Method for producing glucomannan processed foods with high protein content

Abstract

To provide konjak-like food with high protein content, while utilizing the advantages of konjac, which has a unique texture and a low caloric value.SOLUTION: A liquid mixture contains 0.3 w / w% or more and 2.5 w / w% or less of glucomannan, 0.2 w / w% or more and 2.5 w / w% or less of alginic acid and / or a salt thereof, and 3.0 w / w% or more and 12.0 w / w% or less of vegetable protein, optionally containing 0.1 w / w% or more and 1.5 w / w% or less of xanthan gum, and substantially free of gluten. The liquid mixture is discharged into an aqueous solution containing divalent cations to produce a gel-like product.SELECTED DRAWING: None

Description

Technical Field

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[0006]

[0001] The present invention relates to a food containing glucomannan and protein.

Background Art

[0002] Konjac is obtained by gelatinizing konjac flour mainly composed of glucomannan and solidifying it with calcium. Since glucomannan is indigestible and low in calories, it has attracted attention as a so-called diet food used for weight loss and promoting defecation.

[0003] However, on the other hand, konjac does not contain protein, which is a major nutrient. In fact, athletes who need to strengthen their muscles consume nutritional foods called protein preparations containing milk protein or soy protein, and for the elderly with frailty (a state of physical and mental decline due to aging) and those who need to restrict carbohydrate intake, foods that are low in carbohydrates and fats but can provide a lot of protein are desired.

[0004] Under such circumstances, products containing protein in konjac have been put on the market (Non-Patent Documents 1 and 2). For example, there is thread-like konjac containing protein sold by the applicant. This thread-like konjac is produced by adding calcium hydroxide and milk protein to a gelatinized solution of konjac flour and pouring it into hot water in the form of noodle threads.

[0005] However, according to such a conventional method for producing konjac, the resulting konjac can contain only about 2 w / w% of protein, and at most 3 w / w% empirically.

[0006] Incidentally, it is a known technique to produce gel-like foods by contacting a mixture (or blend) containing alginate and glucomannan with a calcium salt (calcium ions). For example, Japanese Patent Publication No. 61-166378 (Patent Document 1) discloses obtaining a freeze-storable konjac-like gel-like food by adding a mixture containing sodium alginate and konjac powder to an aqueous calcium chloride solution, and Japanese Patent Publication No. 2020-036538 (Patent Document 2) discloses obtaining a gel-like substance by adding a mixture containing glucomannan, sodium alginate, and xanthan gum to a calcium chloride solution, and then drying it to obtain a dry product that rehydrates well.

[0007] Furthermore, Japanese Patent Publication No. 56-55162 (Patent Document 3) discloses that a noodle-like food coagulation having the texture of konjac can be obtained by adding a paste-like mixture containing sodium alginate or sodium pectin salt and various foods containing casein, soy protein, and other proteins to an aqueous solution of water-soluble calcium salt. Japanese Patent Publication No. 2002-209554 (Patent Document 4) discloses that a gel-like food can be obtained by adding a viscous liquid, to which proteins such as gelatin and collagen, dietary fiber, and polysaccharides have been added to a mixture containing glucomannan, sodium alginate, and thickening polysaccharides such as xanthan gum, to a calcium chloride solution. Japanese Patent Publication No. 2011-120541 (Patent Document 5) discloses that soy noodles can be obtained by dispensing a mixture containing sodium alginate and curdlan, to which okara powder, dietary fiber, and konjac powder have been added, into a calcium chloride solution.

[0008] However, the gel-like food described in Patent Document 1 discloses a technique to improve freeze resistance using alginate and konjac powder or xanthan gum, and in the examples, starch is used, so the advantage of konjac as a low-calorie food is not utilized. Furthermore, although examples using wheat protein are disclosed, wheat protein's main component is gluten, and using it causes the mixture containing glucomannan and other ingredients to become too sticky during exhalation, making it impossible to exhale in a noodle-like shape. Moreover, it increases the likelihood of causing allergies when consumed, so it is desirable that the product be gluten-free.

[0009] While Patent Document 2 provides a konjac-like food product, this technology improves the rehydration of the resulting gel-like food product, and does not describe or suggest the inclusion of protein.

[0010] Patent Document 3 attempts to create a food with a konjac-like texture by utilizing the property of alginates to coagulate upon contact with calcium salts, and incorporating non-coagulating substances such as casein, soy protein, and various starches. Patent Document 3 also describes examples containing sodium alginate, glucomannan, and raw kelp, but the protein content of raw kelp is low, and there is no disclosure of a food containing 3 w / w% or more of protein.

[0011] Although Patent Document 4 discloses a dried product using sodium alginate, glucomannan, and locust bean gum as an example, it is either a dried product that does not contain protein, or one that contains rice bran which contains only a small amount of protein, and there is no disclosure of a food product containing 3 w / w% or more of protein. Similarly, the soy noodles disclosed in Patent Document 5 also contain okara powder, but the protein content in the okara powder is about 25%, and the protein content in these soy noodles is thought to be at most about 2 w / w%. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] Japanese Patent Publication No. 166378 / 1983 [Patent Document 2] Japanese Patent Publication No. 2020-036538 [Patent Document 3] Japanese Patent Publication No. 2002-209554 [Patent Document 4] Japanese Patent Publication No. 2002-209554 [Patent Document 5] Japanese Patent Publication No. 2011-120541 [Non-patent literature]

[0013] [Non-Patent Document 1] Nakao Foods Industry, Product Introduction "Beautiful Gut Konjac", [online], [Searched December 26, 2022], Internet <URL:https: / / nakaoshokuhin.co.jp / merchandise / %e7%be%8e%e8%85%b8%e3%81%93%e3%82%93%e3%81%ab%e3%82%83%e3%81%8f / > [Non-Patent Document 2] Nakao Foods Industry, Product Introduction "SHAPE MEN", [online], [Searched December 26, 2022], Internet <URL:https: / / nakaoshokuhin.co.jp / merchandise / shape-men%ef%bc%88%e3%82%b7%e3%82%a7%e3%82%a4%e3%83%97%e3%83%a1%e3%83%b3%ef%bc%89180g / > [Overview of the project] [Problems that the invention aims to solve]

[0014] The problem that this invention aims to solve is to provide a konjac-like food that is rich in protein while taking advantage of the benefits of konjac, such as its unique texture and low calorie content. [Means for solving the problem]

[0015] The present invention is characterized in that a mixed solution containing glucomannan, alginic acid and / or its salt, and vegetable protein is discharged into a solution containing divalent cations to obtain a gel-like substance.

Effects of the Invention

[0016] According to the present invention, there are provided a gel-like food having a konjac-like texture containing a high concentration of vegetable protein, and a dried product that can be rehydrated to a gel-like food having a konjac-like texture.

Embodiments for Carrying Out the Invention

[0017] The production method of the present invention is a method for producing a gel-like food having a konjac-like texture with a high protein content, and further a dried product that becomes a gel-like food having a konjac-like texture with a high protein content when rehydrated.

[0018] The production method of the present invention has a step of discharging a mixed solution containing glucomannan, alginic acid and / or alginate, and vegetable protein serving as a protein source into a solution of divalent cations, preferably a solution that does not show alkalinity, to cause gelation.

[0019] Glucomannan is a polysaccharide that is the main component of konjac powder. The glucomannan used in the present invention does not have to be a polysaccharide purified from raw materials such as konjac tubers and mukago tubers, and may be refined powder or crude powder used in the production of konjac as referred to as konjac powder in the industry. In addition, as disclosed in Japanese Patent Laid-Open No. 62-*163664*, it is not necessary to be a derivative obtained by treating glucomannan or konjac powder.

[0020] Alginic acid is a polysaccharide contained in brown algae and the like. Its salts include, for example, sodium salt, potassium salt, calcium salt, magnesium salt, ammonium salt, and may also be a mixture thereof. Preferably, it is a water-soluble alginate, and sodium salt and potassium salt are preferably used. In addition, alginic acid and alginate may be used in combination.

[0021] The plant from which the vegetable protein is derived is not particularly limited. However, gluten, which is one type of vegetable protein, not only tends to increase the viscosity of the mixture when mixed with water or the like, but can also be an allergen to humans as described above, so it is not used in the present invention. The gel-like substance in the present invention, that is, the mixture, does not substantially contain gluten. Here, "not substantially containing" means that gluten is not intentionally added during mixing, and it does not mean that there is no gluten at all even when gluten is accidentally mixed in the vegetable protein used. The vegetable protein that can be used in the present invention can be, for example, proteins derived from beans such as soybeans, peas, mung beans, and chickpeas, or hemp protein (protein derived from hemp). Also, for proteins derived from animals (animal proteins) such as whey protein and casein, when a mixture of glucomannan and alginic acid and / or alginate is added to an aqueous solution of divalent cations, it did not sufficiently gel even at a concentration of about 1 w / w%, so it is not used in the present invention.

[0022] The medium of the mixture in the production method of the present invention is preferably water, but water-soluble alcohols such as ethanol may be contained as long as a small amount does not affect gelation. The glucomannan, alginates, and vegetable protein used are such that in the mixture, the glucomannan is 0.3 w / w% or more and 2.5 w / w% or less, the alginates are 0.2 w / w% or more and 2.5 w / w% or less, and the protein is 3.0 w / w% or more and 12.0 w / w% or less. Hereinafter, the notation of "%" in this specification means w / w%. Also, when commercially available products are used for glucomannan, alginates, and vegetable protein, respectively, the concentration of each in the mixture is a value converted to a so-called purity of 100%. When these three components and the medium are mixed, it is not necessary for all of them to dissolve in the medium, but it is sufficient that the alginates are in a dissolved state, and heating may be performed as necessary during dispersion, or it may be at room temperature.

[0023] If the amount of glucomannan in the mixture is low, the konjac-like flavor and texture tend to deteriorate. If it is less than 0.3%, it may not be possible to form a gel, or the flavor and texture of the gel may deteriorate, which is undesirable. If the amount of glucomannan is high, the mixture tends to become viscous. If it is more than 2.5%, the moldability deteriorates, for example, it may not be possible to extrude it into noodle strands, which is undesirable. If the amount of alginates in the mixture is less than 0.2%, it may not be possible to incorporate more than 3.0% of protein, resulting in poor moldability, such as not being able to form good noodle strands. On the other hand, if the amount of alginates is high, the mixture becomes viscous, resulting in poor moldability, such as not being able to extrude it into noodle strands, and the flavor and texture also tend to deteriorate. If the amount of alginates is more than 2.5%, it is undesirable from the standpoint of moldability, flavor, and texture. Furthermore, while increasing the amounts of glucomannan and alginates individually can increase the protein content, if the protein content in the mixture exceeds 12.0%, it becomes undesirable because the protein may not dissolve or suspend uniformly, or the mixture may not be able to be extruded into noodle-like strands, resulting in poor moldability, as well as a tendency for the flavor and texture of the gel-like material to deteriorate.

[0024] The mass ratio of glucomannan to alginates in the mixture should ideally be between 1:3 and 3:1, meaning that glucomannan should be between 1 / 3 and 3 times the amount of alginates. Although this varies depending on the amount of protein added, when protein is added to a mixture of glucomannan and alginates, if the amount of glucomannan is less than the amount of alginates, the resulting gel tends to have a poor konjac-like flavor and texture. Similarly, if the ratio of the two exceeds 3.0, the konjac-like flavor and texture tend to deteriorate. Furthermore, if the amount of alginates is less than the amount of glucomannan, the moldability tends to be poor, and if the ratio of the two is less than 1 / 3, there is a strong risk that it will not be possible to form it into noodle-like strands, which is undesirable.

[0025] Although it varies depending on the amount of protein included, when a gel-like substance obtained from a mixture of glucomannan, alginates, and protein is dried, the higher the ratio of glucomannan to alginates, the less soft it becomes when rehydrated (i.e., immersed in water or hot water), resulting in a poor flavor and texture. A ratio of more than 3 is undesirable.

[0026] The mixture may contain flavoring agents as other components for coloring and flavoring. These flavoring agents may include, for example, colorants, fragrances, spices, dried seafood such as seaweed and hijiki, dried vegetables, and various seasonings such as soy sauce and sugar. The amount of flavoring agent can be appropriately determined within a range that does not affect the gelling and rehydration properties of the divalent cations in solution. These flavoring agents are thought to have little effect on the gelling ability of alginates; in this case, the amount may be, for example, 10 w / w% or less, 5 w / w%, 2 w / w%, 1 w / w%, 0.5 w / w%, or 0.1 w / w% in the mixture. Additionally, if necessary, a pH adjuster may be used to maintain the pH of the mixture at a neutral level of approximately 6.5 to 7.5.

[0027] On the other hand, the mixture does not preferably contain carbohydrates such as starch or lipids such as vegetable oil, which can serve as a source of calories. Including carbohydrates and lipids that serve as a source of calories would not only negate the advantages of konjac-like foods as a low-calorie food, but it may also prevent the production of a sufficient gel-like substance. Although commercially available glucomannan, alginates, vegetable proteins, and flavorings added to the mixture may contain carbohydrates and lipids, the above proportions are not expected to result in high levels of carbohydrates and lipids in the mixture, thus preserving the advantages of konjac-like foods as a low-calorie food. On the other hand, some commercially available vegetable proteins have low protein content, in which case the resulting gel-like substance will contain a high amount of carbohydrates and lipids that serve as a source of calories. Therefore, it is preferable to use commercially available products with a high protein content, and it is preferable to use commercially available products with a protein content of at least 50%, preferably 75%, or more, in order to achieve a high protein content.

[0028] The mixture preferably does not contain polysaccharides (thickening polysaccharides) other than xanthan gum, except when the resulting gel-like substance is dried to produce a dry product. Including various thickening agents, including xanthan gum, tends to increase the viscosity of the gel-like substance, resulting in a loss of the konjac-like texture, which is undesirable. On the other hand, when the resulting gel-like substance is dried to produce a dried food such as dried noodles, adding xanthan gum improves the texture and rehydration properties. In other words, it becomes easier to rehydrate the dried food with water or hot water to produce a konjac-like food (gel-like substance). It is preferable to use xanthan gum alone, as other thickening polysaccharides, such as carrageenan or guar gum, result in poor rehydration properties. The amount of xanthan gum in the mixture should be between 0.1% and 1.5%. Furthermore, other thickening polysaccharides such as carrageenan, guar gum, gellan gum, locust bean gum, and galactomannan can be used in place of a portion of the xanthan gum. In this case, it is necessary to include at least 0.1% xanthan gum in the mixture, and the proportion of xanthan gum in the total thickening polysaccharides, including xanthan gum, should be 30% or more, preferably 50% or more. Generally, thickening polysaccharides refer to polysaccharides that increase the viscosity of a mixture. However, in this invention, glucomannan and alginic acid derivatives are not treated as thickening polysaccharides.

[0029] The resulting mixture is discharged into a solution of divalent cations. The divalent cations only need to be able to gel alginates in solution, and are, for example, calcium ions, magnesium ions, or strontium ions, preferably calcium ions, because they produce a strong gel. The solution of the divalent cations is preferably an aqueous solution, obtained by dissolving its salt in water. The salt is preferably a non-alkaline, preferably nearly neutral, salt when prepared as an aqueous solution, and is, for example, calcium chloride, calcium lactate, or magnesium chloride, preferably calcium lactate or calcium chloride.

[0030] The concentration of the divalent cation solution can be appropriately determined as long as it is at a concentration that can gel the mixture. This will vary depending on the concentration of alginates in the mixture, but for example, when using calcium chloride or calcium lactate, it is generally around 0.1% to 20%, preferably 1% to 10%. The divalent cation solution does not require any special heating; it may be warmed, but it can be at room temperature.

[0031] The method of extrusion is not particularly limited as long as it allows for gelation in a solution of divalent cations. The shape after extrusion is also not limited; for example, a method that allows for extrusion in the form of noodles or thin plates is preferred, and granular shapes are also acceptable.

[0032] The resulting gel-like substance is separated from the divalent cation solution, or, if necessary, washed with water to remove calcium deposits from the surface without being separated from the divalent cation solution by adding a large amount of water to the divalent cation solution. For washing, room temperature water or cold water can be used. The gel-like substance thus obtained is then provided as is as a konjac-like food product.

[0033] When a mixture containing xanthan gum is gelled, the gel-like substance can be consumed after washing with water, but it is preferable to dry it. The drying method is not particularly limited, and examples include natural drying, hot air drying at 40-120°C, drying in a drying chamber at 60-120°C, and freeze-drying. However, considering the rehydration properties after drying, natural drying or drying with hot or warm air is preferable. Also, if the temperature is higher than 100°C, there is a strong risk of over-drying and inability to rehydrate, so it is preferable to dry at 100°C or lower. If it is extruded in the form of a thin sheet, it may be dried as is, but if necessary, it may be cut into noodle-like strands or wide noodles either before or after drying. However, it is also acceptable to use it as a dried food in the form of a thin sheet.

[0034] The dried product obtained by drying can be rehydrated and used as instant noodles or instant konjac rice, which have a konjac flavor and a texture similar to konjac. Rehydration can be done with room temperature water or seasoning liquid, but it is preferable to use water or seasoning liquid heated to 80-100°C. The resulting gel does not lose its shape or dissolve in water even when immersed in water for a long time, so it can be packaged and stored in water. Furthermore, the gel obtained by gelation can be frozen as is, or frozen with water or broth, and provided as so-called frozen food. The freezing temperature can be the same as that for general frozen foods, and can be done below freezing point, for example, around -80°C to -10°C. The resulting frozen product can be heated or microwaved to return it to a gel-like food and consumed. In addition to the gel, frozen food may also contain so-called soups, processed vegetables, or other ingredients.

[0035] Next, the present invention will be described in more detail based on the following examples, but it goes without saying that the present invention is not limited to the following examples. [Examples]

[0036] Based on the compositions shown in Tables 1-3, all components were added to water at room temperature (approximately 20°C) to prepare a mixture. This mixture was then extruded in a noodle-like form into a 5 w / v% calcium lactate aqueous solution at room temperature (approximately 20°C). The gel-like substance formed in the aqueous solution was removed and washed with running water at approximately 20°C. Next, it was dried using 80°C hot air to obtain dried noodles.

[0037] The state of the konjac extruded into the calcium lactate solution was evaluated on a three-point scale (○ if it was extruded in a good noodle-like shape, △ if it was extruded in a noodle-like shape but the extruded noodle-like shape was too hard or too soft, and × if the mixture was too hard or too soft and it could not be extruded in a noodle-like shape). Next, the texture of the resulting gel-like substance after washing was evaluated on a three-point scale (○ if the flavor and texture were good, △ if the flavor or texture was not good but it was still edible, and × if the flavor or texture was poor and it was difficult to eat). Furthermore, the dried noodles obtained by drying were immersed in 80°C water, and their rehydration properties, flavor, and texture were evaluated on a three-point scale (○ indicates that the noodles could be fully rehydrated with hot water and the flavor and texture were the same as before drying; △ indicates that the noodles could be rehydrated with hot water, but the flavor and texture were not the same as before drying, although they were still edible; and × indicates that the noodles could not be fully rehydrated with hot water and did not achieve an edible flavor or texture).

[0038] [Table 1]

[0039] [Table 2]

[0040] [Table 3] [Examples]

[0041] Based on the compositions shown in Tables 4 and 5, all components were added to water at room temperature (approximately 20°C) to prepare a mixture. Subsequently, the resulting gel-like substance and dried noodles were evaluated in the same manner as in Example 1.

[0042] [Table 4]

[0043] [Table 5] [Examples]

[0044] Based on the composition shown in Table 6, all components were added to water at room temperature (approximately 20°C) to prepare a mixture. Subsequently, the resulting gel-like substance and dried noodles were evaluated in the same manner as in Example 1.

[0045] [Table 6] [Industrial applicability]

[0046] A konjac-like food product with a high protein content, as well as its dried form, are provided.

Claims

1. The process includes a step of discharging a mixture containing glucomannan, alginic acid and / or its salt, and plant protein into an aqueous solution containing divalent cations to obtain a gel-like substance. The aforementioned mixture is Glucomannan in an amount of 0.3 w / w% to 2.5 w / w%, Alginic acid and / or its salts in an amount of 0.2 w / w% to 2.5 w / w% 3.0 w / w% to 12.0 w / w% of plant-based protein, Contains xanthan gum in an amount of 0.1 w / w% to 1.5 w / w%, The mass of glucomannan in the mixture is between 1 / 3 and 3 times the mass of alginic acid and / or its salt. A method for producing a gluten-free gel-like food.

2. A step of obtaining a gel-like substance by discharging a mixture containing glucomannan, alginic acid and / or its salt, and plant protein into an aqueous solution containing divalent cations, The process includes a step of drying the resulting gel-like substance. The aforementioned mixture is Glucomannan in an amount of 0.3 w / w% to 2.5 w / w%, Alginic acid and / or its salts in an amount of 0.2 w / w% to 2.5 w / w% Contains 3.0 w / w% to 12.0 w / w% of plant-derived protein. Contains xanthan gum in an amount of 0.1 w / w% to 1.5 w / w%, The mass of glucomannan in the mixture is between 1 / 3 and 3 times the mass of alginic acid and / or its salt. A method for producing gluten-free dried foods.

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