JP4111083B2 - Method for producing frozen tofu - Google Patents

Description

【００２５】
尚、ニガリ、「アクティバ」スーパーカードはそれぞれ３０重量％溶液として、固形分として表記濃度になるように添加した。表１中のTGは、「アクティバ」スーパーカードの添加量を示し、「アクティバ」スーパーカードの添加量０．１％、０．３％、０．５％及び１％はそれぞれ、TG０．４U／ｇ蛋白、TG１．２U／ｇ蛋白、TG２．０U／ｇ蛋白、TG１０U／ｇ蛋白に該当する。
【００２６】
さて、このように調製したものを、１週間後に、熱水中に投入解凍し、試食評価したところ、１〜１１までのそれぞれの単独の系、もしくはＴＧが入っていない系に於いては、その評点は非常に低かった。
澱粉、トレハロース及びＴＧを添加した系、すなわち試験区１２、１３，１４、１５、特に試験区１３及び１４の条件が最も優れていることが分かった。その品質は市販の絹ごし豆腐と、その外観、食感、風味等において全く遜色のないものであり、この組合せでニガリで寄せることによって充分な品質の冷凍豆腐が出来ることを確認した。
【００２７】
実施例２：
実施例１と同様にして得た豆乳に対して、実施例１の方法に準じてゼラチン、トレハロース以外の糖（マルトオリゴ糖、日本食品化工（株）製品）、スマシ粉（０．３％）を表２に示す配合（ｗ／ｖ％）で添加した冷凍豆腐について比較した。
その結果、評価結果に示すように、澱粉、トレハロース、ＴＧの組合せてニガリ（０．３％）で寄せたものの品質が最も良いことが確認できた。尚、濁りは、解凍に使用した熱水の濁りの状況を示しており、ゼラチンを使用してＴＧを使用していない系に於いては濁りが大きく、好ましくない。評点は実施例１に準じた。
【００２８】
【表２】

【００２９】
実施例３：
実施例１の試験区１３に示す配合例に於いて、寄せ（凝固）時の温度を表３のように変動させて行ったところ、６０℃においては澱粉の糊化が始まり、粘度があがって、寄せが困難であった。
【００３０】
【表３】

【００３１】
表中の評価基準は、粘度は○：変化なし、×：上昇する、であり、硬さは◎：最も好ましい、○：好ましい、△：やや好ましい、×：好ましくない、であり、評価点は実施例１に準じる。また、３０℃においては、粘度的には全く問題がないが、温度が低すぎるために、ニガリの機能が充分でなく、硬さの足りない、柔らかい豆腐になってしまった。４０〜５０℃が好ましく、特に４５℃での品質がベストであった。
【００３２】
【発明の効果】
本発明の方法により、製造した冷凍豆腐は、解凍しても食感、風味、外観がともに優れており、通常の絹ごし豆腐と同等の品質を有する。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing frozen tofu having the same quality as ordinary silken tofu when thawed.
[0002]
[Prior art]
It is widely known that tofu is denatured by freezing, and its texture is organized (sponge) to cause water separation and the like. Many attempts have been made so far to prevent freezing and denaturation of tofu, that is, as a method for imparting freezing resistance to tofu.
At the beginning of the Showa 50s, after emulsification with starches and / or carbonates, soy protein having a protein content of 50% or more, water, and fats and oils, the tofu is prepared by heating if necessary (Japanese Patent Laid-Open No. No. 54-122755), and a method in which an emulsifier is dissolved in soy milk and then emulsified with soy protein, water, and fats and then heated to make tofu (Japanese Patent Laid-Open No. 54-145247) and the like. Has been.
[0003]
Furthermore, since recently, it has been found that transglutaminase (hereinafter abbreviated as TG) is effective for freezing resistance of tofu, so that tofu is prepared by adding starch, protein, sugar, TG, etc. to soy milk and then freezing it. Manufacturing method (Japanese Patent Laid-Open No. 6-217729), a method for producing tofu (Japanese Patent Laid-Open No. 6-269257) in which soymilk is mixed with starch, carbonate, TG and the like, and subjected to freezing treatment, After heating soy milk with a low viscosity exceeding 10% to 60 ° C or higher, add one or more of saccharides, starch and TG, adjust the tofu by adding a coagulant, and then freeze processing A method for producing tofu (republished patent WO00 / 21389) has been reported.
[0004]
In addition to the above, a method for producing frozen tofu comprising a raw material containing concentrated soy protein, fats and oils, starches, gelatin, a coagulant and TG (Japanese Patent Laid-Open No. 2001-46003), and coagulant and starch are added to soy milk. A method for producing frozen tofu (Japanese Patent Laid-Open No. 2003-52326), in which an appropriate amount of a sticky agent is mixed and stirred, an enzyme is mixed in an appropriate amount, treated at 50 ° C. for 30 minutes, and then heat treated at 95 ° C. for 30 minutes, is disclosed. Has been.
[0005]
Furthermore, although it is disclosed in JP-A-9-252740 and JP-A-10-99040 that trehalose is effective for frozen tofu as a saccharide, these two examples do not disclose the combined use with TG. . The combination of TG and trehalose is described in the above-mentioned re-published patent WO00 / 21389, but there is no description about a specific method using bittern.
[0006]
Conventionally, tofu has been obtained by coagulating soymilk with bittern, but it is difficult to handle due to the high reactivity of bittern, and in recent years calcium sulfate and glucono delta lactone are commonly used as coagulants for tofu.
Even in the above-mentioned application in the field of frozen tofu, although there is a description that bittern can be used as a coagulant for tofu, in the examples, calcium sulfate and glucono delta lactone are mostly disclosed. The soy milk is cooled to 25 ° C. or lower, and a gelling agent, a water retention agent and bittern are added to the soy milk, and then put into a mold and heated to make tofu (Japanese Patent Laid-Open No. 9-252740) Is disclosed. Nigari has a taste different from other coagulants in the flavor and texture of tofu, and there is a strong demand for frozen tofu using bittern, but in reality it is not marketed.
[0007]
[Patent Document 1]
Japanese Patent Laid-Open No. 54-122755 [Patent Document 2]
JP 54-145247 A [Patent Document 3]
JP-A-6-217729 [Patent Document 4]
JP-A-6-269257 [Patent Document 5]
Re-published patent WO00 / 21389 [Patent Document 6]
Japanese Patent Laid-Open No. 2001-46003 [Patent Document 7]
JP 2003-52326 A [Patent Document 8]
JP-A-9-252740 [Patent Document 9]
Japanese Patent Laid-Open No. 10-99040 [Patent Document 10]
Japanese Patent Laid-Open No. 64-27471
[Problems to be solved by the invention]
The present invention relates to a method for producing frozen tofu using bittern, reviewing the prior art as described above, and having the best texture, flavor and appearance at the present time, and producing the frozen tofu efficiently without complicating the production method itself. It is to provide a manufacturing method.
[0009]
[Means for Solving the Invention]
As a result of intensive studies to solve the above-mentioned problems, the present inventors kept ordinary soy milk at 40 to 50 ° C., and added a specific amount of starch, trehalose, and TG to this soy milk, It was found that frozen tofu that was much better than that produced by the prior art could be produced even by freezing and thawing by gathering with bittern, and the present invention was completed.
[0010]
That is, the present invention includes the following inventions.
(1) Soy milk having a solid content concentration of 10 to 15% by weight is kept at 40 to 50 ° C., and 1 to 5 w / v% starch, 2 to 6 w / v% trehalose, 0.1 to 0. After adding 0.01 to 10 units of transglutaminase per gram of 5 w / v% bittern and tofu protein, gather and mature, then heat at 85-95 ° C. to produce tofu and then freeze The manufacturing method of the frozen tofu characterized by these.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Frozen tofu as used in the present invention means adding starch, trehalose and TG to soy milk, and if necessary, adding gelatin etc. to the bittern, ripening, heating and solidifying after freezing, Even if it is thawed, it is a tofu that has a texture, appearance and flavor as silk tofu and is completely different from so-called Koya tofu. As the soy milk used here, soy milk produced by normal methods, i.e. soaking, grinding, boiling, and okara separation of soybeans, may be used as a raw material, or vegetable oil or emulsifier is added to vegetable soybean protein, The soymilk substitute obtained can also be used. In terms of viscosity, if it is the viscosity of normal soymilk, there is no necessity to make it so low-viscosity soymilk. In the present invention, soy milk having a solid concentration of 10 to 15% by weight is usually used.
[0012]
About the starch to be used, the kind is not ask | required. That is, so-called raw raw starch or processed starch can be used. It is more preferable if the starch is imparted with freezing resistance. The temperature of soy milk when starch is added to soy milk is set to 40-50 ° C., so there is no worry that it will gelatinize when starch is added, but it is gelatinized when it is preliminarily made into an aqueous solution It is necessary to dissolve or suspend at a temperature lower than the temperature.
This is because if the added starch is gelatinized, its viscosity will rise abruptly, making subsequent operations difficult, and the texture of the resulting tofu will be unpleasant.
Moreover, the addition amount of starch is 1-5 w / v% normally with respect to soymilk. It should be noted that frozen tofu with sufficient quality cannot be obtained by adding starch alone.
[0013]
The amount of trehalose added is usually 2 to 6 w / v% with respect to soy milk. If it is less than this, the effect of giving the protein freezing property cannot be expected, and if it is too much, the tofu becomes sweet and its flavor is impaired. Preferably it is 2 to 4%. Trehalose functions as a water retention agent, but exhibits the most excellent effect at present among saccharides known as water retention agents. After all, it is not possible to obtain a frozen tofu of sufficient quality alone, but when it is combined with the previous starch, its quality is slightly improved, but it cannot be made satisfactory.
[0014]
Moreover, about TG, about 0.01-10 unit per 1g of protein in soymilk is suitable for the addition amount, Preferably, it is 0.4-4 unit. If the amount is less than this range, the anti-freezing effect due to protein binding inherent to TG is lost, and if the amount is too much, the effect does not increase and is not economical.
Similarly, TG alone cannot provide frozen tofu with sufficient quality, but the quality can be drastically improved by adding TG together with the above-mentioned starch and trehalose. In addition to the formation of higher-order structure by high molecular starch and the protein denaturation prevention effect of trehalose, the formation of covalent bonds of protein in soy milk by TG as a whole is highly resistant to freezing and denaturation of proteins. By forming a very dense structure, it is considered that fine tofu, smooth, high water retention and firm tofu can be produced.
[0015]
The TG used in the present invention is not particularly limited as long as it has TG activity, and its origin is not particularly limited. The TG activity is measured in accordance with Japanese Patent Application Laid-Open No. 64-27471. The activity for producing 1 micromole of hydroxamic acid per minute is defined as 1 unit (u) by the hydroxamic acid method. For the addition of TG at this time, it is convenient to use a commercially available TG preparation. For example, it is convenient to dissolve and add the TG preparation “Activa” super card (containing TG 20 u / g) for tofu prepared from Ajinomoto Co., Inc. The taste and flavor of the “Activa” super card itself is slightly sweet, but since it is odorless, it does not impair the taste and flavor of tofu.
[0016]
In this invention, since the subject exists in the frozen tofu using a bittern, naturally a bittern is used as a tofu coagulant. This refers to what can be described as “garlic” when used in tofu, and for example, one or more food additives such as magnesium chloride and crude seawater magnesium chloride, and natural additives are used. There is no problem with the order of addition of these additives, but it is usually preferable to first disperse the starch, then dissolve the trehalose, add TG, and immediately add bittern (coagulate). Although it is not impossible to use a tofu coagulant other than bittern, bittern is most preferable in order to obtain the best flavor, texture and appearance.
[0017]
In other words, bran powder (Ca sulfate) and glucono delta lactone act at a relatively high temperature, and hardly function in the range of 40 ° C. to 50 ° C. of the present invention. It is difficult to harden. In addition, tofu gathered at a high temperature of 60 ° C. or higher has a high reaction rate, and therefore the tofu structure that can be produced is very rough and rough. This also reduces the water retention rate of the protein, leading to a decrease in freezing tolerance.
[0018]
On the other hand, according to this production method, by combining the starch, trehalose and TG, and using bittern in the middle temperature range of 40 to 50 ° C., a very dense protein tissue is formed. It can be made smooth and fine, and it leads to strong freezing resistance.
Combined with the effects of starch, trehalose, and TG, the reaction of bittern becomes very mild, so the quality of the tofu that has been made has moderate hardness and smoothness that could not be thought of by the conventional method of frozen tofu. You can make tofu of firm quality that you can hold and even keep it from thawing even when thawed.
Therefore, it can be said that the present invention is most difficult to produce tofu, but its taste matches the best method for producing frozen tofu by bittern.
[0019]
As for the approach (coagulation), it can be based on the normal method of silk-cured tofu, but since the soymilk temperature is low in the middle temperature range, a filling tofu method is also possible. That is, starch and trehalose can be dispersed and dissolved in advance in a soymilk storage tank. In the case of the silk production method, soy milk is supplied from a tank to a gathering tank, TG dissolved therein is added thereto, and the coagulant solution is immediately added to perform gathering. Similarly, in the case of the filled tofu system, the soymilk supplied from the tank is mixed with TG and bittern using a line mixer or the like and then filled into a container. What is necessary is just to perform the temperature of close (solidification) normally at 40-50 degreeC.
[0020]
The tofu collected in this manner is usually aged for 30 to 90 minutes, fully expressing the function of TG, and at the same time completes the coagulation by bittern. Thereafter, heating is performed at a temperature of about 80 ° C. to 95 ° C. for about 30 to 60 minutes, and TG is heat-inactivated along with sterilization of microorganisms. The aging here is not a special thing, and it does not differ from the time for hardening with a normal coagulant.
[0021]
The characteristic of frozen tofu treated with TG is that it becomes a tofu that is supple, has a smooth texture and is not crumbled and has excellent water retention. This characteristic can be expected especially for the present invention.
[0022]
The heated tofu is not particularly limited in size after being quickly cooled, but is preferably frozen as quickly as possible after being diced to a size of about 1 to 3 cm. Although it is not necessary to dice here, when smaller than this, it is preferable from a viewpoint of prevention of freezing denaturation, but it is not preferable as a miso soup ingredient or a size used as mapo tofu at the time of use.
On the other hand, if it is too large, it will freeze more slowly, which is not preferable for freezing and denaturation, and it takes time when thawing, which is inconvenient for use.
In addition, although it is not necessary to specify the method of freezing, it is a matter of course that quick freezing is more preferable than slow freezing.
[0023]
【Example】
Example 1:
Soymilk with a solid content of 12% obtained by a normal boil-drawing method was adjusted to 45 ° C., and frozen tofu was prepared with the formulation shown in Table 1 below (ratio to soymilk, w / v%). Potato starch and trehalose (trade name Trehaose manufactured by Hayashibara Co., Ltd.) were added and mixed, and after adding ACTIVA supercard (trade name manufactured by Ajinomoto Co., Inc.) as TG, Nigari (Ako Kasei Co., Ltd.) (Product, trade name: Crystallin) is added to 0.3 w / v% (solidification), filled into a container, aged at 45 ° C. for 1 hour, and then heated at 90 ° C. for 1 hour to complete coagulation and at the same time Deactivation.
After cooling this, it was diced into approximately 1.5 cm squares, placed in a tray, and rapidly frozen at 40 ° C. The score in the table is the result of a comparative evaluation of the prototype using the method of discussion by three persons in charge, with the overall appearance, texture, and flavor of commercially available silk tofu as 10 points, and with no function of frozen tofu as one point. is there. Those with 7 points or more have high commercial value.
[0024]
[Table 1]

[0025]
In addition, bittern and "Activa" super card were added as 30 wt% solutions, respectively, so as to have the indicated concentrations as solid contents. TG in Table 1 indicates the amount of addition of “Activa” supercard, and the amounts of addition of “Activa” supercard are 0.1%, 0.3%, 0.5% and 1%, respectively, TG0.4U / It corresponds to g protein, TG1.2U / g protein, TG2.0U / g protein, and TG10U / g protein.
[0026]
Now, what was prepared in this way, after one week, thawed into hot water and thawed, and evaluated the taste, in each of the individual systems 1 to 11 or the system that does not contain TG, The score was very low.
It was found that the conditions in which the starch, trehalose and TG were added, that is, the conditions of the test sections 12, 13, 14, and 15, particularly the test sections 13 and 14, were the most excellent. The quality is that of commercially available silken tofu and its appearance, texture, flavor, etc. are completely inferior, and it was confirmed that frozen tofu of sufficient quality can be produced with this combination.
[0027]
Example 2:
According to the method of Example 1, sugars other than gelatin and trehalose (malto-oligosaccharides, Nippon Food & Chemicals Co., Ltd. product) and smash powder (0.3%) are applied to the soymilk obtained in the same manner as in Example 1. Comparison was made with frozen tofu added in the formulation (w / v%) shown in Table 2.
As a result, as shown in the evaluation results, it was confirmed that the quality of what was gathered with bittern (0.3%) in combination with starch, trehalose and TG was the best. The turbidity indicates the turbidity of hot water used for thawing, and is unfavorable because the turbidity is large in a system using gelatin and not using TG. The rating was in accordance with Example 1.
[0028]
[Table 2]

[0029]
Example 3:
In the blending example shown in the test section 13 of Example 1, when the temperature at the time of coagulation (coagulation) was changed as shown in Table 3, gelatinization of starch started at 60 ° C, and the viscosity increased. It was difficult to get close.
[0030]
[Table 3]

[0031]
The evaluation criteria in the table are: viscosity: ◯: no change, x: increase, hardness: ◎: most preferred, ○: preferred, △: slightly preferred, x: not preferred, evaluation score: In accordance with Example 1. At 30 ° C., there is no problem in terms of viscosity. However, since the temperature is too low, the function of the bittern is not sufficient, and the tofu becomes soft with insufficient hardness. 40-50 degreeC was preferable and especially the quality in 45 degreeC was the best.
[0032]
【The invention's effect】
The frozen tofu produced by the method of the present invention is excellent in texture, flavor and appearance even when thawed, and has the same quality as ordinary silken tofu.

Claims (1)

Soy milk having a solid content concentration of 10 to 15% by weight is kept at 40 to 50 ° C., 1 to 5 w / v% starch, 2 to 6 w / v% trehalose, 0.1 to 0.5 w / v with respect to this soy milk. After adding 0.01 to 10 units of transglutaminase per gram of 1% bittern and tofu protein, it was brought to maturation at 40 to 50 ° C , and then heated at 85 to 95 ° C to produce tofu, A method for producing frozen tofu characterized by freezing.