Natural cheese and method for producing the same

Abstract

To provide a method for producing natural cheese comprising a greater amount of short-chain fatty acids.SOLUTION: Provided is a method for producing natural cheese that comprises, as the starter lactic acid bacterium, at least one plant-derived lactic acid bacterium selected from the group consisting of Pediococcus pentosaceus FHC1 (NITE P-03892) and Lactobacillus plantarum FHC3 (NITE P-03893).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to natural cheese and a method for producing the same. [Background technology]

[0002] Natural cheese is made by coagulating raw milk using lactic acid bacteria called starters and rennet, removing the whey, squeezing and solidifying it, and then aging it. To expand the market, various natural cheeses with qualities that meet consumer demands have been developed, but the quality of natural cheese is classified according to its flavor as a food ingredient and its processing and cooking properties, and the functionality of the food, unlike yogurt, has not been given much attention.

[0003] In matured cheese, "umami components," "rich flavor components," and "aroma components" are known as components that constitute the mature flavor of the cheese quality. These components are produced when the milk fat and milk protein that make up the cheese curd are broken down by the action of enzymes in the raw milk, milk-clotting enzymes, and enzymes derived from useful microorganisms, and are converted into various taste and aroma substances. Examples of useful microorganisms include lactic acid bacteria and mold, but the role that lactic acid bacterial enzymes, which are commonly used in many natural cheeses, play in forming the flavor of cheese is particularly important.

[0004] In general, the types of enzymes involved in ripening, such as peptidases and lipases, vary depending on the type of lactic acid bacteria, and the amount of enzymes per cell varies depending on the strain, even for the same species. The components that compose the ripened flavor produced by the action of these enzymes undergo complex changes during the ripening process. Therefore, in order to express the desired cheese flavor, cheese makers select the type and strain of lactic acid bacteria to use in cheese production.

[0005] Various techniques for accelerating ripening and producing cheese with improved ripened flavor have been studied in the prior art. For example, there are natural cheese using Lactobacillus bulgaricus with high peptidase activity as an adjunct starter, koji cheese prepared by inoculating and culturing koji mold into cheese curd, and natural cheese with good flavor that is produced by accelerating or improving the ripening process of cheese using salt derived from deep sea water or crystalline salt derived from deep sea water. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2010 / 001596 [Patent Document 2] JP 2010-246499 A [Patent Document 3] Patent No. 3747366 Summary of the Invention [Problem to be solved by the invention]

[0007] On the other hand, the "aroma components" produced by lactic acid bacteria contain short-chain fatty acids such as acetic acid, propionic acid, and butyric acid, which are expected to have useful functions as food. The functions of these foods are known to be the growth of colonic epithelial cells, secretion of mucus, energy source for water and mineral absorption, keeping the intestinal environment slightly acidic and suppressing the growth of harmful bacteria, stimulating the mucous membrane of the large intestine to promote peristalsis, and controlling human immune responses. However, these short-chain fatty acids are volatile and are constantly volatilized during the manufacturing process, and decrease as the lactic acid bacteria die. In cheese manufacturing so far, mesophilic lactic acid bacteria used as starters include Lactococcus lactis subsp. lactis, Lactococcus lactis subsp. cremoris, and Leuconostoc mesenteroides subsp. cremoris. However, most of these starter lactic acid bacteria die due to the drop in pH caused by excessive production of organic acids, heating during the cooking process to condense the curd, and drying during aging. In addition, short-chain fatty acids volatilize as the cheese dries during aging. Therefore, in order to accumulate short-chain fatty acids in cheese, fermentation by microorganisms other than lactic acid bacteria, such as mold and yeast, is required during the aging process, which makes the cheese manufacturing process complicated. In addition, natural cheese aged using fungi such as mold and yeast is often disliked in countries other than Europe and the United States, including Japan, due to its unique odor, and these fungi are removed just before eating and do not produce short-chain fatty acids in the body, so it was considered unsuitable for effective intake of short-chain fatty acids.

[0008] An object of the present invention is to provide a method for producing natural cheese containing a larger amount of short-chain fatty acids. [Means for solving the problem]

[0009] The present inventors have conducted intensive research in view of the above problems, and have found that the above problems can be solved by a method for producing natural cheese, characterized in that the starter lactic acid bacteria comprises at least one plant-derived lactic acid bacterium selected from the group consisting of Pediococcus pentosaceus FHC1 (Accession Number of the Patent Organism Depositary Center: NITE P-03892) and Lactobacillus plantarum FHC3 (Accession Number of the Patent Organism Depositary Center: NITE P-03893). Based on this finding, the present inventors have conducted further research, and have completed the present invention. That is, the present invention encompasses the following aspects.

[0010] Item 1. A method for producing natural cheese, characterized in that the starter lactic acid bacteria comprises at least one plant-derived lactic acid bacterium selected from the group consisting of Pediococcus pentosaceus FHC1 (Patent Organism Depositary Center Accession Number: NITE P-03892) and Lactobacillus plantarum FHC3 (Patent Organism Depositary Center Accession Number: NITE P-03893).

[0011] Item 2. The method according to Item 1, wherein the temperature of the cooking step is 35°C or lower.

[0012] Item 3. The method according to item 1 or 2, wherein the temperature in the cooking step is 20 to 35°C.

[0013] Item 4. The method according to any one of Items 1 to 3, further comprising a maturation step.

[0014] Item 5. The method according to Item 4, wherein the aging step is carried out for a period of 2 weeks or longer.

[0015] Item 6. The production method according to any one of Items 1 to 5, wherein no microorganisms other than lactic acid bacteria are added.

[0016] Item 7. A natural cheese containing at least one plant-derived lactic acid bacterium selected from the group consisting of Pediococcus pentosaceus FHC1 (Patent Organism Depositary Center Accession Number: NITE P-03892) and Lactobacillus plantarum FHC3 (Patent Organism Depositary Center Accession Number: NITE P-03893).

[0017] Item 8. The natural cheese according to Item 7, which is a hard or semi-hard natural cheese.

[0018] Item 9. The natural cheese according to Item 7 or 8, which has a butyric acid content of 50 mg or more per 10 g of the natural cheese.

[0019] Item 10. At least one plant-derived lactic acid bacterium selected from the group consisting of Pediococcus pentosaceus FHC1 (Patent Organism Depositary Center Accession Number: NITE P-03892) and Lactobacillus plantarum FHC3 (Patent Organism Depositary Center Accession Number: NITE P-03893). Effect of the Invention

[0020] According to the present invention, a method for producing natural cheese containing more short-chain fatty acids can be provided. In addition, according to a preferred embodiment of the present invention, a method for producing natural cheese containing more viable lactic acid bacteria can be provided. [Brief description of the drawings]

[0021] [Figure 1] 1 shows the results of a questionnaire given after tasting the natural cheese obtained in Example 3. The vertical axis shows the number of respondents, and the horizontal axis shows the evaluation items. [Diagram 2] 1 shows the results of a questionnaire given after tasting the natural cheese obtained in Example 4. The vertical axis shows the number of respondents, and the horizontal axis shows the evaluation items. [Diagram 3]The results of the analysis of free amino acids in the fermented milk obtained in Example 5 are shown. The amino acids classified into the five tastes are as shown in Table 1. The values ​​indicate the relative amounts. The legend indicates the starter lactic acid bacteria used. [Figure 4] 1 shows the measurement results of the amount of butyric acid in the fermented milk obtained in Example 5. The horizontal axis shows the starter lactic acid bacteria used. [Diagram 5] 1 shows the results of measuring the amount of bacteria in cheese before and after ripening obtained in Example 6. The vertical axis shows the amount of bacteria surviving in 1 g of cheese, and the horizontal axis shows the temperature during the cooking process. [Figure 6] The results of the free amino acid analysis of the cheese obtained in Example 7 are shown. The amino acids classified into the five tastes are as shown in Table 1. The numbers indicate the relative amounts. The legend indicates the temperature of the cooking process. [Figure 7] 1 shows the results of measuring the organic acid amounts of the cheese obtained in Example 8. The horizontal axis shows the starter lactic acid bacteria used, the temperature in the cooking process, and the maturation stage. [Figure 8] 1 shows the results of an abdominal glucose tolerance test on mice administered cheese in Example 9. The horizontal axis shows the time elapsed after glucose administration, and the vertical axis shows blood glucose levels. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] In this specification, the expressions "contain" and "comprise" include the concepts of "contain", "include", "consist essentially of" and "consist only of".

[0023] In one aspect, the present invention relates to a method for producing natural cheese (sometimes referred to as the "production method of the present invention" herein) characterized in that the starter lactic acid bacteria contains at least one plant-based lactic acid bacterium selected from the group consisting of Pediococcus pentosaceus FHC1 (accession number at the Japan Patent Organism Depositary Center: NITE P-03892) and Lactobacillus plantarum FHC3 (accession number at the Japan Patent Organism Depositary Center: NITE P-03893) (sometimes referred to as the "plant-based lactic acid bacterium of the present invention" herein). This will be described below.

[0024] The term "natural cheese" refers to a natural cheese produced by a method including curdling and squeezing raw milk, and is not particularly limited. Examples of natural cheese include Gouda cheese, Samsoe cheese, Cheddar cheese, Camembert cheese, etc.

[0025] The subject of the present invention is preferably hard or semi-hard natural cheese. Typically, the moisture content in the total weight excluding fat (NFFB%) is preferably 45 to 65%, more preferably 50 to 60%. Generally, cheeses with a NFFB% of 49 to 56% are called hard natural cheeses, and cheeses with a NFFB% of 54 to 69% are called semi-hard natural cheeses.

[0026] The process for producing natural cheese typically includes the steps of curdling, cooking, and pressing.

[0027] The curdling process is a process of adding starter lactic acid bacteria and rennet to raw milk to obtain curd. The production method of the present invention is characterized in that the starter lactic acid bacteria contains the vegetable lactic acid bacteria of the present invention. Due to the characteristics of these vegetable lactic acid bacteria, it is possible to obtain natural cheese containing more short-chain fatty acids.

[0028] The raw milk is not particularly limited so long as it can be used in the production of natural cheese, and examples thereof include cow's milk, goat's milk, and raw sheep's milk. In addition to whole milk, concentrated milk, composition-adjusted milk, partially skimmed milk, skim milk, buttermilk, cream, etc. can also be used.

[0029] The starter lactic acid bacteria may consist of only the above-mentioned vegetable lactic acid bacteria, or may contain one or more other lactic acid bacteria. The other lactic acid bacteria are not particularly limited as long as they can be used in the production of natural cheese, and examples of such other lactic acid bacteria include bacteria belonging to the genera Lactobacillus, Lactococcus, Streptococcus, Enterococcus, Pediococcus, Leuconostoc, and Bifidobacterium.

[0030] The content of the above-mentioned vegetable lactic acid bacteria in the starter lactic acid bacteria is, for example, 10% by mass or more, preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, still more preferably 50% by mass or more, particularly preferably 60% by mass or more, especially more preferably 70% by mass or more, especially more preferably 80% by mass or more, especially even more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

[0031] The amount of starter lactic acid bacteria added is not particularly limited as long as curd can be obtained, but is, for example, 0.4 to 2 g, and preferably 0.8 to 1.2 g, per 1 L of raw milk.

[0032] The rennet is not particularly limited as long as it contains chymosin and can be used in the production of natural cheese, and examples thereof include animal rennet extracted from the stomachs of animals (such as cows, sheep, and goats), vegetable rennet extracted from plants, microbial rennet extracted from microorganisms (including genetically modified chymosin), etc. Rennet may be used alone or in combination of two or more types.

[0033] The amount of rennet added is not particularly limited as long as curd is obtained, but is, for example, 0.2 to 1 g, and preferably 0.3 to 0.5 g, per 1 L of raw milk.

[0034] The timing of adding the starter lactic acid bacteria and rennet is not particularly limited as long as curd can be obtained. Preferably, the starter lactic acid bacteria is added to the raw milk, stirred, left to stand for a certain period of time, and then rennet is added, stirred, and left to stand for a certain period of time. The standing time after the addition of the starter lactic acid bacteria is, for example, 30 to 180 minutes, preferably 80 to 120 minutes. The standing time after the addition of rennet is, for example, 20 to 50 minutes, preferably 30 to 40 minutes.

[0035] The temperature in the curdling step (product temperature of the raw milk) is not particularly limited as long as curd can be obtained, but is, for example, 24 to 35° C., preferably 28 to 33° C., and particularly preferably 31 to 33° C. By setting the temperature at or above the lower limit temperature, it is possible to further suppress the decrease in acidity and the decrease in the amount of short-chain fatty acids due to inhibition of lactic acid bacteria growth, and by setting the temperature at or below the upper or lower limit temperature, it is possible to further suppress the decrease in viability of lactic acid bacteria, suppress the inhibition of short-chain fatty acid production that accompanies a decrease in the number of bacteria, and further suppress the volatilization of short-chain fatty acids from curdling to ripening, and thus the decrease in the amount of short-chain fatty acids in the ripened cheese.

[0036] The cooking step is a step for promoting the separation of the curd and whey by keeping the product temperature of the curd obtained in the curdling step constant. From the viewpoint of promoting the separation of the curd and whey, it is preferable to cut the curd obtained in the curdling step as necessary before the cooking step. From the same viewpoint, it is also preferable to gently stir during the cooking step.

[0037] The temperature in the cooking step (product temperature of the curd) is preferably 35°C or lower from the viewpoint of increasing the amount of lactic acid bacteria cells after aging, increasing the amount of short-chain fatty acids (particularly volatile short-chain fatty acids) before and after aging, and further improving the flavor, etc. From the same viewpoint, the temperature is more preferably 20 to 35°C, even more preferably 24 to 35°C, still more preferably 26 to 34°C, and particularly preferably 28 to 33°C.

[0038] The squeezing step is a step in which the curd obtained in the cooking step is packed into a mold as necessary and squeezed to remove the whey. The mold to be used, the squeezing method, and the degree of squeezing can be appropriately changed depending on the type of natural cheese to be produced.

[0039] The obtained natural cheese has a high content of short-chain fatty acids and the decrease in lactic acid bacteria over time is inhibited, so that the production of short-chain fatty acids by live bacteria can be maintained at a higher level even during long-term storage or aging periods.

[0040] The obtained natural cheese can be subjected to a salting step and a maturing step as necessary. The specific aspects of these steps can also be appropriately changed depending on the type of natural cheese to be produced.

[0041] The production method of the present invention preferably includes a maturation step, which makes it possible to obtain a natural cheese having a further improved flavor, a large amount of short-chain fatty acids, and a large amount of lactic acid bacteria.

[0042] The period of the aging step is, for example, 2 weeks or more, preferably 4 weeks or more, more preferably 8 weeks or more, and even more preferably 12 weeks or more.

[0043] In one embodiment of the present invention, the viable cell count of lactic acid bacteria in the natural cheese obtained by the production method of the present invention is preferably 1.0 × 10 7 CFU / g (for cheese) or more, preferably 1.0×10 8CFU / g (of cheese) or more. By adding starter lactic acid bacteria so that the bacterial count is at least this number, a more favorable maturation effect and maturation flavor can be obtained.

[0044] In one embodiment of the present invention, the pH of the natural cheese obtained by the production method of the present invention is, for example, 4.0 or higher, and preferably 5.0 to 6.5.

[0045] In one embodiment of the present invention, the content of butyric acid in 10 g of natural cheese obtained by the production method of the present invention is, for example, 50 mg or more, preferably 75 mg or more. According to the production method of the present invention, a high amount of butyric acid can be maintained even after storage or aging. EXAMPLES

[0046] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.

[0047] Example 1. Isolation of lactic acid bacteria 1 Pediococcus pentosaceus was isolated from pickled radishes produced in Fukui Prefecture and deposited at the Patent Microorganism Depositary (NPMD) of the National Institute of Technology and Evaluation (NITE) on May 23, 2023 (Pediococcus pentosaceus FHC1, Patent Microorganism Depositary accession number: NITE P-03892).

[0048] Example 2. Isolation of lactic acid bacteria 2 Lactobacillus plantarum was isolated from buckwheat grown in Fukui Prefecture and deposited at the Patent Microorganism Depositary Center (NPMD) of the National Institute of Technology and Evaluation (NITE) on May 23, 2023 (Lactobacillus plantarum FHC3, Patent Microorganism Depositary Center accession number: NITE P-03893).

[0049] Example 3. Flavor evaluation of natural cheese 1 Natural cheese was produced by the following steps 1 to 7. Step 1 (sterilization): The raw milk was heat-sterilized at 65°C for 30 minutes. After sterilization, the temperature was lowered to around 30°C. Step 2 (curd): 10 g of starter lactic acid bacteria (Pediococcus pentosaceus FHC1) was added to 30 L of pasteurized milk, and the mixture was gently stirred and then left to stand for 60 minutes at 29° C. 2 g of rennet was added thereto, and the mixture was gently stirred and then left to stand for 60 minutes at 29° C. to obtain curd. Step 3 (Cutting the card): The card was cut into 2 cm square pieces. Step 4 (cooking step): The mixture was kept at 29°C and gently stirred for 180 minutes, and finally the curd was allowed to shrink at 31°C for 10 minutes. Process 5 (molding and squeezing): The curd grains were packed into a mold (shape: shallow cylinder, size: 24 cm) and put into a squeezer to squeeze out the whey. Step 6 (salting): The curd was salted by soaking it in salt water with a concentration of about 19%. Step 7 (ripening): The mixture was allowed to stand at 10° C. and a humidity of 85% for 60 days to obtain natural cheese.

[0050] The resulting natural cheese was tasted by 10 people and rated on a 5-point scale (very bad, bad, neutral, good, very good) for 10 evaluation items (satisfaction, umami, bitterness, sweetness, sourness, richness, aroma quality, aroma strength, texture, color).

[0051] The results are shown in Figure 1. The taste was judged to be strong, with a sweet and umami flavor, and the quality of the aroma was also good. No unpleasant odor was noted.

[0052] Example 4. Flavor evaluation of natural cheese 2 Natural cheese was produced by the following steps 1 to 7. Step 1 (sterilization): The raw milk was heat-sterilized at 65°C for 30 minutes. After sterilization, the temperature was lowered to around 30°C. Step 2 (curd): 27 g of starter lactic acid bacteria (Lactobacillus plantarum FHC3) was added to 30 L of pasteurized milk, and the mixture was gently stirred and then left to stand at 30° C. for 90 minutes. 12.5 g of rennet was added thereto, and the mixture was gently stirred and then left to stand at 30° C. for 30 minutes to obtain curd. Step 3 (Cutting the card): The card was cut into 2 cm square pieces. Step 4 (cooking step): The curd was shrunk by gently stirring for 160 minutes while maintaining the temperature at 33°C. Process 5 (molding and squeezing): The curd grains were packed into a mold (shape: shallow cylinder, size: 24 cm) and put into a squeezer to squeeze out the whey. Step 6 (salting): The curd was salted by soaking it in salt water with a concentration of about 20%. Step 7 (ripening): The cheese was left to stand at 12° C. and 90% humidity for 7 days for primary ripening, and then left to stand at 4° C. and 80% humidity for 90 days to obtain natural cheese.

[0053] The resulting natural cheese was tasted by 242 people and rated on a 5-point scale (weak, slightly weak, just right, slightly strong, strong) for each of the seven evaluation categories (umami, bitterness, sweetness, sourness, aroma quality, aroma strength, texture).

[0054] The results are shown in Figure 2. The taste was judged to be strong in umami and sweetness, and the quality of the aroma was also good. No unpleasant odor was noted.

[0055] Example 5. Characterization of starter strains Fermented milk was produced by the following steps A to B. Step A (sterilization): The raw milk was heat-sterilized at 63°C for 30 minutes. After sterilization, the temperature was lowered to around 30°C. Step B (fermentation): 2 g of starter lactic acid bacteria (Pediococcus pentosaceus FHC1, Lactobacillus plantarum FHC3, or Lactococcus lactis subsp. cremoris) was added to 2 L of pasteurized milk, gently stirred, and then kept at 28° C. and allowed to stand for 24 hours to obtain fermented milk.

[0056] The amino acids contained in fermented milk were analyzed. The specific method is as follows. 500 μl of 10% (w / v) sulfosalicylic acid was added to 500 μl of the measurement sample and stirred, and the resulting precipitate was removed by centrifugation. The resulting supernatant was precision filtered and then subjected to a fully automated high-speed amino acid analyzer to quantify the free amino acids.

[0057] The results are shown in Figure 3. The amino acids classified into the five tastes in Figure 3 are as shown in Table 1. When Pediococcus pentosaceus FHC1 and Lactobacillus plantarum FHC3 were used, there were fewer amino acids that gave off a bitter taste, and there were more amino acids that gave off umami and sweet tastes, and the amounts were equal to or greater than when the existing starter Lactococcus lactis subsp. cremoris was used.

[0058] [Table 1]

[0059] The amount of butyric acid contained in cheese was also measured. The specific method was as follows: 900 μL of a water-acetonitrile mixed solvent was added to 100 mg of sample. After shaking at 37°C for 30 minutes, the mixture was homogenously dispersed for 10 minutes using an ultrasonic disintegrator. 600 μL of a water-acetonitrile mixed solution and 5 μL of a 2.5 N sodium hydroxide solution were added to 200 μL of the centrifuged supernatant to obtain an extract. 100 μL of the extract was applied to a solid-phase column Flash-SPE AX (Asti Science). Next, 500 μL of a water-acetonitrile mixed solution and 200 μL of acetonitrile were added to wash the column. 50 μL of N-tert-butyldimethylsilyl-N-methyltrifluoroacetamide (MTBSTFA)-toluene solution was slowly impregnated into the column and left at room temperature for 1 minute to carry out a derivatization reaction. The liquid eluted with 80 μL of hexane was used as the sample solution and quantitatively analyzed by gas chromatography mass spectrometry.

[0060] The results are shown in Figure 4. When Pediococcus pentosaceus FHC1 and Lactobacillus plantarum FHC3 were used, more butyric acid was produced than when the existing starter Lactococcus lactis subsp.

[0061] Example 6. Analysis of differences in survival rate depending on cooking temperature Natural cheese was produced by the following steps 1 to 7. Step 1 (sterilization): The raw milk was heat-sterilized at 65°C for 30 minutes. After sterilization, the temperature was lowered to around 30°C. Step 2 (curd): 2 g of starter lactic acid bacteria (Lactobacillus plantarum FHC3) was added to 2 L of pasteurized milk, and the mixture was gently stirred and then left to stand for 30 minutes at 28° C. 0.2 g of rennet was added thereto, and the mixture was gently stirred and then left to stand for 60 minutes at 28° C. to obtain curd. Step 3 (Cutting the card): The card was cut into 2 cm square pieces. Step 4 (cooking step): The curd was shrunk for 90 minutes with gentle stirring while maintaining the temperature at 25°C, 30°C, 35°C or 40°C. Process 5 (molding and squeezing): The curd grains were packed into a mold (shape: shallow cylinder, size: 12 cm) and put into a squeezer to squeeze out the whey. Step 6 (salting): The curd was salted by soaking it in salt water with a concentration of about 20%. Step 7 (aging): The mixture was left to mature at 16°C and 85% humidity for 21 days (3 weeks).

[0062] The amount of surviving bacteria in 1 g of cheese was examined by colony counting method immediately before the start of step 7 and immediately after the completion of step 7.

[0063] The results are shown in Figure 5. At 25°C, the bacteria continued to grow even during aging, whereas at 30°C, roughly the same number of bacteria was maintained. On the other hand, at temperatures above 35°C, which are used in typical natural cheese manufacturing methods, the bacteria stopped growing and began to decrease. This result does not contradict the experimental results reported previously (Int. Dairy J., 5, 855-875. (1995)), which showed that the amount of bacteria in Cheddar cheese, cooked at 38°C, decreased to about 1 / 10,000 after about six months of aging.

[0064] Example 7. Analysis of changes in amino acid balance due to cooking temperature Natural cheese was produced by the following steps 1 to 7. Step 1 (sterilization): The raw milk was heat-sterilized at 65°C for 30 minutes. After sterilization, the temperature was lowered to around 30°C. Step 2 (curd): 2 g of starter lactic acid bacteria (Pediococcus pentosaceus FHC1) was added to 2 L of pasteurized milk, and the mixture was gently stirred and then left to stand for 30 minutes at 28° C. 0.2 g of rennet was added thereto, and the mixture was gently stirred and then left to stand for 60 minutes at 28° C. to obtain curd. Step 3 (Cutting the card): The card was cut into 2 cm square pieces. Step 4 (cooking step): The curd was kept at 18°C, 28°C or 38°C and gently stirred for 120 minutes to allow the curd to shrink. Process 5 (molding and squeezing): The curd grains were packed into a mold (shape: shallow cylinder, size: 12 cm) and put into a squeezer to squeeze out the whey. Step 6 (salting): The curd was salted by soaking it in salt water with a concentration of about 20%. Step 7 (ripening): The cheese was left to ripen at 16° C. and a humidity of 85% for 7 days to obtain natural cheese.

[0065] The resulting cheese was subjected to amino acid analysis. The specific method is as follows: 4 ml of 80% ethanol was added to 1 g of the measurement sample, and the mixture was homogenously dispersed using an ultrasonic disintegrator. After centrifugation, 500 μl of 10% (w / v) sulfosalicylic acid was added to the collected supernatant, which was then stirred, and the resulting precipitate was removed by centrifugation. The resulting supernatant was precision filtered and then subjected to a fully automated high-speed amino acid analyzer to quantify the free amino acids.

[0066] The results are shown in Figure 6. The amino acids classified into the five tastes in Figure 6 are as shown in Table 1. The umami taste was at its maximum at 28°C, and decreased at both 18°C ​​and 38°C.

[0067] Example 8. Analysis of organic acid content Natural cheese was produced by the following steps 1 to 7. Step 1 (sterilization): The raw milk was heat-sterilized at 65°C for 30 minutes. After sterilization, the temperature was lowered to around 30°C. Step 2 (curd): 2 g of starter lactic acid bacteria (Pediococcus pentosaceus FHC1 or Lactococcus lactis subsp. cremoris) was added to 2 L of pasteurized milk, and the mixture was gently stirred and then left to stand for 30 minutes at 28° C. 0.2 g of rennet was added thereto, and the mixture was gently stirred and then left to stand for 60 minutes at 28° C. to obtain curd. Step 3 (Cutting the card): The card was cut into 2 cm square pieces. Step 4 (cooking step): The curd was allowed to shrink with gentle stirring for 120 minutes while being kept at 28°C (for both lactic acid bacteria) or 38°C (for Lactococcus lactis subsp. Cremoris only). Process 5 (molding and squeezing): The curd grains were packed into a mold (shape: shallow cylinder, size: 12 cm) and put into a squeezer to squeeze out the whey. Step 6 (salting): The curd was salted by soaking it in salt water with a concentration of about 20%. Step 7 (ripening): The mixture was left to stand at 16° C. and 85% humidity for 7 days for primary ripening, and then was allowed to ripen at 4° C. for secondary ripening to obtain natural cheese.

[0068] The amount of organic acids at each aging stage was measured. The specific method is as follows. 900 μL of water-acetonitrile mixed solvent was added to 100 mg of sample. After shaking at 37°C for 30 minutes, it was uniformly dispersed for 10 minutes using an ultrasonic disintegrator. 600 μL of water-acetonitrile mixed solution and 5 μL of 2.5 N sodium hydroxide solution were added to 200 μL of the centrifuged supernatant to obtain an extract. 100 μL of the extract was applied to a solid-phase column Flash-SPE AX (Asti Science). Next, 500 μL of a water-acetonitrile mixed solution and 200 μL of acetonitrile were added to wash the column. 50 μL of MTBSTFA-toluene solution and 50 μL of toluene solution were slowly impregnated into the column and left at room temperature for 1 minute to carry out a derivatization reaction. The liquid eluted with 80 μL of hexane was used as the sample solution and quantitatively analyzed by gas chromatography mass spectrometry.

[0069] The results are shown in Figure 7. When L. lactis was used as a starter and the mixture was cooked at 28°C, the amount of butyric acid was below the detection limit after one month of aging at 16°C. On the other hand, when P. pentosaseus was used, the amount of butyric acid was maintained even after six months of aging.

[0070] Example 9. Administration test Natural cheese was produced by the following steps 1 to 7. Step 1 (sterilization): The raw milk was heat-sterilized at 65°C for 30 minutes. After sterilization, the temperature was lowered to around 30°C. Step 2 (curd): 2 g of starter lactic acid bacteria (Pediococcus pentosaceus FHC1, Lactobacillus plantarum FHC3, or Lactococcus lactis subsp. cremoris) was added to 2 L of pasteurized milk, gently stirred, and then left to stand at 28°C for 30 minutes. However, control cheese was produced without adding lactic acid bacteria. After standing, 0.2 g of rennet was added, gently stirred, and then left to stand at 28°C for 60 minutes to obtain curd. Step 3 (Cutting the card): The card was cut into 2 cm square pieces. Step 4 (cooking step): The curd was shrunk by gently stirring for 120 minutes while maintaining the temperature at 28°C. Process 5 (molding and squeezing): The curd grains were packed into a mold (shape: shallow cylinder, size: 12 cm) and put into a squeezer to squeeze out the whey. Step 6 (salting): The curd was salted by soaking it in salt water with a concentration of about 20%. Step 7 (ripening): The cheese was left to mature at 16° C. and 85% humidity for 7 days to obtain natural cheese. The obtained cheese was vacuum-packed and stored at 4° C. until it was administered as feed.

[0071] Six-week-old male C57BL mice were used and acclimatized on a high-fat diet (HFD) until the age of 8 weeks, after which a cheese feeding test was conducted. The mice were divided into three groups: a lactic acid bacteria FHC1 strain cheese group (6 mice), an FHC3 strain cheese group (6 mice), a L. lactis cheese group (6 mice), and a control group (6 mice) with no bacteria. Cheese was administered by mixing each cheese with the HFD in a 1:1 ratio. An intraperitoneal glucose tolerance test was conducted at 35 weeks of age.

[0072] The results are shown in Figure 8. Compared to the bacteria-free cheese group, blood glucose levels decreased more quickly with the FHC3 strain cheese, suggesting that this lactic acid bacteria shows an effect of improving glucose tolerance not only when administered directly, but also when eaten with cheese.

Claims

1. A method for producing natural cheese, characterized in that the starter lactic acid bacteria contains at least one plant-derived lactic acid bacterium selected from the group consisting of Pediococcus pentosaceus FHC1 (Patent Organism Depositary Center Accession Number: NITE P-03892) and Lactobacillus plantarum FHC3 (Patent Organism Depositary Center Accession Number: NITE P-03893).

2. The method according to claim 1, wherein the temperature of the cooking step is 35°C or less.

3. The method according to claim 1, wherein the temperature of the cooking step is 20 to 35°C.

4. The method according to any one of claims 1 to 3, further comprising an aging step.

5. The method according to claim 4, wherein the aging step is carried out for a period of 2 weeks or more.

6. The method according to any one of claims 1 to 3, wherein no microorganisms other than lactic acid bacteria are added.

7. A natural cheese containing at least one plant-derived lactic acid bacterium selected from the group consisting of Pediococcus pentosaceus FHC1 (Patent Organism Depositary Center Accession Number: NITE P-03892) and Lactobacillus plantarum FHC3 (Patent Organism Depositary Center Accession Number: NITE P-03893).

8. The natural cheese according to claim 7, which is a hard or semi-hard natural cheese.

9. 9. The natural cheese according to claim 7 or 8, which has a butyric acid content of 50 mg or more per 10 g of the natural cheese.

10. At least one plant-derived lactic acid bacterium selected from the group consisting of Pediococcus pentosaceus FHC1 (Patent Organism Depositary Center Accession Number: NITE P-03892) and Lactobacillus plantarum FHC3 (Patent Organism Depositary Center Accession Number: NITE P-03893).

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