JPS6115663A - Preparation of bean curd - Google Patents

Abstract

PURPOSE:To prepare delicious and sweet bean curd, by squeezing the soybean suspension without heating to obtain raw bean curd refuse an raw soya milk, and making theraw soya milk preservable at a low temperature, thereby suppressing the generation of the component having unagreeable taste. CONSTITUTION:Soaked soybeans are steamed for a short time, and ground under the addition of cold water. The obtained soybean suspension is squeezed without heating to obtain raw bean curd refuse and raw soya milk. The raw soya milk is optionally added with a small amount of sodium bicarbonate to adjust the pH of the milk, and stored at <=15 deg.C for 2-3 days. The stored milk is taken out of the storage tank at need, and coagulated by a conventional method.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing tofu, and in particular, it involves squeezing soybean soup without heating and separating it into raw okara and raw soy milk, and producing the obtained raw soy milk in a relatively short time. This invention relates to a method for producing tofu that can be stored at low temperatures.

In general, tofu is produced by soaking raw soybeans in water and then grinding them while adding water to create a soybean soup.
The process involved heating and filtering at ℃ to separate the okara to obtain soymilk, and adding a coagulant to this soymilk to coagulate it to make tofu.

With soymilk heated through this normal process, the enzymes in the soymilk are deactivated, so it easily spoils and cannot be stored.All of the soymilk produced had to be made into tofu, making it impossible to adjust the production. . In addition, unpleasant taste components contained in raw soybeans,
For example, saponin (bitter taste component), isoflavone (astringent taste component), and lipoxygenase (grassy taste component) remain in tofu, and even though tofu itself is nutritionally excellent, young people tend to avoid it. At present, the demand for dust has not increased significantly.

As a result of intensive research into the storage stability of this soymilk and the reduction of unpleasant flavor components, the applicant focused on the fact that unpleasant flavor components are rapidly extracted when the processing temperature exceeds 40°C. [Raw okara-j and "raw soy milk" are separated and this raw soy milk is stored at low temperature. Due to the nature of the raw materials, this storage period is only 2 to 3 days, but in addition to being able to produce soymilk in response to daily demand, we are also able to respond to sudden large orders with production equipment. This makes it possible to adjust production, and since the soymilk is processed and stored at low temperatures, the generation of unpleasant components can be suppressed, making it possible to provide extremely delicious tofu.

Next, to explain the method for manufacturing tofu of the present invention, raw soybeans are soaked, steamed for 3 to 15 seconds at a pressure of 1 atm or higher, and crushed while adding cold water to the soybeans to prepare the soybean soup. However, the temperature at the time of grinding is set to 40°C or less. The obtained mogo liquid is squeezed without heating and separated into raw okara and raw soy milk. Then, the pH of the squeezed raw soymilk is adjusted. Normally, soy milk has a pH of 6.4 to 6.5, but depending on the water added, the pH may be lower.

In this case, protein insolubilization occurs during storage of soymilk, making it impossible to produce smooth tofu, so baking soda is added to reduce the PHf!
:Needs to be adjusted.

This raw soymilk is then stored at 15°C or lower.

This storage period is 2 to 3 days, and there is a risk of spoilage if the storage period is longer than that.

When making tofu using preserved raw soymilk, it can be done in the usual way, by taking out the required amount, heating it, and adding a coagulant to obtain tofu.

In the present invention, the reason why soaked soybeans are first steam-treated for a short time is to prevent the generation of grassy taste (lipoxygenase) in soybeans when soybeans are squeezed raw. be.

Soy milk that has undergone conventional heat treatment has unpleasant taste components. After examining the extraction conditions for unpleasant taste components, we found that protein A does not change depending on temperature as shown in the attached figure, but the unpleasant taste components saponin B and isoflavone O change when the processing temperature exceeds 40°C. As a result of research, it was found that it can be extracted in large quantities, and compared to conventional methods, it is
When heated at ℃, a large amount of these unpleasant components are released. Therefore, in the method of the present invention, the temperature at the time of grinding is kept below 40°C, and furthermore, the raw soymilk of the present invention has unpleasant components that are absorbed during storage to the extent that it is not felt, and sweet and delicious tofu can be obtained. .

Next, to show an example, raw soybeans 60 and 7 were immersed in 200 tons of water at 20° C. for 8 hours. The soaked soybean contained water and had a weight of 140~.

This is subjected to steam treatment by applying steam at 1 atm for 8 seconds, and ground while adding 300 tons of water at 8°C to produce soybean soup.

The temperature of this soybean soup was 25°C.

This soybean soup is squeezed and separated into raw okara and raw soy milk. The raw soy milk obtained was 2801. Sugar content was 12° and PI (6.5). This raw soy milk was stored at 10°C for 2 days, taken out, heated at 100°C for 10 minutes, and a coagulant was added to make silken tofu (400?) 640 pieces. I got it.

When I ate this tofu cold, it was sweeter and extremely delicious compared to commercially available tofu.

[Brief explanation of the drawing]

The figure shows the extraction rate of proteins and unpleasant taste components depending on temperature. A...Protein%B...Saponin C...Isoflavone

Claims (2)

[Claims] (1) After steam-treating the soaked soybeans for a short time, they are crushed while adding cold water to make the soybean soup, and the soybean soup is squeezed without heating to separate into raw okara and raw soymilk. A method for producing tofu, which comprises storing the raw soymilk at a low temperature, taking out the stored raw soymilk as needed, heating it, adding a coagulant, and coagulating it by a conventional method. (2) The scope of the patent claim (
1) The method for producing tofu according to item 1).