Method for inhibiting microbiological growth in food and composition for the same

Abstract

To provide a technology that uses natural components to effectively inhibit microbiological growth in food.SOLUTION: There is provided a method for inhibiting microbiological growth in food that comprises adding geranylgeraniol and licorice oil extract to food.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to methods and compositions for inhibiting the growth of microorganisms in food. More specifically, it relates to a method for inhibiting the growth of microorganisms in food, which uses a combination of geranylgeraniol and licorice oil extract.

Background Art

[0002] In order to inhibit the growth of microorganisms in food, naturally derived antibacterial agents have been developed. Patent Document 1 discloses an antibacterial agent containing geranylgeraniol, and it is stated that it is preferable to apply natural geranylgeraniol extracted from seeds of Bixa orellana, etc. to food and drink. Further, Patent Document 2 discloses a method for improving the preservability of food by adding a licorice extract.

[0003] Although naturally derived antibacterial agents can be expected to have high safety compared to synthetic preservatives, there are cases where a sufficient effect of inhibiting the growth of microorganisms cannot be obtained with the addition amount within the range that does not affect the color, smell, and taste of food.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The main object of the present disclosure is to provide a technique for more effectively inhibiting the growth of microorganisms in food using naturally derived components.

Means for Solving the Problems

[0006] To solve the above problems, the present disclosure provides the following [1]-

[33] . [1] A method for inhibiting the growth of microorganisms in food by adding geranylgeraniol and licorice oil extract to the food. [2] The method according to [1], wherein the addition concentration of geranylgeraniol to the food is 50 - 1000 ppm, and the addition concentration of licorice oil extract is 100 - 1000 ppm. [3] The method according to [1] or [2], wherein the food is stored at 10°C or lower. [4] The method according to any one of [1]-[3], wherein geranylgeraniol is contained in annatto oil and added. [5] The method according to any one of [1]-[4], wherein the food is meat sauce or custard cream. [6] The method according to any one of [1]-[5], wherein the microorganisms include lactic acid bacteria. [7] The method according to [6], wherein the lactic acid bacteria are Leuconostoc mesenteroides or / and Weissella viridescens.

[0007] [8] A composition for inhibiting the growth of microorganisms in food, comprising geranylgeraniol and licorice oil extract. [9] The composition according to [8], wherein the addition concentration of geranylgeraniol to the food is 50 - 1000 ppm, and the addition concentration of licorice oil extract is 100 - 1000 ppm.

[10] The composition according to [8] or [9], wherein the food is stored at 10°C or lower.

[11] The composition according to any one of [8]-

[10] , wherein geranylgeraniol is contained in annatto oil and added.

[12] The composition according to any one of [8]-

[11] , wherein the food is meat sauce or custard cream.

[13] The composition according to any one of [8]-

[12] , wherein the microorganisms include lactic acid bacteria.

[14] The composition according to

[13] , wherein the lactic acid bacteria are Leuconostoc mesenteroides or / and Weissella viridescens.

[0008]

[15] Use of a combination of geranylgeraniol and licorice oil extract for inhibiting the growth of microorganisms in food.

[16] The use according to

[15] , wherein the addition concentration of geranylgeraniol in the food is 50 - 1000 ppm, and the addition concentration of licorice oil extract is 100 - 1000 ppm.

[17] The use according to

[15] or

[16] , wherein the food is stored at 10°C or lower.

[18] The use according to any one of

[15] -

[17] , wherein the food is meat sauce or custard cream.

[19] The use according to any one of

[15] -

[18] , wherein the microorganisms include lactic acid bacteria.

[20] The use according to

[19] , wherein the lactic acid bacteria are Leuconostoc mesenteroides or / and Weissella viridescens.

[0009]

[21] A composition for inhibiting the growth of microorganisms in food, which contains geranylgeraniol and is used in combination with licorice oil extract.

[22] The composition according to

[21] , wherein the addition concentration of geranylgeraniol in the food is 50 - 1000 ppm.

[23] The composition according to

[21] or

[22] , wherein the food is stored at 10°C or lower.

[24] The composition according to any one of

[21] -

[23] , which is annatto oil.

[25] The composition according to any one of

[21] -

[24] , wherein the food is meat sauce or custard cream.

[26] The composition according to any one of

[21] -

[25] , wherein the microorganisms include lactic acid bacteria.

[27] The composition according to

[26] , wherein the lactic acid bacteria are Leuconostoc mesenteroides or / and Weissella viridescens.

[0010]

[28] Use of geranylgeraniol for suppressing the growth of microorganisms in food, which is combined with the use of licorice oil extract.

[29] The use according to

[28] , wherein the addition concentration of geranylgeraniol to the food is 50 - 1000 ppm.

[30] The use according to

[28] or

[29] , wherein the food is stored at 10°C or lower.

[31] The use according to any one of

[28] -

[30] , wherein the food is meat sauce or custard cream.

[32] The use according to any one of

[28] -

[31] , wherein the microorganisms include lactic acid bacteria.

[33] The use according to

[32] , wherein the lactic acid bacteria are Leuconostoc mesenteroides or / and Weissella viridescens.

Advantages of the Invention

[0011] The present disclosure provides a technique for more effectively suppressing the growth of microorganisms in food using natural - derived components.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0013] Hereinafter, preferred embodiments for carrying out the present disclosure will be described. Note that the embodiments described below show an example of typical embodiments of the present disclosure, and thus the scope of the present disclosure should not be construed narrowly thereby.

[0014] A composition for suppressing the growth of microorganisms in food according to the present disclosure (hereinafter also referred to as "antibacterial composition") is characterized by containing a combination of geranylgeraniol and an oily extract of licorice. In the present disclosure, "suppression of microorganism growth" and "antibacterial" are used interchangeably and both include the meanings of both bactericidal action of killing bacteria and bacteriostatic action of inhibiting or suppressing the growth of bacteria.

[0015] Geranylgeraniol may be a natural product or a synthetic product, but is preferably of natural origin. Geranylgeraniol can be obtained, for example, by production methods such as chemical synthesis (Japanese Patent Laid-Open No. 08-133999), microbial production (Japanese Patent Laid-Open No. 2005-52037), extraction from Bixa orellana (Japanese Patent Laid-Open No. 2007-238508), etc.

[0016] When geranylgeraniol is of natural origin, anatto oil extracted from the seeds of Bixa orellana (annatto) can be blended as a composition containing geranylgeraniol in the antibacterial composition according to the present disclosure. The anatto oil may be produced by the above-described extraction method from Bixa orellana, or commercially available products can also be used. Examples of commercially available anatto oil include Geranylgeraniol-50 of Mitsubishi Chemical Corporation.

[0017] The oily extract of licorice is obtained by extracting licorice with an organic solvent such as acetone, methanol, ethanol, etc., contains several kinds of antibacterial substances, and is known to exhibit antibacterial properties in vitro. The oily extract of licorice can be prepared by a conventionally known method, or commercially available products can also be used.

[0018] By combining geranylgeraniol and licorice oil extract and adding them to food, a synergistic effect of inhibiting the growth of microorganisms can be obtained compared to the case where they are added alone. By inhibiting the growth of microorganisms, food spoilage and deterioration can be suppressed, and the shelf life can be improved. Geranylgeraniol and licorice oil extract may be contained in food, or may be applied to the outer surface of food by coating or spraying.

[0019] Annatto oil or geranylgeraniol, and licorice oil extract are preferably extracted using alcohol (especially ethanol) as a solvent from the viewpoint of addition to food.

[0020] The addition concentration of geranylgeraniol in food is not particularly limited as long as the intended antibacterial effect can be obtained, but is preferably 50 - 1000 ppm, more preferably 50 - 500 ppm, and even more preferably 125 - 250 ppm. The addition concentration of licorice oil extract in food is also not particularly limited as long as the intended antibacterial effect can be obtained, but is preferably 100 - 1000 ppm, more preferably 100 - 500 ppm, and even more preferably 250 - 500 ppm.

[0021] The microorganisms targeted by the antibacterial composition according to the present disclosure are microorganisms (such as bacteria and fungi) that can be contained in food, and are not particularly limited as long as they are the cause of food spoilage and deterioration, and a wide range of microorganisms are targeted. Exemplary microorganisms include those belonging to the genera Bacillus, Clostoridium, Escherichia, Helicobacter, Salmonella, Listeria, Lactobacillus, Lactiplantibacillus, Leuconostoc, Lactococcus, Weissella, Porphyromonas, Staphylococcus, Streptococcus, Saccharomyces, Aspergillus, Penicillium, etc. More specifically, Bacillus subtilis, Bacillus cereus, Clostoridium butyricum, Clostoridium sporogenes, Escherichia coli, Helicobacter pylori, Salmonella enterica serovar Typhimurium, Salmonella enterica serovar Enteritidis, Listeria monocytogenes, Lactobacillus delbrueckii, Lactiplantibacillus plantarum, Leuconostoc mesenteroides, Lactococcus lactis, Weissella viridescens, Porphyromonas gingivalis, Staphylococcus aureus, Streptococcus mutans, Saccharomyces serevisiae, Aspergillus flavus, Penicillium expansum can be mentioned. The evaluation of the antibacterial ability of the antibacterial composition according to the present disclosure can be carried out particularly using the growth of lactic acid bacteria as an index. The lactic acid bacteria are not particularly limited, and examples thereof include Leuconostoc mesenteroides and Weissella viridescens.

[0022] The food targeted by the antibacterial composition according to the present disclosure is not particularly limited, and for example, it may be a non-cooked product of various food ingredients such as vegetables, beans, tubers, wild vegetables, fruits, livestock meat, chicken, seafood, grains, etc., or it may be a cooked or semi-cooked food such as prepared vegetables, rice, noodles, confectioneries, soups, dairy products, tofu, etc., that is, a so-called processed food. Here, the so-called semi-cooked refers to unfinished cooking. For example, semi-cooked products refer to foods that have been prepared such as seasoning, cutting, peeling, skewering, dusting with powder, etc. of food ingredients, which are heated but not fully seasoned, those that are in a state with a coating and a base flavor but not heated, and cut vegetables, etc. Regarding the antibacterial composition according to the present disclosure, the evaluation of the antibacterial ability can be carried out particularly using the growth of microorganisms in meat sauce or custard cream as an index. The antibacterial composition according to the present disclosure can be suitably applied particularly to those of the foods exemplified above that are stored at 10°C or lower. The antibacterial composition according to the present disclosure can be added in an effective amount to, for example, meat sauce, and can significantly suppress the growth of microorganisms after storage at 10°C for 3 days. Also, the antibacterial composition according to the present disclosure can be added in an effective amount to, for example, custard cream, and can significantly suppress the growth of microorganisms after storage at 10°C for 7 days.

[0023] The antibacterial composition according to the present disclosure may be in any dosage form such as liquid, powder, granule, tablet, etc. The antibacterial composition according to the present disclosure may contain antibacterial substances and other components other than geranylgeraniol and licorice oil extract. Examples of other components include known additives and adjuvants that can be usually used in the field of food and beverage formulation technology, such as excipients, binders, disintegrants, lubricants, coloring agents, flavoring and odor-correcting agents, solubilizing agents, suspending agents, coating agents, physiologically acceptable carriers, etc. Examples of additives and adjuvants include, for example, lysozyme, glucose, fructose, sucrose, maltose, sorbitol, stevioside, dextrin, corn syrup, lactose, citric acid, tartaric acid, malic acid, succinic acid, lactic acid, L-ascorbic acid, dl-α-tocopherol, sodium erythorbate, glycerin, propylene glycol, glycerin fatty acid ester, polyglycerin fatty acid ester, sucrose fatty acid ester, sorbitan fatty acid ester, propylene glycol fatty acid ester, xanthan gum, gum arabic, carrageenan, casein, gelatin, pectin, agar, B vitamins, nicotinamide, calcium pantothenate, amino acids, calcium salts, various dyes and flavors, preservatives, and the like.

Example

[0024] [Example 1: Growth inhibition test of lactic acid bacteria in meat sauce by the combination of annatto oil and licorice oil extract] Annatto oil (geranylgeraniol-50; Mitsubishi Chemical Corporation) and licorice oil extract (licorice oil extract; Tokiwa Phytochemical Co., Ltd.) were dissolved in DMSO and added to meat sauce at a single concentration of 500 ppm or a total concentration of 1000 ppm (500 ppm each) or 500 ppm (250 ppm each). At this time, the concentration of DMSO in the meat sauce was 10,000 ppm. DMSO was added to the sample without annatto oil and licorice oil extract to a concentration of 10,000 ppm. Lactic acid bacteria (Leuconostoc mesenteroides NBRC 100496 strain) were inoculated into these meat sauces and stored at 10°C for 3 days.

[0025]

Table 1

[0026] The number of bacteria in the meat sauce was measured at the start of storage (0 day), on the 1st day, and on the 3rd day as follows. Put 10 g of meat sauce into a stomacher bag, add 90 mL of phosphate-buffered saline to this stomacher bag, and stomach for 60 seconds to obtain a sample suspension. After diluting the sample suspension stepwise with phosphate-buffered saline as needed, dispense 1 mL into a petri dish, pour Trypticase soy agar (Nippon Becton Dickinson Co., Ltd.), and mix by spreading. Incubate the solidified agar medium at 35°C for 48 hours, and use the value obtained by multiplying the number of colonies grown by the dilution factor as the number of bacteria.

[0027] The results are shown in Figure 1. In the non-additive group 1, bacteria grew beyond 1.0×10 5 CFU / g, which is the standard for spoilage on the 3rd day of storage (Log CFU / g = 5.45). In the annatto oil-added group 2 and the licorice oil extract-added group 3, the growth of bacteria was suppressed, and the Log CFU / g values were 4.97 and 3.83, respectively. In the combined group 5 of annatto oil and licorice oil extract (250 ppm each), the Log CFU / g was 3.21, showing a significant improvement in antibacterial ability. In the combined group 4 of annatto oil and licorice oil extract (500 ppm each), the Log CFU / g was 1.86, and the antibacterial ability was further improved.

[0028] The test was carried out in the same manner with the solvent changed from DMSO to ethanol.

[0029]

Table 2

[0030] The results are shown in Figure 2. In the non-additive group 1, bacteria grew to about 1.0×10 5 CFU / g, which is the standard for spoilage on the 3rd day of storage (Log CFU / g = 4.98). In the annatto oil-added group 2, the Log CFU / g was also 5.07. In the licorice oil extract-added group 3, the growth of bacteria was suppressed, and the Log CFU / g was 3.97. In the combined group 4 of annatto oil and licorice oil extract (500 ppm each), the Log CFU / g decreased to 2.70, showing a high antibacterial effect.

[0031] [Example 2: Growth inhibition test of lactic acid bacteria in custard cream by the combination of annatto oil and licorice oil extract] Annatto oil (geranylgeraniol-50; Mitsubishi Chemical Corporation) and licorice oil extract (licorice oil extract; Tokiwa Phytochemical Co., Ltd.) were dissolved in ethanol and then added to custard cream so that the total concentration was 500 ppm (250 ppm each). Lactic acid bacteria (Weissella viridescens NBRC3949 strain) were inoculated and stored at 10°C for 7 days. The number of bacteria in the custard cream was measured on the start day of storage (day 0), day 4, and day 7 by the same method as in Example 1.

[0032]

Table 3

[0033] The results are shown in Figure 3. In the non-added group 1, the bacteria grew to about 1.0×10 5 CFU / g, which is the standard for spoilage on the 7th day of storage (Log CFU / g = 4.85). In the combined group 2 of annatto oil and licorice oil extract (250 ppm each), the Log CFU / g decreased to 2.95, showing a high antibacterial effect.

[0034] [Example 3: Comparison of the combined effects of annatto oil and licorice oil extract or other plant extracts] Annatto oil (geranylgeraniol-50; Mitsubishi Chemical Corporation) and various antibacterial plant extracts were dissolved in DMSO and then added to meat sauce alone or in combination. Lactic acid bacteria (Leuconostoc mesenteroides NBRC 100496 strain) were inoculated and stored at 10°C for 3 days. The number of bacteria in the meat sauce was measured on the start day of storage (day 0) and day 3 by the method described in Example 1.

[0035] The final concentrations of each plant extract are as follows for both single addition and combined addition. Annatto oil (geranylgeraniol-50; Mitsubishi Chemical Corporation): 500 ppm Licorice oil extract (Licorice oil extract; manufactured by Tokiwa Phytochemical Co., Ltd.): 500 ppm Guava extract (Guavaphenone; manufactured by Bizen Kasei Co., Ltd.): 2000 ppm Pomegranate extract (Pomegranate extract; manufactured by Bioactive Japan Co., Ltd.): 4000 ppm Banaba leaf extract (Corosolic acid - 18%; manufactured by Tokiwa Phytochemical Co., Ltd.): 2000 ppm Terminalia bellirica extract (Terminalia bellirica extract; manufactured by Bioactive Japan Co., Ltd.): 4000 ppm Rosemary extract (RM - 21B base; manufactured by Mitsubishi Chemical Corporation): 500 ppm

[0036] The results are shown in Table 4. It is clear that when using a combination of annatto oil and licorice oil extract, the number of bacteria hardly increases, and a synergistic antibacterial effect not observed in combinations of annatto oil and other plant extracts is obtained.

[0037]

Table 4

[0038] [Example 4: Confirmation test of the combined effect of annatto oil and licorice oil extract by a test for inhibiting the growth of lactic acid bacteria in a medium system] Annatto oil and licorice oil extract were added alone or in combination at the concentrations shown in Table 5 to Trypticase soy broth (manufactured by Nippon Becton Dickinson Co., Ltd.) and dispensed into microplates. A suspension of lactic acid bacteria (Leuconostoc mesenteroides NBRC 100496 strain) was added thereto, and after culturing at 37°C for 48 hours, the Minimum Inhibitory Concentration (MIC) value was measured based on the presence or absence of bacterial growth. Regarding the presence or absence of growth, when no turbidity or precipitation of bacteria was observed, or when there was precipitation but the diameter of the precipitate mass was less than 1 mm and there was only one, it was determined that growth was not observed. In the table, “+” indicates growth and “-” indicates no growth. The presence or absence of a synergistic effect was evaluated using the Fractional Inhibitory Concentration (FIC). The FIC value was calculated using the following formula. When the minimum FIC value was 0.5 or less, it was considered a synergistic effect; when it was greater than 0.5 and 1.0 or less, it was considered an additive effect; when it was greater than 1.0 and 2.0 or less, it was considered irrelevant; and when it was greater than 2.0, it was considered an antagonistic effect.

[0039] FIC value = (MIC value of extract A at combination / MIC value of extract A alone) + (MIC value of extract B at combination / MIC value of extract B alone)

[0040] Annatto oil and licorice oil extract were added to the medium alone or in combination at the concentrations shown in Table 5, and the presence or absence of bacterial growth was determined. In the table, "+" indicates growth and "-" indicates no growth.

[0041]

Table 5

[0042] The MIC value of annatto oil alone was 7.81 ppm, and the MIC value of licorice oil extract alone was 31.3 ppm. The MIC values of the combination of annatto oil and licorice oil extract were 1.95 ppm for annatto oil and 15.6 ppm for licorice oil extract. The FIC value was calculated to be 0.75 by the calculation of "1.95 / 7.81 + 15.6 / 31.3". The combination of annatto oil and licorice oil extract showed only an additive effect in the evaluation system in the medium, and no synergistic effect was observed. The synergistic antibacterial effect of the combination of annatto oil and licorice oil extract was not obtained in a simple test using a medium frequently used in screening tests, but was only obtained in a test using a food that required labor for the test.

Claims

1. A method for inhibiting the growth of microorganisms in food by adding geranylgeraniol and licorice oil extract to the food.

2. The method according to claim 1, wherein the addition concentration of geranylgeraniol to the food is 50 - 1000 ppm, and the addition concentration of licorice oil extract is 100 - 1000 ppm.

3. The method according to claim 2, wherein the food is stored at 10°C or lower.

4. The method according to claim 3, wherein geranylgeraniol is contained in and added as annatto oil.

5. The method according to claim 4, wherein the food is meat sauce or custard cream.

6. The method according to claim 5, wherein the microorganisms include lactic acid bacteria.

7. The method according to claim 6, wherein the lactic acid bacteria are Leuconostoc mesenteroides or / and Weissella viridescens.

8. A composition for inhibiting the growth of microorganisms in food, comprising geranylgeraniol and licorice oil extract.

9. Combined use of geranylgeraniol and licorice oil extract for inhibiting the growth of microorganisms in food.

10. A composition for inhibiting the growth of microorganisms in food, comprising geranylgeraniol and used in combination with licorice oil extract.

11. The composition according to claim 10, which is annatto oil.

12. Use of geranylgeraniol for inhibiting the growth of microorganisms in food, which is combined with the use of licorice oil extract.

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