WO2011052793A1 - Method for producing soy milk and method for producing tofu - Google Patents

Abstract

Provided are a method for producing a soy milk having an improved taste which comprises separating and removing offensive taste components from soy milk with the use of a high-speed centrifugal machine, and processed foods produced by using said soy milk. Also provided is a method for producing a soy milk having a reduced fat content which comprises, before removing insoluble components such as okara (bean curd refuse) components, treating a starting soybean solution with a high-speed centrifugal machine to thereby efficiently separate fat as floats and then separating and collecting the residual soy milk. Also provided is a method for continuously producing a tofu having an excellent elasticity and a good flavor, comprising using a liquid coagulating agent which is prepared by mixing a liquid tofu-coagulating agent containing nigari (magnesium chloride) as the main component with the liquid float layer obtained by the aforesaid high-speed centrifugation, can be easily mixed with soy milk and dispersed therein and can exert a sufficiently delayed effect on solidification.

Description

Method for producing soy milk and method for producing tofu

According to the first aspect of the present invention, the “unpleasant taste component” generated when producing soy milk from soybean raw material is separated and removed from the soy milk by a high-speed centrifuge, thereby reducing the unpleasant taste component and improving the taste. The present invention relates to a method for producing soymilk and processed foods produced using the soymilk.
The second aspect of the present invention is a raw koji obtained by grinding or crushing soybeans after adding water, a boiled koji obtained by heating the soybeans, a raw powdered soymilk obtained by dissolving soybean powder in water, and a heated powdered soymilk obtained by heating the soymilk. By applying the soybean raw material liquid before removing insoluble components such as okara components to a high-speed centrifuge, the fat is efficiently separated as a floating component, and the remaining soy milk is separated and collected at that stage, The present invention relates to a method for producing soy milk in which soy milk with reduced fat is efficiently obtained.
The third invention relates to a method for producing tofu by adding a tofu coagulant mainly composed of bittern (magnesium chloride) to soy milk, and more specifically, it is easy to disperse and mix in soy milk, and The present invention relates to a method for producing tofu that continuously obtains tofu that has excellent elasticity and good flavor by developing a coagulant solution that can exhibit a sufficient delayed action effect (slow effect) on the coagulation reaction.

Describing the background art of the first invention, soy milk produced by processing soybeans and processed soybean foods such as tofu made using soy milk are recognized as traditional health foods. However, since these products contain an unpleasant odor and unpleasant taste peculiar to soybeans, they tend to be avoided from the younger generation, and their consumption tends to reach a peak.
In order for young people to eat soy food widely, the appearance of soy milk processed foods such as soy milk and tofu that does not have such “unpleasant odor” and “unpleasant taste” is required.
A typical “unpleasant odor” unique to soybeans is “blue odor”.
The causative substance of this blue odor is hexanal, which is a kind of aldehyde produced by lipid peroxidation involving enzymes such as lipoxygenase. In addition, there are aldehydes and alcohol-based “unpleasant odor components” produced by enzyme oxidation and auto-oxidation.
In addition, “unpleasant taste components” include saponins and isoflavones having astringent taste. However, these substance groups usually exist as glycosides, and the astringent taste becomes stronger when the sugar portion of the glycoside is separated by β-glucosidase to become an aglycon.
There are other unpleasant taste components such as astringency and bitterness, but details such as the components and generation mechanism are not clear.
In this way, the main causes of unpleasant odor and unpleasant taste (consumed by consumers) are the oxidation reaction and decomposition reaction involving the enzyme and the auto-oxidation reaction not involving the enzyme. Various methods for producing soy milk in which unpleasant odor and unpleasant taste are reduced as much as possible have been proposed.
Among them, as a method for suppressing and reducing the occurrence of “unpleasant odor”, in the so-called heat milk squeezing method, a method of quickly heating soybeans to a temperature at which lipoxygenase is deactivated after grinding is taken, It is a common practice to reduce the unpleasant odor by applying a deaeration device in the latter half of the soymilk production process.
In addition, a method of grinding soybeans while deactivating enzymes with hot water (Patent Document 1), a method of grinding soybeans in an oxygen-free environment (Patent Document 2), a method of performing immersion and grinding in a low temperature environment ( Patent Document 3), Method of Fermenting Soy Milk (Patent Document 4), Method of Treating Soy Milk with Ultra High Pressure (Patent Document 5), Method of Treating Ultra High Temperature (Patent Document 6), Method of Treating Soy Milk with Activated Carbon (Patent Document 7) Various techniques are disclosed. In addition, soybeans lacking lipoxygenase have been developed for the purpose of suppressing the generation of hexanal.
As the background art of the first invention, the following prior art documents can be cited.
JP-A-53-047553 JP 52-154545 A Japanese Patent Laid-Open No. 11-243895 JP 2001-57858 A JP-A-5-244866 JP 2006-288253 A JP 2009-34060 A Japanese Patent Laid-Open No. 62-232349 Japanese Patent Publication No. 56-050818 WO2008 / 081948 Journal of Japanese Society for Food Science and Technology, Vol. 45, No. 2, 122-128 (1998) Journal of Japan Society for Food Science and Technology, Vol. 48, No. 4, pages 253-262 (2001)

On the other hand, as a method of suppressing or reducing the occurrence of “unpleasant taste”, a method of reducing the carry-on of saponins, isoflavones, and oxidation-related enzymes by performing molting and de-embryonic axis treatment before grinding of soybean (the above-mentioned patent document) 8) A method for inhibiting β-glucosidase by containing gluconodeltalactone in immersion water (the above-mentioned Patent Document 9) is disclosed.
As described above, the causal components have become relatively clear particularly with respect to “unpleasant odors”, and techniques for suppressing or reducing their generation have been widely developed.
It is known that tofu made using the aforementioned lipoxygenase-deficient soybean generally has a pale taste. There is also a finding that the lipid oxidation product by lipoxygenase affects the taste of the better side of tofu (non-patent documents 1 and 2 above), while excessive oxidation inhibition during soymilk production can reduce unpleasant odors, It is thought to lead to lighter taste.
In view of such knowledge, a soymilk production apparatus having both an oxidation suppression process and a process of causing appropriate oxidation in the soymilk production process has been proposed. (Patent Document 10 above)
On the other hand, regarding “unpleasant taste”, the causal component has not been clarified so much, and only technical measures for saponins and isoflavones have been made. In particular, the technology for suppressing “astringency” is insufficient. It was.
An object of the first invention is to provide a method for producing soymilk with improved taste and a processed food produced by using the soymilk, while maintaining an appropriate flavor and reducing "unpleasant taste" such as astringency. It is to provide.
Next, the background art of the second invention will be described. Recently, consumer interest in food functionality has increased, and various health functions of soybean have become widely known. The main functional components of soybean include soybean protein, isoflavone, lecithin, saponin, soybean oil, etc. Of which soybean oil contains polyunsaturated fatty acids such as linoleic acid and linolenic acid, and does not contain cholesterol. Therefore, the evaluation has been established as an oil that is healthier than animal oil.
In addition, soy milk and tofu have the image of diet food, but if you eat more of them, the calorie intake will increase accordingly.
For example, according to the 5th amendment Japanese food standard ingredient table, the energy of ordinary milk is 67 kcal per 100 g and the lipid content is 3.8 g per 100 g, whereas in the case of tofu, the filling tofu has an energy of 59 kcal and a lipid content. In 3.1 g of cotton tofu, the energy is 72 kcal and the lipid content is 4.2 g.
Therefore, when trying to consume a large amount of soy protein with soy milk or tofu, naturally, a large amount of lipid is also consumed, and as a result, a large amount of energy (so-called calories) is consumed.
Recently, calorie-off products have been developed in various food fields, and they are gaining popularity. In the field of soy milk and tofu, it is necessary to develop products that respond to consumers' desire to reduce calorie intake. It has become.
In general, in order to develop foods with reduced calories, it is necessary to reduce any of the carbohydrate, protein, and lipid components that are the source of energy.
Even in the case of processed foods made by combining various food ingredients, methods such as reducing the proportion of sugar and oil from conventional recipes or replacing sugar with low-calorie oligosaccharides or other non-calorie sweet ingredients are adopted. Has been.
However, for natural products such as milk, the method of reducing the calories by separating and reducing the fat content in the components contained therein is actually used. Of course, skim milk powder and separated milk protein are of course used. Although dairy products with reduced fats have been manufactured by utilizing the dairy products, the dairy products obtained in this way are dairy products that are qualitatively different from the general manufactured milk. There was a reality.
In the case of soymilk, soymilk produced by adding only water to soybean is a product close to nature, and the result is that the fat originally contained in soybean remains as it is.
In order to reduce calories from the soymilk, the most practical method is to reduce fat by the same method as milk. In addition, as with milk, a method using defatted soybeans or separated soybean protein is also conceivable, but in any case, the actual situation is that soy milk obtained is not widely used in the world due to the large quality gap.
As the background art of the second invention, the following prior art documents can be cited.
JP-A-7-27485 WO2002 / 026788 Journal of Japanese Society of Food Industry Vol.19, No.12, 580-584 (1972)

In the case of milk, generally, using a dedicated centrifuge such as a cream separator, fat content is separated into a so-called light liquid side as a cream layer, and low fat milk is separated into a heavy liquid side. Thus, in milk, since the light liquid side (cream) and the heavy liquid side (low fat milk) are separated under relatively weak centrifugal conditions, it is relatively easy to separate and collect the low fat milk.
On the other hand, even in the case of soymilk, methods for fractionating components such as proteins and fats by applying soymilk to a high-speed centrifuge or ultracentrifuge have been performed (Patent Documents 11 and 12 and Non-Patent Document 3). . For example, Patent Document 11 uses a centrifugal separation method as a means for fractionating and measuring a protein, and Patent Document 12 uses a centrifugal separation method as a means for separating an oil body in soy milk.
However, as described in Non-Patent Document 3, in soy milk, the emulsified state is very stable, and thus strong centrifugal conditions are required to separate fat (cream layer). Therefore, in Patent Documents 11 and 12, soy milk is centrifuged under strong centrifugal conditions based on such knowledge to separate necessary components for separation. As described above, it is known that soy milk can also be separated by centrifugal separation in the same manner as milk. However, since the emulsified state of soy milk is more stable than milk, the separation efficiency for separating fat is high. Poorness has been a challenge in developing fat reduction products in the soy milk and tofu industries. An object of the second invention is to provide a method for producing soy milk that can improve the separation efficiency for separating fat and efficiently produce soy milk with reduced fat.
The background art of the third invention will be explained. In the production of tofu, a so-called slow-acting coagulant having a slow coagulation reaction with soy milk such as calcium sulfate or glucono delta lactone (GDL) has been used. There were many.
These slow-acting coagulants have been favorably used for mass production of tofu because of good workability and yield of tofu production.
Recently, however, consumer preference has shifted to tofu using traditional bittern (magnesium chloride) in terms of flavor, and tofu production using bittern has become the mainstream.
But originally, bittern is a fast-acting (that is, the coagulation reaction is remarkably fast) coagulant, so when tofu is made using this bittern, it requires skill to produce stable quality tofu, Therefore, there was a problem in mass production of tofu.
In order to deal with this problem, add a bittern solution to hot soymilk and devise a stirring device so that it can be dissolved immediately and uniformly, or once cool the hot soymilk and add bittern under that condition Methods such as controlling the coagulation reaction have been employed.
However, the former is difficult to stabilize the quality of tofu and is insufficient in terms of production capacity, and the latter has the difficulty of requiring equipment for cooling soy milk and increasing energy costs. .
Therefore, in order to solve the above problem, research for slowing the coagulation reaction of bittern has been advanced and various methods have been proposed.
For example, various coagulant preparations have been proposed in which an oil or fat or an emulsifier is mixed with an inorganic salt-based coagulant such as magnesium chloride to ensure the slow action of the coagulation reaction (Patent Documents 13 to 23, etc.). These coagulants are so-called emulsifying coagulants in which the coagulation reaction is delayed by coating magnesium chloride or the like with an emulsifier or oil. Several types of such emulsifying coagulants have already been put into practical use, and contribute to mass production of tofu using bittern as a coagulant.
On the other hand, there is also proposed a method (Patent Document 24) that uses not only an emulsifying coagulant using a food additive but also tofu or soy milk with bittern added at a high concentration as a coagulant solution.
As for the background art of the third invention, the following prior art documents can be cited.
JP-A-5-304923 JP-A-10-57002 JP-A-10-179072 Japanese Patent Laid-Open No. 11-98970 JP 2000-32942 A JP 2005-176551 A JP 2006-204184 A JP 2008-154526 A JP 2008-193999 A JP 2006-101848 A JP 2008-295381 A JP 2002-112728 A

In the conventional emulsion coagulant described above, a large dispersion shear force is required in order to finely disperse and mix the emulsion of the coagulant in soy milk. In addition, when synthetic emulsifiers such as glycerin fatty acid esters are used, some people who are sensitive to the flavor of tofu have pointed out that the flavor of tofu is impaired due to the flavor of the synthetic emulsifier. Improvement was desired.
In the case of the technique of Patent Document 24, it is considered that the natural emulsification action of soy milk is utilized, but there is a problem that the effect is insufficient as a method for controlling the coagulation reaction.
The object of the third invention is to develop a coagulant liquid that can be easily dispersed and mixed in soy milk and that can achieve a slow-acting coagulation reaction, and this coagulant liquid has excellent elasticity and good flavor. Is to be able to be manufactured continuously.

As a first invention (Claims 1 and 2), the present inventors have maintained a proper flavor without excessive oxidation suppression in producing soy milk from soybean raw materials in order to solve the above-mentioned problems. As a result of diligent research on methods to reduce "unpleasant taste" such as astringency, the soymilk is subjected to a high-speed centrifuge to remove the upper-floating components and fractionate the lower-layer soymilk to maintain an appropriate flavor. The inventors have found that soy milk with reduced unpleasant taste such as can be obtained, and have completed the first invention.
That is, the invention according to claim 1 relating to the first invention is a method in which soy milk produced from a soybean raw material is subjected to a high-speed centrifuge, the suspended components in the upper layer separated after the centrifugal action are removed, and left in the lower layer A method for producing soymilk with improved taste, wherein only soymilk is fractionated.
The invention according to claim 2 is a method in which soy milk produced from soybean raw material is subjected to a high-speed centrifuge, suspended components in the upper layer separated after the centrifugal action are removed, and only the soy milk remaining in the lower layer is separated. It is the processed food manufactured using the soymilk obtained.
According to the method for producing soymilk with improved taste according to the first invention (inventions 1 and 2), there is an effect that soymilk with reduced unpleasant taste can be obtained only through a simple centrifugation step.
Processed foods such as traditional soymilk and processed tofu made from it have an unpleasant taste mainly due to the astringency remaining in the taste afterwards, so there is a tendency to avoid eating to young people in particular, and demand has peaked. However, according to the present invention, since the soy milk and its processed food improved in taste by reducing the aftertaste astringency is obtained, it is also accepted by consumers who have avoided astringency, The effect of leading to an increase in demand for soybean food as a health food can also be achieved.
In addition, as a second invention (claims 3 to 5), the present inventors have intensively studied a method capable of efficiently producing soy milk with reduced fat. As a result, the raw koji obtained by grinding or crushing soybeans after adding water Boiled cucumber that has been heat-treated, raw soymilk in which soybean powder is dissolved in water, and soy raw material liquid before removing insoluble components such as okara ingredients such as heated powdered soymilk that has been heated By applying the centrifuge, fat can be easily separated as a floating component, and the separation efficiency of fat is significantly improved compared to the conventional method of removing soy milk after removal of insoluble components such as okara components. As a result, the second invention was completed.
That is, in the invention according to claim 3 relating to the second invention, the soybean raw material liquid before removing insoluble components such as okara components is subjected to a high-speed centrifuge to efficiently separate fat as a floating component, and the rest A method for producing soymilk, wherein the soymilk is separated and collected as fat-reduced soymilk.
In the invention of claim 4, the soybean raw material liquid is raw koji obtained by pulverizing or crushing soybeans after being added, boiled koji obtained by heat-treating the raw koji, or soy powder is dispersed and dissolved in water. 4. The method for producing soymilk according to claim 3, wherein the soymilk is either raw powder soymilk or heated powdered soymilk obtained by heat-treating the raw powdered soymilk.
Further, the invention according to claim 5 is characterized in that the soybean powder is either a powder obtained by pulverizing soybean or a pulverized processed powder of soybean treated so as to be easily dispersed and dissolved in water. It is a manufacturing method of the soymilk of Claim 3 or Claim 4.
According to the method for producing soymilk of the second invention (claims 3 to 5), the fat can be efficiently separated and the soymilk with reduced fat can be obtained efficiently only through a simple centrifugation step. The effect is achieved.
In conventional soymilk technology, fat-reduced soymilk, which has not been put into practical use due to poor fat separation efficiency, can be produced efficiently according to the present invention. The effect of being able to meet the expectations of the person is also achieved.
Furthermore, as a third invention (Claims 6 to 9), the present inventors added a coagulant such as bittern to the floating layer liquid obtained by applying soy milk or soybean raw material liquid to a high-speed centrifuge to solve the above-mentioned problems. Obtaining a coagulant solution for tofu that has been mixed and dissolved, adding a coagulant solution to soy milk, delaying the coagulation reaction of soy milk, finding a method for producing tofu that is rich in elasticity and good in flavor, The third invention has been completed.
That is, the invention according to claim 6 relating to the third invention is to produce a coagulant liquid by mixing a coagulant for tofu with a floating layer liquid obtained by subjecting soy milk to a high-speed centrifuge. A method for producing tofu characterized by being added to soy milk to cause a coagulation reaction.
The invention according to claim 7 is characterized in that a coagulant for tofu is mixed with a floating layer solution obtained by subjecting a soy material solution before removing insoluble components such as okara components to a high-speed centrifuge, and a coagulant solution. And the coagulant solution is added to soy milk to cause a coagulation reaction.
Next, the invention according to claim 8 is that the soybean raw material liquid is raw cucumber obtained by pulverizing or crushing soybeans, or boiled cucumber obtained by heat-treating the raw cucumber, or by dispersing and dissolving soybean powder in water. The method for producing tofu according to claim 7, wherein the raw material is either raw powder soymilk or heated powdered soymilk obtained by heat-treating the raw powdered soymilk.
Further, the invention according to claim 9 is characterized in that the soybean powder is either a powder obtained by pulverizing soybean or a pulverized processed powder of soybean treated so as to be easily dispersed and dissolved in water. The method for producing tofu according to claim 8.
According to the method for producing tofu of the third invention (Inventions 6 to 9), it is possible to obtain a coagulant liquid that is easy to disperse and mix in soy milk and that can exhibit a sufficient slow-acting effect on the coagulation reaction, By using the coagulant, the effect of producing tofu with excellent elasticity and good flavor can be achieved.

It is a graph (radar chart) of the sensory evaluation test result of Table 4. It is a graph (radar chart) of the sensory evaluation test result of Table 6.

Embodiments of the first invention will be described below, but these are exemplarily shown, and it goes without saying that various modifications are possible without departing from the technical idea of the present invention.
The soybean raw material used in the first invention is not particularly limited as long as it is a raw material capable of producing soy milk, such as whole soybeans, molted soybeans, molted and dehulled soybeans, and powdered soybeans. Moreover, it can use arbitrarily regardless of domestic soybean and foreign soybean, and these mixtures may be sufficient.
The soy milk used in the first invention may be obtained by a conventional method. For example, the raw koji obtained by pulverizing the soy raw material soaked in water is heated to obtain boiled koji, which is separated into solid and liquid. And soy milk. Alternatively, soy milk (powder soy milk) obtained by dissolving powdered soybeans in water or hot water may be used.
As mentioned above, when using soy milk to produce an excessively low-oxidation process, how much flavor is left in consideration of the fact that unpleasant odors are reduced, while the flavor tends to be pale. The soymilk production apparatus and production conditions can be selected.
The high-speed centrifuge may be a batch type or a continuous type. In the case of mass production, a continuous centrifuge is preferable, and for example, a cream separator used in the dairy industry can be used.
The conditions under which the soymilk is centrifuged can vary depending on the desired soymilk quality after centrifugation. According to the present invention, the soy milk obtained after centrifugation is a soy milk with a refreshing aftertaste and enhanced sweetness, particularly since the astringency component remaining as an aftertaste is removed. Unfortunately, at present, it has not been clarified academically what kind of component the astringency remaining as the aftertaste is due to.
However, this astringent taste is a major factor of unpleasant taste over isoflavones and saponins, and it is considered that soy milk and its processed food are the main cause of avoidance. According to experiments, as a result of comparing the isoflavone composition and content of soymilk before centrifugation and soymilk after centrifugation, there was almost no change in both. Despite the current situation, there was a clear difference in the sensory evaluation test for the astringency that was felt as a aftertaste.
On the other hand, uncomfortable odor components were compared in the same manner, but unpleasant odors such as hexanal, 1-pentanol, 1-hexanol, 1-octen-3-ol, 1-penten-3-ol, 2-pentylfuran, etc. The component referred to as the component was the same before and after centrifugation, or only slightly decreased after centrifugation. Therefore, it is considered that the clear reduction in astringency is different from the change in the conventional unpleasant odor component.
In 1st invention, the lipid content of soybean floats as a cream, so that the centrifugal force at the time of centrifugation is applied strongly. Therefore, soy milk with reduced lipid can be obtained according to the strength of centrifugal force. However, since the astringent component remaining in the aftertaste, which is a major cause of unpleasant taste, moves to the upper layer if there is a certain amount of centrifugal force, the taste is improved regardless of the residual amount of lipid in the soy milk obtained by separation. The
Specifically, a centrifugal force of 2000 × g or more at centrifugal acceleration, or a centrifugal force of 3500 × g or more may be applied for efficient separation.
The temperature of the soymilk at the time of centrifugation is not particularly limited as long as the soymilk can be kept in a liquid state, but it is not necessary to make the temperature so low. Good temperature range.
However, since the lipid content is easily separated as the soy milk temperature is higher, it is more efficient to increase the soy milk temperature for the purpose of obtaining soy milk with reduced lipids.
According to the first invention, the soy milk in which the centrifugal force is increased and the lipid is reduced becomes clean and sweet with no unpleasant taste, and if it is made tofu, it can be made a delicious calorie-reduced tofu.
Examples of the First Invention Hereinafter, the first invention will be specifically described with reference to Examples 1 and 2, but the first invention is not limited to Examples 1 and 2.

The soy milk manufactured based on the conventional method in the tofu factory manufacturing field was used for the test. This soy milk is a soy milk obtained by using Canadian soybeans, soaking overnight and then grinding with a grinder while adding water, heating in an indirect steamer, and separating okara with a screw press. This soy milk was dispensed into a centrifuge tube for a high-speed centrifuge (Hitachi Koki Co., Ltd. 18PR-52) in a laboratory, and centrifuged at 8000 rpm (centrifugal acceleration of the tube center: about 6000 × g) for 15 minutes. .
The temperature immediately before centrifugation of the soymilk was 40 ° C. After centrifuging, the suspended matter in the upper layer of the tube was removed, and the lower layer of soymilk was collected to obtain soymilk. The component analysis and the sensory evaluation test were compared using the soy milk to be controlled subjected to centrifugation as the pre-separation soy milk and the soy milk separated after the centrifugation as the soy milk after separation.
<Nutrition analysis>
The solid content, protein, lipid, and ash content of each soymilk were analyzed based on a conventional method, and the remainder obtained by subtracting the protein, lipid, and ash content from the soymilk solid content was expressed as a carbohydrate content. That is, the solid content was shown as a dry solid content by measuring the weight after drying at 105 ° C. for 24 hours. The protein content was measured using a Kjeldahl analyzer (Keltech system manufactured by Foss Japan Co., Ltd.) and calculated using a nitrogen conversion factor of 5.71.
Lipid content was measured by extracting lipids by the hexane-isopropanol method. Ash content was measured by ashing using a muffle furnace (Carbolite Furnaces). The analysis results are shown in Table 1.

<Isoflavone analysis>
The analysis of isoflavones in each soymilk was performed as follows. Isoflavones were extracted from accurately weighed soymilk with 70% ethanol and analyzed by high-performance liquid chromatography in accordance with the soy isoflavone test method of the “Health Food Standards Collection” of the Japan Health and Nutrition Food Association. . The results are shown in Table 2.

<Flavor component analysis by gas chromatography>
Analysis of volatile flavor components in each soymilk was performed by gas chromatography (GC-MS). In other words, soy milk with 5 mM EDTA and 1 ppm cyclohexanol (internal standard) added is sealed in a 20 ml sealed bottle, and volatile components of soy milk are adsorbed by solid phase microextraction (SPME) method at 40 ° C. for 30 minutes. And subjected to GC-MS analysis (Shimadzu Corporation GCMS-QP2010).
The analysis results are shown in Table 3.

As described above, the soy milk after separation had about 10% less lipid than the pre-separated soy milk, but there was almost no difference in isoflavone composition, and the unpleasant odor components were the same for both or 10% for the soy milk after separation. It was about to decrease around.
Next, a sensory evaluation test of each soymilk was performed.
The sensory evaluation test was conducted by 15 panelists, and the five items of sweetness, body, astringency, astringency and blue odor were evaluated by a 5-point method. With 3 points as standard, the higher the value, the lower the value, the stronger the taste and the flavor of each. Table 4 shows the average value of the results, and FIG. 1 shows the graph (radar chart).

As described above, the soy milk after separation was clearly evaluated to have a reduced astringency and enhanced sweetness compared to the soy milk before separation. In particular, there were many opinions that the astringency remaining as a normal aftertaste was drastically reduced, and it was estimated that the sweetness was easily felt.
This astringent component is considered to be a component different from isoflavones, flavor components, and lipid components, but is for further study.

The same soymilk used in Example 1 was used and centrifuged under the following conditions. That is, soybean milk was ground and steamed, and the soy milk immediately after separating okara with a screw press was collected from the production site and subjected to a high-speed centrifuge. The soymilk temperature immediately before centrifugation was 65 ° C. Centrifugation was carried out at a centrifugal acceleration of 6000 × G for 20 minutes to remove the upper layer floating components and to separate the lower layer soymilk to obtain soymilk. Table 5 shows component analysis values of soy milk before separation and soy milk after separation.

The soymilk after separation had half of the lipid before separation. Therefore, if tofu is made using this soy milk, it becomes tofu with reduced calories.
Filled tofu was prepared as follows using each soymilk. That is, a coagulant (magnesium chloride) was added to each soymilk cooled to 5 ° C. so as to be 0.3% by weight with respect to the weight of the soymilk, and filled into filled tofu containers. The package film was covered and sealed, and heated and solidified in a constant temperature water bath at 85 ° C. for 45 minutes. After solidification, the sample was cooled in cold water and then subjected to a sensory evaluation test.
The sensory evaluation test was conducted by 15 panelists, and the five items of sweetness, body, astringency, astringency and blue odor were evaluated by a 5-point method. With 3 points as standard, the higher the value, the lower the value, the stronger the taste and the flavor of each. Table 6 shows the average value of the results, and FIG. 2 shows the graph (radar chart).

The tofu produced using the soy milk after separation is a tofu with a lipid content of 1/2 and reduced calories. Although there was a slight decrease in the body, the astringency was drastically reduced and it was evaluated as sweet tofu. Therefore, delicious calorie-reduced tofu can be produced by adjusting the centrifugation conditions according to the present invention.
Next, embodiments of the second invention will be described. These are exemplarily shown, and it goes without saying that various modifications are possible without departing from the technical idea of the second invention.
In general, soymilk is produced as described below. That is, the raw material soybean is immersed in water overnight, and after adding water, it is ground or crushed to obtain “Ikugo”. In some cases, a method is also employed in which soybean is moulted and hydrated without being immersed in water and ground or crushed.
This raw kure is heated to 80 ° C. to 120 ° C. to obtain “boiled kure”, and further solid-liquid separation (generally referred to as “squeezed”) is removed to obtain soy milk. In order to obtain soy milk by squeezing the boiled rice after heating in this way, this method is called the “heating squeezing method”.
On the other hand, the method of obtaining soy milk from which components have been removed after solid-liquid separation of raw kure as it is and then heating it is called the “raw squeezing method”.
In general, the former “heating squeezing method” is used by paying attention to the rapid deactivation of endogenous enzymes involved in oxidation such as lipoxygenase which leads to generation of unpleasant odor.
Furthermore, with the recent progress in soybean powdering technology, soy milk, tofu, etc. are partially produced using soybean powder as a raw material. In this case, soybean powder mainly made from molted soybeans is used, and soy milk, tofu, etc. can be produced without separation from okara. In particular, due to the development of a fine pulverizer and the like, even when powder is used, problems of discomfort such as a rough feeling, which has been a problem in the past, have been remarkably improved.
The soybean raw material used in the second invention is not particularly limited as long as it is a raw material capable of producing soy milk, such as whole grain soybeans, molted soybeans, and molted dehulled soybeans. Moreover, it can use arbitrarily regardless of domestic soybean and foreign soybean, and these mixtures may be sufficient.
In the second invention, the “soybean raw material liquid” is raw koji obtained by pulverizing or crushing soybeans, further boiled koji obtained by heating the soybeans, or soybean powder obtained by pulverizing soybeans. It means either raw powder soymilk dispersed and dissolved in water, or heated powder soymilk that has been heat-treated.
In the second invention, “soybean powder” refers to a powder obtained by finely pulverizing soybeans or a finely pulverized processed powder of soybeans that has been treated so as to be easily dispersed and dissolved in water. Specifically, in addition to powder obtained by simply pulverizing soybeans, powder pulverized so as to have a particle size of several tens of μm or less, or powder produced by minimizing leaching of fats and oils during pulverization, frozen It refers to pulverized powder, powder containing other food materials and food additives to enhance solubility.
The soybean powder used in the second invention may be a commercially available soybean powder, or may be a soybean powder that has been home-grown using a pulverizer, reducing the burden on the centrifuge as much as possible. For this purpose, a soy powder devised so as to be finely dispersed and easily dissolved is preferable.
The high-speed centrifuge used in the second invention may be a batch type or a continuous type, but in the case of mass production, a continuous centrifuge is preferable.
A continuous centrifuge called a screw decanter may be used for okara separation, but the current separation machine cannot separate and collect fat from the viewpoint of a two-phase separation type device structure and centrifugal capacity. Therefore, utilization of a three-phase separation type high-speed centrifuge or its improved machine can be considered.
As a condition for preparing the soybean raw material liquid, considering that the burden on the centrifuge is less when the amount from the side of the centrifuge is as small as possible, for example, the use of moulted soybean as a raw material, and grinding / It is conceivable to make the degree of crushing as fine as possible.
In addition, when dispersing and dissolving soybean powder in water, it may be devised to increase the solubility by a method such as slightly raising the pH.
The conditions for subjecting the soy material solution to the centrifuge will vary depending on the desired quality of the reduced-fat soy milk after separation. That is, the centrifugal acceleration is preferably 3500 × g or more, and the higher the centrifugal acceleration, the higher the fat separation efficiency.
The temperature of the soybean raw material liquid is not particularly limited as long as the raw material liquid can be kept in a liquid state, but it is not necessary to lower the temperature.
In the case of soy milk after okara separation, the higher the temperature during centrifugation, the easier it is to separate fat, but in the case of the soybean raw material liquid in the present invention, the difference in the separation efficiency of fat due to temperature is not large. Depending on the type of soy raw material liquid to be used and the desired quality of the reduced-fat soy milk, the optimum conditions are selected and adjusted in the balance between the fat separation efficiency and the energy efficiency. However, when using a soybean raw material solution prior to heating, such as uncooked rice, the oxidation-related enzymes such as lipoxygenase are not inactivated, and thus control thereof is necessary.
As described above, in the case of milk, fat (cream) and low-fat milk can be separated under relatively weak centrifugal conditions. However, when separating fat (cream) and fat-reduced soy milk from soy milk, strong centrifugal conditions are required. . The reason is considered that soy milk is in a more stable emulsified state than milk.
In the second invention, since the soy milk before the removal of insoluble components such as okara components is used as the soybean raw material liquid, the separation efficiency of fat is improved. The reason for this is that the solubilized state of soymilk is insufficient at the stage before removing insoluble components such as okara components, and so-called homogenization effect occurs in the squeezing step for separating okara, which further stabilizes the emulsified state. Therefore, the separation efficiency of fat is reduced after okara separation.
According to the second invention, raw koji before removing insoluble components such as okara, boiled koji obtained by heat-treating it, or raw powdered soymilk, or heated powdered soymilk, if applied to a centrifuge, okara components, etc. A larger amount of fat can be separated than when the soymilk after removing insoluble components is centrifuged under the same centrifugal conditions. Moreover, since insoluble components such as okara components can be separated at the same time, it is possible to obtain soy milk with reduced fat efficiently in one centrifugation step even if insoluble components are not present in the soybean raw material liquid.
Examples of the Second Invention Hereinafter, the second invention will be specifically described with reference to Examples 3 and 4, but the second invention is not limited to these Examples.

At the production site of the tofu factory, the soy milk separated from the raw koji, boiled kew, and okara was collected from the line that was continuously produced according to a conventional method, and used for the test.
In this production line, soy milk was produced using Canadian soybeans, immersed in water overnight and then ground with a grinder while adding water, heated in a continuous heating kettle, and separated from okara with a screw press.
From the process of continuous flow, “Ikugo” immediately after grinding with a grinder, “Nigure Kure” immediately after heating in a continuous heating kettle, and “Soymilk” immediately after separating okara with a screw press device were collected. Is.
Each raw material solution is dispensed into a centrifuge tube for a high-speed centrifuge (Hitachi Koki Co., Ltd. 18PR-52) in a laboratory, and centrifuged at 8000 rpm (centrifugal acceleration at the center of the tube is about 6000 × g) for 30 minutes. went.
The temperature of each raw material liquid was 40 ° C., and the temperature condition of the centrifuge was 40 ° C.
Each raw material liquid is separated into three layers, that is, a fat (cream) layer, a soy milk layer, and a precipitation layer by centrifugation. From this, the cream layer on the upper layer of the tube was removed, and soy milk layers other than the precipitated layer were collected. Using the soy milk before being centrifuged as a control, the ingredients were compared with the soy milk from which the fat from each raw material liquid was separated.
In the component analysis, the solid content, lipid, protein, and ash content of each soymilk were analyzed based on a conventional method, and the remainder obtained by subtracting the lipid, protein, and ash content from the soymilk solid content was expressed as a carbohydrate content. That is, the solid content was measured as the weight after drying at 105 ° C. for 24 hours and indicated as the dry solid content.
Lipid content was measured by extracting lipids by the hexane-isopropanol method.
The protein content was measured using a Kjeldahl analyzer (Keltech system manufactured by Foss Japan Co., Ltd.) and calculated using a nitrogen conversion factor of 5.71.
The ash content was measured by ashing using a muffle furnace (manufactured by Carbolite Furnaces).
The analysis results are shown in Table 7.

As shown in Table 7, regarding the lipid content, the ratio to the solid content was also described.
8%, 5%, and 11% of the fat-separated soymilk in the case of raw kyu, boiled kyu, and soymilk as a raw material solution, respectively, as a percentage (%) of the solid content (29% for the control soymilk) Thus, it was found that the separation efficiency of fat was significantly improved when raw koji and boiled kure were used as raw material solutions than when soy milk was used as raw material solutions.

The following tests were carried out using commercially available domestic soybean powder as a raw material.
First, water 5 times the weight of soybean powder was added and dispersed and dissolved using a homogenizer to obtain “raw powder soymilk”. This raw powder soymilk was placed in a round bottom round flask and heated while blowing steam in a boiling water bath. When reaching 95 ° C., the steam blowing was stopped, and the mixture was further heated in a boiling water bath for 2 minutes. The soy milk thus obtained was designated as “heated powdered soy milk”.
This heated powdered soymilk was subjected to a centrifugal dehydrator (H-112 manufactured by Kokusan Co., Ltd.) equipped with a filter cloth to remove insoluble components (okara components), soymilk was obtained, and “filtered soymilk” was obtained.
Each soymilk was used as a raw material solution and subjected to a high-speed centrifuge in the same manner as in Example 1.
The centrifugation conditions were the same as in Example 1, 40 ° C., 8000 rpm, 30 minutes.
After centrifugation, the upper cream layer was removed, and the soymilk layer other than the precipitated layer was separated and collected.
Using the filtered soymilk before being subjected to the centrifuge as a control, the components were compared with the fat-separated soymilk from each raw material liquid.
Component analysis was performed in the same manner as in Example 3.
The analysis results are shown in Table 8.

As shown in Table 8, regarding the lipid content, the ratio to the solid content was also described.
When the fat content of each fat-separated soymilk using raw powdered soymilk, heated powdered soymilk, and filtered soymilk as a raw material liquid is compared with the ratio (%) to the solid content, 15%, 14%, and 17% respectively (the control soymilk is 22%), and the separation efficiency of fat was better when raw powdered soymilk and heated powdered soymilk were used as raw material solutions than when filtered soymilk was used as the raw material solution.
However, when compared with the examples of raw and boiled cucumbers shown in Example 3, the difference in fat separation efficiency of the powdered soymilk was not significant. This is considered to be due to the influence of component modification during powder production and subsequent, and the effect of stabilizing the emulsified state because the dispersion is homogenized using a homogenizer when the powder is dissolved in water. However, if it supplements about this, although it does not show in the Example, it will become possible to raise the separation efficiency of fat further by adjusting conditions, such as raising the temperature of the raw material liquid at the time of centrifugation.
Embodiments of the third invention will be described below, but these are exemplarily shown, and it goes without saying that various modifications are possible without departing from the technical idea of the third invention.
The soybean raw material liquid in the third invention is raw koji obtained by grinding or crushing soy after adding water, boiled koji obtained by heat-treating the raw kyu, or raw powder soymilk in which soybean powder is dispersed and dissolved in water. It means any raw material liquid of heated powdered soymilk obtained by heat-treating the raw powdered soymilk. On the other hand, soy milk means a product obtained by removing insoluble components by subjecting the soybean raw material liquid to various solid-liquid separation operations including filtration.
The tofu coagulant used in the third invention is a coagulant mainly composed of magnesium chloride (nigari) and means a combination of sodium chloride, calcium chloride, calcium sulfate, glucono delta lactone (GDL) and the like.
The high-speed centrifuge used in the third invention may be a batch type or a continuous type, but a continuous type centrifuge is preferable for mass production.
A continuous centrifuge called a screw decanter may be used for okara separation. However, the present separator does not use the floating layer liquid of the present invention in view of the structure of the two-phase separation type and the centrifugal capacity. I can't get it.
Then, when using soy milk, a continuous high-speed centrifuge such as a “cream separator” used in the dairy industry can be used. In the case of using the soybean raw material liquid, utilization of a three-phase separation type high-speed centrifuge or its improved machine is conceivable.
The floating layer liquid obtained by applying the soymilk or soybean raw material liquid used in the third invention to the high-speed centrifuge is obtained by applying a continuous high-speed centrifuge as an "upper layer liquid" as a result of applying the soymilk or soybean raw material liquid to the high-speed centrifuge. When used, it is obtained as a “light liquid”.
When soy milk or soybean raw material liquid is selected and subjected to a high-speed centrifuge under appropriate conditions, it is separated into three layers: a floating layer mainly composed of a cream component, a soy milk layer reduced in fat, and a precipitated layer of insoluble components. If a continuous high-speed centrifuge is used, the floating layer is obtained by separating it on the “light liquid” side and the soy milk layer on the “heavy liquid” side.
The conditions for applying the soymilk or soybean raw material liquid to the centrifuge are not particularly limited as long as the floating layer is separated as described above, but considering the efficiency, the centrifugal acceleration is preferably 3500 × g or more, The temperature at the time of the centrifugal separation is not particularly limited as long as the raw material liquid can be kept in a liquid state, but it is not necessary to lower the temperature.
Like the soy milk, the resulting floating layer liquid is composed of water, protein, lipids, and carbohydrates, and is characterized by a high lipid content, but it can also be used to make tofu. It can be said that the soy milk is concentrated in fat.
Patent Document 24 discloses a coagulant liquid obtained by mixing tofu or soymilk with magnesium chloride (bittery). As in the present invention, soymilk (floating layer liquid) in which fat is concentrated by a centrifugal separation method is used. There is no mention about that.
The mixing ratio of the floating layer liquid and the coagulant in the coagulant liquid of the third invention is adjusted according to the desired degree of delayed action and the final coagulant concentration, but the mixing ratio of the coagulant is increased. If it is too high, it will be difficult to dissolve in the floating layer solution, and if it is too low, the concentration of the coagulant in the coagulant solution will be diminished, resulting in an excessive amount of coagulant solution required to produce tofu. The ratio is preferably 1: 1 to 20: 1.
Mixing of the floating layer liquid and the coagulant may be performed manually using a stirring device, or may be performed using a stirring device such as a general propeller stirrer.
In addition, soymilk has the property of causing a coagulation reaction to become tofu when an appropriate amount of coagulant is added and mixed, and does not cause a coagulation reaction if the amount of coagulant added is too small or too large.
As described above, the floating layer liquid of the present invention is composed of water, protein, lipid, and carbohydrate, and thus tofu can be produced by adding an appropriate amount of a coagulant thereto.
However, in the scene where the coagulant is added to the above floating layer solution in order to prepare the coagulant solution of the third invention, the mixing ratio as described above is taken, and as a result, the floating layer solution On the other hand, since an excessive coagulant is added and mixed, the coagulation reaction does not occur in that scene.
The mixing of the coagulant liquid used in the third invention with soy milk disperses relatively easily without requiring a particularly large dispersion force, so there is no need to use a special high-performance emulsifier or the like, and general stirring The device can be used.
Further, the temperature of the soy milk at the time of mixing the coagulant liquid is not particularly limited, but in order to effectively utilize the delayed action of the coagulant liquid which is the object of the third invention, it is set to 60 to 90 ° C. desirable.
In addition, the common emulsification coagulant marketed has a W / O type emulsified state, and exhibits delayed action by dispersing it in soy milk to obtain a W / O / W type emulsified state. However, since the coagulant liquid in the third invention is considered to be rather an O / W type, it is presumed that it exerts a delayed action effect by a mechanism different from that of a general emulsion coagulant.
Furthermore, according to the third invention, once the floating layer liquid is separated from the soy milk, a coagulant liquid prepared by mixing an appropriate amount of bittern into this is prepared, and once again returned to the remaining soy milk to produce tofu, It is possible to produce tofu with the exact same composition as when simply adding bittern.
Example of Third Invention The third invention will be described more specifically based on Example 5 below, but the third invention is not limited to these.

Soy milk was collected from a line that was continuously produced at a tofu factory production site based on a conventional method, and was subjected to a test. This production line is made from Canadian soybeans, soaked in water overnight, ground with a grinder while adding water, heated in a continuous steamer and separated from okara with a screw press to produce soy milk.
From the continuous flow process, the soymilk collected immediately after separating the okara with a screw press is separated into a centrifuge tube for a high-speed centrifuge (Hitachi Koki Co., Ltd. 18PR-52) in the laboratory. Then, centrifugation was performed at 8000 rpm (centrifugal acceleration at the center of the tube of about 6000 × g) for 30 minutes.
The temperature of the soymilk was 40 ° C., and the temperature condition of the centrifuge was 40 ° C.
The soy milk was separated into three layers by a centrifugal separation operation: a floating layer (a liquid layer mainly composed of a cream component), a soy milk layer (a soy milk layer with reduced fat), and a precipitation layer. From this, the floating layer was separated to prepare a coagulant solution. Magnesium chloride was used as a coagulant. Table 9 shows the composition of the composition of the floating layer liquid and the coagulant.

The above coagulant solution was mixed with soy milk to produce tofu. The temperature of soymilk was 65 ° C., and the amount of coagulant solution was adjusted so that the magnesium chloride concentration was 0.28% by weight. Then, it kept warm at 80 degreeC for 30 minutes.
Comparative Example 1
Tofu was produced under the same conditions as in Example 1 using a coagulant solution as an aqueous magnesium chloride solution.
Comparative Example 2
Tofu was produced under the same conditions as in Example 1 using a mixture of soymilk: magnesium chloride.hexahydrate = 3: 1 (weight ratio) as a coagulant solution. The soy milk used was soy milk before being subjected to the centrifuge described in Example 1.
Comparative Example 3
Tofu was produced under the same conditions as in Example 1 using the coagulant solution as a commercially available emulsion coagulant. The dispersion and mixing of the emulsifying coagulant in soymilk was performed using a homogenizer (D-7801 manufactured by Ystral GmbH).
The physical property value measurement of the tofu produced in Example 5, Comparative Example 1, Comparative Example 2, and Comparative Example 3 and a sensory evaluation test by 10 professional panelists were performed.
Measurement of physical properties of tofu was performed using a rheometer (CR-500DX-SII, manufactured by Sun Kagaku Co., Ltd.), breaking strength by compression test (using a disk type plunger with a diameter of 10 mm) and compression test (a disk type plan with a diameter of 50 mm). 2 index of breaking strain by using a jar). The breaking strength is hardness and the breaking strain is a measure of elasticity. The higher the value, the greater the degree.
The sensory evaluation was performed on a five-point scale for smoothness and flavor, with an average score of 3.0 or more represented by ◯, 2.0 or more and less than 3.0 by Δ, and less than 2.0 by x.
The results are summarized in Table 10.

Like the result shown in the said Table 10, the tofu (Example 5) created with the coagulant | flocculant liquid by 3rd invention is close to the tofu (comparative example 3) manufactured using the commercially available emulsifying coagulant physically. In the sensory evaluation of flavor, an evaluation exceeding that was obtained.

The present invention is used in the industry for producing soy milk, tofu and processed foods thereof.

Claims (9)

1. The soy milk produced from soybean raw material is subjected to a high-speed centrifuge, the floating component in the upper layer separated after the centrifugal separation action is removed, and only the remaining soy milk in the lower layer is separated. A method for producing soy milk.
2. Manufactured from soy milk produced from soy raw material by using a high-speed centrifuge, removing suspended components in the upper layer separated by two layers after centrifugation, and separating only the soy milk remaining in the lower layer Processed food.
3. The soybean raw material liquid before removing insoluble components such as okara components is subjected to a high-speed centrifuge, so that fat is efficiently separated as a floating component, and the remaining soy milk is separated and collected as fat-reduced soy milk. Manufacturing method.
4. The raw raw soy bean obtained by grinding or crushing the soy raw material after the soy raw material is hydrated is either the boiled cucumber obtained by heat-treating the raw cucumber, the raw powdered soymilk in which the soybean powder is dispersed and dissolved in water, or the raw powdered soymilk The method for producing soymilk according to claim 3, wherein the soybean raw material liquid is any one of heat-treated heated powdered soymilk.
5. 5. The soybean powder according to claim 3 or 4, wherein the soybean powder is either a powder obtained by finely pulverizing soybean or a finely pulverized processed powder of soybean treated so as to be easily dispersed and dissolved in water. Of manufacturing soy milk.
6. It is characterized in that the coagulant for tofu is mixed with the floating layer liquid obtained by subjecting soy milk to a high-speed centrifuge to produce a coagulant liquid, and the coagulant liquid is added to the soy milk to cause a coagulation reaction. Tofu production method.
7. A coagulant solution is prepared by mixing the soy raw material liquid before removing insoluble components such as okara ingredients with a high-speed centrifuge and the coagulant for tofu to produce a coagulant liquid. A method for producing tofu, characterized in that it is added to a coagulation reaction.
8. The raw soybean liquid is raw koji obtained by grinding or crushing soy after adding water, boiled koji made by heat-treating the raw kyu, or raw powder soy milk in which soybean powder is dispersed and dissolved in water, or the raw powder soy milk. The method for producing tofu according to claim 7, wherein the soybean raw material liquid is any one of heat-treated heated powdered soymilk.
9. 9. The tofu production according to claim 8, wherein the soybean powder is either a powder obtained by finely pulverizing soybean or a finely pulverized processed powder of soybean treated so as to be easily dispersed and dissolved in water. Method.

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