Defoaming agent for tofu and production method

Abstract

Provided are an antifoaming agent for tofu that is not restricted in use under the Food Sanitation Law and has an excellent antifoaming effect on the foam generated during the production of tofu and the like, and a method for producing the same. 【Solution means】An antifoaming agent for tofu and a method for producing the same, characterized in that a vegetable oil hydrolyzate having a composition of 5 to 16% by mass of free fatty acid, 1 to 4% by mass of monoacylglycerol, 13 to 30% by mass of diacylglycerol, and 55 to 80% by mass of triacylglycerol and an acid value of 10 to 30 is used as an active ingredient.

Description

Technical Field

[0001] The present invention relates to an antifoaming agent for tofu used in the production of soy milk, tofu, deep-fried bean curd, etc. (hereinafter sometimes abbreviated as tofu, etc.) and a method for producing the same.

Background Art

[0002] Since soybeans, which are the raw materials for tofu, are rich in surfactants such as proteins and saponins, the generation of foam (foaming) in the manufacturing process of tofu, etc. causes significant problems such as a decrease in production capacity and poor product quality. For example, the generation of foam during the steaming of soybean grindings, so-called "go", results in uneven heat transfer and tofu with inferior flavor and texture. Furthermore, the generation of foam during the conveyance of soy milk and the injection of soy milk into a soy milk tank significantly reduces the production capacity of tofu, etc. In addition, the generation of foam during the addition and dispersion of a coagulant to soy milk and during filling into a mold box or cup impairs the commercial value, and particularly in continuous lines in industrial production, a large amount is currently being discarded, resulting in a significant food loss.

[0003] In order to suppress such foaming and eliminate the generated foam, silicone resin-based antifoaming agents, glycerin fatty acid ester-based antifoaming agents, sorbitan fatty acid ester-based antifoaming agents, etc. are used. Silicone resin-based antifoaming agents are restricted in their usage amount in foods by the Food Sanitation Law and also have poor persistence of antifoaming performance. Glycerin fatty acid ester-based and sorbitan fatty acid ester-based antifoaming agents are treated as food additives for use as polyol fatty acid esters involving chemical reactions, i.e., for so-called emulsifier applications, and there are no usage restrictions under the Food Sanitation Law, and they are used as antifoaming agent formulations containing various ingredients.

[0004] Therefore, an antifoaming agent for tofu using glycerin fatty acid ester without usage restrictions under the Food Sanitation Law (Patent Document 1) and an antifoaming agent for tofu using sorbitan fatty acid ester (Patent Documents 2 and 3) have been proposed. However, these antifoaming agents for tofu are not necessarily satisfactory in terms of antifoaming performance, etc.

Prior Art Documents

Patent Documents

[0005] Patent Document 1 Japanese Patent No. 5789359 Patent Document 2 Japanese Patent No. 6129617 Patent Document 3 Japanese Patent No. 6448953 Summary of the Invention Problems to be Solved by the Invention

[0006] The present invention aims to provide an antifoaming agent for tofu that is not restricted in use under the Food Sanitation Law and has an excellent antifoaming effect on the foam generated during the production of tofu and the like, and a method for producing the same. Means for Solving the Problems

[0007] As a result of intensive studies on the above problems, the present inventors have found that the above problems can be solved by using a vegetable oil hydrolyzate having a specific composition as an active ingredient, and have completed the present invention.

[0008] That is, the present invention is the following invention. (1) An antifoaming agent for tofu, characterized in that it contains a vegetable oil hydrolyzate having a composition of 5 to 16% by mass of free fatty acids, 1 to 4% by mass of monoacylglycerol, 13 to 30% by mass of diacylglycerol, and 55 to 80% by mass of triacylglycerol, and an acid value of 10 to 30 as an active ingredient. (2) The antifoaming agent for tofu according to (1), further containing medium-chain fatty acid triglyceride, plant lecithin, magnesium carbonate and / or calcium carbonate. (3) The antifoaming agent for tofu according to (2), containing 55 to 65% by mass of vegetable oil hydrolyzate, 10 to 20% by mass of medium-chain fatty acid triglyceride, 10 to 15% by mass of plant lecithin, and 8 to 12% by mass of magnesium carbonate and / or calcium carbonate. (4) A method for producing a hydrolyzate of vegetable oil, characterized in that an aqueous solution of 1,3 - positional specific lipase, which is prepared by dissolving 1,3 - positional specific lipase as a lipid - degrading enzyme in water at 0.5 to 5.0% by mass based on the oil, is allowed to act on the vegetable oil, and the hydrolyzate of vegetable oil has a composition of 5 to 16% by mass of free fatty acid, 1 to 4% by mass of monoacylglycerol, 13 to 30% by mass of diacylglycerol, and 55 to 80% by mass of triacylglycerol, and an acid value of 10 to 30. (5) A step of allowing an aqueous solution of 1,3 - positional specific lipase, which is prepared by dissolving 1,3 - positional specific lipase as a lipid - degrading enzyme in water at 0.5 to 5.0% by mass based on the oil, to act on the vegetable oil to obtain a hydrolyzate of vegetable oil having a composition of 5 to 16% by mass of free fatty acid, 1 to 4% by mass of monoacylglycerol, 13 to 30% by mass of diacylglycerol, and 55 to 80% by mass of triacylglycerol, and an acid value of 10 to 30. A step of mixing the hydrolyzate of vegetable oil with medium - chain fatty acid triglyceride, plant lecithin, magnesium carbonate and / or calcium carbonate. A method for producing an antifoaming agent for tofu, characterized by comprising the above steps. (6) A method for producing tofu, characterized in that the antifoaming agent for tofu according to any one of (1) to (3) is used during the production of tofu.

Advantages of the Invention

[0009] The antifoaming agent for tofu of the present invention is excellent in defoaming action and can be used in the production of tofu and the like. In addition, since the antifoaming agent for tofu of the present invention uses a hydrolyzate of vegetable oil by an enzyme aqueous solution of vegetable oil as an active ingredient, it is treated in accordance with general food additives and has no use restrictions under the Food Sanitation Law.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0011] The defoaming agent for tofu of the present invention contains 5 to 16% by mass of free fatty acids, 1 to 4% by mass of monoacylglycerol, 13 to 30% by mass of diacylglycerol, and 55 to 80% by mass of triacylglycerol, and uses a vegetable oil hydrolyzate having an acid value of 10 to 30 as an active ingredient. In this specification, the defoaming agent for tofu refers to a defoaming agent that can eliminate the foam generated in the tofu manufacturing process and can suppress the generation of foam. Further, as will be described later, the glyceride composition of the vegetable oil hydrolyzate is determined by gas chromatography, and the acid value and the amount of free fatty acids are determined by the amount of potassium hydroxide required for neutralizing the free fatty acids contained in the vegetable oil hydrolyzate.

[0012] The above vegetable oil hydrolyzate is not particularly limited as long as it has the above composition, but preferably has a composition of 6 to 14% by mass of free fatty acids, 1 to 3% by mass of monoacylglycerol, 15 to 25% by mass of diacylglycerol, and 60 to 75% by mass of triacylglycerol, and has an acid value of 12 to 28.

[0013] The above vegetable oil hydrolyzate can be obtained by allowing a 1,3-position specific lipase aqueous solution in which 1,3-position specific lipase is dissolved in 0.5 to 5.0% by mass of water with respect to the oil to act on the vegetable oil.

[0014] When producing the above-mentioned hydrolyzate of vegetable oil, the vegetable oil selected as the substrate is not particularly limited as long as it is an edible vegetable oil, and any edible vegetable oil can be used. Examples of edible vegetable oils include palm oil, palm olein, palm kernel oil, coconut oil, corn oil, cottonseed oil, soybean oil, rapeseed oil, rice bran oil, sunflower oil, safflower oil, olive oil, canola oil, and the like. These vegetable oils can be used alone or in combination of two or more. Among these vegetable oils, one or more of rapeseed oil, palm olein, and soybean oil are preferred.

[0015] The hydrolysis of the above-mentioned vegetable oil may be carried out using a lipase that enables the hydrolyzate of vegetable oil after hydrolysis to have the above composition. Examples of such lipases include 1,3-positional specific lipases. Here, 1,3-positional specificity means the property of specifically performing a hydrolysis action on the fatty acid groups ester-bonded to the 1st and / or 3rd positions of triglyceride. In the hydrolyzate of vegetable oil by 1,3-positional specific lipase, the above composition is obtained, and an excellent defoaming action is recognized. However, in the hydrolyzate of vegetable oil by a random lipase (triglyceride lipase) that acts randomly on the fatty acid groups ester-bonded at all positions, the above composition is not obtained, and a satisfactory defoaming action cannot be obtained.

[0016] Examples of the lipase having the above 1,3-positional specificity include lipases produced by microorganisms of the genus Rhizopus, Aspergillus, and Mucor. Such lipases are commercially available as enzyme preparations. For example, Lipase DF (Amano Pharmaceutical) and Palatase (NOVO) are used.

[0017] The addition amount of the 1,3 - positional specific lipase to vegetable oils varies depending on the type of vegetable oil, treatment conditions, etc. Usually, it is 10 - 1000 units (hereinafter referred to as U), preferably 50 - 500 U, and more preferably 100 - 200 U per 1 g of vegetable oil. Here, 1 U is the amount of lipase that produces 1 μmol of fatty acid per minute when measuring the enzyme activity of lipase according to the method described on page 821 of Volume 36 of Oil Chemistry (1987).

[0018] When hydrolyzing the vegetable oil serving as the substrate with the 1,3 - positional specific lipase aqueous solution, the reaction temperature, that is, the temperature of the oil serving as the substrate, is not particularly limited as long as it is appropriately set to the temperature at which the reaction activity of the selected 1,3 - positional specific lipase is maximally efficient. However, from the viewpoints of preventing heat deterioration of the oil, rearrangement of partial glycerides, and further preventing thermal denaturation of the enzyme protein, etc., it is preferably 50°C or lower, and more preferably 34 - 40°C from the reaction activity of the enzyme.

[0019] When producing a vegetable oil hydrolyzate, a certain amount of water is contained in the vegetable oil serving as the substrate. At the start of the hydrolysis reaction by the 1,3 - positional specific lipase, 0.5 - 5.0 mass%, preferably 1.0 - 3.0 mass% of water is contained with respect to 100 mass% (oil - based) of the vegetable oil serving as the substrate. When the amount of water contained in the substrate is less than 0.5 mass% with respect to the oil, the generation of the amount of free fatty acids effective for the defoaming action may not be achieved, and with the passage of the reaction time, the generation of monoacylglycerol that suppresses the defoaming action may increase. When the amount of water contained in the substrate is 5.0 mass% or more with respect to the oil, the hydrolysis reaction may become excessive, and it may be difficult to control the reactivity of the 1,3 - positional specific lipase.

[0020] As a method of containing water in the vegetable oil serving as the substrate, from the viewpoint of efficiently advancing the hydrolysis reaction of the substrate, an aqueous solution of 1,3 - positional specific lipase in which the above - mentioned 1,3 - positional specific lipase is dispersed and dissolved is prepared in water at 0.5 - 5.0, preferably 1.0 - 3.0 mass% with respect to the oil in advance, and it is uniformly dispersed and contained in the vegetable oil in the form of the lipase aqueous solution.

[0021] The conditions for producing the above plant oil hydrolyzate are not particularly limited. For example, under temperature control of 34 to 40 °C (hereinafter, temperature control may also be referred to as temperature regulation), while dropping a 1,3-positional specificity lipase aqueous solution in which the above 1,3-positional specificity lipase is dissolved into the plant oil serving as the substrate, under stirring, it is uniformly dispersed and a hydrolysis reaction is carried out. At this time, it is desirable that a very small amount of the 1,3-positional specificity lipase aqueous solution is uniformly and finely dispersed in the plant oil that is the substrate, and high-speed stirring such as a homomixer or a ball turbine is useful for stirring.

[0022] The end point of the hydrolysis reaction is indicated by the acid value of the plant oil hydrolyzate. It is preferable to terminate the reaction when the acid value of the plant oil hydrolyzate reaches the range of 10 to 30, and it is more preferable to terminate the reaction when the acid value reaches the range of 12 to 28. The hydrolysis reaction time until the optimum degree of decomposition (acid value) is reached varies somewhat depending on the amount of water added, the concentration of the lipase aqueous solution, the reaction temperature, the type of plant oil, the stirring rotation speed, etc., but it is preferably reached within 20 to 60 minutes, and more preferably reached within 20 to 30 minutes. The acid value is an index of the amount of free fatty acid generated by the oil hydrolysis reaction, and is expressed in mg as the amount of potassium hydroxide required to neutralize the free fatty acid generated in 1 g of the oil hydrolyzate.

[0023] In the production of the plant oil hydrolyzate, after reaching the end point of the hydrolysis reaction, deactivation and removal of the 1,3-positional specificity lipase and dehydration treatment are carried out. The plant oil hydrolyzate that has reached the end point is heat-treated at 80 °C for 10 minutes to deactivate the 1,3-positional specificity lipase. Then, by standing, oil-water separation, filtration, or centrifugation, the plant oil hydrolyzate that becomes the active ingredient of the defoaming agent for tofu of the present invention can be obtained as the light part.

[0024] The above-mentioned hydrolyzate of vegetable oil contains 5 to 16% by mass of free fatty acids derived from vegetable oil, with an acid value corresponding to 10 to 30, which is an index of hydrolysis. When the amount of free fatty acids is 5% by mass or less, satisfactory defoaming performance cannot be obtained. Also, when the amount of free fatty acids exceeds 16% by mass, the amount of monoacylglycerol that suppresses the defoaming action increases to 4% by mass or more, and the defoaming performance deteriorates. Therefore, a hydrolyzate of vegetable oil having a composition of 5 to 16% by mass of free fatty acids, 1 to 4% by mass of monoacylglycerol, 13 to 30% by mass of diacylglycerol, and 55 to 80% by mass of triacylglycerol and an acid value of 10 to 30 is effective for the defoaming action.

[0025] The hydrolyzate of vegetable oil described above becomes an active ingredient of a defoaming agent for tofu. Furthermore, it is preferable from the viewpoint of defoaming property to combine it with components used in conventionally known defoaming agents for tofu. It is preferable to combine the hydrolyzate of vegetable oil with a component that has no usage restrictions under the Food Sanitation Law (preferably not containing a component that has usage restrictions under the Food Sanitation Law), and it is more preferable to combine it with medium-chain fatty acid triglyceride, plant lecithin, magnesium carbonate and / or calcium carbonate.

[0026] The above-mentioned medium-chain fatty acid triglyceride is a triglyceride having medium-chain fatty acids as its constituent components, and is a triglyceride composed of caprylic acid, which is a fatty acid having 8 carbon atoms, and capric acid, which is a fatty acid having 10 carbon atoms. The content of medium-chain fatty acid triglyceride in 100% by mass of the defoaming agent for tofu of the present invention is not particularly limited. For example, it is 10 to 20% by mass, and in order to further suppress the foam formation of soy milk protein due to the viscosity reduction effect, it is preferably contained in an amount of 15 to 20% by mass.

[0027] The above-mentioned plant lecithin is obtained from various oilseed grains and is not particularly limited as long as it mainly contains phospholipids. For example, liquid lecithin containing oilseed oil such as soybean lecithin, rapeseed lecithin, sunflower lecithin, etc. can be mentioned. The plant lecithin may be used alone or in combination of two or more. The content of lecithin in 100% by mass of the defoaming agent for tofu of the present invention is not particularly limited, but for example, it is 10 to 15% by mass, and preferably 12 to 15% by mass from the viewpoint of enhancing the defoaming effect.

[0028] It contains the above-mentioned magnesium carbonate and / or calcium carbonate. The content of magnesium carbonate and / or calcium carbonate in 100% by mass of the defoaming agent for tofu of the present invention is not particularly limited, but for example, it is 8 to 12% by mass. If the content exceeds 12% by mass, sedimentation, aggregation, and lumping may progress in the defoaming agent for tofu, which may result in a decrease in dispersibility as a liquid defoaming agent formulation.

[0029] Among the defoaming agents for tofu of the present invention, preferred embodiments containing a vegetable oil hydrolyzate, medium-chain fatty acid triglyceride, plant lecithin, magnesium carbonate and / or calcium carbonate include those containing 55 to 65% by mass of the vegetable oil hydrolyzate, 10 to 20% by mass of the medium-chain fatty acid triglyceride, 10 to 15% by mass of the plant lecithin, and 8 to 12% by mass of the magnesium carbonate and / or calcium carbonate.

[0030] The defoaming agent for tofu of the present invention can be produced, for example, by including the following steps. A 1,3-position specific lipase aqueous solution in which 1,3-position specific lipase is dissolved in 0.5 to 5.0% by mass of water with respect to the oil is allowed to act on vegetable oil to obtain a vegetable oil hydrolyzate having a composition of 5 to 16% by mass of free fatty acid, 1 to 4% by mass of monoacylglycerol, 13 to 30% by mass of diacylglycerol, and 55 to 80% by mass of triacylglycerol and an acid value of 10 to 30. A step of mixing the vegetable oil hydrolyzate, medium-chain fatty acid triglyceride, plant lecithin, magnesium carbonate and / or calcium carbonate.

[0031] In the method for producing the antifoaming agent for tofu, the step of obtaining the hydrolyzate of vegetable oil is as described above.

[0032] In the method for producing the antifoaming agent for tofu, the step of mixing the vegetable oil hydrolyzate with medium-chain fatty acid triglyceride, vegetable lecithin, magnesium carbonate and / or calcium carbonate can be carried out by a method known per se. For example, in a mixing tank equipped with a stirrer and a heating jacket, the liquid raw materials of the vegetable oil hydrolyzate, medium-chain fatty acid triglyceride, and vegetable lecithin are weighed and charged, heated to 50 to 70°C, and mixed and dissolved. Then, while stirring this oil solution raw material, the powder of magnesium carbonate and / or calcium carbonate is uniformly dispersed therein.

[0033] By carrying out the above steps, the antifoaming agent for tofu of the present invention can be produced.

[0034] Since the antifoaming agent for tofu of the present invention is in a liquid state, it can be quantitatively added and used by a simple handling operation during the tofu manufacturing process. And the antifoaming agent for tofu of the present invention can eliminate the bubbles generated in the tofu manufacturing process and can suppress the generation of bubbles. The antifoaming agent may be added at any stage during the tofu manufacturing process, but it is more preferable to add and disperse it in "go" at the stage of grinding the soaked soybeans to prepare "go". By adding it to "go", foaming in the steaming kettle in the next steaming process can be suppressed (primary defoaming), heat transfer can be promoted homogeneously, steaming efficiency can be increased, and high-quality soy milk can be achieved. Also, the separation efficiency of okara and soy milk in the next step is increased. The defoaming effect (secondary defoaming) is most important during the transfer of the soy milk obtained from the separation step, during the storage in the soy milk tank, and during the coagulation molding process of pouring into the mold box or belt line after the coagulant is dispersed. Furthermore, it is required that the defoaming effect (tertiary defoaming) is also maintained in the manufacturing process of filled tofu using cold soy milk by rapidly cooling the obtained soy milk to 10°C or lower.

[0035] The addition amount of the defoaming agent for tofu of the present invention is not particularly limited. For example, it is 0.2 to 1.2% by mass, preferably 0.3 to 0.8% by mass, based on 100% by mass of soybeans (raw soybeans).

[0036] In addition, the defoaming agent for tofu of the present invention can not only eliminate the bubbles generated in the tofu manufacturing process, but also eliminate the bubbles generated in the manufacturing processes of food and beverages using soy milk such as soy milk, deep-fried bean curd, thick deep-fried bean curd, and yuba (hereinafter sometimes referred to as "tofu products"), and can suppress the generation of bubbles.

[0037] The effect of the defoaming agent for tofu of the present invention lies in significantly suppressing the generation of bubbles in the manufacturing process of tofu products (foam suppression property) and bursting and eliminating the generated bubbles. Due to this defoaming action, the heat transfer during steaming becomes uniform, and the improvement of the extraction rate of soybean components and the separation property from okara components bring about the improvement of the quality of soy milk. Furthermore, the defoaming effect is maintained even in the latter stage of the tofu product manufacturing, and the improvement of soy milk coagulability and moldability brings about the improvement of the quality of tofu products and the improvement of the yield.

Examples

[0038] Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

[0039] <Glyceride Composition Analysis Method> The sample of the hydrolyzate of vegetable oil and fat was made up to a fixed volume with chloroform. For the quantification of triglyceride as the internal standard, triheptadecanoin was added, for the quantification of diglyceride, dipalmitin was added, and for the quantification of monoglyceride, monoheptadecanoin was added. The triglyceride fraction, diglyceride fraction, and monoglyceride fraction were respectively separated by column chromatography, methyl esterified, and used as samples for gas chromatography. Gas chromatograph model 7890B (manufactured by Agilent Technologies), capillary column DB-23 (manufactured by Agilent Technologies) Φ0.25mm×30m, column temperature 50°C → temperature increase at 10°C / min → 170°C → temperature increase at 1.2°C / min → 210°C, detector FID 250°C, and quantitative analysis was performed by the internal standard method. The amount of free fatty acids in the hydrolyzate of vegetable oil was determined by converting the number of milligrams of potassium hydroxide required to neutralize the free fatty acids determined according to acid value measurement (potentiometric titration method) into the amount of oleic acid.

[0040] Example 1 Production of hydrolyzate of vegetable oil: (1) Preparation of hydrolyzate using rapeseed oil and palm olein as substrates for vegetable oil In a 2 L glass reaction vessel with a temperature - controllable jacket, 500 g of rapeseed oil (product name: "Nisshin Rapeseed Salad Oil S", manufactured by Nisshin Oillio) and 500 g of palm olein (product name: "Palm Ace N", manufactured by Fuji Oil) as vegetable oils were blended. While stirring using a ball turbine C - MIX (Φ48, manufactured by Emrevo Japan) as a stirrer, the temperature of the oil was adjusted to 36 °C. 500 mg (75,000 U) of lipase DF "Amano" 15 (manufactured by Amano Enzyme, hereinafter may be abbreviated as "DF", lipid - degrading activity: 150 U / mg) as a 1,3 - positional - specificity lipase was weighed and dissolved in 12 g of distilled water (1.2 mass% based on oil) to prepare a 1,3 - positional - specificity lipase aqueous solution. While stirring at 1200 rpm with the ball turbine, this 1,3 - positional - specificity lipase (lipase DF) aqueous solution was dropped into the substrate vegetable oil (rapeseed oil + palm olein) and dispersed. After the dropping was completed, stirring was continued for 35 minutes to carry out the hydrolysis reaction. After the reaction was completed, the rotation speed of the ball turbine was reduced to 200 rpm, and the temperature of the oil in the container was raised to 80 °C and maintained at 80 °C for 10 minutes to inactivate the enzyme. The obtained hydrolysis reaction product was allowed to stand for one day and night, and the supernatant was filtered to obtain a vegetable oil hydrolyzate (sample 1).

[0041] According to the above production method, by adjusting the amount of water added and the reaction time, vegetable oil hydrolyzate samples with different degrees of hydrolysis (acid value) were prepared using 1000 g of vegetable oil (rapeseed oil + palm olein: 500 g + 500 g) as the raw material oil substrate (samples 1 - 5). The reaction conditions, acid value, and composition analysis of the samples in the prepared vegetable oil hydrolyzates are shown in Table 1.

[0042] Preparation of hydrolyzate of vegetable oil using random lipase (triglyceride lipase) as a lipid - degrading enzyme: Using lipase AY "Amano" 30SD, which is a triglyceride lipase (manufactured by Amano Enzyme Inc., lipid-decomposing activity: 30 U / mg) (hereinafter, this may be abbreviated as "AY"), according to the above production method, a vegetable oil hydrolyzate sample was prepared using 1000 g of vegetable oil (500 g of rapeseed oil + 500 g of palm olein) as a substrate (Samples 6 - 7). The reaction conditions, acid value, and composition analysis of the prepared hydrolyzate samples are shown in Tables 1 and 2. An equal mixture of rapeseed oil and palm olein, which is the raw material oil substrate without undergoing hydrolysis treatment, was used as Sample 8.

[0043]

Table 1

[0044]

Table 2

[0045] (2) Preparation of hydrolyzate using soybean oil as a substrate for vegetable oil According to the production conditions of Samples 1 - 5 above, 1000 g of soybean refined oil (manufactured by Nisshin Oillio Group Ltd.) was used as the vegetable oil substrate for the preparation of soybean oil hydrolyzate. The addition amount of 1,3 - positional specificity lipase (lipase DF "Amano" 15) was fixed at 500 ppm based on the oil, the water addition amount was adjusted to 1.0 - 3.0% by mass based on the oil, and the reaction time was adjusted to 25 - 45 minutes to prepare soybean oil hydrolyzates of Sample 9 (acid value 8.1), Sample 10 (acid value 16.0), Sample 11 (acid value 23.8), and Sample 12 (acid value 33.4).

[0046] Furthermore, Samples 10 and 11 were each neutralized with an equal amount of acid value of 0.5% sodium hydroxide aqueous solution in normal hexane to neutralize the free fatty acids contained therein, and were subjected to deacidification treatment to prepare soybean oil hydrolyzates from which free fatty acids were removed (Samples 13, Sample 14). The reaction conditions, acid value, composition analysis of Samples 9 - 12, and composition analysis of Samples 13 and 14 are shown in Tables 3 and 4.

[0047]

Table 3

[0048]

Table 4

[0049] Example 2 Preparation of defoaming agent for tofu: Using the vegetable oil hydrolyzate samples 1 to 14 prepared in Example 1 above (including sample 8 which is a vegetable oil substrate not hydrolyzed with lipase aqueous solution), medium-chain fatty acid triglyceride (MCT: trade name Cocnard MT, manufactured by Kao), plant lecithin (trade name: SLP paste, manufactured by Tsujido Oil Co., Ltd.), and magnesium carbonate (manufactured by Naigai Salt Industry Co., Ltd.) were formulated at the blending ratios shown in Table 5 to prepare a defoaming agent for tofu, and Products 1 to 9 of the present invention and Comparative Products 1 to 7 were obtained. Incidentally, the above plant lecithin is a preparation composed of 63% by mass of phospholipids and 37% by mass of soybean oil.

[0050]

Table 5

[0051] Test Example 1 Defoaming property evaluation test: 10 kg of soybeans (Canadian WIV produced in 2022) were immersed in temperature-controlled water at 18°C for 12 hours and then drained. While adding 4.8 times the amount of water to the immersed soybeans, they were ground with a grinder to prepare "go". Into the prepared "go", 50 g each of Products 1 to 9 of the present invention and Comparative Products 1 to 7 as defoaming agents for tofu were added and dispersed, and then placed in a steaming kettle and heated. When the temperature inside the steaming kettle reached 96°C, the foaming state inside the kettle was observed (evaluation of primary defoaming property). Further, after reaching 102°C, it was steamed for 180 seconds. The "go" after steaming was separated into soymilk and okara using a dehydrator (Economizer: manufactured by Yanagiya), and 45 L of soymilk was stored in a soymilk tank. Incidentally, the series of operations from grinding to steaming was carried out using a soymilk plant (Success Plant · Perfector P-701: manufactured by Sowa).

[0052] Transfer from the soy milk storage tank, mix and disperse 10 L of soy milk heated to 82°C and 95 g of a coagulant preparation for tofu (product name: JS Nibari, manufactured by Taiki Bussan Co., Ltd.) using a disperser dedicated to the coagulant preparation (product name: NS Mixer, manufactured by Taiki Bussan Co., Ltd.), then pour it into a tofu mold box MK box (12 L) at a flow rate of 10 L / 12 seconds. After pouring in the full 10 L, take a photo and record the amount of surface foam at the time when the fluidity of the soy milk in the mold box stops, and measure the foam area in the image (evaluation of secondary defoaming property). The amount of surface foam is the average value of 5 batches. Typical images of each evaluation level in the evaluation of secondary defoaming property are shown in Figures 1 to 5.

[0053] Seal 10 L of soy milk obtained from the above-mentioned storage soy milk tank in a BIB bag and immerse it in cold water at 5°C overnight to prepare cooled soy milk. Put 200 g of this cooled soy milk into a 500 ml glass container, seal it, shake it for 20 seconds, and after standing, observe the disappearance state of the foam on the surface of the cooled soy milk in the container (evaluation of tertiary defoaming property).

[0054] The evaluation criteria for primary defoaming property, secondary defoaming property, and tertiary defoaming property using the defoamers for tofu of the products 1 to 9 and comparative products 1 to 7 of the present invention are shown below. The results evaluated based on this evaluation criteria are shown in Table 6.

[0055] <Evaluation of primary defoaming property> Evaluation content ◎ No foam generation is observed in the steaming kettle. ○ Slight foam generation is observed in the steaming kettle. △ Foam generation is observed in the steaming kettle, but it can be washed away by flushing the kettle with water. × A large amount of foam is generated in the steaming kettle and cannot be washed away even by flushing the kettle with water.

[0056] <Evaluation of secondary defoaming property> Evaluation content ◎ The surface foam area is less than 3.0% and has excellent defoaming effect. ○ The surface foam area is 3.0 - 7.9% and sufficient defoaming effect is recognized. △ The surface foam area is 8.0 - 14.9% and defoaming effect is recognized. × The surface foam area is 15.0% or more

[0057] <Evaluation of Defoaming Property for the Third Time> Evaluation Content ◎ All the bubbles on the inner surface of the container disappear within 1 minute after shaking and standing. ○ All the bubbles on the inner surface of the container disappear within 3 minutes after shaking and standing. △ Partially bubbles remain on the inner surface of the container after 3 minutes of shaking and standing. × The entire inner surface of the container is in a state of crab bubbles after 3 minutes of shaking and standing.

[0058]

Table 6

[0059] From the evaluation of the defoaming performance of the products 1 - 9 of the present invention and Comparative Product 5 (Sample 8: Vegetable oil as the substrate raw material), the remarkable effectiveness of the vegetable oil hydrolyzate by 1,3 - positional specific lipase was recognized. From the evaluation of the defoaming performance with Comparative Product 1 (Sample 9) and Comparative Product 2 (Sample 12), excellent defoaming performance was recognized in the vegetable oil hydrolyzate with an acid value of 10 - 30. Comparative Product 3 (Sample 6) and Comparative Product 4 (Sample 7) were evaluated for the defoaming performance of the hydrolyzate by random lipase (triglyceride lipase), and the defoaming performance decreased due to the increase in monoacylglycerol. Also, Comparative Product 6 (Sample 13) and Comparative Product 7 (Sample 14) were evaluated for the decomposed products obtained by removing the free fatty acids generated in the vegetable oil hydrolyzate. From the evaluations of Product 8 (Sample 10) and Product 9 (Sample 11) of the present invention respectively, the free fatty acids contained in the products of the present invention have brought a remarkable effect on the defoaming action. The tofu produced with the products 1 - 9 of the present invention is excellent in soy flavor and sweetness.

Industrial Applicability

[0060] The defoaming agent for tofu of the present invention is excellent in defoaming action, so it can be used in the production of tofu products.

Claims

1. An antifoaming agent for tofu, characterized in that it contains, as an active ingredient, a hydrolyzate of vegetable oil and fat having a composition of 5 to 16% by mass of free fatty acids, 1 to 4% by mass of monoacylglycerol, 13 to 30% by mass of diacylglycerol, and 55 to 80% by mass of triacylglycerol, and an acid value of 10 to 30.

2. The antifoaming agent for tofu according to Claim 1, further containing medium-chain fatty acid triglyceride, plant lecithin, magnesium carbonate and / or calcium carbonate.

3. The antifoaming agent for tofu according to Claim 2, containing 55 to 65% by mass of a hydrolyzate of vegetable oil and fat, 10 to 20% by mass of medium-chain fatty acid triglyceride, 10 to 15% by mass of plant lecithin, and 8 to 12% by mass of magnesium carbonate and / or calcium carbonate.

4. A step of obtaining a hydrolyzate of vegetable oil and fat having a composition of 5 to 16% by mass of free fatty acids, 1 to 4% by mass of monoacylglycerol, 13 to 30% by mass of diacylglycerol, and 55 to 80% by mass of triacylglycerol, and an acid value of 10 to 30, by allowing a 1,3-position specific lipase aqueous solution in which 1,3-position specific lipase is dissolved in 0.5 to 5.0% by mass of water with respect to the oil to act on vegetable oil and fat; A step of mixing the hydrolyzate of vegetable oil and fat with medium-chain fatty acid triglyceride, plant lecithin, magnesium carbonate and / or calcium carbonate; A method for producing an antifoaming agent for tofu, characterized by including the above steps.

5. A method for producing tofu, characterized by using the antifoaming agent for tofu according to any one of Claims 1 to 3 during the production of tofu.

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