Lactic acid fermented product

Abstract

To provide a method for producing a lactic acid bacteria-fermented product containing ginger diol by fermentation using lactic acid bacteria, and a lactic acid bacteria-fermented product.SOLUTION: The present invention has been completed with the findings that fermenting a raw material for fermentation, which contains a gingerol-containing material, with lactic acid bacteria results in a lactic acid bacteria-fermented product containing ginger diol.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to lactic acid bacteria fermented products and the like.

Background Art

[0002] Gingerol and its derivatives, which are known as components of ginger, have recently attracted attention for their functionality. For example, Non-Patent Document 1 describes that 6-gingerol is converted into (3R,5S)-6-gingerdioneol and (3S,5S)-6-gingerdioneol by cancer cells or mouse metabolism, and that their metabolites induce cytotoxicity in cancer cells.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a method for producing a lactic acid bacteria fermented product containing gingerdioneol and a lactic acid bacteria fermented product.

Means for Solving the Problems

[0005] The inventors discovered that by fermenting a fermentation raw material containing gingerol using lactic acid bacteria, a fermented product with an increased gingerdiol content can be obtained, thus completing the present invention.

[0006] In other words, the present invention relates to the following embodiments [1] to [5]. [1] A method for producing a gingerdiol-containing lactic acid bacteria fermented product, wherein a fermentation raw material containing a gingerol-containing substance is fermented with lactic acid bacteria to obtain a fermented product containing gingerdiol represented by the following chemical formula 1 or 2. [ka] [In the formula, R represents a linear alkyl group having 3, 5, 7, or 9 carbon atoms.] [ka] [In the formula, R represents a linear alkyl group having 3, 5, 7, or 9 carbon atoms.] [2] A method for producing a gingerdiol-containing lactic acid bacteria fermented product according to [1], wherein the gingerol content per solid content in the fermentation raw material is 0.1% by weight or more. [3] A lactic acid fermented product containing gingerdiol represented by chemical formula 1 or 2, obtained by fermenting a fermentation raw material containing gingerol with lactic acid bacteria. [4] The lactic acid bacteria fermented product according to [3], wherein the gingerdiol content per unit of solids in the fermented product is 0.1% by weight or more. [5] A medium for gingerdiol production having a gingerol content of 0.1% by weight or more per solid. [Effects of the Invention]

[0007] The present invention provides a lactic acid fermented product containing gingerdiol by fermenting a fermentation raw material containing gingerol with lactic acid bacteria. Furthermore, it provides a simple method for producing a lactic acid fermented product containing gingerdiol. [Brief explanation of the drawing]

[0008] [Figure 1] The concentrations of 6-gingerol, (3R,5S)-6-zingerdiol, and (3S,5S)-6-zingerdiol per unit of solid content before and after fermentation by lactic acid bacteria are shown. [Figure 2] The concentrations of 6-gingerol, (3R,5S)-6-zingerdiol, and (3S,5S)-6-zingerdiol per unit of solid content before and after fermentation by lactic acid bacteria are shown. [Figure 3] The concentrations of (3R,5S)-6-zingerdiol and (3S,5S)-6-zingerdiol per unit of solid content are shown after fermentation by various lactic acid bacteria in culture media containing CaCO3 or gingerol-containing substances of various concentrations. [Figure 4] This shows the time course of 6-zingerdiol during lactic acid fermentation under conditions with and without CaCO3. [Figure 5] The concentrations of (3R,5S)-6-zingerdiol and (3S,5S)-6-zingerdiol per unit of solid content after fermentation by lactic acid bacteria in culture media containing each gingerol-containing substance are shown. [Modes for carrying out the invention]

[0009] The method for producing a lactic acid bacteria fermentate containing ginger diol of the present invention comprises fermenting a fermentation raw material containing a gingerol-containing substance with lactic acid bacteria to obtain a fermentate containing ginger diol represented by the following Chemical Formula 1 or 2. Examples of ginger diol include 4-ginger diol, 6-ginger diol, 8-ginger diol, and 10-ginger diol. For example, (3R,5S)-6-ginger diol and (3S,5S)-6-ginger diol are known as 6-ginger diol. The lactic acid bacteria capable of producing ginger diol are not particularly limited as long as they can produce ginger diol. Examples of the lactic acid bacteria include bacteria belonging to the genus Lactobacillus, and Lactobacillus brevis, Lactobacillus fermentum, Lactobacillus reuteri, Lactobacillus kefiri, and Lactobacillus fructivorans are preferred, and one or more of them can be used.

[0010] [Chemical Formula] [In the formula, R represents a linear alkyl group having 3, 5, 7 or 9 carbon atoms.]

[0011] [Chemical Formula] [In the formula, R represents a linear alkyl group having the number of carbon atoms of 3, 5, 7 or 9.]

[0012] The fermentation raw materials of the present invention are not particularly limited as long as they are components that can be fermented by bacteria capable of producing gingerdiol, and general culture medium components can be used, but examples include those containing carbon sources, nitrogen sources, inorganic substances, micronutrients, etc., and either synthetic or natural culture media can be used. As carbon sources, glucose, sucrose, lactose, trehalose, glycerin, sorbitol, molasses, etc. can be used. As nitrogen sources, inorganic salts such as ammonium chloride, ammonium nitrate, ammonium sulfate, ammonium citrate, ammonium phosphate, etc., amino acids such as DL-alanine, L-glutamic acid, peptone, meat extract, yeast extract, malt extract, corn steep liquor, milk protein, soy protein, etc. can be used. As inorganic substances, calcium, sodium, potassium, magnesium, manganese, iron, zinc, etc. can be used. Furthermore, surfactants such as Tween 80, emulsifiers such as polyglycerin fatty acid esters, and oils and fats such as olive oil may also be used. The use of calcium carbonate is preferable because it increases the rate of gingerdiol production.

[0013] Furthermore, the gingerol-containing substance may be of natural origin or synthetic origin, and plant extracts obtained by extracting ginger family plants such as ginger or guinea ginger are preferred. Examples of extraction methods for plant extracts include supercritical fluid extraction, steam distillation, and solvent extraction. As long as gingerdiol is produced by fermentation using the aforementioned bacteria, it is not particularly limited, but the gingerol content per solid content in the fermentation raw material is preferably 0.1% by weight or more, more preferably 0.2 to 50% by weight, even more preferably 0.4 to 40% by weight, and particularly preferably 0.6 to 30% by weight. In addition, the gingerol-containing substance may be added during fermentation.

[0014] The gingerol-containing substance is preferably emulsified so as to be well dispersed in the raw material for fermentation, and may also be an emulsified powder. The emulsifier is not particularly limited as long as it is a component having emulsifying ability. For example, gum substances such as acacia gum, ghatti gum, xanthan gum, sodium octenyl succinate starch, casein, glycerin fatty acid ester, polyglycerin fatty acid ester, sucrose fatty acid ester, lecithin, enzymatically treated lecithin, etc. can be exemplified, and one or more of them can be used. The emulsification treatment can be carried out by a general emulsification method. Specifically, it can be carried out using an emulsification device, and examples include a high-pressure homogenizer, a colloid mill, an ultrasonic emulsifier, a homomixer, a homodisper, etc., and two or more types of devices may be combined.

[0015] For the fermentation conditions, after sterilizing the liquid medium containing the raw material for fermentation, lactic acid bacteria can be inoculated and fermented by standing or shaking. However, it is preferably fermented under aerobic conditions by aeration, shaking, stirring, etc. The fermentation temperature can be exemplified by, for example, 10 to 50 °C, preferably 15 to 40 °C. The fermentation time can be exemplified by, for example, 1 to 120 hours, preferably 2 to 96 hours, more preferably 6 to 72 hours. The pH can be exemplified by, for example, 2.0 to 8.0, preferably 3.0 to 7.5, and the pH may be adjusted within the above range during the culture. For pH adjustment, sodium hydroxide, ammonia, etc. can be used. However, when using a calcium compound such as calcium carbonate, as the culture solution becomes acidic during the culture, it gradually dissolves, alleviates the decrease in pH, enables pH adjustment, and is preferable because the growth inhibition of lactic acid bacteria accompanying the decrease in pH can be suppressed.

[0016] The gingerdiol content in the fermented product is preferably 0.05% by weight or more, more preferably 0.1 to 50% by weight, still more preferably 0.2 to 40% by weight, and particularly preferably 0.5 to 30% by weight per solid content. Incidentally, the gingerdiol content is the total of the above Chemical Formulas 1 and 2 as the gingerdiol content.

[0017] Furthermore, the gingerol content in the fermented product after fermentation is preferably lower than the gingerol content before fermentation. When the gingerol content before fermentation is set to 100% by weight, the gingerol content after fermentation is preferably 90% by weight or less, more preferably 70% by weight or less, even more preferably 50% by weight or less, particularly preferably 20% by weight or less, and most preferably 10% by weight or less. The gingerol content in the fermented product is preferably 15% by weight or less per solid content, more preferably 10% by weight or less, even more preferably 5% by weight or less, and particularly preferably 2% by weight or less.

[0018] The fermented product of the present invention may be sterilized after fermentation. The sterilization conditions are not particularly limited as long as they are general methods, but heating at 60-120°C for 1-30 minutes or at 80-100°C for 5-20 minutes is preferred. The recovered fermented product may be used as a liquid obtained by solid-liquid separation using filtration with nonwoven fabric, mesh, etc., centrifugation, etc., or it may be further concentrated and / or dried and used as a concentrated product or dried product. Drying can be carried out by drum drying, air drying, spray drying, vacuum drying and / or freeze-drying, etc.

[0019] The fermented product of the present invention can be added to various foods and beverages to produce foods and beverages containing gingerdiol. This allows for easy addition of the various functional components of the fermented product to various foods and beverages. The amount added to each food and beverage is not particularly limited, but is preferably 0.1 to 80% by weight, more preferably 0.5 to 50% by weight, even more preferably 1.0 to 30% by weight, and especially preferably 2.0 to 20% by weight. The foods and beverages to which it is added are not particularly limited, but can be used in various foods and beverages such as beverages, foods, seasonings, functional foods, and supplements, as well as in pharmaceuticals, quasi-drugs, cosmetics, and animal feed. [Examples]

[0020] The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples. In the present invention, all percentages are by weight unless otherwise specified. [Examples]

[0021] As a gingerol-containing substance, ginger extract powder G2 (6-gingerol content: 2.3%, manufactured by Ikeda Sugar Chemical Industry Co., Ltd.) was added to MRS medium to a final concentration of 5%. After dispensing 20 g each into test tubes, it was heat-sterilized at 121 °C for 15 minutes. One platinum loopful of Lactobacillus brevis NBRC3345 (Examples 1-1 and 1-2) or Lactobacillus fermentum NBRC15885 (Examples 1-3 and 1-4) was inoculated into two cooled liquid media each, and static culture was carried out at 30 °C for 40 hours. After the culture was completed, it was sterilized at 90 °C for 10 minutes to obtain each lactic acid bacteria fermented product.

[0022] Regarding each lactic acid bacteria fermented product obtained in Examples 1-1 to 1-4, the pH after fermentation was measured and described in Table 1, and the content of 6-gingerol was measured under the following HPLC measurement conditions, and the concentration after fermentation is shown in Figure 1.

[0023] <HPLC measurement conditions> · Detector: UV detector (282 nm) · Column: InertSustain C18 (inner diameter 4.6 mm, length 250 mm) · Mobile phase: Gradient from 30% aqueous acetonitrile solution to pure acetonitrile · Flow rate: 0.8 ml / min · Column temperature: 40 °C · Standard: 6-gingerol (molecular weight: 294.39, manufactured by FUJIFILM Wako Pure Chemical Corporation) was dissolved in 95% ethanol to prepare a calibration curve. · Sample: Each sample was appropriately diluted with 80% acetonitrile before use.

[0024] Furthermore, a comparison of the HPLC charts before and after fermentation revealed two additional peaks that appeared after fermentation, separate from 6-gingerol (retention time: around 17 minutes). These peaks (retention time: around 14 minutes for L. brevis and around 15 minutes for L. fermentum) were thought to be substances produced by fermentation. Analysis using LC / MS and NMR revealed that these substances were both structural isomers of 6-gingerdiol (molecular weight: 296.39), namely (3R,5S)-6-gingerdiol and (3S,5S)-6-gingerdiol.

[0025] For (3R,5S)-6-zingerdiol and (3S,5S)-6-zingerdiol, purified samples analyzed by NMR were used as standards, and their concentrations were calculated under the HPLC measurement conditions described above. The concentrations per unit of solids in the fermented product are shown in Figure 1. The sum of (3R,5S)-6-zingerdiol and (3S,5S)-6-zingerdiol is defined as 6-zingerdiol, and the 6-zingerdiol concentration per unit of solids in the fermented product is shown in Table 1. In addition, the measured concentrations of each component in the culture medium immediately before inoculation, per unit of solids before fermentation, are shown in Figure 1.

[0026] [Table 1] [Examples]

[0027] Following the method of Example 1, lactic acid bacteria fermented products were obtained using L. reuteri NBRC15892, L. kefiri NBRC15888, or L. fructivorans NBRC13954 (Examples 2-1, 2-2, or 2-3) under the conditions described in Table 2. 10 μL of glycerol stock was used for inoculation.

[0028] For each lactic acid bacteria fermented product obtained in Examples 2-1 to 2-3, the pH after fermentation was measured and recorded in Table 2, as in Example 1. In addition, the content of 6-gingerol, (3R,5S)-6-zingerdiol, and (3S,5S)-6-zingerdiol per unit of solid content in the fermented product was measured and shown in Figure 2. The total of (3R,5S)-6-zingerdiol and (3S,5S)-6-zingerdiol is shown in Table 2 as the 6-zingerdiol concentration per unit of solid content in the fermented product.

[0029] [Table 2]

[0030] As shown in Figures 1 and 2, in both Examples 1 and 2, culturing lactic acid bacteria in a medium containing gingerol resulted in the production of 6-gingerdiol after fermentation. In particular, L. brevis produced (3R,5S)-6-gingerdiol, and L. fermentum produced (3S,5S)-6-gingerdiol. Furthermore, the amount of 6-gingerol decreased and the amount of 6-gingerdiol increased before fermentation.

[0031] From the above, it was revealed that a lactic acid bacteria fermentation product containing gingerdiol can be produced by culturing lactic acid bacteria in a liquid medium containing gingerol, and it was also suggested that 6-gingerol is converted to 6-gingerdiol. [Examples]

[0032] Each liquid culture medium was prepared in 200 mL baffled Erlenmeyer flasks, with each final concentration being sucrose: 5%, yeast extract (Meeest® P1G (manufactured by Asahi Group Foods Co., Ltd.)): 3%, Zween 80: 0.1%, MnSO4·5H2O: 0.05%, and for Examples 3-1, 3-2, 3-5, and 3-6, the final concentration of CaCO3 was 1.5% (no CaCO3 in Examples 3-3, 3-4, 3-7, and 3-8). For Examples 3-1, 3-3, 3-5, and 3-7, the final concentration of ginger extract powder G2 as a gingerol-containing substance was 5%, or for Examples 3-2, 3-4, 3-6, and 3-8, the final concentration of ginger extract powder G2 was 10%. The culture media were then heat-sterilized at 121°C for 15 minutes. Each cooled liquid medium was inoculated with 1% (v / v) of the lactic acid bacteria pre-culture solution and cultured with shaking at 30°C for 48 hours. For Examples 3-1 to 3-4, the pre-culture solution was obtained by statically culturing Lactobacillus brevis NBRC12005 in a sterile liquid medium with final concentrations of sucrose: 5%, yeast extract: 3%, and CaCO3: 1.5% at 30°C for 24 hours. For Examples 3-5 to 3-8, the pre-culture solution was obtained by culturing Lactobacillus fermentum NBRC15885 under similar culture conditions. After culturing, the cultures were sterilized at 90°C for 10 minutes to obtain each lactic acid bacteria fermentation product. The culture conditions for each are listed in Table 3.

[0033] For each lactic acid bacteria fermented product obtained in Examples 3-1 to 3-8, the pH after fermentation was measured and recorded in Table 3. In addition, 6-zingerdiol ((3R,5S)-6-zingerdiol and (3S,5S)-6-zingerdiol) was measured under the above HPLC measurement conditions and the concentration per unit of solid content in the fermented product is shown in Table 3 and Figure 3. Note that the 6-zingerdiol concentration in Table 3 is defined as the sum of (3R,5S)-6-zingerdiol and (3S,5S)-6-zingerdiol.

[0034] [Table 3]

[0035] Figure 3 shows that the higher the 6-gingerol content before fermentation, the higher the 6-zingerdiol content after fermentation, indicating that 6-zingerdiol is produced regardless of the presence or absence of CaCO3. [Examples]

[0036] Each liquid medium was prepared in 200 mL baffled Erlenmeyer flasks, with each final concentration being sucrose: 5%, yeast extract (Meeest® P1G): 3%, and for Example 4-1, gingerol-containing substances being ginger extract powder G2: 10% and CaCO3: 1.5%, or for Example 4-2, ginger extract powder G2: 10%. The mixtures were heat-sterilized at 121°C for 15 minutes. After cooling, each liquid medium was inoculated with 1% (v / v) of the lactic acid bacteria pre-culture solution and cultured with shaking at 30°C for 24 hours. The pre-culture solution was prepared by culturing Lactobacillus fermentum NBRC15885 with shaking at 30°C for 24 hours in a sterile liquid medium with each final concentration being sucrose: 5%, yeast extract: 3%, and CaCO3: 1.5%.

[0037] From 14 to 24 hours after fermentation, samples were taken every two hours, and the pH of each sample was measured and recorded in Table 4. In addition, the content of 6-zingerdiol ((3S,5S)-6-zingerdiol) was measured under the HPLC measurement conditions described above and is shown in Figure 4.

[0038] [Table 4]

[0039] Figure 4 shows that the rate of 6-zingerdiol formation is faster in the presence of CaCO3. [Examples]

[0040] Each liquid medium was prepared in 200 mL baffled Erlenmeyer flasks, with each final concentration being sucrose: 5%, yeast extract (Meeest® P1G): 3%, CaCO3: 1.5%, and gingerol-containing substance: ginger extract (Ginger soft SCFE 35%, manufactured by Sabinsa Japan Co., Ltd.): 1% in Example 5-1, ginger extract (Ginger soft SCFE 35%, manufactured by Sabinsa Japan Co., Ltd.): 1% in Example 5-2, the aforementioned ginger extract: 1% and polyglycerin fatty acid ester (NIKKOL® Decagyn 1-MVEX PN, manufactured by Nikko Chemicals Co., Ltd.): 2%, or ginger extract powder G2 as the gingerol-containing substance in Example 5-3, with each medium containing 50 g of liquid medium being prepared in a 200 mL baffled Erlenmeyer flask and heat-sterilized at 121 °C for 15 minutes. Each cooled liquid medium was inoculated with 1% (v / v) of the pre-culture solution of lactic acid bacteria and cultured with shaking at 30 °C for 24 hours. Furthermore, the pre-culture solution was prepared by shaking Lactobacillus fermentum NBRC15885 in a sterile liquid medium with final concentrations of sucrose: 5%, yeast extract: 3%, and CaCO3: 1.5% at 30°C for 24 hours. After the culture was completed, the mixture was sterilized at 90°C for 10 minutes to obtain each lactic acid bacteria fermentation product. The culture conditions for each product are listed in Table 5.

[0041] For each lactic acid bacteria fermented product obtained in Examples 5-1 to 5-3, the pH after fermentation was measured and recorded in Table 5. Additionally, the content of 6-zingerdiol ((3R,5S)-6-zingerdiol and (3S,5S)-6-zingerdiol) was measured under the HPLC conditions described above, and the concentration per unit of solid content in the fermented product is shown in Table 5 and Figure 5. Note that in Table 5, the 6-zingerdiol concentration is defined as the sum of (3R,5S)-6-zingerdiol and (3S,5S)-6-zingerdiol.

[0042] [Table 5]

[0043] It was found that by including a gingerol-containing substance in the fermentation raw material, a lactic acid bacteria fermented product containing gingerdiol can be prepared, and furthermore, by emulsifying the gingerol-containing substance, the concentration of gingerdiol per unit of solid content increases.

Claims

1. A method for producing a gingerdiol-containing lactic acid bacteria ferment, comprising the step of fermenting a fermentation raw material containing a gingerol-containing substance with lactic acid bacteria under stirring conditions to produce gingerdiol, wherein the fermentation raw material is a liquid culture medium containing a carbon source and a nitrogen source, the lactic acid bacteria are one or more selected from the group consisting of Lactobacillus brevis, L. fermentum, L. reuteri, L. kefiri and L. fructivorans, and the gingerdiol is represented by the following chemical formula 1 or 2. 【Chemistry 1】 [In the formula, R represents a linear alkyl group having 3, 5, 7, or 9 carbon atoms.] 【Chemistry 2】 [In the formula, R represents a linear alkyl group having 3, 5, 7, or 9 carbon atoms.]

2. A method for producing a gingerdiol-containing lactic acid bacteria fermented product according to claim 1, wherein the gingerol content per unit of solid content in the fermentation raw material is 0.1% by weight or more.

3. A gingerdiol-containing lactic acid bacteria fermented product obtained by a manufacturing method comprising the step of fermenting a fermentation raw material containing a gingerol-containing substance with lactic acid bacteria under stirring conditions to produce gingerdiol, wherein the fermentation raw material is a liquid culture medium containing a carbon source and a nitrogen source, the lactic acid bacteria are one or more selected from the group consisting of Lactobacillus brevis, L. fermentum, L. reuteri, L. kefiri and L. fructivorans, and the gingerdiol is represented by the following chemical formula 1 or 2. 【Chemistry 1】 [In the formula, R represents a linear alkyl group having 3, 5, 7, or 9 carbon atoms.] 【Chemistry 2】 [In the formula, R represents a linear alkyl group having 3, 5, 7, or 9 carbon atoms.]

4. The lactic acid bacteria fermented product according to claim 3, wherein the gingerdiol content per unit of solids in the fermented product is 0.1% by weight or more.

5. A medium for producing gingerdiol, wherein the gingerol content per solid content in the liquid medium according to claim 1 or 3 is 0.1% by weight or more.

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