JP2022026233A - Novel lactic acid bacterium and production method of viscous fermented product using the same - Google Patents

Abstract

To provide a novel lactic acid bacterium that enables the production of food materials with various textures and physical properties even when only rice is used as the raw material.SOLUTION: We have found a novel lactic acid bacterium, Lactobacillus paraplantarum YAMAKOSHI. It makes it possible to impart viscosity and spinnability to food materials containing a vegetable protein such as rice, thereby producing the food materials having physical properties similar to those of yogurt and cheese.SELECTED DRAWING: Figure 4

Description

The present invention relates to a lactic acid bacterium that produces a spinnable component and a method for producing a viscous fermented product using the lactic acid bacterium.

Recently, demand for gluten-free foods as well as plant-based foods, which are foods made only from plant-based raw materials, has increased from the perspectives of reducing environmental burdens such as carbon dioxide emissions, realizing a sustainable society, and making food barrier-free. ing. In Niigata Prefecture, which is one of the leading rice-producing regions in Japan, the development of foods such as bread, noodles, miso, and soy sauce made only from rice has been promoted. However, there is a limit to the production of food materials having various textures and physical properties with rice alone, and a new physical property conversion technology is required.

On the other hand, some fermenting microorganisms, such as Jiuqu, Bacillus natto, and lactic acid bacteria, decompose plant components or produce new components to contribute to the conversion of food materials such as liquefaction and viscous properties. .. Therefore, it is considered useful to have a technique for converting physical properties by fermenting plant-based raw materials.

In addition, when producing fermented foods, attempts have been made to separate local specialty foods and lactic acid bacteria derived from the land and use them as starters to produce fermented foods. For example, a method for producing a fermented food using lactic acid bacteria isolated from Nozawa-na-zuke in the Uonuma area of Niigata prefecture (Patent Document 1), and a method for producing a fermented food using lactic acid bacteria isolated from leaf mold in the Shirakami Mountains (Patent Document 2). ), A method for producing pickles using the lactic acid bacterium Lactobacillus salmon HS1 isolated from fermented kimchi (Patent Document 3) and the like are known.

Japanese Unexamined Patent Publication No. 2013-236604 Japanese Unexamined Patent Publication No. 2007-23364 Japanese Unexamined Patent Publication No. 2001-120173

Therefore, it is an object of the present invention to provide a novel lactic acid bacterium capable of producing a food material having various textures and physical characteristics even when only rice is used as a raw material.

As a result of diligent studies to achieve the above problems, we have found a novel lactic acid bacterium that produces a spinnable component and a method for producing a viscous fermented product using this lactic acid bacterium. Specifically, we found a new lactic acid bacterium that contributes to the conversion of physical properties by imparting viscosity and spinnability (thread pulling property) to food materials from the preserved food "Izekomina" that has been handed down from ancient times in the Yamakoshi district of Niigata prefecture. Was identified and various properties were analyzed. Furthermore, it was found that by fermenting a material containing vegetable protein such as brown rice and soymilk using this strain, a food material having physical characteristics similar to yogurt or cheese can be obtained, which led to the present invention.

That is, the lactic acid bacterium of the present invention is Lactobacillus paraplantarum YAMAKOSHI (accession number NITE P-03243).

Further, the method for producing a viscous fermented product of the present invention is characterized by comprising a step of fermenting the viscous fermented product using the lactic acid bacterium of the present invention.

Further, the viscous fermented product of the present invention is characterized by being obtained by the production method of the present invention.

According to the present invention, it is possible to impart viscosity and spinnability to a food material containing vegetable protein such as rice, and to produce a food material having physical properties similar to yogurt or cheese.

It is a molecular phylogenetic tree based on the recA base sequence. It is a graph which shows the influence which the culture temperature has on the growth of the lactic acid bacterium of this invention. It is a graph which shows the influence which the culture medium pH has on the growth of the lactic acid bacterium of this invention. It is a graph which shows the influence on the viscosity by the addition of various proteins.

The lactic acid bacterium Lactobacillus paraplantarum YAMAKOSHI (Lactobacillus paraplattarum YAMAKOSHI) of the present invention is a lactobacillus paraplan isolated from the traditional preserved food "Izekomina" (unsalted pickled radish) in the Yamakoshi district of Nagaoka City, Niigata Prefecture. It is a new bacterium belonging to Lactobacillus paraplatum, and was sent to the Patent Microbial Depositary Center (Kazusakamatari 2-5-8, Kisarazu City, Chiba Prefecture) on July 7, 2020. It has been deposited under the accession number NITE P-03243. Hereinafter, the lactic acid bacterium of the present invention is referred to as a YAMAKOSHI strain.

The YAMAKOSHI strain of the present invention produces a viscous component from a substrate containing vegetable proteins such as brown rice and soymilk. Further, the higher the protein concentration of the substrate, the higher the viscosity due to the fermentation of the YAMAKOSHI strain of the present invention, and in particular, the stronger the spinnability is exhibited for soybean and rice bran. Therefore, when brown rice or soymilk is fermented using the YAMAKOSHI strain of the present invention, it becomes possible to produce yogurt and cheese-like foods having viscous and spinnability.

In addition, lactic acid bacteria that produce strongly viscous and spinnable components are rare, and by using the YAMAKOSHI strain of the present invention, it is possible to create gluten-free, plant-based foods having new physical characteristics. For example, it is possible to adjust the viscosity using only plant raw materials such as rice and soybean, which opens the way to the development of new processed foods.

Hereinafter, the present invention will be described in more detail based on Examples. The present invention is not limited to the following examples, and various modifications can be made without departing from the idea of the present invention.

The isolation and identification of the novel lactic acid bacterium of the present invention will be described.

Sterile saline was added to the traditional preserved food "Izekomina" (unsalted pickled root vegetables, 25 days after pickling) in the Yamakoshi district of Nagaoka City, Niigata Prefecture, and homogenized with a stomacher. A part of it was cultured in an MRS white agar medium for separating lactic acid bacteria, and 40 strains of lactic acid bacteria having a clear zone (zona pellucida) formed by dissolving calcium carbonate added to the medium were collected.

Of these, BLAST homology analysis was performed on the partial base sequence of 16S ribosomal DNA of the strain showing very strong spinnability (thread pulling property) on the medium. As a result, it was found to be one of Lactobacillus plantarum, Lactobacillus pentosus, and Lactobacillus paraplantarum.

Next, in order to identify this strain, we commissioned Technosuruga Lab Co., Ltd. to perform recA (recombinase A protein) base sequence analysis. As a result of the BLAST homology search against the international base sequence database, the partial base sequence of the recA gene of this strain was found in Lactobacillus plantarum group L. It showed high homology to the recA gene base sequence of L. paraplatum. L. As a result of the molecular phylogenetic analysis performed by acquiring the recA gene base sequence (Table 1) of the bacterial group included in the plantarum group, this strain was found to be L. It was contained within a cluster formed by L. paraplatum (Fig. 1). Therefore, from these results, this strain is L. It was identified as L. paraplantalum and named YAMAKOSHI strain.

Next, the growth characteristics of the YAMAKOSHI strain were examined. The effect of the culture temperature in the MRS medium (pH 6.8) on the growth is shown in FIG. The optimum temperature for growth was around 28 ° C, and it was shown that the plants were proliferative at low temperatures, but did not grow at 40 ° C or higher. Further, FIG. 3 shows the influence of the medium pH of the MRS medium at 30 ° C. on the growth. It has been shown to be proliferative at low pH (pH 3.5 and above).

Next, the saccharide assimilation property of the YAMAKOSHI strain was examined. The YAMAKOSHI strain showed assimilation to L-arabinose, D-ribose, D-sorbitol, methyl-αD-glucopyranoside, and D-turanose, but not to escaline. The YAMAKOSHI strain was recognized as a novel strain because it had a different assimilation property from the allogeneic lactic acid bacterium reference strain (L. paraplattarum NBRC107151) and further produced a spinnable component.

The YAMAKOSHI strain produces a spinnable component. Therefore, the conditions for imparting viscosity to the sugar solution by the YAMAKOSHI strain were examined.

Various proteins (rice germ milk protein: Oryza protein P-70 (made by Oryza Yuka); gluten: VITAL WHEAT GLUTEN AG-850 (made by AMD); soybean protein: protein powder (soybean-derived, Fujifilm)) in 150 g of commercially available koji sweet sake Wako Junyaku)) was added to 1%, 3%, 5% (w / w), and a suspension of YAMAKOSHI strain (OD660 nm = 1.0) was added in 1% (v / w). After fermenting at 25 ° C. for 24 hours, the viscosity was measured with a B-type viscosity meter (BM type, manufactured by Toki Sangyo, rotor No. 3, 30 rpm). As a result, as shown in FIG. 4, the viscosities differed depending on the protein species, but the viscosities increased in each case in a concentration-dependent manner. Of these, the addition of soy protein had the highest viscosity and also showed spinnability.

Next, rice bran milk protein (manufactured by Oryza Yuka) and rice oil (manufactured by Tsukino Foods Co., Ltd.) were added to koji amazake as shown in Table 3, and a suspension of YAMAKO SHI strain (OD660 nm = 1.0) was added at 1%. (V / w) was added, and the mixture was fermented at 25 ° C. for 24 hours, and then the viscosity was evaluated with a B-type viscosity meter (rotor No. 3, 30 rpm). In addition, Zahn Cup No. The spinnability was measured by measuring the liquid drainage time when No. 7 was used. In order to elucidate the factors that affect the viscosity of the rice sugar solution, rice endosperm protein and rice oil were added to the rice sugar solution and fermented, but as shown in Table 4, the viscosity and spinnability were not affected. There wasn't.

Next, hemi to 3 L of rice bran suspension (rice bran or defatted rice bran 750 g (25% (w / v)), glucose 60 g (2% (w / v)), citric acid 30 g (1% (w / v)). 3 g (0.1% (w / v)) of cellulase was added and reacted at 50 ° C. for 24 hours. 1% (v / v) of a lactic acid bacterium suspension adjusted to OD660 nm = 1.0 was added to this suspension. ) Was added and fermented at 25 ° C. for 24 hours. Samples were taken over time and the viscosity and spinnability were evaluated. As shown in Table 5, liquefied defatted rice bran or rice bran using hemicellulase was used. As a result of fermenting with the YAMAKO SHI strain as a substrate, defatted rice bran did not show citric acidity, and rice bran showed citric acidity. Therefore, among the components contained in rice bran, a plurality of components were towed by lactic acid fermentation. It was speculated that it was involved in the impartation of filamentousness.

Using the YAMAKOSHI strain, a yogurt-like food made only from rice was produced.

360 mg (0.04% (w / w)) of α-amylase was added to 900 g of cooked brown rice or white rice, and 9 ml (1% (v / w)) of a suspension of YAMAKOSHI strain (OD660 = 1.0) was added. In addition, the number of initial lactic acid bacteria was adjusted to ¹⁰⁶ cfu / g and fermented at 30 ° C. or 25 ° C. for 24 hours to obtain a fermented rice product. The fermented rice was strained with 30 mesh (595 μm), and then the viscosity was measured with a B-type viscometer, the spinnability was evaluated with a Zahn cup, and the sensory evaluation was performed.

The spinnability was evaluated using a Zahn cup (No. 7, manufactured by Rigosha). That is, 200 ml of a sample kept at 25 ° C. was placed in a 200 ml beaker, a Zahn cup placed at a height of 10 cm from the sample liquid surface was submerged in the sample in the beaker, and the beaker was quickly pulled apart by a constant operation. The time from the moment when the bottom of the cup left the liquid surface to the interruption of the flow of the sample flowing out from the orifice (hole) at the bottom of the Zahn cup was measured, and the duration of the steady flow was used as the evaluation of spinnability.

The fermented white rice could not be found to be spinnable, but the fermented brown rice was found to be spinnable, making it possible to produce foods with yogurt-like viscosity.

A yogurt-like food product using soy milk was produced.

900 ml of commercially available soymilk (solid content 10%, protein 5%, pH 6.5) is placed in a 1 L volume centrifuge tube, and 9 ml (1% (v / v)) of a suspension of lactic acid bacteria (OD660 = 1.0) is added. In addition, the number of initial lactic acid bacteria was adjusted to ¹⁰⁶ cfu / g and fermented at 25 ° C. for 24 hours to obtain a soymilk fermented product.

Manufactured cheese-like food.

900 ml of commercially available soymilk (solid content 10%, protein 5%, pH 6.5) is placed in a 1 L volume centrifuge tube, and 9 ml (1% (v / v)) of a suspension of lactic acid bacteria (OD660 = 1.0) is added. In addition, the number of initial lactic acid bacteria was adjusted to ¹⁰⁶ cfu / g and fermented at 25 ° C. for 24 hours to obtain a soymilk fermented product. The fermented soymilk was centrifuged (2000 rpm, 20 min) to remove the supernatant. The precipitate was transferred to a 250 ml centrifuge tube and centrifuged again (10000 rpm, 15 min) to remove the supernatant to obtain a cheese-like solid content (cheese-like food).

The cheese-like food was subjected to sensory evaluation by a panel of 23 people, with texture (hardness, smoothness, stickiness), flavor (sourness, umami, aroma) and comprehensive evaluation (preference) as evaluation items.

The cheese-like foods using the YAMAKOSHI strain were evaluated as having a high evaluation of smoothness and stickiness, a strong acidity, and a high overall evaluation as compared with those using other strains.

A fermented liquid bran bed was manufactured.

Add 2160 g of water to 750 g (25% (w / w)) of rice bran, 60 g (2% (w / w)) of glucose, and 30 g (1% (w / w)) of citric acid, mix well, and sterilize under pressure. 121 ° C., 15 minutes). After cooling, 3 g (0.1% (w / w)) of hemicellulase (hemicellulase "Amano" 90, manufactured by Amano Enzyme Co., Ltd.) was added and reacted at 50 ° C. for 24 hours, and then the pH was adjusted to 6. Adjusted to 5. A suspension of the YAMAKOSHI strain of the present invention (OD660 = 1.0) was added in an amount of 30 ml (1% (v / w)) to prepare the initial lactic acid bacteria count to ¹⁰⁶ cfu / g, and the temperature was 25 ° C. for 24 hours. Fermented to obtain fermented liquid rice bran.

Claims (3)

Lactobacillus paraplantarum YAMAKOSHI (Lactobacillus paraplantarum YAMAKOSHI: accession number NITE P-03243) is a lactic acid bacterium. A method for producing a viscous fermented product, which comprises a step of fermenting using the lactic acid bacterium according to claim 1. A viscous fermented product, which is obtained by the production method according to claim 2.

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