JP2591635B2 - Production method of red yeast rice using rice as raw material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing red koji using rice as a koji-making raw material,
It enables high-enzyme titration and the production of purified large-scale koji of red koji with bright pigment.

Recently, red koji made from Monascus sp. As a seed bacterium is a vinegar,
It is being used not only as a raw material for brewing miso and the like, but also as a direct additive for bread and the like.

However, such Monascus spp. Are extremely weak in fertility and also have the property of being easily contaminated by other fungi, so that it is necessary to maintain a clean environment for a long time during koji making, This tendency is particularly remarkable when rice is used as a koji-making raw material.

On the other hand, when it is directly added as a food material as described above, there is a problem that germ contamination must be absolutely avoided.

(Prior Art) Conventionally, when such red yeast rice is produced, a clean environment, for example, a closed container such as a flask or a sterile culture bag is adopted for the above-described reason, and aseptic koji production is performed in this. Is being done.

On the other hand, as an open-type koji making method that does not require such a strict koji making environment, for example, koji making raw materials as disclosed in JP-B-55-7229 and JP-B-60-4706 are disclosed. A method has also been proposed in which an acid is added before the inoculation to suppress the propagation of various bacteria to make koji.

(Problems to be Solved by the Invention) However, in the former method using a closed container, high-quality red koji can be obtained, but large-scale koji production is difficult,
In addition, there is a problem in terms of production and workability, such as necessity of operations such as sterilization and cleaning of the container.

Also, in the latter method of adding an acid to the koji-making raw material before inoculation, the fertility is strong like Aspergillus spp. As described above, this method is effective in the case of koji-making raw materials in which koji-making is relatively easy. However, in the case of red koji-making using rice as a koji-making raw material, good results cannot be obtained even if it is applied as it is.

The present invention, as a result of diligent research on such points, has found a method that does not require a special container and is capable of producing a large amount of koji with simple management.

(Means for Solving the Problems) However, the present invention relates to a method of koji making of red koji using steam-sterilized polished rice as a koji raw material, in which 0.1 to 0.4% (V / W ) And the addition of an appropriate amount of a strong acid to adjust the pH of the koji raw material itself to 3 to 4.5.
After the inoculation of red yeast mold cells with this, a strong acid is added as needed until the koji-making is completed, so that the pH of the koji-making raw material itself is constantly maintained in the range of 3 to 5 for koji-making. And a method for producing red yeast rice which is characterized by adding 0.5 to 2.0% (W / W) of calcium chloride together with the above-mentioned acetic acid to produce koji. The pH is a value measured when 5 g of a sample is collected, 15 ml of water is added thereto, and the mixture is stirred, and the pH in the following description is all measured by this method.

That is, the present invention has been made as a result of further detailed examination of the effectiveness of the koji-making method of adding an acid to the above-mentioned koji-making raw material and its effect.

(Action) In the action, the present invention prevents the propagation of various bacteria, particularly by setting limited koji making conditions centering on acid,
The present invention enables the production of high-quality red yeast rice which propagates red yeast mold and does not cause contamination even in a normally sterilized clean environment. Hereinafter, an example will be described in comparison with a comparative example.

(Comparative Example 1)-Koji Making by Adjusting pH-This experiment examined the effectiveness of acid and the range of effective pH in producing red koji using rice as a koji making raw material.

The experimental method is to prepare a medium with different pH by adding hydrochloric acid to the steam-sterilized polished rice before inoculation, inoculate this with koji mold, and make the koji under the following conditions. is there.

Aspergillus species: Monascus pilosas IFO 4520 Koji making temperature: 25 to 30 ° C Koji making period: 7 days Koji making environment: Normally sanitized clean environment Raw material moisture: always maintained at 35 to 40% Acetic acid, 99% pure, and dihydrate calcium chloride were used.

As a result, as shown in Table 1, the range of pH at which red yeast mold can be propagated while suppressing the growth of various bacteria is a very limited narrow range of 2.0 to 3.0, and it is effective only in a strongly acidic region. I understood that.

However, koji making in such a strongly acidic region tends to hinder the propagation of bacteria, and is not necessarily a suitable koji making condition.

(Comparative Example 2)-Addition of acetic acid to koji-making raw material-In this experiment, the effectiveness of adding acetic acid in place of the above-described hydrochloric acid and the amount of acetic acid used were considered.

As a result, acetic acid has a bacteriostatic action different from that of the above-mentioned ordinary acid, and although its addition is extremely effective, it is controlled by an amount different from the control of pH, that is, as shown in Table 2, 0.1-0.4% of the weight of milled rice, the raw material for koji making
(V / W), it was found to be effective only in the limited range of pH 4.1 to 4.9.

In other words, this is thought to be due to the peculiarity of cultivation of red aspergillus, which has a low fertility, and if the added amount exceeds 0.4% (V / W), there is a problem that the growth of the bacterium itself is suppressed and no pigment appears. On the other hand, if it is less than 0.1% (V / W), it enters the breeding area of various bacteria as shown in the table, causing a problem of contamination.

In addition, even in the addition of such effective acetic acid, at the time of inoculation, and even after addition or addition of acetic acid in such a range after inoculation, in terms of propagation of Aspergillus oryzae and contamination of various bacteria. There is a problem that cannot be solved sufficiently, and the advent of technology that follows this problem is desired.

On the other hand, when another experiment was attempted in connection with this, the following findings were obtained.

That is, even if a certain amount of acetic acid is added at the time of inoculation as described above, if this is subjected to long-term koji-making, the obtained red koji becomes contaminated with various bacteria.

However, this is thought to be due to the fact that as the koji mold grows after inoculation, the pH of the koji-making raw material itself increases, and in the final stage of koji-making, the bacteriostatic effect of acetic acid is lost because it reaches the neutral region. This tendency is remarkable in the case of the present invention in which a starch-rich rice is used as a raw material and a red fermenter with a low fertility is cultured for a long period of time, for example, a medium started at pH 4.0 gradually starts the next day. It begins to rise and reaches pH 6.0 one week after koji making, far exceeding the bacteriostatic action of acetic acid.

The present invention has been made on the basis of such knowledge, and has made it possible to produce a large amount of a special bacterium called Monascus under a limited condition with high quality.

 Hereinafter, this will be described with reference to examples.

(Example 1)-Addition of acetic acid and combined use of strong acid-An appropriate amount of hydrochloric acid was added to 0.2% (V / W) acetic acid,
Raw materials for koji making with different pH were prepared.

Next, this was inoculated with the same red koji mold as in the comparative example,
Propagation of red koji mold and contamination of various fungi when koji was made in the same environment were observed.

As a result, as shown in Table 3, the breeding area of Red Aspergillus was expanded to pH 2.9 to 5.1 as compared with the breeding area of various germs, and easier management became possible.

In addition, the koji-making raw material adjusted to pH 4.0 in this table was koji-produced while maintaining the pH at 3.5-4.5 with hydrochloric acid until the koji-making period was completed.
A highly active red yeast rice was obtained.

(Example 2)-Addition of acetic acid and calcium chloride and combined use of strong acid-0.2% (V / W) acetic acid and 1.0% (W
/ W) to the koji making raw material to which calcium chloride was added, an appropriate amount of hydrochloric acid was added to prepare koji making raw materials having different pHs.

Next, red yeast mold similar to that in Example 1 was inoculated into the same, and the bacteria were grown under the same environment as in the case of koji making and the state of contamination was observed.

As a result, as shown in Table 4, the breeding area of Red Aspergillus was further expanded to pH 2.9 to 5.9 than in Example 1, and management became easier.

In addition, as shown in Table 5, the koji-making was performed using the koji-making raw material adjusted to pH 4.0 in the above table while maintaining the pH at 3.5 to 4.5 with hydrochloric acid until the koji making period was completed. Furthermore, red yeast koji having a high enzyme titer without contamination by various bacteria was obtained.

In addition, Comparative Example 1 in Table 5 was inoculated after adjusting the pH to 2.5, and Comparative Example 2 was inoculated after adding 0.2% (V / M) acetic acid, and then koji-made without adjusting the pH. The evaluation items are evaluated according to the prescribed analysis method of the NTA.

Table 6 shows data comparing the contamination properties due to the difference between the treatments.

The koji making in Table 6 was carried out in a flask. In such koji making, 0.2% (V / W) acetic acid was added when adding acetic acid, and 1.0% (W / W) calcium chloride was added when adding calcium chloride. No additive means that no additive is added.

The phrase "with pH adjustment" refers to the case where the pH is always adjusted to 4.0 with a hydrochloric acid solution, and the term "without pH adjustment" refers to the case where such adjustment is not performed.

Further, the symbols in the table indicate the degree of proliferation of the bacteria, "+" indicates that the proliferation is observed, "" indicates that the proliferation is more remarkable, and "-" indicates that the proliferation is not. In addition, this evaluation method is to indicate the degree of normal microbial propagation,
This was performed by visual observation and microscopic observation.

(Effects of the Invention) As is clear from the results of the examples, the method according to the present invention is free from contamination by various bacteria as compared with the method according to the comparative example, and the red yeast mold itself shows good propagation, Pigment red yeast rice was obtained. In particular, the effect of adding calcium chloride is great.

In addition, since the management in the koji making process can be performed in a wide pH range, the management is extremely easy.

In the present invention, the amount of acetic acid used must be in the range of 0.1 to 0.4% (V / W) for the reasons described above regardless of the amount of strong acid added. The pH range is 3 to 5 at the time of inoculation, more preferably 3 to 5.
It is necessary to maintain the pH range from 3 to 5 by using a strong acid as needed for the purpose of suppressing the rise of pH during the koji making period.

However, if the pH falls below this range, the growth of red yeast mold is suppressed, and if it exceeds this range, the resistance to various bacteria decreases, which is not preferable. The amount of acetic acid added is that at a purity of 99%.

On the other hand, as the acid used for pH adjustment in the present invention, strong acids such as hydrochloric acid and sulfuric acid are particularly optimal from the viewpoint of easiness of pH adjustment and cost, and Monascus as a Monascus fungus to which the present invention can be applied. -All Monascus genus bacteria, such as Pilousus and Monascus pupleus.

Furthermore, in addition of calcium chloride, 0.5 to
The range of 2.0% (W / W) is lower than this, since no bacteriostatic effect is observed, and conversely, if it is higher than this, the proliferation of red yeast rice is suppressed and the pigment production ability decreases. It is desired to be within this range. The amount used is that of monohydrate and dihydrate.

As described above, the present invention is very easy and open by maintaining the pH of the raw koji raw material itself in a certain range from before inoculation until completion of koji. It has the advantage of being able to produce a large amount of red koji having low fertility and low resistance to various germs in a given environment, and has the advantage that it can be provided at low cost.

Claims (2)

(57) [Claims] 1. Koji-making raw material is obtained by using steamed and sterilized polished rice as a koji-making raw material, adding 0.1 to 0.4% (V / W) acetic acid to the koji-making raw material and adding an appropriate amount of a strong acid. The pH of the koji-making raw material itself is constantly maintained in the range of 3 to 5 by adjusting the pH of the koji-making raw material itself to 3 to 4.5, adding a strong acid as needed until the koji-making is completed after inoculating the red koji mold cells. A method for producing red koji using rice as a raw material for koji making. 2. Steam-sterilized polished rice is used as a koji-making raw material, and 0.1-0.4% (V / W) acetic acid and 0.5-2.0% (W / W) calcium chloride are added to the koji-making raw material. In addition, by adding an appropriate amount of a strong acid,
The pH of the koji-making raw material itself is constantly maintained in the range of 3 to 5 by adjusting the pH of the koji-making raw material itself to 3 to 4.5, adding a strong acid as needed until the koji-making is completed after inoculating the red koji mold cells. A method for producing red koji using rice as a koji raw material, characterized by koji making.