Milk component-containing beverage and method for producing same

Abstract

To provide a milk component-containing beverage having bacteriostatic action against anaerobic heat-resistant spore-forming bacteria, and to provide an emulsion stabilizer for the milk component-containing beverage, used for preparing the beverage.SOLUTION: The milk component-containing beverage contains sorbitan palmitic acid ester, wherein the ratio of the sorbitan palmitic acid ester is ≥ 0.0015 pts. mass based on 1 pt. mass of milk solid in the milk component-containing beverage.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a dairy beverage and a method for producing the same. More specifically, the present disclosure relates to a dairy beverage having bacteriostatic activity against anaerobic heat-resistant spore-forming bacteria and a method for producing the same. The present disclosure also relates to an emulsion stabilizer for dairy beverages, more specifically, an emulsion stabilizer having bacteriostatic activity against anaerobic heat-resistant spore-forming bacteria. [Background technology]

[0002] Widely available dairy beverages in Japan include coffee drinks containing milk, black tea drinks containing milk, cocoa drinks containing milk, and matcha drinks containing milk. These dairy beverages are filled into pressure-resistant containers, such as retort cans, and then subjected to retort sterilization at approximately 120°C for 20 to 40 minutes before being distributed to the market in order to kill bacteria that cause spoilage or spoilage. However, some highly heat-resistant anaerobic heat-resistant spore-forming bacteria remain viable even after heat sterilization. When the beverages are sold heated in a hot vending machine or heated vending machine, the anaerobic heat-resistant spore-forming bacteria may germinate and multiply, resulting in spoilage or deterioration.

[0003] To kill such anaerobic heat-resistant spore-forming bacteria, methods include increasing the sterilization temperature or lengthening the sterilization time during the manufacturing process, but these methods adversely affect the flavor and physical and chemical properties of the dairy beverage, significantly reducing the quality of the dairy beverage.

[0004] Another known method is to prevent spoilage by adding a sucrose fatty acid ester to suppress the growth of anaerobic heat-resistant spore-forming bacteria. Patent Document 1 (Patent Document 1) proposes a method for stably dispersing fats and oils in fat-containing beverages, such as milk coffee and cocoa, while suppressing spoilage caused by heat-resistant flat sour bacteria. It involves the combined use of a sucrose fatty acid ester with an HLB value of 13 or more and an organic acid monoglyceride. Patent Document 1 describes that if the proportion of sucrose fatty acid ester in a beverage is less than 0.05% by mass, the effect of preventing spoilage caused by heat-resistant flat sour bacteria is insufficient, while if it exceeds 0.3% by mass, the bitterness of the sucrose fatty acid ester tends to impair the flavor of the beverage. It also describes that if a sucrose fatty acid ester with a low HLB value is used, the effect of preventing spoilage caused by heat-resistant flat sour bacteria is not obtained. It is also described that when sorbitan monostearate (sorbitan stearic acid monoester) is used in combination with sucrose fatty acid ester instead of organic acid monoglyceride, the oil dispersion stabilizing effect is reduced, and oil release (creaming, oil-off) occurs during long-term storage.

[0005] Furthermore, Patent Document 2 proposes a method of adding 0.0001 to 1% of an antibacterial emulsifier such as sucrose fatty acid ester, polyglycerol fatty acid ester, monoglycerol ester, lecithin, or enzyme-modified lecithin as a method for improving the deterioration of beverages due to the persistence of mesophilic spore-forming bacteria, which is a problem in the sterilization process used in the production of PET bottled beverages. However, Patent Document 2 also describes that sorbitan stearic acid monoester, a sorbitan fatty acid ester, has no antibacterial effect against B. coagulans spores (Table 6).

[0006] Furthermore, Patent Document 3 proposes a method of adding 0.01 to 1 wt % of a sorbitan fatty acid ester, which is a saturated fatty acid having 12 or 14 carbon atoms, to the entire beverage in order to suppress spoilage caused by the germination and proliferation of anaerobic heat-resistant bacterial spores in a sealed container. Patent Document 3 describes that a sorbitan fatty acid ester having a fatty acid having 12 or 14 carbon atoms has a stronger inhibitory effect on the germination and proliferation of anaerobic heat-resistant bacterial spores than sucrose fatty acid esters, polyglycerin fatty acid esters, etc., and has less impact on the taste of the beverage.

[0007] Furthermore, Patent Document 4 proposes a method of adding lysolecithin and an organic acid monoglyceride as a method for producing a dairy-containing coffee beverage that inhibits the germination and proliferation of heat-resistant bacterial spores during long-term storage at high temperatures and has good emulsion stability. Patent Document 4 also discloses that no antibacterial effect can be obtained even when sorbitan monostearate is used in combination with lysolecithin instead of an organic acid monoglyceride.

[0008] Furthermore, Patent Document 5 proposes an emulsion stabilizer for dairy beverages made from milk and dairy products, such as coffee milk beverages, milk tea, and cocoa beverages, that contains 6-16% by weight of sucrose fatty acid ester, 29-69% by weight of glycerin monofatty acid ester, 9-21% by weight of sorbitan fatty acid ester, 8-28% by weight of organic acid monoglyceride, and 3-7% by weight of sodium caseinate, and adjusts the pH value of a 0.4% aqueous solution to 5-9. It describes that such an emulsifier has good storage stability and can be used stably without requiring a special stirring device when heated and dissolved. However, there is no mention of the antibacterial effect of the emulsion stabilizer. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 2-16959 [Patent Document 2] Japanese Patent Application Publication No. 6-261718 [Patent Document 3] Japanese Patent Application Publication No. 6-105669 [Patent Document 4] Japanese Patent Application Publication No. 7-123956 [Patent Document 5] Japanese Patent Application Laid-Open No. 2002-142670 Summary of the Invention [Problem to be solved by the invention]

[0010] An object of the present disclosure is to provide a dairy beverage and a method for producing the same. More specifically, an object of the present disclosure is to provide a dairy beverage having bacteriostatic activity against anaerobic heat-resistant spore-forming bacteria and a method for producing the same.

[0011] Another object of the present disclosure is to provide an emulsion stabilizer for dairy beverages. More specifically, an object of the present disclosure is to provide an emulsion stabilizer used to impart bacteriostasis against anaerobic heat-resistant spore-forming bacteria to dairy beverages.

[0012] Furthermore, an object of the present disclosure is to provide a method for imparting bacteriostatic activity against anaerobic heat-resistant spore-forming bacteria to a dairy-containing beverage. [Means for solving the problem]

[0013] As a result of extensive research to solve the above-mentioned problems, the present inventors have confirmed that blending a dairy beverage with sorbitan palmitate at a ratio of 0.0015 parts by mass or more per part by mass of milk solids in the dairy beverage effectively inhibits the growth of anaerobic heat-resistant spore-forming bacteria in the beverage (bacteriostatic effect), and that the bacteriostatic effect of sorbitan palmitate is significantly greater than that of sucrose fatty acid esters or other sorbitan fatty acid esters, which have previously been known to have bacteriostatic effects. Furthermore, the present inventors have found that combining a sucrose fatty acid ester with a sorbitan palmitate can reduce the amount of sucrose fatty acid ester used and minimize the impact of the sucrose fatty acid ester on the flavor of the dairy beverage while still exerting an effective bacteriostatic effect. The present invention was completed based on these findings and has the following embodiments.

[0014] (I) Dairy beverages (I-1) A dairy beverage containing sorbitan palmitate, A dairy beverage in which the proportion of sorbitan palmitate per part by mass of milk solids in the dairy beverage is 0.0015 parts by mass or more. (I-2) A dairy beverage according to (I-1), wherein the dairy beverage contains 0.5 to 11.5% by mass of milk solids. (I-3) A dairy beverage according to (I-1) or (I-2), in which the proportion of sorbitan palmitate in 100% by mass of the dairy beverage is 0.001 to 0.5% by mass. (I-4) A dairy beverage according to any one of (I-1) to (I-3), further containing a sucrose fatty acid ester. (I-5) A dairy beverage according to (I-4), in which the ratio of sucrose fatty acid ester to 100 parts by mass of sorbitan palmitate is 1 to 300 parts by mass. (I-6) A dairy beverage according to any one of (I-1) to (I-5), characterized by having bacteriostatic properties against anaerobic heat-resistant spore-forming bacteria. (I-7) A dairy beverage according to any one of (I-1) to (I-6), which is a packaged beverage, preferably a sterilized packaged beverage.

[0015] (II) Method for producing dairy beverages (II-1) A method for producing a dairy beverage, comprising a step of blending sorbitan palmitate with a dairy beverage so that the ratio of sorbitan palmitate per part by mass of milk solids in the dairy beverage is 0.0015 parts by mass or more. (II-2) The production method according to (II-1), wherein the dairy beverage contains 0.5 to 11.5% by mass of milk solids. (II-3) A production method according to (II-1) or (II-2), in which sorbitan palmitate is blended so that the concentration of sorbitan palmitate in the dairy beverage (100% by mass) is 0.001 to 0.5% by mass. (II-4) A production method according to any one of (II-1) to (II-3), further comprising a step of blending a sucrose fatty acid ester into the dairy beverage. (II-5) The production method according to (II-4), wherein the ratio of the sucrose fatty acid ester to 100 parts by mass of the sorbitan palmitate is 1 to 300 parts by mass. (II-6) The production method according to any one of (II-1) to (II-5), further comprising a heat sterilization treatment step. (II-7) A manufacturing method described in any of (II-1) to (II-6), which is a manufacturing method for a dairy beverage for imparting bacteriostasis against anaerobic heat-resistant spore-forming bacteria to the dairy beverage.

[0016] (III) A method for imparting bacteriostatic activity against anaerobic heat-resistant spore-forming bacteria to a dairy beverage The manufacturing methods (II-1) to (II-6) can also be rephrased as follows. (III-1) A method for imparting bacteriostatic activity against anaerobic heat-resistant spore-forming bacteria to a dairy beverage, A method characterized by blending sorbitan palmitate into a dairy beverage so that the ratio of sorbitan palmitate per part by mass of milk solids in the dairy beverage is 0.0015 parts by mass or more. (III-2) The method according to (III-1), wherein the dairy beverage contains 0.5 to 11.5% by mass of milk solids. (III-3) The method according to (III-1) or (III-2), in which sorbitan palmitate is blended so that the concentration of sorbitan palmitate in the dairy beverage (100% by mass) is 0.001 to 0.5% by mass. (III-4) The method according to any one of (III-1) to (III-3), further comprising blending a sucrose fatty acid ester into the dairy beverage. (III-5) The method according to (III-4), wherein the ratio of the sucrose fatty acid ester to 100 parts by mass of the sorbitan palmitate is 1 to 300 parts by mass.

[0017] (IV) Emulsion stabilizer for dairy beverages (IV-1) An emulsion stabilizer for dairy beverages containing sorbitan palmitate as an active ingredient, An emulsion stabilizer for dairy beverages used so that the ratio of sorbitan palmitate per part by mass of milk solids in the dairy beverage is 0.0015 parts by mass or more. (IV-2) An emulsion stabilizer for dairy beverages according to (IV-1), which is a preparation used to impart bacteriostasis against anaerobic heat-resistant spore-forming bacteria to dairy beverages. (IV-3) An emulsion stabilizer for dairy beverages according to (IV-1) or (IV-2), wherein the dairy beverage contains 0.5 to 11.5% by mass of milk solids. (IV-4) An emulsion stabilizer for dairy beverages according to any one of (IV-1) to (IV-3), which is used in the production process of a dairy beverage so that the concentration of sorbitan palmitate in 100% by mass of the dairy beverage is 0.001 to 0.5% by mass. (IV-5) An emulsion stabilizer for a dairy beverage according to any one of (IV-1) to (IV-4), wherein the dairy beverage further contains a sucrose fatty acid ester. (IV-6) An emulsion stabilizer for dairy beverages according to (IV-5), in which the ratio of sucrose fatty acid ester to 100 parts by mass of sorbitan palmitate is 1 to 300 parts by mass. [Effects of the Invention]

[0018] According to the present disclosure, it is possible to provide a dairy beverage having a high growth inhibitory effect (bacteriostatic effect) on anaerobic heat-resistant spore-forming bacteria, and a method for producing the same. In particular, it is possible to provide a heat-sterilized dairy beverage having a high growth inhibitory effect on anaerobic heat-resistant spore-forming bacteria that may remain even after heat sterilization, and having good storage stability, and a method for producing the same.

[0019] Furthermore, the present disclosure can provide a method for imparting bacteriostatic activity against anaerobic heat-resistant spore-forming bacteria to a dairy beverage while minimizing the impact on the flavor of the dairy beverage.

[0020] Furthermore, the present disclosure provides emulsion stabilizing agents for dairy beverages that can be used to impart bacteriostasis to dairy beverages against anaerobic heat-resistant spore-forming bacteria. DETAILED DESCRIPTION OF THE INVENTION

[0021] (I) Dairy beverages The dairy beverages covered by this disclosure are beverages (dairy beverages) that contain at least milk solids as a dairy component, but are not milk itself, such as raw milk, cow's milk, special milk, adjusted milk, low-fat milk, and non-fat milk.

[0022] The target milk is milk from livestock such as cows (dairy cows such as Holstein, Jersey, and Brown Swiss), sheep, and goats, and preferably milk derived from dairy cows (hereinafter referred to as "milk derived from dairy cows").

[0023] Examples of milk solids include milk fat and non-fat milk solids. Non-fat milk solids include milk-derived proteins, carbohydrates, minerals, and vitamins. The beverages targeted by the present invention contain at least one milk solid selected from the milk fat and non-fat milk solids. Preferably, the beverage contains milk fat and non-fat milk solids as the milk solids, and more preferably, the beverage contains milk itself as the milk component. Incidentally, raw milk from Holstein cows is composed of 87.7% water by mass and 12.3% milk solids by mass, which consist of milk fat (3.7% by mass) and non-fat milk solids (8.6% by mass). The non-fat milk solids also contain protein (3.2% by mass), carbohydrates (4.7% by mass), minerals such as calcium (0.7% by mass), and vitamins (see Chapter 2 (Data), Food Code 13002, of the Standard Tables of Food Composition in Japan, 8th Edition, published by the Ministry of Education, Culture, Sports, Science and Technology of Japan).

[0024] When raw milk from Holstein cows is used as the milk component, the milk solids content in the milk component-containing beverage can be calculated using the following formula. [formula] Milk solids in dairy beverages (mass%) = 12.3 (amount of milk solids in raw milk) x amount of raw milk (mass%)

[0025] Furthermore, when raw milk derived from Holstein cows is used as the milk component, the milk solids (total amount) in the beverage containing the milk component can also be calculated from the amount of milk fat and / or milk protein in the beverage based on the composition ratio of the milk solids in cow's milk described above.

[0026] Furthermore, when milk other than Holstein-derived raw milk is used as the dairy ingredient in a dairy beverage, the same calculation can be performed by substituting the value "12.3" for the milk solids content of the milk in question. This value can be derived from Chapter 2 (Data) of the Standard Tables of Food Composition in Japan, 8th Edition (see Food Code 13000). For example, Jersey-derived raw milk is composed of 85.5% water by mass and 14.5% milk solids by mass, with the milk solids consisting of milk fat (3.7% by mass) and non-fat milk solids (9.3% by mass). The non-fat milk solids also contain protein (3.9% by mass), carbohydrates (4.7% by mass), minerals such as calcium (0.7% by mass), and vitamins (Food Code 13001). Similarly, regular milk is composed of 87.4% water by mass and 12.6% milk solids by mass, which consist of milk fat (3.8% by mass) and non-fat milk solids (8.8% by mass). The non-fat milk solids also contain protein (3.3% by mass), carbohydrates (4.8% by mass), minerals such as calcium (0.7% by mass), and vitamins (food code 13003).

[0027] The dairy beverage may be any beverage containing the dairy component, and includes, but is not limited to, dairy coffee beverages such as milk coffee, coffee milk beverage, cafe au lait, cafe latte, and cappuccino; dairy black tea beverages such as milk tea (black tea); dairy matcha beverages or green tea beverages such as matcha milk and green tea milk; dairy fruit juice beverages; dairy cocoa beverages; dairy chocolate drinks; milkshakes, etc. Although not limited to, preferred beverages are those produced using milk from dairy cows as one of the ingredients. More preferred are dairy coffee beverages.

[0028] Suitable dairy beverages include those with a milk solids content of 0.5 to 11.5% by mass, preferably 0.5 to 10.0% by mass, and more preferably 0.6 to 9.0% by mass.

[0029] The pH range of the dairy beverage is not limited, but can usually be selected from the range of pH 5.0 to 8.0, preferably pH 5.5 to 7.5, and more preferably pH 5.8 to 7.2.

[0030] An example of a component (referred to herein as a "bacteriostatic component" for convenience) used to produce a dairy beverage having a bacteriostatic effect against anaerobic heat-resistant spore-forming bacteria is (A) sorbitan palmitate (hereinafter also simply referred to as "component A"). Component A can be used alone as a bacteriostatic component, or can be used in combination with (B) sucrose fatty acid ester (hereinafter also simply referred to as "component B"). It is known that polyglycerol fatty acid esters, monoglycerol esters, lecithin, enzyme-treated lecithin, etc. also have antibacterial properties. However, there is little need to use these ingredients in the dairy beverage of the present disclosure, and it is preferable not to use them.

[0031] The sorbitan palmitate used in the present invention is an ester obtained by reacting sorbit with a saturated fatty acid having 16 carbon atoms in a conventional manner. The ester includes monoesters, diesters, and triesters. The monoester is preferred.

[0032] The sucrose fatty acid ester used in the present invention is an esterification product of sucrose and a fatty acid. The chain length of the fatty acid is 12 to 22 carbon atoms, preferably 12 to 20 carbon atoms, more preferably 14 to 18 carbon atoms, and particularly preferably 16 carbon atoms. Saturated fatty acids are desirable. The degree of esterification may include mono-, di-, and triesters, with monoesters being preferred. The fatty acid composition and mono-, di-, and triesters may be either single or mixed. The fatty acid composition preferably contains 50% or more of saturated fatty acids having 14 to 18 carbon atoms, and the monoesters preferably account for 50% or more, preferably 60% or more, more preferably 70% or more. The HLB of the sucrose fatty acid ester is not particularly limited, but is preferably in the range of 10 to 20, more preferably 14 to 18, and particularly preferably 16.

[0033] (When using component A as a bacteriostatic component without using component B in combination) When component A is used as a bacteriostatic component without being used in combination with component B, the blending ratio of component A to a dairy beverage can be 0.0015 mass parts or more per mass part of milk solids in the dairy beverage. Examples of lower limit values ​​include 0.00155 parts by mass or more, 0.002 parts by mass or more, 0.003 parts by mass or more, 0.004 parts by mass or more, 0.005 parts by mass or more, 0.006 parts by mass or more, and 0.007 parts by mass or more. The upper limit value is not limited as long as it does not impede the effects of the present disclosure, but is 0.3 parts by mass or less per 1 part by mass of milk solids in the dairy beverage. Examples of upper limit values ​​include 0.25 parts by mass or less, 0.2 parts by mass or less, 0.18 parts by mass or less, 0.16 parts by mass or less, 0.15 parts by mass or less, 0.13 parts by mass or less, and 0.1 parts by mass or less. These lower and upper limits can be arbitrarily combined to set the blending ratio.

[0034] [Table 1]

[0035] The milk solids content in a dairy beverage can be determined from the total amount of milk fat and non-fat milk solids in the dairy ingredients used as raw materials for producing the dairy beverage.

[0036] The proportion of component A in 100% by mass of the dairy beverage is not particularly limited as long as the blending ratio per part by mass of the milk solids in the dairy beverage is within the above range, but can be in the range of 0.001 to 0.5% by mass, preferably 0.004 to 0.4% by mass, and more preferably 0.006 to 0.3% by mass.

[0037] (When using component A and component B together as bacteriostatic components) When component A and component B are used in combination as bacteriostatic components, the proportion of component A in a dairy beverage is not particularly limited as long as it is within the above-mentioned range, but the total amount of component A and component B in a dairy beverage can be adjusted to a ratio of 0.0015 parts by mass or more per part by mass of milk solids in the beverage. Examples of lower limits include 0.00155 parts by mass or more, 0.002 parts by mass or more, 0.003 parts by mass or more, 0.004 parts by mass or more, 0.005 parts by mass or more, 0.0055 parts by mass or more, 0.006 parts by mass or more, 0.0065 parts by mass or more, 0.007 parts by mass or more, 0.0075 parts by mass or more, 0.008 parts by mass or more, and 0.0085 parts by mass or more. The upper limit is not limited as long as it does not impair the effects of the present invention, but is preferably 0.5 parts by mass or less per part by mass of milk solids in the beverage. Examples of the upper limit include 0.4 parts by mass or less, 0.3 parts by mass or less, 0.2 parts by mass or less, 0.1 parts by mass or less, 0.08 parts by mass or less, 0.06 parts by mass or less, and 0.05 parts by mass or less. The blending ratio can be set by arbitrarily combining these lower and upper limits.

[0038] [Table 2]

[0039] The ratio of the combined use of component A and component B can be in the range of 1 to 300 parts by mass of component B per 100 parts by mass of component A. Preferably, the ratio is 1 to 250 parts by mass, and more preferably 10 to 200 parts by mass of component B per 100 parts by mass of component A.

[0040] The total amount of components A and B in 100% by mass of the dairy beverage is not particularly limited as long as the total amount of components A and B per part by mass of milk solids in the dairy beverage is within the above range, but can be in the range of 0.005 to 0.5% by mass, preferably 0.0055 to 0.4% by mass, and more preferably 0.006 to 0.3% by mass.

[0041] The total amount of component B in 100% by mass of the dairy beverage is not limited as long as the above ratio is satisfied, but may be in the range of 0.00005 to 0.375% by mass, preferably 0.000055 to 0.3% by mass, and more preferably 0.00006 to 0.1% by mass.

[0042] According to the present invention, by using the above-described bacteriostatic component in the above-described ratio in a dairy beverage, a dairy beverage having bacteriostatic properties against anaerobic heat-resistant spore-forming bacteria can be prepared. This dairy beverage inhibits the germination and proliferation of anaerobic heat-resistant spore-forming bacteria, which are problematic in sealed-container beverages, thereby preventing spoilage of the sealed-container beverage. More preferably, according to the present invention, the germination and proliferation of anaerobic heat-resistant spore-forming bacteria, which remain problematic even in sealed-container beverages that have been heat-sterilized, can be inhibited, preventing spoilage of the sealed-container beverage. Although not limited to, Thermoanaerobacter mathranii is one example of the anaerobic heat-resistant spore-forming bacteria that are generally problematic in sealed-container beverages. The presence or absence of bacteriostatic properties against anaerobic heat-resistant spore-forming bacteria (the presence or absence of a bacteriostatic effect) can be determined based on the "bacteriostatic test" described in the Examples section below.

[0043] Examples of sealed containers that can be used for the beverage of the present invention include cans, bottles, PET bottles, paper packs, laminate packs, etc., but heat-resistant and / or retort-resistant cans or bottles are preferred, and retort cans are more preferred.

[0044] (II) Method for producing dairy beverages The present disclosure relates to a method for producing a dairy beverage. The production method of the present disclosure can be suitably used to impart bacteriostasis against anaerobic heat-resistant spore-forming bacteria to a dairy beverage. The production method is characterized by comprising the step of blending a sorbitan palmitate ester (component A) into a dairy beverage in a proportion of 0.0015 parts by mass or more per part by mass of milk solids in the dairy beverage. This production method can be carried out by blending component A alone as the component that imparts bacteriostasis, or by blending a sucrose fatty acid ester (component B) in addition to component A. In addition, in the present production method, there is little need to blend other bacteriostatic components known to have antibacterial activity, and it is preferable not to use them. Examples of such bacteriostatic components include the aforementioned polyglycerol fatty acid esters, monoglycerol esters, lecithin, and enzyme-treated lecithin.

[0045] The dairy beverages, anaerobic heat-resistant spore-forming bacteria, sorbitan palmitate ester (component A) and sucrose fatty acid ester (component B) to be blended in the dairy beverages that are the subject of this disclosure, as well as their blending ratios, are as explained in section (I) above, and the descriptions therein can be used by reference in this section.

[0046] The dairy beverages targeted by the present disclosure are preferably beverages in sealed containers, more preferably beverages in sealed containers that have been heat-sterilized. Therefore, the manufacturing method of the present disclosure includes a step of heat-sterilizing a dairy beverage containing component A or a blend of components A and B. The heat-sterilization may be performed before or after filling into a container, and the order is not particularly limited. Examples of the former method include, but are not limited to, a method in which a prepared dairy beverage is heat-sterilized and then filled into a container that has been sterilized under aseptic conditions. Examples of the latter method include, but are not limited to, a method in which a prepared dairy beverage is filled into a heat-resistant and retort-resistant container and then heat-sterilized.

[0047] The heat sterilization treatment may be any sterilization treatment commonly used in the production of beverages. For example, there are no particular limitations on the sterilization conditions or sterilization equipment, and a wide range of commonly used sterilization treatments and sterilization conditions can be used, such as boiling sterilization, retort sterilization, UHT sterilization (e.g., indirect methods such as plate sterilization and tubular sterilization, and direct methods such as steam injection sterilization), and autoclave sterilization. A preferred embodiment includes pressurized heat treatment at 121°C for 20 minutes or more, preferably 30 minutes or more or 40 minutes or more. If the pressurized heat treatment time is too long, it may have a negative impact on the flavor, physical, and chemical properties of the dairy beverage. For this reason, the heat treatment time at 121°C is preferably 60 minutes or less, and preferably 50 minutes or less.

[0048] (III) A method for imparting bacteriostatic activity against anaerobic heat-resistant spore-forming bacteria to a dairy beverage The present disclosure relates to a method for imparting bacteriostatic activity against anaerobic heat-resistant spore-forming bacteria to a dairy-containing beverage. The method of the present disclosure can be carried out by blending a sorbitan palmitate ester (component A) into a dairy beverage in a proportion of 0.0015 parts by mass or more per part by mass of milk solids in the dairy beverage during the production process of the dairy beverage. Furthermore, the method can be carried out by blending component A alone as a component that imparts bacteriostatic activity, or by blending a sucrose fatty acid ester (component B) in addition to component A.

[0049] The dairy beverages, anaerobic heat-resistant spore-forming bacteria, sorbitan palmitate ester (component A) and sucrose fatty acid ester (component B) to be blended in the dairy beverages that are the subject of this disclosure, as well as their blending ratios, are as explained in section (I) above, and the descriptions therein can be used by reference in this section.

[0050] (IV) Emulsion stabilizer for dairy beverages The present disclosure is an emulsion stabilizer for dairy beverages. The emulsion stabilizer of the present disclosure is characterized by containing sorbitan palmitate (component A) as an active ingredient for emulsion stabilization. When used in a dairy beverage such that the ratio of component A per part by mass of milk solids in the dairy beverage is 0.0015 parts by mass or more, the emulsion stabilizer exerts an excellent bacteriostatic effect on the dairy beverage. Therefore, in this usage mode, the emulsion stabilizer has the effect (use) of both being an emulsion stabilizer and a bacteriostatic agent.

[0051] The present emulsion stabilizer may contain the above-mentioned component A alone as an active ingredient for emulsion stabilization or as an ingredient having both emulsion stabilizing and bacteriostatic effects, but may also contain a sucrose fatty acid ester (component B) in addition to component A.

[0052] The present emulsion stabilizer may contain Component A in the range of 1% by mass to 100% by mass, or may consist of 100% by mass of Component A. Furthermore, when Component A and Component B are contained, the emulsion stabilizer may contain them in a total amount of 2% by mass to 100% by mass, or may consist of 100% by mass of Component A and Component B.

[0053] The form of the emulsion stabilizer is not particularly limited and can be appropriately selected from liquid (liquid), emulsified (emulsion), and solid (powder, granule, tablet) forms. Depending on the form, various excipients, diluents, binders, lubricants, etc. can be contained.

[0054] The dairy beverages covered by this disclosure; the anaerobic heat-resistant spore-forming bacteria; the sorbitan palmitate ester (component A) and sucrose fatty acid ester (component B) blended in this emulsion stabilizer, and their blending ratios; and the usage ratios of the dairy beverages (blending ratios of component A and component B) are as explained in section (I) above, and the descriptions therein can be used by reference in this section.

[0055] As described above, in this specification, the terms "comprise" and "contain" encompass the meanings of "consist of" and "consist essentially of." [Example]

[0056] The present invention will be explained below using experimental examples to aid in understanding the configuration and effects of the present invention. However, the present invention is not limited by these experimental examples. Unless otherwise specified, the following experiments were carried out at room temperature (25±5°C) and atmospheric pressure. Unless otherwise specified, "%" and "parts" in the following descriptions mean "% by mass" and "parts by mass," respectively.

[0057] The materials used in the following experimental examples and examples are as follows: Sorbitan palmitate ester: 100% sorbitan palmitate monoester, product name Homogen (registered trademark) 3369 (manufactured by San-Ei Gen F.F.I. Co., Ltd.). Sorbitan laurate: 100% sorbitan laurate monoester, Homogen (registered trademark) 3367 (manufactured by San-Ei Gen F.F.I. Co., Ltd.). Sorbitan myristate ester: 100% sorbitan myristate monoester, Homogen (registered trademark) 3368 (manufactured by San-Ei Gen F.F.I. Co., Ltd.). Sorbitan stearate: 100% sorbitan stearate monoester, Homogen (registered trademark) 3370 (manufactured by San-Ei Gen F.F.I. Co., Ltd.). Sucrose fatty acid ester: Ryoto Sugar Ester P-1670 (sucrose palmitate ester), HLB approximately 16, bound fatty acid purity (approximately 80), monoester content (approximately 80%), di- and tri-polyester content (approximately 20%) (manufactured by Mitsubishi Chemical Corporation). Anaerobic heat-resistant spore-forming bacterium 5901: Thermoanaerobacter mathranii (obtained from the Japan Canned, Bottled and Retort Food Association, a public interest incorporated association). Modified TGC medium: A medium in which the agar content of TGC medium "Nissui" (manufactured by Nissui Pharmaceutical Co., Ltd.) has been increased from 0.07% to 0.15%. SS liquid medium: A 9:1 (mass ratio) mixture of sterilized dry soil and sterilized calcium carbonate was added to a solution of 10 g of bactosoitone and 0.5 g of anhydrous sodium sulfite in 1000 mL of distilled water, and the medium was sterilized at 121°C for 20 minutes.

[0058] The evaluation methods used in the following experimental examples are as follows. (1) Bacteriostatic test The prepared coffee beverage containing dairy ingredients (hereinafter referred to as "beverage") was placed in a medium bottle and degassed by boiling in hot water at 100°C for 20 minutes, and then cooled to room temperature. A spore solution of anaerobic heat-resistant spore-forming bacteria 5901 was added to the cooled beverage until the initial cell count reached 10 4 The mixture was added with stirring to a level on the order of CFU / g.

[0059] The spore-forming bacteria solution used was prepared by pre-culturing the anaerobic heat-resistant spore-forming bacteria 5901 in modified TGC medium, followed by main culturing in SS liquid medium for spore formation, followed by centrifugation to remove the precipitate.

[0060] Next, 3 ml of the beverage containing the spore-forming bacteria solution was aseptically dispensed into sterilized TDT tubes (hard glass, inner diameter 6 mm) and heat-sealed using a gas burner. These were then heat-sterilized in an oil bath at 124.2°C for a predetermined time (e.g., 5 to 30 minutes), and then placed in a test tube rack and cultured in an incubator at 55°C for 4 weeks (n=5 for each).

[0061] After 4 weeks of cultivation, the appearance and pH were compared with those of a blank, which differed only in that no spore-forming solution was added (a beverage cooled after degassing in a hot water bath was sealed in a TDT tube in the same manner as above, heat-sterilized, and then cultivated under the same conditions, without adding spore-forming solution), to evaluate the bacteriostatic effect.

[0062] In the appearance evaluation, if a difference in appearance from the blank was observed, for example, the culture became cloudy, it was judged to be "spoiled" and judged as "positive." Even if no difference in appearance from the blank was observed in the appearance evaluation, if the pH was 0.3 or more lower than the blank, it was judged as "positive." If no difference in appearance from the blank was observed in the appearance evaluation and the difference in pH from the blank was less than 0.3, it was judged as "negative." If all of the five tests were judged to be negative (0 / 5), the test was deemed to have a bacteriostatic effect.

[0063] Sterilization times of 5, 10, 12.5, 15, 17.5, 20, and 30 minutes at 124.2°C correspond to 10, 20, 25, 30, 35, 40, and 60 minutes, respectively, when converted to sterilization times at 121°C. Therefore, in the tables described below, the F0 value is expressed as the value obtained by converting the sterilization time under 124.2°C conditions to the sterilization time at 121°C (for example, sterilization at 124.2°C for 5 minutes is expressed as "F0 = 10". Similarly, sterilization times at 124.2°C for 10, 12.5, 15, 17.5, 20, and 30 minutes are expressed as "F0 = 20", "F0 = 25", "F0 = 30", "F0 = 35", "F0 = 40", and "F0 = 60", respectively).

[0064] (2) Confirmation of the initial bacterial count The initial cell count of the anaerobic heat-resistant spore-forming bacterium 5901 added to the prepared milk-containing coffee beverage was confirmed by the following method. One milliliter of the beverage containing the spore-forming bacteria solution was placed in a sterilized test tube and diluted 10 times with sterilized peptone water. The solution was then heated in a hot water bath at 100°C for 30 minutes to activate the bacteria, after which the solution was diluted appropriately and inoculated onto modified TGC medium. After culturing anaerobically in an anaerobic culture pouch at 65°C for one week, the number of bacteria was measured. The resulting number of bacteria was multiplied by the dilution factor (total factor) to obtain the initial number of bacteria.

[0065] (3) pH measurement The pH of the culture was measured using a pH meter (HORIBA compact pH meter LAQUAtwin B-71X) after the temperature of the culture was adjusted to room temperature.

[0066] Production Example 1: Production of a dairy-containing coffee drink (1) Preparation of coffee extract After roasted coffee beans are ground (coarsely ground), five times the amount of hot water (80-100°C) is added and the beans are left to steep for 40 minutes, then filtered to obtain a coffee extract.

[0067] (2) Preparation of dairy-containing coffee beverages Coffee extract, milk, sugar, emulsifier, baking soda, and water were mixed according to the recipe below and adjusted to a pH of 7.0. The emulsifier used was prepared in advance by dissolving the emulsifier and a portion of the baking soda in hot water at approximately 75°C and stirring at 75°C for 5 minutes. After mixing all the ingredients (adjusting the pH to 7.0 with the remaining baking soda), the mixture was heated to 75°C and homogenized (using a two-stage high-pressure homogenizer, first stage at 10 MPa, second stage at 5 MPa), after which it was filled into retort cans to produce a dairy-containing coffee beverage.

[0068] <Prescription> Coffee extract 1.2% (as coffee solids) 注1 Milk See Tables 3-6, 11-14 Sugar 6.0% Emulsifiers shown in Tables 3-6, 11-14 Baking soda pH adjustment amount (pH 7.0) water remainder Total 100% 注2

[0069] Note 1: Coffee solids The amount of solids in the coffee extract (coffee solids) (total dissolved solids (TDS)) was determined by measuring the coffee extract with a digital saccharometer (ATAGO PR101α). Measuring the refractive index with a digital saccharometer allows the concentration of dissolved solids in the coffee extract to be determined.

[0070] Note 2: Milk solids in the final dairy coffee beverage The amount of milk solids in the final beverage can be calculated using the following formula. [formula] Milk solids (mass%) = 12.6 (milk solids) x milk blending amount (%)

[0071] The milk-containing coffee beverage packed in the retort cans described above was retort sterilized at 121°C for 20 minutes, and then stored at 55°C for 4 weeks. Dairy coffee beverages prepared by adding only sucrose fatty acid esters as an emulsifier generated solids over time during storage and had a bitter aftertaste (Comparative Examples 1-3, 2-3, 3-3, 4-3, 9-1, 9-2, 10-1, 10-2, 11-1, 11-2, 12-1 to 12-4). In contrast, dairy coffee beverages prepared by adding sorbitan palmitate as an emulsifier (Examples 1 to 4 and 9 to 12) did not show any effect on physical properties, such as the generation of solids, or on flavor, such as the taste of the emulsifier.

[0072] Production Example 2: Production of dairy beverages According to the recipe below, milk, sugar, emulsifier, baking soda, and water were mixed and adjusted to a pH of 7.0. The emulsifier used was prepared in advance by dissolving the emulsifier and a portion of the baking soda in hot water at about 75°C by stirring at 75°C for 5 minutes. After mixing all the ingredients (adjusting the pH to 7.0 with the remaining baking soda), the mixture was heated to 75°C and homogenized (using a two-stage high-pressure homogenizer, first stage at 10 MPa, second stage at 5 MPa), and then filled into retort cans to produce a dairy beverage.

[0073] <Prescription> Milk See Tables 7-10 Sugar 6.0% Emulsifiers shown in Tables 7 to 10 Baking soda pH adjustment amount (pH 7.0) water remainder Total 100% 前記注2

[0074] The dairy coffee beverages (Tables 5 to 8) filled into retort cans as described above were retort sterilized at 121°C for 20 minutes and then stored at 55°C for 4 weeks. None of these dairy beverages were found to have any effect on the physical properties, such as the formation of solids, or on the flavor, such as the taste of an emulsifier.

[0075] Experimental Example 1: Evaluation of the bacteriostatic effect of sorbitan palmitic acid fatty acid esters (Part 1) Various dairy coffee beverages (before filling into retort cans) were prepared according to the description of Production Example 1 using the emulsifiers listed in Tables 3 to 6. The prepared dairy coffee beverages were placed in medium bottles and subjected to the bacteriostatic test described above (heat treatment at 124.2°C followed by storage at 55°C for 4 weeks). If all of the five samples (n = 5) were judged to be negative (0 / 5), the beverage was judged to have a bacteriostatic effect; if not (1 / 5 to 5 / 5), the beverage was judged to have no bacteriostatic effect.

[0076] [Table 3]

[0077] [Table 4]

[0078] [Table 5]

[0079] [Table 6]

[0080] As shown in Tables 3 to 6, it was confirmed that sorbitan fatty acid monoesters generally have a stronger bacteriostatic effect against anaerobic heat-resistant spore-forming bacteria in dairy coffee beverages than sucrose fatty acid esters. Among sorbitan fatty acid monoesters, sorbitan palmitate in particular was found to have a stronger bacteriostatic effect. In particular, it was confirmed that by incorporating sorbitan palmitate in a ratio of 0.004 parts by mass or more per part by mass of milk solids in a dairy coffee beverage, it is possible to impart bacteriostatic effect against anaerobic heat-resistant spore-forming bacteria to the dairy coffee beverage.

[0081] Experimental Example 2: Evaluation of the bacteriostatic effect of sorbitan palmitic acid fatty acid esters (part 2) Various dairy beverages (before filling into retort cans) were prepared according to the description of Production Example 2 using the emulsifiers listed in Tables 7 to 10. The prepared dairy coffee beverages were placed in medium bottles and subjected to the bacteriostatic test described above (heat treatment at 124.2°C followed by storage at 55°C for 4 weeks). If all of the five samples (n = 5) were judged to be negative (0 / 5), the beverage was judged to have a bacteriostatic effect; if not (1 / 5 to 5 / 5), the beverage was judged to have no bacteriostatic effect.

[0082] [Table 7]

[0083] [Table 8]

[0084] [Table 9]

[0085] [Table 10]

[0086] As shown in Tables 7 to 10, it was confirmed that sorbitan palmitate has a high bacteriostatic effect against anaerobic heat-resistant spore-forming bacteria in dairy beverages. In particular, it was confirmed that by blending sorbitan palmitate in a ratio of 0.0015 parts by mass or more per part by mass of milk solids in a dairy beverage, it is possible to effectively impart bacteriostatic effect against anaerobic heat-resistant spore-forming bacteria to the dairy beverage.

[0087] Experimental Example 3 Evaluation of the bacteriostatic effect of combined use of sorbitan palmitate and sucrose fatty acid ester Various dairy coffee beverages (before filling into retort cans) were prepared according to the description of Production Example 1 using the emulsifiers listed in Tables 11 to 16. The prepared dairy coffee beverages were placed in medium bottles and subjected to the bacteriostatic test described above (heat treatment at 124.2°C followed by storage at 55°C for 4 weeks). If all of the five samples (n = 5) were judged to be negative (0 / 5), the beverage was judged to have a bacteriostatic effect; if not (1 / 5 to 5 / 5), the beverage was judged to have no bacteriostatic effect.

[0088] [Table 11]

[0089] [Table 12]

[0090] [Table 13]

[0091] [Table 14]

[0092] [Table 15]

[0093] [Table 16]

[0094] As shown in Tables 11 to 16, it was confirmed that the combined use of sucrose fatty acid ester and sorbitan fatty acid ester can enhance the bacteriostatic effect against anaerobic heat-resistant spore-forming bacteria in dairy beverages, which was previously only weakly effective when sucrose fatty acid ester was used alone. It is known that sucrose fatty acid esters can impair the flavor of beverages depending on the amount used. The results of this experiment demonstrated that by combining sucrose fatty acid ester with sorbitan fatty acid ester, a high bacteriostatic effect can be achieved while reducing the amount of sucrose fatty acid ester used, which may affect the flavor depending on the amount used.

[0095] Experimental Example 4 Evaluation of the bacteriostatic effect of sorbitan palmitic acid fatty acid esters (Part 3) Various dairy coffee beverages (before filling into retort cans) were prepared according to the description of Production Example 1 using the emulsifiers listed in Tables 17 to 19. The prepared dairy coffee beverages were placed in medium bottles and subjected to the bacteriostatic test described above (heat treatment at 124.2°C followed by storage at 55°C for 4 weeks). If all of the five samples (n = 5) were judged to be negative (0 / 5), the beverage was judged to have a bacteriostatic effect; if not (1 / 5 to 5 / 5), the beverage was judged to have no bacteriostatic effect.

[0096] [Table 17]

[0097] [Table 18]

[0098] [Table 19]

[0099] As shown in Tables 17 to 19, it was confirmed that sorbitan palmitate has a high bacteriostatic effect against anaerobic heat-resistant spore-forming bacteria in dairy beverages. In particular, it was confirmed that by blending sorbitan palmitate in a ratio of 0.0015 parts by mass or more per part by mass of milk solids in a dairy beverage, it is possible to effectively impart bacteriostatic effect against anaerobic heat-resistant spore-forming bacteria to the dairy beverage.

[0100] Experimental Example 5 Evaluation of the bacteriostatic effect of sorbitan palmitic acid fatty acid esters (Part 4) Various dairy beverages (before filling into retort cans) were prepared according to the description of Production Example 2 using the emulsifiers listed in Tables 20 to 22. The prepared dairy beverages were placed in medium bottles and subjected to the bacteriostatic test described above (heat treatment at 124.2°C followed by storage at 55°C for 4 weeks). If all of the five samples (n = 5) were judged to be negative (0 / 5), the beverage was judged to have a bacteriostatic effect; if not (1 / 5 to 5 / 5), the beverage was judged to have no bacteriostatic effect.

[0101] [Table 20]

[0102] [Table 21]

[0103] [Table 22]

[0104] As shown in Tables 20 to 22, sorbitan palmitate has a high bacteriostatic effect against anaerobic heat-resistant spore-forming bacteria in dairy beverages, and it was confirmed that by incorporating sorbitan palmitate in a ratio of 0.0015 parts by mass or more per part by mass of milk solids in a dairy beverage, it is possible to effectively impart bacteriostatic effect against anaerobic heat-resistant spore-forming bacteria to dairy beverages.

Claims

1. A dairy beverage containing sorbitan palmitate monoester, The proportion of sorbitan palmitate monoester per part by mass of milk solids in the dairy beverage is 0.0015 parts by mass or more. Dairy drinks.

2. 2. The dairy beverage according to claim 1, wherein the dairy beverage contains 0.5 to 11.5% by mass of milk solids.

3. 3. The dairy beverage according to claim 1, wherein the proportion of sorbitan palmitate monoester in 100% by mass of the dairy beverage is 0.001 to 0.5% by mass.

4. The dairy beverage according to claim 1, further comprising a sucrose fatty acid ester.

5. 5. The dairy beverage according to claim 4, wherein the ratio of the sucrose fatty acid ester to 100 parts by mass of the sorbitan palmitate monoester is 1 to 300 parts by mass.

6. An emulsion stabilizer for dairy beverages, comprising sorbitan palmitate monoester as an active ingredient, The sorbitan palmitate monoester is used so that the ratio of the sorbitan palmitate monoester per part by mass of milk solids in the dairy beverage is 0.0015 parts by mass or more. Emulsifying stabilizer for dairy beverages.

7. 7. The emulsion stabilizer for dairy beverages according to claim 6, which is a preparation used to impart bacteriostasis against anaerobic heat-resistant spore-forming bacteria to dairy beverages.

Images