JPS5856618B2 - How to dehydrate tofu meal - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention involves adding an acidic solution to tofu lees to adjust its pH to 5.5.
~2.5, and then dehydrated in a dehydrator to improve the dehydration rate, prevent the loss of nutrients, and obtain tofu cake that is low in moisture, lightweight, and has a good shelf life. This relates to a method for dehydrating lees.

Conventionally, tofu lees is difficult to dehydrate, and even when pressure dehydration is used, its water content is generally 80% or more.

Furthermore, this tofu cake contains a considerable amount of unused nutrients (eg, protein) as shown in Table 1, which together with its water content has extremely poor storage stability, which is an obstacle to the effective use of the tofu cake.

For this reason, the effective use of tofu meal is currently limited to a limited number of uses, mainly livestock feed, due to the high moisture content and high transportation costs, and the majority of it is currently disposed of as industrial waste, although it contains valuable nutrients.

However, in this invention, by adding an appropriate amount of an acidic solution to tofu lees (for example, an amount that can adjust the pH of tofu lees to 5.5 to 2.5), the nutrients (e.g., proteins) contained in tofu lees are coagulated. However, this reduces the water retention capacity of the tofu lees, making dehydration extremely easy as seen in the attached graph.The nutrients coagulated by the organic acids in the external acidic solution remain in the tofu lees, as shown in Table 2. As shown, in the nutrient composition, only water decreases, and no major changes are seen in other nutrients.

Therefore, the pH of the tofu lees dehydrated by the method of this invention is lowered, which suppresses the growth of bacteria and dramatically improves the shelf life.
(See Table 3).

This not only makes it possible to greatly extend transportation distances, but also enables storage* with less deterioration.

Furthermore, the reduction in water content due to dehydration not only reduces transportation costs, but also greatly reduces the drying costs for drying tofu cake.

In this way, the tofu lees obtained by dehydration using the method of the present invention can be advantageously used, and the scope of use can be expanded, and unused resources can be used effectively for energy conservation. There is a table of effects.

The dehydration method according to the present invention can also be applied to cases where the residue after soybean protein extraction other than tofu lees is dehydrated and effectively utilized.

Next, each table and graph will be explained.

Table 1 shows the ratio between the general components of tofu meal and the components of the residue after extracting soybean protein from dedigitated soybeans.

Table 2 shows the changes in tofu lees components when dehydrated using the method of this invention. The analytical value refers to the value of each component when the tofu lees is removed, and the analytical value indicates the tofu lees component after dehydration according to the method of the present invention.

Comparing this value with the theoretical value, it can be said that only 11 remaining components of moisture were removed without much difference.

Table 3 shows the results of an investigation regarding the shelf life of tofu meal dehydrated using the method of the present invention, based on criteria for use as feed for livestock.

As for storage conditions, conventional tofu lees packed in plastic bags and kept at a constant temperature of 30 to 34°C can only be stored for 2 to 3 days, whereas tofu lees after dehydration by the method of the present invention is made from organic acids from the beginning. Although there was an odor, there was not a single change in appearance during the 50 days during which mold was observed to grow, and after 60 days there was no change in the preference given to livestock.

It should be noted that the organic acid odor that is present from the beginning does not necessarily improve palatability when used as livestock feed, but when used for purposes other than livestock feed, deodorization is performed by drying, and the odor required for drying at this time is The amount of heat can be reduced by about 50% if the moisture content of conventional tofu lees is, for example, 85% and the moisture content after dehydration is 70%.

Table 4 shows the components of the organic acid solution before dehydration and the dehydration when dehydration according to the method of this invention is performed using an organic acid solution made by fermenting a liquid containing carbohydrates etc. obtained during the tofu manufacturing process. This is a table that analyzes and compares the components of the waste liquid generated.

As can be seen from this table, there is almost no change in the main components.

Therefore, it can be said that almost no tofu lees components leak out due to dehydration.

Table 5 is a comparison of dehydration between the method according to the present invention when tofu cake was dehydrated using the same dehydrator (filter press) and the method in which tofu cake was dehydrated in Part 1.

As seen in this table, it can be seen that the method according to the present invention has good retention of protein and fat.

The figure shows the dehydration properties of tofu lees at various pH levels after adding and mixing organic acids to tofu lees. The dehydration properties begin to improve at around pH 6, and rapidly improve when the pH drops below 5.5. p
It is clearly shown that it reaches a maximum around pH 3.5 and rapidly deteriorates again from around pH 3.

Next, the invention will be explained by way of examples.

Example 1 When 10 Ky of tofu lees (moisture content 84.9%) was dehydrated using the 11 dehydrator (filter press), the moisture content of tofu lees could be reduced to 815%1.
The weight of tofu lees after dehydration is 8. It was I Ky.

That's a 19% weight loss. Furthermore, as shown in Table 5, the tofu lees components at this time were reduced in protein and fat.

This is because the main components were washed out due to dehydration and the nutritional value of the tofu cake decreased.

In contrast, by the method of the present invention, tofu meal (moisture content 84.9%) is kept at 35°C to 50°C for 5 hours at 10 o'clock in the waste liquid containing nutrients such as carbohydrates generated during the tofu manufacturing process. Organic acid solution obtained by lactic acid fermentation for ~12 hours (pH 3,
When 301 of 8) was added and mixed, the tofu lees after mixing was p.
H was 4.6.

When this was dehydrated using a dehydrator (filter press), the moisture content was 71.3%.The weight of the tofu lees obtained at this time after dehydration was 5.3 hours, resulting in a water reduction of 4.7 Ky. be.

Therefore, the dehydration effect of the method of the present invention is 2 times higher than that of the conventional method.
．． This means that the dehydration properties are five times better.

Moreover, the components after dehydration are as shown in Table 5, and there are no major changes compared to before dehydration.

Furthermore, the main components of the organic acid solution and the main components of the dehydrated solution used at this time were not much different as shown in Table 4, and from this it can be seen that the main nutrients contained in the tofu meal remained in the tofu meal. 1
＼It can be said that only water was removed.

Example 2 Tofu lees (moisture content 84.5%) At 10 o'clock, 301 lactic acid solution (pH 2.65) obtained from waste liquid was added and mixed, and the pH of the tofu lees after mixing became 3.5.

When this was dehydrated using a dehydrator (filter press), the moisture content was 70.1%, and the weight of the resulting tofu lees after dehydration was 5.19:9.

This means that we were able to achieve a water reduction of 9 to 4.81 times.

When the components of the tofu lees obtained in this way were analyzed and compared with the components before dehydration, the results were as shown in Attached Table 3, and no major changes were observed in the main nutrients.

Example 3 Residue after soy protein extraction (moisture content 85.0%) 10! When 301 lactic acid solution (pH 2,46) was added to 9 and mixed, the pH of the soybean protein extraction residue after mixing became 3.85.

When this was dehydrated using a dehydrator (filter press), the moisture content was 74.0%, and the weight of the resulting dehydrated residue was 5.8 Kp.

Therefore, the water at 4.2 o'clock was removed.

[Brief explanation of drawings]

The figure is a graph showing the relationship between the dehydration properties of tofu lees and pH.

Claims (1)

[Scope of Claims] 1. Tofu lees characterized by adding to the tofu lees an acidic solution obtained by lactic acid fermentation of a waste liquid containing carbohydrates generated during the tofu manufacturing process, adjusting the pH, and then dehydrating the tofu lees. Dehydration method. 2. The method for dehydrating tofu lees according to claim 1, which comprises adjusting the pH of the tofu lees to 5.5 or less and 2.5 or more. 3. Claim 1, characterized in that the waste liquid contains nutrients such as carbohydrates generated during the tofu manufacturing process.
The method for dehydrating tofu meal described in section.