Therefore, carrageenan jelly containing a high concentration (30% by mass) of the branched α-glucan mixture was prepared, and the gel strength, surface smoothness, and texture were evaluated when agar or locust bean gum was added in combination.

[0079] <Experiment 4-1: Strength comparison of gels containing a high proportion of branched α-glucan mixture> The κ-carrageenan gel containing 30% by mass of this branched α-glucan mixture was prepared according to Experiment 1. Specifically, κ-carrageenan (trade name "CSK-1", manufactured by San-Ei Gen F.F.I. Co., Ltd.) was added to water to make a 2.0% by mass mixture based on the final mass, and the mixture was heated with stirring using a heater until completely dissolved. Next, the same branched α-glucan mixture used in Experiment 1 was added to make a 30% by mass mixture based on the final mass, and dissolved. Water was then added to adjust the total volume. When κ-carrageenan and another gelling agent were used in combination, the gelling agent was dissolved to make 1.0% by mass of κ-carrageenan and 1.0% by mass of agar, or 1.0% by mass of κ-carrageenan and 1.0% by mass of locust bean gum (trade name "GENU® GUM type RL-200-J", manufactured by Sansho Co., Ltd.) instead of the 2.0% by mass of κ-carrageenan described above. Approximately 60 g of each gel solution was filled into a truncated cone-shaped plastic jelly cup and refrigerated overnight at 4°C to prepare the samples. The gel strength of each sample was measured three times per specimen using a creep meter in accordance with the method in Experiment 1-2, and the breaking load of the gel is shown in Table 6 as an index of gel strength. A small sensory panel also evaluated the texture of each sample, including the feel, chewiness, and mouthfeel, and the characteristics were also listed in the table.

[0080] [Table 6]

[0081] As shown in Table 6, in a gel composition containing 30% by mass of a branched α-glucan mixture, contrasting textures were achieved, either a firm and chewy gel or a soft and loose gel, depending on the combination of gelling agents. This suggests that the texture, including the hardness, strength, and elasticity of the gel, can be varied over a wide range by changing the combination and formulation of gelling agents. On the other hand, when a high concentration of branched α-glucan mixture was added to a carrageenan gel, the gel surface became rough, creating a gritty feeling and causing the gel to lose its smoothness. However, this problem was resolved by using locust bean gum as a gelling agent.

[0082] <Experiment 4-2: Sensory Test> The texture improvement of the branched α-glucan mixture-rich gel due to the combined use of κ-carrageenan and locust bean gum, as revealed in Experiment 4-1, was confirmed by a sensory test. The sensory test was conducted by a trained panel of 10 men and women (7 women, 3 men) to evaluate the appearance (smoothness) and texture (feel on the tongue) of an orange juice jelly with a high branched α-glucan mixture containing 0.5% by mass of κ-carrageenan and locust bean gum as gelling agents, and the same jelly gelled with 1.0% by mass of κ-carrageenan alone.

[0083] The jelly was prepared as follows: 150 parts by weight of the branched α-glucan mixture obtained by the method of Example 1, 0.25 parts by weight of sucralose, and 5.0 parts by weight of κ-carrageenan (trade name "Carrageenin CSK-1" sold by San-Ei Gen F.F.I. Co., Ltd.) as a gelling agent were added to 250 parts by weight of water, heated to a boil while mixing, and maintained at a boil for at least 5 minutes. The liquid was cooled to approximately 70°C, and 5 parts by weight of a 50% by weight aqueous citric acid solution, 100 parts by weight of orange juice, and 1 part by weight of orange flavoring were added. The final weight was adjusted to 500 parts by weight with water, filled into a jelly cup, and sterilized at 80°C for 30 minutes. This was then refrigerated at 4°C to obtain an orange-flavored jelly, which served as a control sample. Next, a test sample was prepared using the same procedure, except that half (2.5 parts by weight) of the κ-carrageenan as a gelling agent was replaced with locust bean gum.

[0084] In the sensory evaluation, each panelist evaluated the appearance by scooping up a piece of jelly with a metal spoon and examining the apparent smoothness of the cross-section of the gel. For texture (feel), the panelists evaluated the texture of the jelly when crushing it with their tongues in their mouths. For both items, the control sample was rated as a 3-point score (median), and the test samples were rated on a 5-point scale. The average scores (rounded to the nearest whole number) of the 10 panelists were calculated based on the following criteria, and the results are shown in Table 7. Statistical analysis was performed using a t-test for the control and test samples. A significance level of p<0.05 was considered significant, and p<0.01 was indicated with ** in the table. Photographs of representative gel cross-sections of the control and test samples are shown in Figure 1. <Grading criteria> 5 points: Significantly better than the control 4 points: better than control 3 points: Equivalent to control 2 points: Inferior to control 1 point: Significantly worse than the control

[0085] [Table 7]

[0086] As shown in Table 7, the test sample, which contained 30% by mass of a branched α-glucan mixture and replaced half of the κ-carrageenan used as a gelling agent with locust bean gum, had a smoother gel cross-section and a better texture when crushed with the tongue than the control jelly, which was gelled with κ-carrageenan alone. Figure 1 shows cross-sectional photographs of the control and test jelly samples. The control jelly exhibited a wavy cross-section, indicating the roughness of the gel, while the test sample exhibited a very smooth cross-section, demonstrating a clear visual difference. These results demonstrate that when a branched α-glucan mixture is incorporated into a gel composition at a high concentration, combining locust bean gum with κ-carrageenan, which is used as a gelling agent, reduces the roughness of the gel surface, improving both the appearance and texture, and providing a more desirable texture for a jelly food.

[0087] <Experiment 5: Improving the texture of lacto ice cream> In Experiments 1 to 3, it was found that the branched α-glucan mixture has the effect of suppressing syneresis of the gel composition. To investigate whether this property can be applied to other compositions with high water content, the mixture was blended with lacto ice cream and the properties of the composition were evaluated.

[0088] The samples were prepared as follows: 1.0 or 2.5 parts by mass of the same branched α-glucan mixture used in Experiment 1 was added to 14 parts by mass of sugar, followed by 0.2 parts by mass of emulsifier (trade name "Homogen", sold by San-Ei Gen F.F.I. Co., Ltd.) and 0.3 parts by mass of stabilizer (trade name "Sunbest NN-305", sold by San-Ei Gen F.F.I. Co., Ltd.) and mixed. Next, 58 parts by mass of milk, 15 parts by mass of fresh cream, and 10 parts by mass of egg yolk were added, heated to 85°C, sterilized, and then pre-emulsified by mixing in a mixer for 10 minutes. After that, the mixture was homogenized at 150 kg / cm using a high-pressure homogenizer. 2 The mixture was emulsified and cooled under the above conditions, and then frozen at -20°C while stirring in an ice cream freezer to produce lacto ice cream. Additionally, lacto ice cream obtained in the same manner as above, except that no branched α-glucan was added, served as a control.

[0089] The sensory test was conducted by a trained panel of six people (three men and three women), and the results are shown in Table 8. The ease of spooning, melting in the mouth, and flavor were evaluated relative to the control using the following criteria: ◎ is 3 points, ○ is 2 points, △ is 1 point, and × is 0 point, and the symbol representing the average score (rounded to the nearest decimal place) of the six panelists is shown in Table 8 as the evaluation of that sample. The overrun was calculated using the following formula. Overrun (%) = [(Wm-Wp) / Wp] x 100 Wm: Weight of mix before freezing (g) Wp: Weight (g) of the same volume of product (ice milk) <Spoonful> ◎: Easy to use ○: Fairly easy to handle △: Equal ease of use to the control ×: Easier to eat than the control <Melting in the mouth> ◎: Smooth and melts in your mouth ○: Slightly smooth melting in the mouth △: Melts in the mouth just like the control ×: Melts in the mouth less than the control <flavor> ○: Enhances flavor △: Flavor equivalent to the control ×: Flavor is inferior to the control

[0090] [Table 8]

[0091] As shown in Table 8, the lacto ice cream containing the branched α-glucan mixture had better spoonability and melt-in-the-mouth feel than the control. Microscopic observations have confirmed that this branched α-glucan has the property of stabilizing ice crystals and also of causing the ice crystals to pack in a partially non-uniform manner, and it is speculated that these properties may have improved the spoonability and melt-in-the-mouth feel of frozen desserts such as ice cream.

[0092] <Experiment 6: Evaluation of the hydration potential of water-soluble polysaccharides by pulsed NMR> The above experiments 1 to 3 clarified that this branched α-glucan mixture has the effect of suppressing syneresis and improving texture. Since all of the compositions used in these experiments had a high water content, and the interaction between the branched α-glucan mixture and water was considered to be an important factor in exhibiting its performance, the interaction between the water-soluble polysaccharide and water molecules in an aqueous solution state was investigated using pulsed NMR.

[0093] For the measurements, the branched α-glucan mixture and resistant dextrin (Fibersol 2) used in Experiment 1 were used, as well as dextran (trade name "Dextran T3.5" sold by Pharmacosmos, average molecular weight 3,500). Resistant dextrin (Fibersol 2) was used as a model for hyperbranched polysaccharides that contain primarily α-1,4 bonds but also α-1,2 and α-1,3 bonds in addition to α-1,6 bonds. Resistant dextrin is a water-soluble dietary fiber prepared by enzymatically hydrolyzing roasted dextrin, obtained by treating starch with hydrochloric acid, with α-amylase and glucoamylase. Dextran was used as a model for polysaccharides that essentially contain only α-1,6 bonds.

[0094] A JEOL JMM-MU25 pulsed NMR spectrometer was used. Each polysaccharide was dissolved in ultrapure water at 5, 10, 15, 20, and 25% by mass / volume, and 1 ml of the solution was transferred to a dedicated glass tube for measurement. Ultrapure water was used as a control. The spin-spin relaxation time (T2 relaxation time) measurements were performed at room temperature using the following measurement parameters: RF pulse interval (Pi1) of 1.0 ms, signal integration number (SCAN) of 8, pulse sequence repetition time (REP) of 5.0 s, number of consecutive RF pulses (LOOP) of 1,000, and pulse width (PW1) of 2.0 μs. The T2 relaxation time was fitted to multiple components using the analysis software provided with the JMM-MU25. Using a Lorentzian function, the T2 relaxation time of each component and its percentage were calculated.

[0095] In this measurement, for example, the Journal of the Crop Science Society of Japan, Vol. 77, No. 4, pp. 527-532, 1 As shown in "Monitoring the Temperature Response of Crops by H-NMR" (Inoue Mari, 2008), the free induction decay signal can be separated into three components with different T2 relaxation times, namely, short, medium, and long components, and these components are interpreted as representing bound water, medium water, and free water, in order of shortest T2 relaxation time. Figure 2 shows a graph comparing the ratio of the short component, which represents the amount of bound water in aqueous polysaccharide solutions.

[0096] As shown in Figure 2, in the aqueous solution of this branched α-glucan mixture, the ratio of short components, which are thought to represent the amount of bound water, was significantly higher than that of other polysaccharides in the range of 5 to 25% by mass to volume, and this value even exceeded that of dextran, which is composed only of α-1,6 bonds and is thought to easily form hydrogen bonds with water molecules.

[0097] Based on the short component ratios of T2 relaxation times shown in Figure 2, the estimated bound water content of each polysaccharide in a 15% by mass / volume aqueous solution was calculated, ignoring the presence of polysaccharide-derived protons. The bound water content per mass of each polysaccharide was 0.302 g / g for the branched α-glucan mixture, 0.256 g / g for the resistant dextrin (Fibersol 2), and 0.266 g / g for dextran. This indicates that the branched α-glucan mixture retains more than 10% more bound water than dextran. Although the detailed molecular behavior of this phenomenon is unknown, the complex, multi-branched structure unique to the branched α-glucan mixture is presumed to contribute to the retention of bound water. This is considered to be the main reason for the high syneresis suppression effect when incorporated into gel compositions. Furthermore, the hydration properties resulting from this structure are thought to be an important factor in the characteristic texture changes observed in other applications.

[0098] The syneresis inhibitor of the present invention, which contains the branched α-glucan mixture as an active ingredient, and its uses will be described in detail below with reference to examples, but the present invention is not limited to these examples in any way. [Example]

[0099] <Synthesization inhibitor> According to the method described in Example 5 of WO 2008 / 136331, sodium bisulfite was added to a 27% by mass corn starch liquefaction solution (3.6% hydrolysis rate) to a final concentration of 0.3% by mass and calcium chloride to a final concentration of 1 mM. The mixture was then cooled to 50°C. A concentrated crude enzyme solution of α-glucosyltransferase derived from Bacillus circulans PP710 (FERM BP-10771), prepared as described in Example 1 of WO 2008 / 136331, was added at 11.1 units per gram of solids and reacted at 50°C and pH 6.0 for 48 hours. The reaction mixture was then kept at 80°C for 60 minutes, cooled, and filtered. The filtrate was decolorized with activated carbon, desalted with H-type and OH-type ion resins, purified, concentrated, and spray-dried to produce a branched α-glucan mixture. The obtained branched α-glucan mixture was analyzed by the α-glucosidase and glucoamylase digestion test method described in paragraph 0080 of International Publication No. WO2008 / 136331, the methylation analysis method described in paragraphs 0076 to 0078, the isomaltodextranase digestion test method described in paragraph 0079, and the high-performance liquid chromatography method for determining water-soluble dietary fiber content (enzyme-HPLC method) described in paragraphs 0069 to 0075. The mixture was found to have the following characteristics (a) to (d). (a) Its constituent sugar is glucose. (i) It has a branched structure with a glucose polymerization degree of 1 or more linked via a bond other than an α-1,4 bond to a non-reducing terminal glucose residue located at one end of a linear glucan with a glucose polymerization degree of 3 or more linked via an α-1,4 bond. (c) Digestion with isomaltodextranase produces isomaltose at 37% by mass per solid of the digest. (e) The water-soluble dietary fiber content is 80.2% by mass.

[0100] Furthermore, the results of the analysis using the above-mentioned methylation analysis method revealed that the branched α-glucan mixture has the following characteristics (e) to (h) in addition to the above-mentioned characteristics. (e) The ratio of α-1,4-linked glucose residues to α-1,6-linked glucose residues is 1:2.5. (f) The sum of α-1,4-linked glucose residues and α-1,6-linked glucose residues accounts for 69.3% of all glucose residues. (g) α-1,3-linked glucose residues account for 2.3% of all glucose residues. (H) α-1,3,6-linked glucose residues account for 6.0% of all glucose residues.

[0101] Furthermore, the molecular weight distribution of the obtained branched α-glucan mixture was analyzed using the conventional gel filtration HPLC method described in paragraph 0081 of International Publication No. WO2008 / 136331, and it was found that in addition to the above characteristics, this branched α-glucan mixture also has the following characteristics (K) and (K). (i) The mass average molecular weight is 4,430. (J) Mw / Mn is 2.0.

[0102] As described above, the branched α-glucan mixture obtained in this example satisfied the aforementioned characteristics (A) to (E) that characterize this branched α-glucan mixture.

[0103] Furthermore, the branched α-glucan mixture obtained in this example also satisfied the above-mentioned characteristics (F) and (G) that characterize this branched α-glucan mixture.

[0104] Furthermore, the branched α-glucan mixture met the characteristic that Mw / Mn was less than 20.

[0105] This product can be incorporated into foods, cosmetics, pharmaceuticals, etc., and can be widely used as a syneresis inhibitor, either alone or mixed with other appropriate ingredients. It is also highly water-soluble, and its aqueous solution is colorless and transparent. Due to its high dietary fiber content, it can also be used in foods for nutritional enhancement. This product is a white powder that is tasteless and odorless, does not absorb moisture or discolor, and is stable for over a year at room temperature. [Example]

[0106] <Synthesization inhibitor> A branched α-glucan mixture powder was prepared according to the method described in Example 3 of International Publication No. WO2008 / 136331. The obtained branched α-glucan mixture powder had the following characteristics (A) to (K). (a) Its constituent sugar is glucose. (i) It has a branched structure with a glucose polymerization degree of 1 or more linked via a bond other than an α-1,4 bond to a non-reducing terminal glucose residue located at one end of a linear glucan with a glucose polymerization degree of 3 or more linked via an α-1,4 bond. (c) Digestion with isomaltodextranase produces isomaltose at 36.5% by mass per solid of the digest. (e) The water-soluble dietary fiber content determined by high performance liquid chromatography (enzyme-HPLC method) is 79.4% by mass. (e) The ratio of α-1,4-linked glucose residues to α-1,6-linked glucose residues is 1:2.5. (f) The sum of α-1,4-linked glucose residues and α-1,6-linked glucose residues accounts for 68.4% of all glucose residues. (g) α-1,3-linked glucose residues account for 2.6% of all glucose residues. (H) α-1,3,6-linked glucose residues account for 6.8% of all glucose residues. (i) The mass average molecular weight is 4,097. (J) Mw / Mn is 2.1.

[0107] As described above, the branched α-glucan mixture obtained in this example satisfied the characteristics (A) to (E) that characterize this branched α-glucan mixture, as well as the characteristics (F) and (G) described above.

[0108] This product can be widely used as a syneresis inhibitor because it can be incorporated into foods, cosmetics, pharmaceuticals, etc., similar to the branched α-glucan mixture prepared in Example 1. This product is tasteless and odorless, does not absorb moisture or discolor even at room temperature, and is stable for more than one year. [Example]

[0109] <Synthesization inhibitor> A branched α-glucan mixture powder was prepared according to the method described in Example 6 of International Publication No. WO2008 / 136331. The obtained branched α-glucan mixture powder had the following characteristics (A) to (K). (a) Its constituent sugar is glucose. (i) It has a branched structure with a glucose polymerization degree of 1 or more linked via a bond other than an α-1,4 bond to a non-reducing terminal glucose residue located at one end of a linear glucan with a glucose polymerization degree of 3 or more linked via an α-1,4 bond. (c) Digestion with isomaltodextranase produces isomaltose at 32.7% by mass per solid of the digest. (e) The water-soluble dietary fiber content determined by high performance liquid chromatography (enzyme-HPLC method) is 80.7% by mass. (e) The ratio of α-1,4-linked glucose residues to α-1,6-linked glucose residues is 1:3.4. (f) The sum of α-1,4-linked glucose residues and α-1,6-linked glucose residues accounts for 66.7% of all glucose residues. (g) α-1,3-linked glucose residues account for 2.8% of all glucose residues. (h) α-1,3,6-linked glucose residues account for 7.6% of all glucose residues. (i) The mass average molecular weight is 4,860. (J) Mw / Mn is 2.1.

[0110] As described above, the branched α-glucan mixture obtained in this example satisfied the characteristics (A) to (E) that characterize this branched α-glucan mixture, as well as the characteristics (F) and (G) described above.

[0111] This product is a white powder with excellent fluidity and is itself tasteless and odorless, similar to the branched α-glucan mixtures prepared in Examples 1 and 2. In addition, it has low hygroscopicity, heat stability, and good cold water solubility, making it suitable for incorporation into foods, cosmetics, pharmaceuticals, etc., and therefore can be widely used as a syneresis inhibitor. [Example]

[0112] <Syneresis Inhibition of Orange Jelly> 930 parts by weight of orange juice was heated to 85°C, and 8 parts by weight of κ-carrageenan (trade name "Carrageenin CSK-1", sold by San-Ei Gen F.F.I. Co., Ltd.), 20 parts by weight of sugar, and 50 parts by weight of the branched α-glucan mixture obtained by the method of Example 1 as a syneresis inhibitor were added and dissolved with stirring for 15 minutes. After cooling to 60°C, 1 part by weight of 2-O-α-D-glucosyl-L-ascorbic acid (trade name "Ascofresh", manufactured by Hayashibara Co., Ltd.) was added and dissolved with stirring. The resulting mixture was filled into containers and stored refrigerated to obtain orange jelly. This product had a good texture and flavor, and due to the water-retaining effect of the branched α-glucan mixture, syneresis was inhibited even after storage at 4°C for 14 days, making it a stable, high-quality orange jelly. [Example]

[0113] <Syneresis Suppression of Drink-Type Jelly> 842 parts by weight of water, 55 parts by weight of sugar, 15 parts by weight of trehalose (trade name "Treha", manufactured by Hayashibara Co., Ltd.), 6 parts by weight of a gelling agent (trade name "Inagel DJ-88K", manufactured by Ina Food Industry Co., Ltd.), and 0.6 parts by weight of calcium lactate as a gelling aid were heated and dissolved at 85°C for 5 minutes, and then 60 parts by weight of 5x concentrated orange juice, 15 parts by weight of a 15% by volume citric acid aqueous solution, 1 part by weight of flavoring, and 5 parts by weight of the branched α-glucan mixture obtained by the method of Example 2 as a syneresis suppression agent were added and mixed. The mixture was filled into a plastic container with a drinking spout, sterilized at 80°C for 20 minutes, and cooled to obtain an orange-flavored drink-type jelly. This product was a high-quality drink jelly with a good texture and flavor, and the branched α-glucan mixture's ability to retain water was demonstrated, resulting in long-term suppression of syneresis. [Example]

[0114] <Gel-type cosmetics> 0.8 parts by mass of a synthetic water-soluble thickener, acrylates / C10-30 alkyl acrylate crosspolymer (trade name "Akupec HV501" sold by Sumitomo Seika Chemicals Co., Ltd.), was dissolved in 40 parts by mass of purified water, and an appropriate amount of sodium hydroxide solution was added to neutralize and gelate the mixture. 6.0 parts by mass of concentrated glycerin, 3.0 parts by mass of pentylene glycol, 2.0 parts by mass of 1,3-butylene glycol, 3.0 parts by mass of dipropylene glycol, and polyethylene glycol-8, which had been previously dissolved in 20 parts by mass of purified water, were added to the mixture. 1.5 parts by mass of the branched α-glucan mixture from Example 1 and 4.0 parts by mass of the branched α-glucan mixture from Example 1 were added and mixed thoroughly. An aqueous solution prepared by dissolving 2 parts by mass of ascorbic acid 2-glucoside (Hayashibara Sales Co., Ltd., product name "AA2G (registered trademark)") in 10 parts by mass of purified water and adjusting the pH with an appropriate amount of aqueous sodium citrate solution was then added and mixed thoroughly. Finally, the pH was adjusted to 6.5 to 6.8 with aqueous sodium hydroxide solution, and the total parts by mass was adjusted to 100 with purified water to prepare a weakly acidic whitening gel cosmetic. Due to the properties of the branched α-glucan mixture, syneresis is suppressed for a long period of time without affecting the color or fragrance of the gel, resulting in a gel cosmetic with excellent feel and appearance. [Example]

[0115] <Improving the Texture of Sherbet> 300 parts by weight of mango puree, 185 parts by weight of water, 35 parts by weight of trehalose, 70 parts by weight of granulated sugar, and 1.5 parts by weight of the branched α-glucan mixture of Example 2 as a syneresis inhibitor were added and heated to completely dissolve the sugars. After cooling the mixture, the mixture was stirred in a sorbeteur (sherbet maker) while freezing to produce mango sherbet. A control sherbet was also prepared using the same method as above, except that the branched α-glucan mixture was not added. Compared to the control, the sherbet of the present invention had a smoother texture with less crunchiness from the ice crystals and a better melt-in-the-mouth texture. This branched α-glucan mixture can improve the texture of frozen desserts by modifying the packing pattern of the ice crystals. [Example]

[0116] <Improving the Quality of Ice Cream> 3 parts by weight of skim milk powder, 10 parts by weight of sugar, and 4 parts by weight of trehalose were added to 8 parts by weight of the branched α-glucan mixture of Example 1 and mixed thoroughly. Then, 55 parts by weight of milk, 18 parts by weight of cream, 2 parts by weight of egg yolk, and 0.2 parts by weight of emulsifier were added and stirred in a mixer while heating until the solids were completely dissolved. 0.1 parts by weight of vanilla extract was added as a flavoring, and the mixture was sterilized by heating at 90°C. The mixture was then cooled again for aging, and frozen while stirring in an ice cream freezer to produce ice cream. A control was a sorbet obtained in the same manner as above, except that the branched α-glucan mixture was not added. Both were stored in a freezer at -20°C. Compared to the control, the ice cream containing the syneresis inhibitor of the present invention exhibited a uniform spooning experience, a smooth melting sensation, and a high quality with minimal frosting on the surface during storage. [Example]

[0117] <Improvement of Texture of Fruit Juice-Containing Ice Confection> 30 parts by weight of sugar, 20 parts by weight of trehalose, 0.1 parts by weight of flavoring, and 0.5 parts by weight of the branched α-glucan mixture of Example 2 were completely dissolved in 600 parts by weight of grapefruit juice and 350 parts by weight of water. The mixture was stirred while frozen in a sorbeteur (sherbet maker) to produce grapefruit-flavored sherbet, which was then filled into plastic cups and stored in a freezer at -20°C. A control ice confection was also prepared using the same method as above, except that the branched α-glucan mixture was not added. The ice confection of the present invention has a low solids content and sugar content, and is characterized by a refreshing, low sweetness and the texture of the ice itself. Compared to the control, the ice chunks were smaller and more uniform, and the ice melted easily in the mouth. [Example]

[0118] <Improvement of Gelato Quality> 22 parts by weight of sugar, 12 parts by weight of trehalose, 0.8 parts by weight of pectin, and 1 part by weight of the branched α-glucan mixture of Example 1 were added to 100 parts by weight of peach juice, 30 parts by weight of milk, and 35 parts by weight of water, and the mixture was stirred and mixed while heating in a mixer until the solids were completely dissolved. After sterilization by heating at 90°C, the mixture was cooled again and aged, and then frozen while stirring in an ice cream freezer to produce gelato. A gelato obtained in the same manner as above, except that the branched α-glucan mixture was not added, served as a control, and both were stored in a freezer at -20°C. Compared to the control, the gelato prepared using the syneresis inhibitor of the present invention was of high quality, with an easy spoonful and smooth melt-in-the-mouth texture. [Example]

[0119] <Gel base for topical skin application> Ingredients (parts by weight) (1) Trioctanoin 50.0 (2) Branched α-glucan mixture prepared in Example 1 8.0 (3) Polyglyceryl-10 monomyristate 5.2 (4) Polyglyceryl-10 monostearate 1.75 (5) Ascorbic acid 2-glucoside 1.0 (6) Licorice extract 0.1 (7) Hyaluronic acid 0.25 (8) 1,2-pentanediol 0.1 (9) Fragrance (as needed) Add purified water to bring the total to 100 parts by weight.

[0120] The gel base for topical skin application in the above formulation example can sustainably exert the desired action effects by appropriately blending active pharmaceutical ingredients, and since the syneresis-inhibiting effect of the branched α-glucan suppresses syneresis for a long period of time, it is a high-quality pharmaceutical gel base with excellent stability. [Example]

[0121] <Ice Pack> 20 parts by weight of the branched α-glucan mixture prepared in Example 2 as a syneresis inhibitor were added to 0.8 parts by weight of agar and 2.0 parts by weight of sodium chloride, and the mixture was dissolved by heating with an appropriate amount of water. Water was then added to adjust the total volume to 100 parts by weight, and the mixture was filled into a flexible plastic package and cooled to gel, producing an ice pack. This was stored frozen in a -20°C freezer for one week, and then repeatedly frozen and thawed at room temperature to evaluate its appearance and performance. The ice pack containing the syneresis inhibitor of the present invention maintained its gel shape and transparency even after repeated freezing and thawing, and no syneresis was observed, demonstrating no change in its ice-keeping performance. This ice pack is not limited to uses in food, cosmetics, pharmaceuticals, industrial applications, etc., but because it is made from food ingredients, it is a highly durable ice pack suitable for repeated use and can be safely used with food and beverages. [Industrial Applicability]

[0122] As explained above, according to the present invention, it is possible to provide a syneresis inhibitor that can be used for a variety of purposes without impairing the original color, flavor, and texture of food. Furthermore, the present invention can provide a syneresis inhibitor that can be used safely and advantageously not only in food but also in the fields of cosmetics, quasi-drugs, pharmaceuticals, industrial products, etc., and its uses. Products using the syneresis inhibitor of the present invention are highly valuable as commercial products, and this is a truly significant invention that will make a great contribution to this field. [Explanation of symbols]

[0123] In Figure 1, A: Control gel (containing 30% by mass of a branched α-glucan mixture and 1.0% by mass of κ-carrageenan as a gelling agent) B: Test gel (containing 30% by mass of a branched α-glucan mixture and 0.5% by mass of κ-carrageenan and 0.5% by mass of locust bean gum as gelling agents) In Figure 2, a: Branched α-glucan mixture b: Indigestible dextrin c: dextran

Claims

1. A syneresis inhibitor for a gel composition containing carrageenan and / or agar as a gelling agent, the gel composition comprising a branched α-glucan mixture having the following characteristics (A) to (E) as an active ingredient: (A) glucose as a constituent sugar; (B) has a branched structure with a glucose polymerization degree of 1 or more linked via a bond other than an α-1,4 bond to a non-reducing terminal glucose residue located at one end of a linear glucan with a glucose polymerization degree of 3 or more linked via an α-1,4 bond; (C) producing isomaltose in an amount of 25% by mass or more and 50% by mass or less based on the solid content of the digestion product by isomaltodextranase digestion; (D) the ratio of α-1,4-linked glucose residues to α-1,6-linked glucose residues is in the range of 1:0.6 to 1:4; and (E) The sum of α-1,4-linked glucose residues and α-1,6-linked glucose residues accounts for 60% or more of the total glucose residues.

2. The syneresis inhibitor according to claim 1, wherein the branched α-glucan mixture further has the following characteristics (F) and (G): (F) α-1,3-linked glucose residues are 0.5% or more but less than 10% of all glucose residues; and (G) α-1,3,6-linked glucose residues account for 0.5% or more of the total glucose residues.

3. 3. The syneresis inhibitor according to claim 1, wherein the water-soluble dietary fiber content of the branched α-glucan mixture determined by high performance liquid chromatography (enzyme-HPLC) is 40% by mass or more.

4. The syneresis inhibitor according to any one of claims 1 to 3, characterized in that the value (Mw / Mn) obtained by dividing the mass average molecular weight (Mw) of the branched α-glucan mixture by the number average molecular weight (Mn) is less than 20.

5. A food product in the form of a gel composition containing the syneresis inhibitor according to any one of claims 1 to 4 and containing carrageenan and / or agar as a gelling agent.

6. 6. The food product according to claim 5, wherein the product contains 0.2 to 30% by mass of a branched α-glucan mixture as an active ingredient of a syneresis inhibitor.

7. 7. The food product according to claim 5, having a water content of 60% by mass or more.

8. 7. The food according to claim 6, comprising carrageenan and locust bean gum as gelling agents, and a branched α-glucan mixture as an active ingredient of the syneresis inhibitor in an amount of 10% by mass or more of the composition.

9. A frozen dessert comprising milk and dairy products, and containing 1 to 5% by mass of a branched α-glucan mixture as an active ingredient of a syneresis inhibitor, characterized by having good melt-in-the-mouth properties and being easy to spoon (excluding, however, frozen desserts containing 1 to 2% by mass of a branched α-glucan mixture and frozen desserts containing 5% by mass of a branched α-glucan mixture).

10. A method for inhibiting syneresis of a gel composition containing carrageenan and / or agar as a gelling agent, the method comprising incorporating a branched α-glucan mixture having the following characteristics (A) to (E) into the gel composition: (A) glucose as a constituent sugar; (B) has a branched structure with a glucose polymerization degree of 1 or more linked via a bond other than an α-1,4 bond to a non-reducing terminal glucose residue located at one end of a linear glucan with a glucose polymerization degree of 3 or more linked via an α-1,4 bond; (C) producing isomaltose in an amount of 25% by mass or more and 50% by mass or less based on the solid content of the digestion product by isomaltodextranase digestion; (D) the ratio of α-1,4-linked glucose residues to α-1,6-linked glucose residues is in the range of 1:0.6 to 1:4; and (E) The sum of α-1,4-linked glucose residues and α-1,6-linked glucose residues accounts for 60% or more of the total glucose residues.

11. The method for inhibiting syneresis according to claim 10, wherein the branched α-glucan mixture further has the following characteristics (F) and (G): (F) α-1,3-linked glucose residues are 0.5% or more but less than 10% of all glucose residues; and (G) α-1,3,6-linked glucose residues account for 0.5% or more of the total glucose residues.

12. The syneresis suppression method according to claim 10 or 11, wherein the water-soluble dietary fiber content of the branched α-glucan mixture determined by high performance liquid chromatography (enzyme-HPLC) is 40% by mass or more.

13. The method for suppressing syneresis according to any one of claims 10 to 12, characterized in that the value (Mw / Mn) obtained by dividing the mass average molecular weight (Mw) of the branched α-glucan mixture by the number average molecular weight (Mn) is less than 20.

14. The method for inhibiting syneresis according to any one of claims 10 to 13, wherein the gel composition is in the form of a food product.

15. 15. The method for inhibiting syneresis according to claim 14, wherein the product contains a branched α-glucan mixture as an active ingredient of the syneresis inhibitor in an amount of 0.2 to 30% by mass.

16. The method for inhibiting syneresis according to claim 14 or 15, wherein the water content of the food is 60% by mass or more.

17. the food product contains carrageenan and locust bean gum as gelling agents; The syneresis suppression method according to claim 15, wherein the product contains a branched α-glucan mixture as an active ingredient of the syneresis suppressant in an amount of 10% by mass or more.

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