JP5732003B2 - Fermented soymilk and method for producing the same - Google Patents

Description

  The present invention relates to a fermented soymilk and a method for producing the same.

  Soy milk produced by processing soybeans is known as a health food because it contains abundant nutritional components derived from soybeans in addition to low calories and cholesterol. In addition, foods obtained by processing soy milk, for example, fermented soy milk obtained by fermenting soy milk with lactic acid bacteria are known. Patent Document 1 discloses a yogurt made by mixing lactic acid bacteria with soy milk.

Japanese Patent Laid-Open No. 2002-262771

  Lactobacillus delbrueckii subspecies bulgaricus and Streptococcus thermophilus are lactic acid bacteria commonly used for lactic fermentation of milk. These lactic acid bacteria are also used for fermentation of soy milk. However, the fermented soymilk fermented with these lactic acid bacteria has a problem that the flavor is not preferable because it has a strong soymilk odor and lacks freshness.

  Therefore, an object of the present invention is to provide a method for producing a savory soymilk fermented product in which the soymilk odor is sufficiently reduced. Another object of the present invention is to provide a savory soymilk fermented product having a sufficiently reduced soymilk odor and a food or drink containing the same.

  The present invention includes an enzyme treatment step of hydrolyzing soy milk with a peptide bond hydrolase, an enzyme deactivation step of deactivating the peptide bond hydrolase to obtain a fermentation substrate, and the fermentation substrate as Lactobacillus brevis (Lactobacillus). and a fermentation step of fermenting with lactic acid bacteria belonging to Brevis).

  The present inventors have used a lactic acid bacterium belonging to Lactobacillus brevis, which has not been conventionally used for fermentation of soy milk, as a fermenting bacterium, soy milk odor of the fermented soy milk is sufficiently reduced, and the soy milk fermentation has a refreshing flavor. It was found that a product was obtained. Since the production method of the present invention includes a fermentation process using lactic acid bacteria belonging to Lactobacillus brevis, a savory soymilk fermented product with a sufficiently reduced soymilk odor can be obtained.

  On the other hand, lactic acid bacteria belonging to Lactobacillus brevis have a problem that the fermentation rate is extremely slow when soymilk is used as a substrate. For this reason, it takes a long time to produce a fermented soymilk, and there are problems such as high production costs and a high risk of contamination, making industrial use difficult. In contrast, the present inventors have found that the fermentation rate can be improved by using soybean milk hydrolyzed with a peptide bond hydrolase in advance as a fermentation substrate. Therefore, since the manufacturing method of the present invention includes the above-described steps, the manufacturing method is good and can be used industrially.

  The peptide bond hydrolase can be at least one enzyme selected from the group consisting of peptidases and proteases. The enzyme preferably contains an exo-type peptidase or an exo-type protease. Thereby, the soymilk odor can be further reduced, and a soymilk fermented product with even better flavor can be obtained.

  The amount of free amino acid contained in the fermentation substrate is preferably 6000 ppm by mass or less based on the total amount of the fermentation substrate. When the amount of free amino acids is within the above range, a fermented soymilk fermented product with a sufficiently reduced bitterness can be obtained.

  The lactic acid bacterium is preferably Lactobacillus brevis SBC8803 (Accession number: FERM BP-10632). By using Lactobacillus brevis SBC8803 for fermentation, it is possible to obtain a soymilk fermented product with a more refreshing and savory flavor that is further reduced in soymilk odor.

  In addition, Lactobacillus brevis SBC8803 was patented biological deposit center, National Institute of Advanced Industrial Science and Technology (JST 28th, 1st, 1st East, Tsukuba City, Ibaraki, Japan) on June 28, 2006. Strain having the deposit number of FERM BP-10632. In the present specification, this strain is also referred to as “SBL88 strain”.

  The present invention also provides a soymilk fermented product obtained by the above production method. Lactobacillus brevis is a type of lactic acid bacterium that has been used for fermented foods for a long time, and its safety to living bodies is well established. Since the safety to living bodies is high, the fermented soymilk can be taken continuously for a long period of time.

  The present invention further provides a food or drink containing the fermented soymilk obtained by the above production method. By ingesting the food and drink, it is possible to efficiently ingest soy-derived nutritional components that are abundantly contained in soy milk. Further, the fermented soymilk has a soymilk odor sufficiently reduced and has a good flavor, so even a person who is not good at the smell of soymilk can easily take it.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the savory soymilk fermented material in which the soymilk odor was fully reduced, and the fermented soymilk obtained by this manufacturing method are provided. Moreover, the food / beverage products containing the said fermented soybean milk are provided.

  Hereinafter, although the form for implementing this invention is demonstrated more concretely, this invention is not limited to these.

  In the present specification, “soy milk” means a milky beverage obtained by eluting proteins and other components from soybeans with hot water or the like and removing the fibers. The “soy milk” preferably has a soybean solid content of 8% by mass or more. “Soy milk” includes, for example, raw soy milk, unadjusted soy milk, and the like.

  The production method of the present invention includes an enzyme treatment step, an enzyme deactivation step, and a fermentation step. Hereinafter, each step will be described.

[Enzyme treatment process]
The enzyme treatment step is a step of hydrolyzing soy milk with a peptide bond hydrolase. By carrying out this step, it is possible to improve the fermentation rate by lactic acid bacteria belonging to Lactobacillus brevis.

  The peptide bond hydrolase is an enzyme that hydrolyzes a peptide bond (—C (═O) —NH—). Peptide bond hydrolases include peptidases that hydrolyze peptides and proteases that hydrolyze proteins. Here, “peptide” refers to a polymer in which amino acids of less than 100 residues are linked by peptide bonds. Similarly, “protein” refers to a polymer in which amino acids of 100 residues or more are linked by peptide bonds.

  As the peptide bond hydrolase, for example, at least one enzyme selected from the group consisting of peptidases and proteases can be used.

  Peptidases and proteases are exo-type peptidases and proteases having an activity of cleaving amino acid residues by 1 to 2 residues from the end of a peptide or protein sequence, and endo-types having an activity of cleaving the inside of a peptide or protein sequence. It can be classified into peptidases and proteases.

  It is preferable that the peptide bond hydrolase used in the enzyme treatment step includes an exo-type peptidase activity or an exo-type protease activity. Thereby, the reduction effect of the soymilk odor in the fermented soymilk product and the effect of improving the flavor are further exhibited. Further, those having higher exo-type activity than end-type activity are more preferable, and those having no end-type activity are more preferable.

  Commercial products can also be used as peptidases and proteases. For example, Proteax (manufactured by Amano Enzyme Co., Ltd., a mixture of endo-type and exo-type, strong exo-type activity), Sumiteam ACP-G (manufactured by Shin Nippon Chemical Industry Co., Ltd., exo-type only), protease M “Amano” SD (manufactured by Amano Enzyme Co., Ltd., a mixture of an end type and an exo type, with strong exo type activity), Sumiteam FLAP (manufactured by Shin Nippon Chemical Industry Co., Ltd., exo type only) and the like.

  The enzyme treatment step is preferably carried out so that the amount of free amino acid contained in the obtained fermentation substrate is 6000 mass ppm or less based on the total amount. Thereby, the bitterness of fermented soymilk can be reduced or eliminated. The amount of free amino acid is more preferably 5800 ppm by mass or less, and further preferably 5500 ppm by mass or less. Although there is no restriction | limiting in particular in the minimum of the amount of free amino acids, Usually, it is 1000 mass ppm or more.

  The “free amino acid amount” is obtained, for example, by collecting a sample of soy milk, centrifuging, treating the supernatant with 0.02N hydrochloric acid, and then adding an amino acid analyzer (for example, L-8800, manufactured by Hitachi High-Technologies Corporation). ) To determine the content of each amino acid.

  What is necessary is just to determine suitably the addition amount of a peptide bond hydrolase by the kind of peptide bond hydrolase to be used. For example, when using Proteax, it can be 0.01 U to 0.7 U per gram of soy milk, and when using Sumiteam ACP-G, it can be 0.01 U to 0.5 U per gram of soy milk. it can.

  The treatment time and treatment temperature of soymilk with peptide bond hydrolase may be determined as appropriate depending on the type and amount of peptide bond hydrolase used, for example, at 1-50 hours at 40-50 ° C. Can do.

  The amount of peptide bond hydrolase added, and the treatment time and temperature of soy milk with peptide bond hydrolase are preferably adjusted so that the amount of free amino acids is within the above range.

[Enzyme deactivation process]
The enzyme deactivation step is a step of obtaining a fermentation substrate by deactivating the peptide bond hydrolase. By carrying out this step, hydrolysis by the peptide bond hydrolase in the fermentation step can be suppressed, so that the bitter taste of the fermented soymilk can be reduced.

  What is necessary is just to determine suitably the method of inactivating an enzyme according to the kind of peptide bond hydrolase to be used. For example, a method of inactivating by adjusting pH, a method of inactivating by heating, a method of inactivating by adding an organic solvent (for example, ethanol), and a method of inactivating by adjusting the salt concentration. it can. Among them, the method of heating and deactivating is preferable because the operation is easy.

  What is necessary is just to determine suitably the heating temperature and heating time in the case of heating according to the kind of peptide bond hydrolase to be used, for example, it is good also as 30 minutes-120 minutes at 60 to 100 degreeC.

  In the enzyme deactivation step, it is sufficient that the activity of the peptide bond hydrolase can be sufficiently reduced, and it is not always necessary to deactivate completely. On the other hand, from the viewpoint of further reducing the bitterness of the fermented soymilk, the residual ratio of the peptide bond hydrolase (the ratio of the activity after the deactivation treatment to the added activity) is preferably 10% or less, preferably 5% Or less, more preferably 2.5% or less, and even more preferably 0% (complete deactivation).

[Fermentation process]
The fermentation process is a process of fermenting a fermentation substrate with lactic acid bacteria belonging to Lactobacillus brevis. In the fermentation process, the lactic acid bacteria are added to the fermentation substrate obtained through the enzyme treatment process and the enzyme deactivation process, and lactic acid fermentation is performed with the lactic acid bacteria to obtain a fermented soymilk.

  You may further add additives other than the said lactic acid bacteria to a fermentation substrate. Examples of such additives include sugar (sucrose, maltose, fructose, glucose, stachyose, raffinose, etc.), plant extract (eg, malt extract), flavor (eg, yogurt flavor), sweetener (eg, trehalose, aspartame, sucralose). , Acesulfame potassium, etc.). These additives may be added before the enzyme deactivation step. When the enzyme deactivation step is performed by heat treatment, there is an advantage that the additive can be sterilized at the same time.

  Examples of lactic acid bacteria belonging to Lactobacillus brevis include SBL88 strain. Lactic acid bacteria belonging to Lactobacillus brevis can be used singly or in combination of two or more.

There are no particular limitations on conditions such as the amount of lactic acid bacteria used in the fermentation process and the fermentation temperature, and optimal conditions may be set according to the type of lactic acid bacteria used. For example, when the SBL88 strain is used as the lactic acid bacterium, the lactic acid bacterium may be added to 1 × 10 ⁶ to 1 × 10 ⁷ cfu / mL and allowed to stand at 25 to 38 ° C.

  The fermentation time is preferably shorter from the viewpoint of reducing the production cost and the risk of contamination. Since the manufacturing method of this invention is equipped with the said enzyme treatment process and enzyme deactivation process, it can shorten fermentation time. Therefore, as fermentation time in a fermentation process, it can be set as 24 hours or less, for example. The fermentation time is more preferably 22 hours or less, and still more preferably 20 hours or less.

[Fermented soymilk]
The fermented soymilk obtained by the above production method is rich in nutritional components derived from soybeans, has a sufficiently reduced soymilk odor, and has a refreshing flavor. Therefore, the fermented soybean milk can be used as it is as a food or drink, or can be used as a food or drink material.

[Food and Drink]
The food and drink of the present invention may be the fermented soymilk itself or a food or drink containing the fermented soymilk. Examples of the food and drink that are the fermented soymilk itself include fermented soymilk, yogurt, cheese, and the like. In addition, as foods and drinks containing the fermented soybean milk, for example, emulsified seasonings (margarine, dressing, mayonnaise, etc.), seasonings (sauce, ketchup, etc.), confectionery (ice cream, candy, caramel, chocolate, etc.), Examples include beverages (non-alcoholic beverages, alcoholic beverages, etc.).

  Hereinafter, the present invention will be described in more detail based on examples.

[Preparation and Evaluation of Fermented Soymilk (1)]
Using soy milk (delicious unregulated soy milk, manufactured by Kikkoman Corporation) as a raw material, fermented soy milk was prepared under the conditions shown in Table 1 below.

<Material>
Lactic acid bacteria SBL88: Lactobacillus brevis SBC8803
SBC8982: Lactobacillus delbruecki subspecies Bulgarix SBC8982
SBC8772: Streptococcus thermophilus SBC8772
Peptidase Sumiteam ACP-G (New Nippon Chemical Industry Co., Ltd.)
Protease Proteax (Amano Enzyme)

<Enzyme treatment process>
Protease or peptidase (both in the case of adding both) was added to soymilk, and the enzyme treatment was performed at 45 ° C. for 2 hours.

<Enzyme deactivation process>
After completion of the enzyme treatment, sugar and fructose-glucose liquid sugar were added to 2% (w / w), respectively, and heat treatment was performed at 80 ° C. for 60 minutes.

<Fermentation process>
After the heat treatment, the mixture was cooled to the fermentation temperature to obtain a fermentation substrate. Lactic acid bacteria were added to this fermentation substrate so as to be 3 × 10 ⁶ cfu / g. During the fermentation time shown in Table 1, stationary culture was performed. After completion of the fermentation, it was quickly cooled for evaluation.

<Sensory evaluation of fermented soymilk>
The obtained fermented soymilk was subjected to sensory evaluation by a panel of 10 people. In the sensory evaluation, the soymilk odor was scored according to the following evaluation criteria, and the average value of the scores given by 10 panels was obtained. In addition, each panel freely commented on the flavor. The results are shown in Table 1.
-Score-
1: No smell of soy milk 2: Slightly scented soy milk 3: Slightly scented soy milk 4: Strongly scented soy milk 5: Very scented soy milk

<Measurement of free amino acid content>
The amount of free amino acids contained in the fermentation substrate was measured by the method shown below. First, a measurement sample was collected, centrifuged, and the supernatant was treated with 0.02N hydrochloric acid. Using this, an amino acid analyzer (L-8800, manufactured by Hitachi High-Technologies Corporation) was used to quantify the content of each amino acid. From the quantitative value, the content (mass ppm) of all free amino acids based on the total amount of the fermentation substrate was calculated. The results are shown in Table 1.

  The fermented soymilk (Examples 1 to 4) obtained by the production method of the present invention had a sufficiently reduced soymilk odor (Table 1). In addition, there were many free comments saying “feeling refreshed”. On the other hand, in Comparative Example 1 using the SBL88 strain but not subjected to the enzyme treatment, the reduction in odor of soy milk was not sufficient, and the fermentation rate was very slow (that is, the rate of pH decrease was slow, cfu increase rate is slow).

  In SBC 8882 and SBC 8972, which are lactic acid bacteria widely used for lactic acid fermentation of milk, the soymilk odor remained strong and was not a preferred flavor (Comparative Examples 2 to 5). In these lactic acid bacteria, the soymilk odor became stronger by the enzyme treatment (Comparative Examples 2 and 3, and Comparative Examples 4 and 5).

[Preparation and evaluation of fermented soymilk (2)]
Fermented soymilk was prepared and evaluated in the same manner as in [Preparation and evaluation of fermented soymilk (1)] under the conditions shown in Table 2 below. The results are shown in Table 2 together with representative free comments.

  In Reference Examples 2 and 3 in which the enzyme treatment time was increased, and in Reference Example 4 in which the enzyme addition amount was increased, the amount of free amino acid contained in the fermentation substrate increased (Example 3 and Reference Examples 1 to 4). In Reference Examples 2 to 4 in which the amount of free amino acid exceeded 6000 ppm by mass, although the soymilk odor was reduced, there were many free comments such as “the bitter taste remains in the aftertaste”. In particular, the fermented soymilk of Reference Example 4 in which the amount of free amino acids exceeded 15000 ppm by mass was sufficiently reduced in soymilk odor (the soymilk odor (average for 10 people) was 1.58). The bitterness was very strong, and some panels commented that it was difficult to drink (Table 2).

Claims (7)

An enzyme treatment step of hydrolyzing soymilk with a peptide-bonded hydrolase to obtain a fermentation substrate;
Fermenting the fermentation substrate with lactic acid bacteria belonging to Lactobacillus brevis ,
Manufacturing method of the amount of free amino acid contained in the fermentation substrate is, based on the total amount, Ru der than 6000 weight ppm 1000 ppm by weight, soy milk fermented product.   The production method according to claim 1, further comprising an enzyme deactivation step of deactivating the peptide bond hydrolase in the fermentation substrate.   The production method according to claim 1 or 2, wherein the peptide bond hydrolase is at least one enzyme selected from the group consisting of peptidases and proteases.   The production method according to any one of claims 1 to 3, wherein the peptide bond hydrolase contains an exo-type peptidase or an exo-type protease. The lactic acid bacteria, Lactobacillus brevis SBC8803 (accession number: FERM BP-10632) is a method according to any one of claims 1-4. A soymilk fermented product obtained by the production method according to any one of claims 1 to 5 . Food-drinks containing the fermented soymilk obtained by the manufacturing method as described in any one of Claims 1-5 .