JPS6260056B2 - - Google Patents

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) The present invention provides a silk strainer that can be mass-produced using only bittern without using glucono delta-lactone or the like as a coagulant. Concerning the manufacturing method of cotton bittern tofu.

(Prior technology) Since ancient times, tofu has traditionally been produced using bittern as a coagulant, but the coagulation reaction is rapid and cannot be adjusted, making it unsuitable for mass production. Filled tofu using lactone etc. accounts for the majority of mass-produced manufacturing methods.

However, this type of tofu had many drawbacks, such as being highly sour and lacking in the natural flavor of soybeans, and consumers were increasingly calling for a revival of the traditional bittern tofu.

Therefore, as a result of research into a manufacturing method that allows mass production of gari using traditional methods, the present inventors discovered that the synergistic effect of alkali adjustment and thermal denaturation of go is effective in delaying the coagulation reaction. We have developed a method for mass-producing bittern tofu using 100% bittern.

Although a technique focusing on alkaline adjustment for a purpose similar to the present invention is disclosed in JP-A-58-5156, this technique simply uses an alkaline substance and a slow-acting acid such as glucono delta-lactone. This technology is essentially different from the present invention in that it does not take heat denaturation into account at all, and as a result, a relatively large amount of alkali and acid substances are used to adjust the pH, which destroys the taste of tofu. Moreover, it was not possible to successfully produce tofu using 100% bittern because glucono delta-lactone was used for coagulation.

[Structure of the Invention] (Summary of the Invention) The present invention involves grinding soybeans after soaking to produce go, and adding an alkaline substance such as sodium bicarbonate to the soybean after boiling in the next step to form a PH6.7-6.9 solution. Next, this alkaline adjustment liquid is boiled to heat denature it, and the soybean content is removed in a separator to produce soymilk, which is then cooled to below about 15°C. The gist is that soy milk is solidified after being filled into a container.

(Specific steps of the invention and their effects) (Soaking and production of gourd) Soybeans are soaked in water and water is supplied until cotyledons form.
This is then put through a grinding machine and ground into appropriate particles to produce go.

(Alkali adjustment) Next, add alkaline substances such as sodium hydrogen carbonate, calcium carbonate, magnesium carbonate, caustic soda, and sodium carbonate to the Go solution after boiling in the next step.
Pour in an amount equivalent to a PH6.7-6.9 solution. This promotes the delay of the coagulation reaction described below, and although the delay effect is observed even at pH 7 or higher, too much alkali destroys the taste, so the pH should be kept within the range of 6.7-6.9. In addition, since the pH adjustment causes a slight decrease due to buffering properties etc. in the boiling process, a surplus is added in anticipation of the decrease. Among the above alkaline substances, sodium hydrogen carbonate is the most effective.

(Heat denaturation) Next, this alkaline solution is boiled to promote heat denaturation, but it is important to perform the alkali adjustment before this boiling process, and no matter how much alkali is added after boiling, it will never be satisfied. Please note that you will not be able to obtain the desired effect.

Therefore, the adjusted solution after adding the alkali is carried into a boiling pot, and steam is blown into the solution to boil and stir for about 15 to 20 minutes to induce a cooperative action between the soybean protein and the alkali solution with thermal denaturation.

The reaction that occurs during this period is the most important one in the present invention, and although the physicochemical reaction mechanism has not yet been sufficiently proven, it can be inferred that soybean protein consists of repeating amino acids [NH-CHR-CO]. It has a chemical structure of , but when heat is added here,
Although there is no change in the chemical structure of the amino acid itself, changes in the higher-order structure in terms of spatial arrangement are promoted. That is,
Hydrogen bonds between N-H and C=O, which are responsible for the fibrous β-structure and α-helical structure of the peptide chain, and -S
A part of -S- is cut, causing a higher-order structural change in which part of the helix unravels or becomes fibrous. When alkali ions intervene here, hydrogen bonds, etc. are broken due to this structural change, and the ions gather near the surface of the free N-H, C=O, and -S-, and these polar groups An electrical relationship occurs between the alkali ions and the alkali ions, and some kind of protective structure is formed. The protective structure formed by the cooperative action of this thermal denaturation and ions exerts a protective function when the nigari coagulant is administered in the subsequent process, mitigating the rapid coagulation reaction and producing a delay effect. Conceivable.

(Production and cooling of soymilk) Next, this solution is passed through a separator to remove the okara content to produce soymilk, which is further cooled to about 20°C or lower through a heat exchanger. This cooling also assists in suppressing solidification when adding bittern.

(Adding bittern) Add 100% bittern as a coagulant to this soymilk liquid, and do not use any glucono delta lactone other than bittern.

Even if this bittern is added, the effect of the bittern is extremely slow due to the ion protection structure and cooling effect explained in the section on heat denaturation, and it does not solidify rapidly like in the past, and at temperatures below 20℃. Approximately 10−
Clotting is delayed for about 15 minutes.

(Filling and Heat Solidification) While this bittern-containing soymilk retains its fluidity, it is filled into individual containers and sealed, and finally hot boiled. Here, the protective structure of alkali ions that moderated the coagulation reaction is destroyed by hot boiling, and the bittern lowers the solubility of the soymilk as a whole, prompting coagulation and solidification to become a tofu product. When making firm tofu, an additional pressing process is added.

In addition, since the tofu of the present invention has a relatively high PH value (it is not acid-coagulated like conventional filled tofu), it is necessary to allow sufficient time for this hot boiling to improve the so-called shelf life.

(Example) Soybeans are soaked in water at a temperature of 17°C for about 15 hours and then crushed to produce go, which is then added with 1.3g of sodium bicarbonate per 1kg of soybeans to make an alkaline adjustment liquid, and then heated to a boiling device. Boil at 100℃ for 15 minutes. Next, the soybean pulp is removed in a separator to produce soymilk, and the sugar content of the soymilk at this time is 12.5-13.0 as measured by a Brix sugar meter. Furthermore, the soy milk
After cooling to 15℃, add about 3.4g of Agari (magnesium chloride hexahydrate) per liter of soymilk.
Fill individual containers, and finally soak in hot water at 90℃ for 90 minutes.
The tofu product is obtained by soaking the tofu for about a minute and boiling it to solidify it.

[Effects of the Invention] As described above, the present invention can obtain an effective effect of retarding the coagulation reaction of bittern through the special cooperative action of alkaline solution and soybean protein accompanied by thermal denaturation, as described at the beginning. A relatively small pH value of 6.7-6.9 is sufficient. Therefore, there is almost no effect on the taste, and the original taste and flavor of tofu from ancient times can be enjoyed as is, thus meeting the demands of consumers.

Moreover, since it can be realized through a mass production process, it can be economically supplied at low cost, making it a truly advantageous invention today.

Claims (1)

[Claims] 1. Grind the soybeans after soaking to produce go, add an alkaline substance such as sodium bicarbonate to the go and add an amount equivalent to a pH 6.7-6.9 solution after boiling in the next step, and then add this alkaline adjustment solution. After boiling and heat denaturing, further separating and removing okara components to produce soymilk, it is cooled to below about 20℃, bittern liquid is added as a coagulant, and finally, the soymilk is filled into a container. A method for producing bittern tofu characterized by hot boiling and solidifying it.