Antifoaming agent for tofu and manufacturing method

Abstract

The present invention provides a tofu defoaming agent that is not subject to usage restrictions under the Food Sanitation Act and has excellent defoaming properties against foam generated during the production of tofu, and a method for producing the same. [Solution] An antifoaming agent for tofu and a method for producing the same, characterized in that the active ingredient is a hydrolyzed vegetable oil having a composition of 5-16% by mass of free fatty acids, 1-4% by mass of monoacylglycerol, 13-30% by mass of diacylglycerol, and 55-80% by mass of triacylglycerol, and having an acid value of 10-30.

Description

Technical Field

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

Background Art

[0002] Soybeans, which are the raw material for tofu, contain abundant surfactants such as proteins and saponins. Therefore, in the manufacturing process of tofu, etc., the generation of foam (foaming) causes significant problems such as a decrease in production capacity and poor product quality. For example, the generation of foam during the steaming of so-called "go" which is soybean grindings results in uneven heat transfer and tofu with inferior flavor and texture. Furthermore, the generation of foam during the conveyance of soy milk or 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 then during the filling into a mold box or cup impairs the commercial value, and particularly in the continuous line 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 Hygiene 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 Hygiene Law, and they are used as antifoaming agent preparations formulated with various materials.

[0004] Therefore, an antifoaming agent for tofu using glycerin fatty acid ester without usage restrictions under the Food Hygiene 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 always satisfactory in terms of antifoaming performance, etc.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Patent No. 5789359 [Patent Document 2] Patent No. 6129617 [Patent Document 3] Patent No. 6448953 [Overview of the project] [Problems that the invention aims to solve]

[0006] The present invention aims to provide a tofu defoaming agent and a method for producing the same, which are not subject to restrictions on use under the Food Sanitation Act and have excellent defoaming properties against foam generated during the production of tofu and the like. [Means for solving the problem]

[0007] As a result of diligent research into the above-mentioned problems, the inventors of this invention discovered that the above-mentioned problems can be solved by using a hydrolyzed vegetable oil having a specific composition as an active ingredient, and thus completed the present invention.

[0008] In other words, the present invention is as follows: (1) An antifoaming agent for tofu, characterized in that it contains a hydrolyzed vegetable oil as an active ingredient, having a composition of 5-16% by mass of free fatty acids, 1-4% by mass of monoacylglycerol, 13-30% by mass of diacylglycerol, and 55-80% by mass of triacylglycerol, with an acid value of 10-30. (2) The tofu defoamer according to (1), further comprising medium-chain triglyceride, plant lecithin, magnesium carbonate and / or calcium carbonate. (3) The tofu defoamer according to (2), containing 55-65% by mass of hydrolyzed vegetable oil, 10-20% by mass of medium-chain triglyceride, 10-15% by mass of plant lecithin, and 8-12% by mass of magnesium carbonate and / or calcium carbonate. (4) A method for producing a hydrolyzed vegetable oil having a composition of 5 to 16% by mass of free fatty acids, 1 to 4% by mass of monoacylglycerols, 13 to 30% by mass of diacylglycerols, and 55 to 80% by mass of triacylglycerols, and an acid value of 10 to 30, characterized by reacting a vegetable oil with an aqueous solution of 1,3-position-specific lipase, which is obtained by dissolving 1,3-position-specific lipase as a lipid-degrading enzyme in 0.5 to 5.0% by mass of water relative to the oil. (5) A step to obtain a hydrolyzed vegetable oil having a composition of 5-16% by mass of free fatty acids, 1-4% by mass of monoacylglycerols, 13-30% by mass of diacylglycerols, and 55-80% by mass of triacylglycerols, with an acid value of 10-30, by reacting a vegetable oil with an aqueous solution of 1,3-position-specific lipase, which is obtained by dissolving 1,3-position-specific lipase as a lipid-degrading enzyme in 0.5-5.0% by mass of water relative to the oil. A step of mixing the aforementioned hydrolyzed vegetable oil with medium-chain triglyceride, plant lecithin, magnesium carbonate and / or calcium carbonate. A method for producing an antifoaming agent for tofu, characterized by containing [the specified ingredient]. (6) A method for producing tofu, characterized by using any of the tofu defoaming agents described in (1) to (3) during the production of tofu. [Effects of the Invention]

[0009] The tofu defoamer of the present invention has excellent defoaming properties and can therefore be used in the production of tofu and other products. Furthermore, since the tofu defoamer of the present invention uses hydrolyzed vegetable oils produced by an enzyme aqueous solution of vegetable oils as its active ingredient, it is treated similarly to general food additives and is not subject to usage restrictions under the Food Sanitation Act. [Brief explanation of the drawing]

[0010] [Figure 1] An example of the surface foam area (1.1%: excellent rating) of product 3 of the present invention in the secondary defoaming performance evaluation of Test Example 1 is shown. [Figure 2] This shows an example of the surface foam area (9.3%: evaluation △) of comparative product 3 in the secondary defoaming performance evaluation of Test Example 1. [Figure 3]An example of the surface foam area (2.7%: excellent rating) of product 9 of the present invention in the secondary defoaming performance evaluation of Test Example 1 is shown. [Figure 4] This shows an example of the surface foam area (15.9%: evaluation failed) of comparative product 7 in the secondary defoaming performance evaluation of Test Example 1. [Figure 5] This shows an example of the surface foam area (73.5%: evaluation failed) of comparative product 5 in the secondary defoaming performance evaluation of Test Example 1. [Modes for carrying out the invention]

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

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

[0013] The above-mentioned hydrolyzed vegetable oils are obtained by reacting vegetable oils with an aqueous solution of 1,3-position-specific lipase, which is prepared by dissolving 1,3-position-specific lipase as a lipid-degrading enzyme in 0.5 to 5.0% by mass of water relative to the 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 specificity lipase. Here, 1,3-positional specificity means the property of specifically hydrolyzing 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 specificity lipase, it has the above composition and an excellent defoaming effect 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, it does not have the above composition and a satisfactory defoaming effect 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, Mucor, and the like. Such lipases are commercially available as enzyme preparations. For example, Lipase DF (Amano Pharmaceutical), Palatase (NOVO), etc. are used.

[0017] The amount of 1,3 - positional specific lipase added to vegetable oils varies depending on the type of vegetable oil, processing conditions, etc. Usually, it is 10 to 1000 units (hereinafter referred to as U), preferably 50 to 500 U, and more preferably 100 to 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 an aqueous solution of 1,3 - positional specific lipase, 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 maximized. However, from the viewpoints of preventing thermal degradation 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 to 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 1,3 - positional specific lipase, 0.5 to 5.0% by mass, preferably 1.0 to 3.0% by mass of water is contained with respect to 100% by mass (oil - based) of the vegetable oil serving as the substrate. When the amount of water contained in the substrate is less than 0.​​​​​

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

[0022] The endpoint of the hydrolysis reaction is indicated by the acid value of the hydrolyzed vegetable oil. It is preferable to terminate the reaction when the acid value of the hydrolyzed vegetable oil reaches a range of 10 to 30, and more preferably when the acid value reaches a range of 12 to 28. The hydrolysis reaction time to reach the optimal degree of decomposition (acid value) varies somewhat depending on the amount of water added, the concentration of the lipase aqueous solution, the reaction temperature, the type of vegetable oil, the stirring speed, etc., but it is preferable to reach this point in 20 to 60 minutes, and more preferably in 20 to 30 minutes. The acid value is an indicator of the amount of free fatty acids produced by the hydrolysis reaction of oils and fats, and is expressed in milligrams as the amount of potassium hydroxide required to neutralize the free fatty acids produced in 1 g of hydrolyzed vegetable oil.

[0023] In the production of hydrolyzed vegetable oils, after reaching the endpoint of the hydrolysis reaction, the 1,3-position-specific lipase is inactivated and removed, and dehydration is performed. The hydrolyzed vegetable oil that has reached the endpoint is heated at 80°C for 10 minutes to inactivate the 1,3-position-specific lipase. Subsequently, by standing, oil-water separation and filtration, or centrifugation, the hydrolyzed vegetable oil, which is the active ingredient of the tofu defoaming agent of the present invention, can be obtained as the light portion.

[0024] The above-mentioned hydrolyzed vegetable oil contains 5-16% by mass of free fatty acids derived from vegetable oil, with an acid value of 10-30, which is an indicator of hydrolysis. If the amount of free fatty acids is 5% by mass or less, satisfactory defoaming performance cannot be obtained. Furthermore, if the amount of free fatty acids exceeds 16% by mass, the amount of monoacylglycerol, which suppresses the defoaming effect, increases to 4% by mass or more, and the defoaming performance decreases. Therefore, a hydrolyzed vegetable oil with a composition of 5-16% by mass of free fatty acids, 1-4% by mass of monoacylglycerol, 13-30% by mass of diacylglycerol, and 55-80% by mass of triacylglycerol, and an acid value of 10-30, is effective for defoaming.

[0025] The hydrolyzed vegetable oils described above can be used as active ingredients in tofu defoaming agents, and it is preferable from the standpoint of defoaming properties to combine them with ingredients that are conventionally known and used in tofu defoaming agents. Hydrolyzed vegetable oils are preferably combined with ingredients that are not restricted under the Food Sanitation Act (preferably not containing ingredients that are not restricted under the Food Sanitation Act), and it is more preferable to combine them with medium-chain triglycerides, plant lecithin, magnesium carbonate and / or calcium carbonate.

[0026] The above-mentioned medium-chain fatty acid triglyceride is a triglyceride whose constituent component is a medium-chain fatty acid, and is a triglyceride composed of caprylic acid, a fatty acid with 8 carbon atoms, and capric acid, a fatty acid with 10 carbon atoms. The content of medium-chain fatty acid triglyceride in 100% by mass of the tofu defoaming agent of the present invention is not particularly limited, but for example, it is 10 to 20% by mass, and to further suppress foam formation of soy milk protein by reducing viscosity, it is preferable to contain 15 to 20% by mass.

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

[0028] The above-mentioned magnesium carbonate and / or calcium carbonate are contained. The content of magnesium carbonate and / or calcium carbonate in 100% by mass of the tofu defoamer of the present invention is not particularly limited, but is, for example, 8 to 12% by mass. If the content exceeds 12% by mass, sedimentation, aggregation, and clumping may occur in the tofu defoamer, leading to a decrease in the dispersibility of the liquid defoamer formulation.

[0029] Among the defoaming agents for tofu of the present invention, a preferred embodiment containing a hydrolyzed vegetable oil, medium-chain triglycerides, plant lecithin, magnesium carbonate and / or calcium carbonate is one in which the hydrolyzed vegetable oil contains 55-65% by mass, medium-chain triglycerides contains 10-20% by mass, plant lecithin contains 10-15% by mass, and magnesium carbonate and / or calcium carbonate contains 8-12% by mass.

[0030] The tofu defoaming agent of the present invention can be manufactured, for example, by the following steps: 1. Reacting a vegetable oil with an aqueous solution of 1,3-position-specific lipase, obtained by dissolving 1,3-position-specific lipase as a lipid-degrading enzyme in 0.5-5.0% by mass of water relative to the oil, to obtain a vegetable oil hydrolysate having a composition of 5-16% by mass of free fatty acids, 1-4% by mass of monoacylglycerol, 13-30% by mass of diacylglycerol, and 55-80% by mass of triacylglycerol, with an acid value of 10-30. The process of mixing the hydrolyzed vegetable oil with medium-chain triglyceride, vegetable lecithin, magnesium carbonate and / or calcium carbonate.

[0031] The process for obtaining the hydrolyzed vegetable oil in the above-mentioned method for producing the defoaming agent for tofu is as described above.

[0032] In the above-mentioned method for producing an antifoaming agent for tofu, the step of mixing the hydrolyzed vegetable oil with medium-chain triglycerides, plant lecithin, magnesium carbonate and / or calcium carbonate can be carried out by a method known to the public. For example, liquid raw materials of hydrolyzed vegetable oil, medium-chain triglycerides and plant lecithin are weighed and added to a mixing tank equipped with a stirrer and a heating jacket, heated to 50-70°C, and mixed and dissolved. Then, while stirring this oil solution, powdered magnesium carbonate and / or calcium carbonate is uniformly dispersed in it.

[0033] By performing the above steps, the tofu defoaming agent of the present invention can be manufactured.

[0034] Since the tofu defoaming agent of the present invention is liquid, it can be added quantitatively with simple handling operations during the tofu manufacturing process. Furthermore, the tofu defoaming agent of the present invention can eliminate foam generated during the tofu manufacturing process and suppress foam generation. The defoaming agent may be added at any stage in the tofu manufacturing process, but it is more preferable to add and disperse it in the "go" (soybean paste) at the stage when soaked soybeans are ground to prepare "go". By adding it to "go", foaming in the steaming pot during the subsequent steaming process is suppressed (primary defoaming), which promotes uniform heat transfer, increases steaming efficiency, and leads to higher quality soy milk. It also improves the separation efficiency of okara and soy milk in the next step. The defoaming action (secondary defoaming) is most important during the transfer of soy milk obtained from the separation process, during storage in the soy milk tank, and during the coagulation molding process after dispersion of the coagulant and pouring into molds or belt lines. Furthermore, it is required that the defoaming effect (tertiary defoaming) be maintained even in the manufacturing process of filled tofu using chilled soy milk, after rapidly cooling the obtained soy milk to below 10°C.

[0035] There are no particular restrictions on the amount of the tofu defoaming agent of the present invention added, but 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 beans).

[0036] Furthermore, the tofu defoaming agent of the present invention can eliminate foam generated not only in the tofu manufacturing process, but also in the manufacturing process of soy milk-based food and beverage products such as soy milk, fried tofu, thick fried tofu, and yuba (hereinafter sometimes referred to as "tofu products"), thereby suppressing foam generation.

[0037] The effect of the tofu defoamer of the present invention is to significantly suppress the generation of foam during the tofu manufacturing process (foam suppression) and to break and eliminate any foam that does occur. This defoaming action results in uniform heat transfer during steaming, improving the extraction rate of soybean components and the separation of okara components, leading to higher quality soy milk. Furthermore, the defoaming effect persists even in the later stages of tofu production, improving soy milk coagulation and moldability, which leads to improved product quality and yield of tofu. [Examples]

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

[0039] <Method for analyzing glyceride composition> Vegetable oil hydrolysate samples were diluted to a fixed volume with chloroform. Triheptadecanoin was added as an internal standard for the quantification of triglycerides, dipalmitin for the quantification of diglycerides, and monoheptadecanoin for the quantification of monoglycerides. The triglyceride, diglyceride, and monoglyceride fractions were separated by column chromatography, methyl esterified, and then subjected to gas chromatography. Quantitative analysis was performed using an Agilent Technologies 7890B gas chromatograph, an Agilent Technologies DB-23 capillary column (Φ0.25mm x 30m), column temperature increased from 50°C to 170°C to 210°C, and an FID detector at 250°C, using the internal standard method. The amount of free fatty acids in hydrolyzed vegetable oils was determined by converting the amount of potassium hydroxide required to neutralize the free fatty acids, which is determined by acid value measurement (potentiometric titration), into the amount of oleic acid.

[0040] Example 1 Manufacturing of hydrolyzed vegetable oils: (1) Preparation of hydrolysates using rapeseed oil and palm olein as substrates for vegetable oils. In a temperature-controlled, jacketed 2L glass reaction vessel, 500g of rapeseed oil (product name "Nisshin Rapeseed Salad Oil S," manufactured by Nisshin Oillio) and 500g of palm olein (product name "Palm Ace N," manufactured by Fuji Oil Co., Ltd.) were blended as vegetable oils, and the mixture was stirred using a ball turbine C-MIX (Φ48: manufactured by Emrevo Japan Co., Ltd.) to maintain a temperature of 36°C. 500mg (75,000U) of lipase DF "Amano" 15 (manufactured by Amano Enzyme Co., Ltd. (hereinafter sometimes abbreviated as "DF"), lipid decomposition activity: 150U / mg) was weighed out as a 1,3-position-specific lipase, dissolved in 12g of distilled water (1.2% by mass relative to the oil), and an aqueous solution of 1,3-position-specific lipase was prepared. Under stirring at 1200 rpm by a ball turbine, an aqueous solution of this 1,3-position-specific lipase (lipase DF) was added dropwise and dispersed into the substrate, a vegetable oil (rapeseed oil + palm olein). After the addition of the solution, stirring was continued for 35 minutes to allow the hydrolysis reaction to occur. After the reaction was complete, the rotation speed of the ball turbine was reduced to 200 rpm, and the oil temperature in the container was raised to 80°C. The temperature was maintained at 80°C for 10 minutes to deactivate the enzyme. The resulting hydrolysis product was allowed to stand overnight, and the supernatant was filtered to obtain a hydrolyzed vegetable oil product (sample 1).

[0041] Following the manufacturing method described above, the amount of water added and the reaction time were adjusted to prepare vegetable oil hydrolysate samples with different degrees of hydrolysis (acid value) using 1000g of vegetable oil (rapeseed oil + palm olein: 500g + 500g) as the raw material substrate (Samples 1-5). The reaction conditions, acid value, and compositional analysis of the prepared vegetable oil hydrolysates are shown in Table 1.

[0042] Preparation of hydrolyzed vegetable oils using random lipase (triglyceride lipase) as a lipid-degrading enzyme: Using the triglyceride lipase lipase AY "Amano" 30SD (manufactured by Amano Enzyme Co., Ltd. (lipid decomposition activity: 30 U / mg)) (hereinafter sometimes abbreviated as "AY"), hydrolyzed vegetable oil samples were prepared using 1000 g of vegetable oil (500 g rapeseed oil + 500 g palm olein) as a substrate according to the above manufacturing method (Samples 6-7). The reaction conditions, acid value, and compositional analysis of the prepared hydrolyzed samples are shown in Tables 1 and 2. Sample 8 was an oil mixture of rapeseed oil and palm olein in equal parts, which was the raw material oil substrate that was not subjected to hydrolysis treatment.

[0043] [Table 1]

[0044] [Table 2]

[0045] (2) Preparation of hydrolysates using soybean oil as a substrate for vegetable oils Following the manufacturing conditions for samples 1 to 5 described above, 1000 g of refined soybean oil (manufactured by Nisshin Oillio) was used as the substrate vegetable oil to prepare soybean oil hydrolysates. The amount of 1,3-position-specific lipase (lipase DF "Amano" 15) added was fixed at 500 ppm relative to the oil, the amount of water added was adjusted to 1.0 to 3.0% by mass relative to the oil, and the reaction time was adjusted to 25 to 45 minutes to prepare soybean oil hydrolysates for 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 subjected to deacidification treatment by adding an equivalent amount of 0.5% sodium hydroxide aqueous solution in n-hexane to neutralize the free fatty acids contained therein, thereby preparing soybean oil hydrolysates from which the free fatty acids were removed (samples 13 and 14). The reaction conditions, acid values, and compositional analysis of samples 9-12, and the compositional 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 hydrolyzed vegetable oil samples 1 to 14 prepared in Example 1 (including sample 8, which is a vegetable oil substrate not subjected to hydrolysis with lipase aqueous solution), medium-chain triglyceride (MCT: trade name Coconad MT, manufactured by Kao Corporation), plant lecithin (trade name: SLP Paste, manufactured by Tsuji Oil Co., Ltd.), and magnesium carbonate (manufactured by Naigai Salt Industry Co., Ltd.) were blended in the proportions shown in Table 5 to prepare tofu defoaming agents, yielding products 1 to 9 of the present invention and comparative products 1 to 7. The plant lecithin mentioned above is a formulation consisting of 63% by mass of phospholipid and 37% by mass of soybean oil.

[0050] [Table 5]

[0051] Example Test 1 Antifoaming performance evaluation test: 10 kg of soybeans (2022 Canadian WIV) were soaked in 18°C ​​temperature-controlled water for 12 hours, and then drained. These soaked soybeans were then ground in a grinder while adding 4.8 times the amount of water to prepare "kure" (soybean paste). 50 g each of the present invention products 1-9 and comparative products 1-7 were added and dispersed in the prepared "kure" as tofu defoaming agents, and the mixture was placed in a steaming pot and heated. When the temperature inside the steaming pot reached 96°C, the foaming state inside the pot was observed (evaluation of primary defoaming properties). Furthermore, after reaching 102°C, it was steamed for 180 seconds. After steaming, the "kure" was separated into soy milk and okara (soybean pulp) using a dehydrator (Economeister: manufactured by Yanagiya), and 45 L of soy milk was stored in a soy milk tank. The entire process from grinding to steaming was carried out using a soy milk plant (Success Plant Perfector P-701: manufactured by Soei).

[0052] 10L of soy milk, transferred from the storage tank and temperature-controlled to 82°C, and 95g of tofu coagulant preparation (product name: JS Nigari Okinawa, manufactured by Taiki Bussan) were mixed and dispersed using a dedicated coagulant preparation disperser (product name: NS Mixer, manufactured by Taiki Bussan). The mixture was then poured into a tofu mold box (MK box, 12L) at a flow rate of 10L / 12 seconds. After pouring in the entire 10L, the amount of foam on the surface was photographically recorded when the flow of the soy milk in the mold box stopped, and the foam area was measured by image (evaluation of secondary defoaming ability). Note that the amount of foam on the surface is the average value for 5 batches. Typical images of each evaluation level in the evaluation of secondary defoaming ability are shown in Figures 1 to 5.

[0053] Ten liters of soy milk obtained from the above-mentioned storage tank were sealed in a BIB bag and immersed overnight in 5°C cold water to prepare chilled soy milk. 200 g of this chilled soy milk was placed in a 500 ml glass container, sealed tightly, shaken for 20 seconds, and after standing, the state of foam disappearance on the surface of the chilled soy milk in the container was observed (evaluation of tertiary defoaming properties).

[0054] The evaluation criteria for primary, secondary, and tertiary defoaming properties using the tofu defoaming agents of the present invention (products 1-9) and comparative products (products 1-7) are shown below. The results of the evaluation based on these criteria are shown in Table 6.

[0055] <Evaluation of primary defoaming properties> Evaluation details ◎ No bubbles were observed inside the steaming pot. ○ A small amount of foam is observed inside the steaming pot. △ Although foam is observed inside the steaming pot, it can be washed away by rinsing the pot with water. × A lot of foam is generated inside the steaming pot, and it cannot be washed away even by rinsing the pot with water.

[0056] <Evaluation of secondary defoaming properties> Evaluation details ◎ The surface foam area is less than 3.0%, and it has excellent defoaming properties. ○ The surface foam area is 3.0-7.9%, indicating sufficient defoaming action. △ The surface foam area is 8.0-14.9%, indicating an antifoaming effect. × Surface foam area is 15.0% or more

[0057] <Evaluation of tertiary defoaming properties> Evaluation details ◎ After shaking and letting it stand, all bubbles on the inner surface of the container will disappear within 1 minute. ○ After shaking and letting it stand, all bubbles on the inner surface of the container will disappear within 3 minutes. △ After shaking and letting it stand for 3 minutes, some bubbles remain on the inner surface of the container. × After shaking and letting it stand for 3 minutes, the entire inner surface of the container is covered in a foamy substance.

[0058] [Table 6]

[0059] From the evaluation of the defoaming performance of products 1-9 of the present invention and comparative product 5 (sample 8: vegetable oil as a substrate raw material), the remarkable effectiveness of hydrolyzed vegetable oils by 1,3-position-specific lipase was observed. From the evaluation of the defoaming performance with comparative product 1 (sample 9) and comparative product 2 (sample 12), excellent defoaming performance was observed in hydrolyzed vegetable oils with an acid value of 10-30. Comparative products 3 (sample 6) and 4 (sample 7) were evaluated for the defoaming performance of hydrolyzed products by random lipase (triglyceride lipase), and the defoaming performance decreased with increasing monoacylglycerol. Furthermore, comparative products 6 (sample 13) and 7 (sample 14) were evaluated for decomposition products from which free fatty acids generated in hydrolyzed vegetable oils were removed, and from the evaluation of products 8 (sample 10) and 9 (sample 11), respectively, the free fatty acids contained in the present invention contribute significantly to the defoaming effect. The tofu produced using products 1 to 9 of this invention is tofu with excellent soybean flavor and sweetness. [Industrial applicability]

[0060] The tofu defoamer of the present invention has excellent defoaming properties and can therefore be used in the production of tofu products.

Claims

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

2. Furthermore, the tofu defoamer according to claim 1, further comprising medium-chain triglyceride, plant lecithin, magnesium carbonate and / or calcium carbonate.

3. The tofu defoamer according to claim 2, comprising 55 to 65% by mass of hydrolyzed vegetable oil, 10 to 20% by mass of medium-chain 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 hydrolyzed vegetable oil having a composition of 5 to 16% by mass of free fatty acids, 1 to 4% by mass of monoacylglycerols, 13 to 30% by mass of diacylglycerols, and 55 to 80% by mass of triacylglycerols, and an acid value of 10 to 30, characterized by reacting a vegetable oil with an aqueous solution of 1,3-position-specific lipase, which is obtained by dissolving 1,3-position-specific lipase as a lipid-degrading enzyme in 0.5 to 5.0% by mass of water relative to the oil.

5. A process to obtain a hydrolyzed vegetable oil having a composition of 5 to 16% by mass of free fatty acids, 1 to 4% by mass of monoacylglycerols, 13 to 30% by mass of diacylglycerols, and 55 to 80% by mass of triacylglycerols, with an acid value of 10 to 30, by reacting a vegetable oil with an aqueous solution of 1,3-position-specific lipase, which is obtained by dissolving 1,3-position-specific lipase as a lipid-degrading enzyme in 0.5 to 5.0% by mass of water relative to the oil. A step of mixing the aforementioned hydrolyzed vegetable oil with medium-chain triglyceride, plant lecithin, magnesium carbonate and / or calcium carbonate. A method for producing an antifoaming agent for tofu, characterized by containing [the specified ingredient].

6. A method for producing tofu, characterized by using a tofu defoaming agent described in any one of claims 1 to 3 during the production of tofu.

Images