Milk-containing beverage and method for producing the same

Abstract

The present disclosure provides: a milk component-containing beverage which has a bacteriostatic activity against anaerobic heat-resistant spore-forming bacteria; and a method for producing the milk component-containing beverage. This milk component-containing beverage contains sorbitan palmitate ester, wherein the content ratio of the sorbitan palmitate ester is 0.0015 part by mass or more per 1 part by mass of milk solid content in the milk component-containing beverage.

Description

Technical Field

[0001] The present disclosure relates to a milk component-containing beverage and a method for producing the same. More specifically, the present disclosure relates to a milk component-containing beverage having a bacteriostatic effect against anaerobic heat-resistant spore-forming bacteria and a method for producing the same. Further, the present disclosure relates to an emulsifying stabilizer for a milk component-containing beverage, more specifically, an emulsifying stabilizer having a bacteriostatic effect against anaerobic heat-resistant spore-forming bacteria.

Background Art

[0002] [[ID=SECTION=12]]Examples of milk component-containing beverages widely distributed in the Japanese market include coffee beverages containing milk, tea beverages containing milk, cocoa beverages containing milk, and matcha beverages containing milk. In order to kill bacteria that cause spoilage and corruption, these milk component-containing beverages are filled into pressure-resistant containers such as retort cans and then subjected to retort sterilization treatment at about 120°C for 20 to 40 minutes before being distributed on the market. However, some anaerobic heat-resistant spore-forming bacteria with strong heat resistance still survive even after the heat sterilization treatment, and when heated and sold in hot vending machines or heated vending machines, etc., there is a possibility that spoilage and deterioration may occur due to the germination and growth of anaerobic heat-resistant spore-forming bacteria.

[0003] In order to kill such anaerobic heat-resistant spore-forming bacteria, there are methods of increasing the sterilization temperature and lengthening the sterilization time in the production process. However, this method has an adverse effect on the flavor, physical and chemical properties of the milk component-containing beverage, and significantly reduces the quality of the milk component-containing beverage.

[0004] Another known method involves adding sucrose fatty acid esters to suppress the growth of anaerobic heat-resistant spore-forming bacteria and prevent spoilage. Furthermore, a method has been proposed to stably disperse fats and oils in fat-containing beverages such as milk coffee and cocoa, while also suppressing spoilage by heat-resistant flat sour bacteria, by using a combination of sucrose fatty acid esters with an HLB of 13 or higher and organic acid monoglycerides (Patent Document 1). According to Patent Document 1, if the proportion of sucrose fatty acid esters in the beverage is less than 0.05% by mass, the spoilage prevention effect by heat-resistant flat sour bacteria is insufficient, while if it exceeds 0.3% by mass, the bitterness of the sucrose fatty acid esters tends to impair the flavor of the beverage. Additionally, it is stated that if sucrose fatty acid esters with a low HLB value are used, the spoilage prevention effect by heat-resistant flat sour bacteria cannot be obtained. Furthermore, it has been noted that when sorbitan monostearate (sorbitan stearate monoester) is used in combination with sucrose fatty acid esters instead of organic acid monoglycerides, the oil dispersion stabilization effect decreases, and oil release (creaming, oil off) occurs during long-term storage.

[0005] Furthermore, Patent Document 2 proposes a method to improve spoilage of beverages due to the remaining mesophilic spore-forming bacteria, which is a problem in the sterilization process used in the manufacture of PET bottle beverages, by 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. However, Patent Document 2 states that sorbitan stearate monoester, which is a sorbitan fatty acid ester, does not have antibacterial activity against B. coagulans spores (Table 6).

[0006] Furthermore, Patent Document 3 proposes a method of adding 0.01 to 1% by weight of sorbitan fatty acid ester, a saturated fatty acid with 12 or 14 carbon atoms, to the entire beverage in order to suppress spoilage due to germination and proliferation of anaerobic heat-resistant bacterial spores in sealed beverages. According to Patent Document 3, sorbitan fatty acid ester with 12 or 14 carbon atoms has a higher inhibitory effect on the germination and proliferation of anaerobic heat-resistant bacterial spores than sucrose fatty acid ester or polyglycerol fatty acid ester, and has less impact on the taste of the beverage.

[0007] Furthermore, Patent Document 4 proposes a method for producing a coffee beverage containing milk components that suppresses the germination and proliferation of heat-resistant bacterial spores during long-term storage at high temperatures and has good emulsification stability, by adding lysolecithin and organic acid monoglycerides. According to Patent Document 4, it is stated that no antibacterial effect can be obtained by using sorbitan monostearate ester in combination with lysolecithin instead of organic acid monoglycerides.

[0008] Furthermore, Patent Document 5 proposes an emulsifying stabilizer for milk beverages made from milk and dairy products, such as coffee milk beverages, milk tea, and cocoa beverages, containing 6-16% by weight of sucrose fatty acid ester, 29-69% by weight of glycerin mono fatty 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 adjusted so that the pH value of a 0.4% aqueous solution is 5-9. It is stated that such an emulsifier has good storage stability and can be used stably without requiring a special stirring device when heated and dissolved. However, the antibacterial effect of the emulsifying stabilizer is not described. [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 Publication No. 2002-142670 [Overview of the Initiative] [Problems that the invention aims to solve]

[0010] The object of this disclosure is to provide a beverage containing milk components and a method for producing the same. More specifically, the object of this disclosure is to provide a beverage containing milk components that has a bacteriostatic effect against anaerobic heat-resistant spore-forming bacteria and a method for producing the same.

[0011] Furthermore, this disclosure aims to provide an emulsifying stabilizer for beverages containing milk components. More specifically, the object of this disclosure is to provide an emulsifying stabilizer used to impart bacteriostatic properties against anaerobic heat-resistant spore-forming bacteria to beverages containing milk components.

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

[0013] The inventors, after diligent research to solve the aforementioned problems, have found that by incorporating sorbitan palmitate ester into a milk-containing beverage at a ratio of 0.0015 parts by mass or more per 1 part by mass of milk solids in the milk-containing beverage, the growth of anaerobic heat-resistant spore-forming bacteria in the beverage can be effectively suppressed (bacteriostatic effect). Furthermore, they have confirmed that the bacteriostatic effect of sorbitan palmitate ester is significantly higher than that of sucrose fatty acid esters and other sorbitan fatty acid esters, which are conventionally known to have bacteriostatic effects. In addition, the inventors have found that by using sorbitan palmitate ester in combination with sucrose fatty acid ester, the amount of sucrose fatty acid ester used can be reduced, minimizing the impact of sucrose fatty acid esters on the flavor of the milk-containing beverage while still exhibiting an effective bacteriostatic effect. The present invention was completed based on these findings and has the following embodiments.

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

[0015] (II) Method for producing milk-containing beverages (II-1) A method for producing a milk component-containing beverage, comprising a step of blending sorbitan palmitate with the milk component-containing beverage such that the ratio of sorbitan palmitate per 1 part by mass of milk solids in the milk component-containing beverage is 0.0015 parts by mass or more. (II-2) The production method according to (II-1), wherein the milk component-containing beverage contains milk solids in a proportion of 0.5 to 11.5% by mass. (II-3) The production method according to (II-1) or (II-2), wherein sorbitan palmitate is blended such that the concentration of sorbitan palmitate in 100% by mass of the milk component-containing beverage is 0.001 to 0.5% by mass. (II-4) The production method according to any one of (II-1) to (II-3), further comprising a step of blending sucrose fatty acid ester with the milk component-containing beverage. (II-5) The production method according to (II-4), wherein the ratio of sucrose fatty acid ester to 100 parts by mass of 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) The production method according to any one of (II-1) to (II-6), which is a method for producing a milk component-containing beverage for imparting bacteriostatic properties against anaerobic thermophilic spore-forming bacteria to the milk component-containing beverage.

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

[0017] (IV) Emulsifying stabilizers for beverages containing milk ingredients (IV-1) An emulsifying stabilizer for beverages containing milk components, having sorbitan palmitate as an active ingredient, An emulsifying stabilizer for beverages containing milk components, which is used such that the ratio of sorbitan palmitate per 1 part by mass of milk solids in the beverage containing milk components is 0.0015 parts by mass or more. (IV-2) The emulsifying stabilizer for beverages containing milk components according to (IV-1), which is a preparation used to impart bacteriostatic properties against anaerobic thermophilic spore-forming bacteria to the beverage containing milk components. (IV-3) The emulsifying stabilizer for beverages containing milk components according to (IV-1) or (IV-2), wherein the beverage containing milk components contains milk solids in a proportion of 0.5 to 11.5% by mass. (IV-4) The emulsifying stabilizer for beverages containing milk components according to any one of (IV-1) to (IV-3), which is used in the manufacturing process of the beverage containing milk components such that the concentration of sorbitan palmitate in 100% by mass of the beverage containing milk components is 0.001 to 0.5% by mass. (IV-5) Furthermore, an emulsifying stabilizer for milk-containing beverages, as described in any of (IV-1) to (IV-4), which contains a sucrose fatty acid ester in the milk-containing beverage. (IV-6) An emulsifying stabilizer for milk-containing beverages as described in (IV-5), wherein the ratio of sucrose fatty acid ester to 100 parts by mass of sorbitan palmitate ester is 1 to 300 parts by mass. [Effects of the Invention]

[0018] This disclosure provides a milk-containing beverage with a high inhibitory effect (bacteriostatic effect) on the growth of anaerobic, heat-resistant spore-forming bacteria, and a method for producing the same. In particular, this disclosure provides a heat-sterilized milk-containing beverage with a high inhibitory effect on the growth of anaerobic, heat-resistant spore-forming bacteria that may remain even after heat sterilization, and a method for producing the same that has good storage stability.

[0019] Furthermore, this disclosure provides a method for imparting a bacteriostatic effect against anaerobic heat-resistant spore-forming bacteria to a beverage containing milk components while minimizing the impact on the flavor of the beverage.

[0020] Furthermore, this disclosure provides emulsification stability for milk-containing beverages that can be used to impart bacteriostatic properties against anaerobic heat-resistant spore-forming bacteria to milk-containing beverages. [Modes for carrying out the invention]

[0021] (I) Beverages containing dairy ingredients The milk-containing beverages covered by this disclosure are beverages (milk beverages) that contain at least milk solids as milk components. However, they are not milk itself, such as raw milk, cow's milk, special milk, adjusted milk, low-fat milk, and non-fat milk.

[0022] The milk subject to this study is that of livestock such as cows (dairy cows such as Holstein, Jersey, and Brown Swiss), sheep, and goats, and is preferably milk derived from dairy cows (hereinafter referred to as "dairy cow-derived milk").

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

[0024] When using, for example, raw milk derived from Holstein cows as a milk component, the milk solids content in a beverage containing that milk component can be calculated using the following formula. [formula] Milk solids content (by mass) in beverages containing milk ingredients = 12.3 (amount of milk solids in raw milk) × amount of raw milk used (mass %).

[0025] Furthermore, when using raw milk derived from Holstein cows as a milk component, the total amount of milk solids in the beverage can be calculated based on the milk fat and / or milk protein content of the beverage, according to the aforementioned ratio of milk solids in milk.

[0026] Furthermore, when using milk other than raw milk from Holstein cows as the milk component in a milk-containing beverage, the same calculation can be performed by substituting the value "12.3" in the above formula for the amount of milk solids in that milk. Such a value can be derived from the information in Chapter 2 (Data) of the 8th edition of the Standard Tables of Food Composition in Japan (see food number 13000). For example, raw milk from Jersey cows consists of 85.5% water by mass and 14.5% milk solids by mass, and the milk solids consist of milk fat (3.7% by mass) and non-fat milk solids (9.3% by mass). In addition, non-fat milk solids contain protein (3.9% by mass), carbohydrates (4.7% by mass), minerals such as calcium (0.7% by mass), and vitamins (food number 13001). Similarly, regular milk consists of 87.4% water and 12.6% milk solids, with the milk solids comprising milk fat (3.8%) and non-fat milk solids (8.8%). The non-fat milk solids also contain protein (3.3%), carbohydrates (4.8%), minerals such as calcium (0.7%), and vitamins (food number 13003).

[0027] The beverages containing milk components are not limited to any beverage containing the aforementioned milk components, but examples include: milk coffee, coffee milk beverages, café au lait, café latte, and cappuccino; milk tea beverages containing milk components; matcha or green tea beverages containing milk components, such as matcha milk and green tea milk; fruit juice beverages containing milk components; cocoa beverages containing milk components; chocolate drinks containing milk components; milkshakes, etc. Although not limited, the beverages are preferably manufactured using milk derived from dairy cows as one of the raw materials. More preferably, they are coffee beverages containing milk components.

[0028] Suitable milk-containing beverages include those with a milk solids content of 0.5 to 11.5% by mass. Preferably, the milk solids content is 0.5 to 10.0% by mass, and more preferably, the milk-containing beverage has a milk solids content of 0.6 to 9.0% by mass.

[0029] Furthermore, while there are no restrictions on the pH range of beverages containing dairy ingredients, it can usually be selected from the range of pH 5.0 to 8.0. Preferably, it is pH 5.5 to 7.5, and more preferably pH 5.8 to 7.2.

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

[0031] The sorbitan palmitate used in this invention is an esterified product obtained by reacting sorbitol with a saturated fatty acid having 16 carbon atoms by a conventional method. Esterified products include monoesters, diesters, and triesters. Monoesters are preferred.

[0032] The sucrose fatty acid ester used in the present invention is an esterified product of sucrose and a fatty acid. The chain length of the fatty acid has 12 to 22 carbon atoms, preferably 12 to 20, more preferably 14 to 18, and particularly preferably 16 carbon atoms, and saturated fatty acids are desirable. The degree of esterification can be mono, di, or triester, but monoesters are preferred. The fatty acid composition, as well as the mono, di, and triester compounds, may be either single compounds or mixtures, but the fatty acid composition preferably contains 50% or more of saturated fatty acids with 14 to 18 carbon atoms, and preferably contains 50% or more, more preferably 60% or more, and more preferably 70% or more of monoester compounds. Furthermore, 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 especially preferably 16.

[0033] (When using component A as a bacteriostatic agent without using component B in combination) When component A is used as a bacteriostatic component without being used in combination with component B, the recommended blending ratio of component A in a milk-containing beverage is 0.0015 parts by mass or more per 1 part by mass of milk solids in the milk-containing 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, 0.006 parts by mass or more, and 0.007 parts by mass or more. The upper limit is not limited to the extent that it does not impede the effects of this disclosure, but is 0.3 parts by mass or less per 1 part by mass of milk solids in a milk-containing beverage. Examples of upper limits 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 beverage containing milk ingredients can be determined from the total amount of milk fat and non-fat milk solids in the milk raw materials used as ingredients in the production of the beverage.

[0036] The proportion of component A in 100% by mass of the milk-containing beverage is not particularly limited as long as the blending ratio to 1 part by mass of milk solids in the milk-containing beverage is within the range mentioned above, but it can be in the range of 0.001 to 0.5% by mass. Preferably it is 0.004 to 0.4% by mass, and more preferably 0.006 to 0.3% by mass.

[0037] (When using components A and B together as bacteriostatic agents) When components A and B are used in combination as bacteriostatic components, the proportion of component A added to the milk-containing beverage is not particularly limited as long as it is within the above range. However, the total amount of components A and B added to the milk-containing beverage can also be adjusted to a ratio of 0.0015 parts by mass or more per 1 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 to the extent that it does not hinder the effects of the present invention, but it is 0.5 parts by mass or less per 1 part by mass of milk solids in the beverage. Examples of upper limits 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. These lower and upper limits can be arbitrarily combined to set the blending ratio.

[0038] [Table 2]

[0039] The ratio in which component A and component B are used together 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 of component B, 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 component A and component B in 100% by mass of the milk-containing beverage is not particularly limited as long as the total amount of component A and component B per 1 part by mass of milk solids in the milk-containing beverage is within the above range, but it can be said to be in the range of 0.005 to 0.5% by mass. Preferably it is 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 a milk-containing beverage is not limited, provided that the above proportion is satisfied, but can be in the range of 0.00005 to 0.375% by mass. Preferably, it is 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 aforementioned bacteriostatic component in the aforementioned proportions with a beverage containing milk components, a beverage containing milk components that exhibits bacteriostatic activity against anaerobic heat-resistant spore-forming bacteria can be prepared. With this beverage containing milk components, the germination and proliferation of anaerobic heat-resistant spore-forming bacteria, which are problematic in beverages in sealed containers, can be suppressed, and spoilage of beverages in sealed containers can be prevented. More preferably, according to the present invention, the germination and proliferation of anaerobic heat-resistant spore-forming bacteria, which are still problematic even in heat-sterilized beverages in sealed containers, can be suppressed, and spoilage of beverages in sealed containers can be prevented. Generally, anaerobic heat-resistant spore-forming bacteria that are problematic in beverages in sealed containers can be limited to Thermoanaerobacter mathranii, but one example is Thermoanaerobacter mathranii. The presence or absence of bacteriostatic activity (presence or absence of bacteriostatic effect) against anaerobic heat-resistant spore-forming bacteria can be determined based on the "bacteriostatic test" described in the Examples section below.

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

[0044] (II) Method for producing milk-containing beverages This disclosure relates to a method for producing a beverage containing milk components. The production method of this disclosure can be suitably used to impart bacteriostatic properties against anaerobic heat-resistant spore-forming bacteria to a beverage containing milk components. The manufacturing method is characterized by comprising a step of blending sorbitan palmitate ester (component A) into a milk-containing beverage at a ratio of 0.0015 parts by mass or more per 1 part by mass of milk solids in the milk-containing beverage. This manufacturing method can be carried out by blending component A alone as a bacteriostatic component, but sucrose fatty acid ester (component B) can also be blended in addition to component A. Furthermore, in this manufacturing method, there is little need to include other bacteriostatic components known to have antibacterial properties, and it is preferable not to use them. Examples of such bacteriostatic components include the aforementioned polyglycerol fatty acid esters, monoglycerol esters, lecithin, enzyme-treated lecithin, and the like.

[0045] The milk-containing beverages covered by this disclosure, anaerobic heat-resistant spore-forming bacteria, sorbitan palmitate ester (component A) and sucrose fatty acid ester (component B) incorporated into the milk-containing beverages, and their respective proportions are as described in section (I) above, and that description can be referenced in this section.

[0046] The milk-containing beverages covered by this disclosure are preferably beverages in sealed containers, and more preferably beverages in sealed containers that have been heat-sterilized. Therefore, the manufacturing method of this disclosure includes a step of heat-sterilizing a milk-containing beverage containing component A, or a beverage containing both component A and component B. The heat-sterilization treatment may be performed before or after filling into containers, and is not particularly limited to this order. As an example of the former method, although not limited, an example can be given of a method in which the prepared milk-containing beverage is heat-sterilized and then filled into a sterile container. As an example of the latter method, although not limited, an example can be given of a method in which the prepared milk-containing beverage is filled into a heat-resistant and retort-resistant container and then heat-sterilized.

[0047] The heat sterilization treatment can be any sterilization treatment commonly used in beverage production. For example, it is not particularly limited by sterilization conditions or equipment, and commonly used sterilization treatments and conditions such as boiling, retort, UHT (e.g., indirect methods such as plate sterilization and tubular sterilization, or direct methods such as steam injection sterilization), and autoclave sterilization can be widely adopted. One preferred embodiment is a 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 adversely affect the flavor, physical and chemical properties of the beverage containing milk components. For this reason, it is preferable that the heat treatment time at 121°C be within 60 minutes, preferably within 50 minutes.

[0048] (III) A method for imparting a bacteriostatic effect against anaerobic heat-resistant spore-forming bacteria to a milk-containing beverage. This disclosure relates to a method for imparting a bacteriostatic effect against anaerobic heat-resistant spore-forming bacteria to a milk-containing beverage. The method disclosed herein can be carried out in the manufacturing process of a milk-containing beverage by adding sorbitan palmitate ester (component A) to the milk-containing beverage at a ratio of 0.0015 parts by mass or more per 1 part by mass of milk solids in the milk-containing beverage. Furthermore, this method can be carried out by adding component A alone as a component that imparts bacteriostatic action, but it can also be carried out by adding sucrose fatty acid ester (component B) in addition to component A.

[0049] The milk-containing beverages covered by this disclosure, anaerobic heat-resistant spore-forming bacteria, sorbitan palmitate ester (component A) and sucrose fatty acid ester (component B) incorporated into the milk-containing beverages, and their respective proportions are as described in section (I) above, and that description can be referenced in this section.

[0050] (IV) Emulsifying stabilizers for beverages containing milk ingredients This disclosure relates to an emulsifying stabilizer for beverages containing milk components. The emulsifying stabilizer of this disclosure is characterized by containing sorbitan palmitate (component A) as an active ingredient for emulsifying stability. When this emulsifying stabilizer is used in a beverage containing milk components such that the ratio of component A per 1 part by mass of milk solids in the beverage is 0.0015 parts by mass or more, it exhibits excellent bacteriostatic activity in the beverage containing milk components. Therefore, in this mode of use, it has the effect (use) of both an emulsifying stabilizer and a bacteriostatic agent.

[0051] This emulsifying stabilizer may contain component A alone as an active ingredient for emulsifying stability, or as an ingredient possessing both emulsifying stabilizing and bacteriostatic properties, but it may also contain sucrose fatty acid ester (component B) in addition to component A.

[0052] This emulsifying stabilizer may contain component A in an amount ranging from 1% to 100% by mass, or it may consist of 100% by mass of component A. Furthermore, if it contains both component A and component B, it may contain them in a total amount ranging from 2% to 100% by mass, or it may consist of 100% by mass of both component A and component B.

[0053] The form of this emulsifying stabilizer is not particularly limited and can be appropriately selected from liquid (liquid formulation), emulsion, and solid (powder, granules, tablets). Depending on the form, it may also contain various excipients, diluents, binders, lubricants, etc.

[0054] The milk-containing beverages covered by this disclosure; anaerobic heat-resistant spore-forming bacteria; sorbitan palmitate ester (component A) and sucrose fatty acid ester (component B) incorporated into this emulsifying stabilizer, and their respective proportions; and the usage ratio of milk-containing beverages (proportions of components A and B), etc., are as described in section (I) above, and that description may be referenced in this section.

[0055] In this specification, the terms “contains” and “includes” include the meanings of “consisting of” and “substantially consisting of.” [Examples]

[0056] The present invention will be described below using experimental examples to aid in understanding its structure and effects. However, the present invention is not limited in any way by these experimental examples. Unless otherwise specified, the following experiments were conducted at room temperature (25±5℃) and under atmospheric pressure conditions. Unless otherwise specified, "%" below means "mass percent" and "parts" means "parts by mass".

[0057] The materials used in the following experimental examples and embodiments are as follows. • Sorbitan palmitate: 100% sorbitan palmitate monoester, product name Homogen (registered trademark) 3369 (manufactured by San-Ei Gen F.F.I. Co., Ltd.). • Sorbitan laurate ester: 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), HLB approximately 16, bound fatty acid purity (approximately 80), monoester content (approximately 80%), di-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 Foods 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 medium prepared by dissolving 10g of Bactosoiton and 0.5g of anhydrous sodium sulfite in 1000mL of distilled water, to which a mixture of sterile dried clay and sterile calcium carbonate in a 9:1 (mass ratio) ratio is added, and the medium is sterilized at 121°C for 20 minutes.

[0058] The evaluation method used in the following experimental examples is as follows. (1) Bacteriostatic test The prepared coffee beverage containing milk components (hereinafter referred to as "beverage") was placed in a medium bottle, degassed by heating in a water bath 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, with an initial bacterial count of 10 4 The mixture was added while stirring until it reached a CFU / g level.

[0059] The spore-forming bacterial suspension used was prepared by pre-culturing anaerobic, heat-resistant spore-forming bacteria 5901 in modified TGC medium, then performing the main culture in SS liquid medium for spore formation, and finally centrifuging the culture to remove the precipitate.

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

[0061] After 4 weeks of incubation, the bacteriostatic effect was evaluated by comparing the appearance and pH with a blank (a beverage that had been degassed in a water bath, cooled, sealed in a TDT tube in the same manner as above, heat-sterilized, and then incubated under the same conditions, without the addition of spore-forming bacteria solution).

[0062] In the visual evaluation, if a difference in appearance from the blank was observed, such as the culture becoming cloudy, it was judged as "spoiled" and determined to be "positive." Even if no difference in appearance from the blank was observed in the visual evaluation, if the pH was 0.3 or more lower than the blank, it was determined to be "positive." If no difference in appearance from the blank was observed in the visual evaluation, and the difference in pH from the blank was less than 0.3, it was determined to be "negative." A bacteriostatic effect was considered to have occurred if all five samples (n=5) were determined to be negative (0 / 5).

[0063] Note that sterilization at 124.2°C for 5 minutes, 10 minutes, 12.5 minutes, 15 minutes, 17.5 minutes, 20 minutes, and 30 minutes corresponds to 10 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, and 60 minutes, respectively, when converted to sterilization time at 121°C. Therefore, in the table below, the F0 value will be expressed as the value obtained by converting the sterilization time at 124.2°C to sterilization time at 121°C (for example, sterilization at 124.2°C for 5 minutes will be expressed as "F0=10". Similarly, sterilization at 124.2°C for 10 minutes, 12.5 minutes, 15 minutes, 17.5 minutes, 20 minutes, and 30 minutes will be 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 bacterial count of anaerobic, heat-resistant spore-forming bacteria 5901 added to the prepared coffee beverage containing milk components was confirmed by the following method. One ml of beverage containing spore-forming bacteria was placed in a sterile test tube and diluted 10-fold with sterile peptone water. The mixture was heated in a water bath at 100°C for 30 minutes to activate the bacteria. After activating the bacteria, the mixture was diluted as needed and inoculated onto modified TGC medium. The cultures were then incubated anaerobically at 65°C for one week in an anaerobic culture pouch, and the bacterial count was measured. The obtained bacterial count was multiplied by the dilution ratio (total ratio) to determine the initial bacterial count.

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

[0066] Manufacturing Example 1: Manufacturing of a coffee beverage containing dairy ingredients (1) Preparation of coffee extract After grinding the roasted coffee beans (coarsely ground), add five times the amount of hot water (80-100°C) and let it steep for 40 minutes. Then filter to obtain the coffee extract.

[0067] (2) Preparation of coffee beverages containing milk ingredients According to the following formula, coffee extract, 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 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 10 MPa, second stage 5 MPa), then filled into retort cans to produce a coffee beverage containing milk components.

[0068] <Prescription> Coffee extract 1.2% (as coffee solids) 注1 Milk (as shown in Tables 3-6 and 11-14) Sugar 6.0% Emulsifiers are shown in Tables 3-6 and 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 (coffee solids) (Total Dissolved Solids (TDS)) in the coffee extract was determined by measuring the coffee extract using a digital refractometer (ATAGO PR101α). The concentration of solids dissolved in the coffee extract can be determined by measuring the refractive index with the digital refractometer.

[0070] Note 2: Milk solids in the final milk-containing coffee beverage The amount of milk solids in the final beverage can be calculated using the following formula. [formula] Milk solids content (mass%) = 12.6 (solids content of milk) × Amount of milk used (%)

[0071] The coffee beverage containing milk components, which was filled into retort cans as described above, was sterilized using a retort process at 121°C for 20 minutes, and then stored at 55°C for 4 weeks. Coffee beverages containing milk components prepared by adding only sucrose fatty acid ester as an emulsifier developed solid matter over time during storage and left 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, 12-1~12-4). In contrast, coffee beverages containing milk components prepared by adding sorbitan palmitate ester as an emulsifier (Examples 1~4 and 9~12) did not show any effects on physical properties such as the formation of solid matter, nor any effects on flavor such as the taste of the emulsifier.

[0072] Manufacturing Example 2: Manufacturing of a beverage containing dairy ingredients Milk, sugar, emulsifier, baking soda, and water were mixed according to the following formula 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 10 MPa, second stage 5 MPa), then filled into retort cans to produce a milk-containing beverage.

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

[0074] The coffee beverages containing milk components, which were filled into retort cans as described above (Tables 5-8), were retort-sterilized at 121°C for 20 minutes and then stored at 55°C for 4 weeks. None of these milk-containing beverages showed any effects on physical properties, such as the formation of solid matter, nor on flavor, such as the taste of emulsifiers.

[0075] Experimental Example 1: Evaluation of the bacteriostatic effect of sorbitan palmitate fatty acid ester (Part 1) Using the emulsifiers listed in Tables 3-6, various coffee beverages containing milk components (beverages before filling into retort cans) were prepared according to the instructions in Manufacturing Example 1. The prepared coffee beverages containing milk components were placed in medium bottles, and the bacteriostatic test described above (heat treatment at 124.2°C followed by storage at 55°C for 4 weeks) was performed. If all of the 5 samples (n=5) were determined to be negative (0 / 5), it was determined that there was a bacteriostatic effect; otherwise (1 / 5 to 5 / 5), it was determined that there was no bacteriostatic effect.

[0076] [Table 3]

[0077] [Table 4]

[0078] [Table 5]

[0079] [Table 6]

[0080] As shown in Tables 3-6 above, sorbitan fatty acid monoesters generally exhibited higher bacteriostatic activity against anaerobic, heat-resistant spore-forming bacteria in coffee beverages containing milk components compared to sucrose fatty acid esters. Among sorbitan fatty acid monoesters, sorbitan palmitate ester showed particularly strong bacteriostatic activity. Specifically, it was confirmed that incorporating sorbitan palmitate ester at a ratio of 0.004 parts by mass or more per 1 part by mass of milk solids in coffee beverages containing milk components could impart a bacteriostatic effect against anaerobic, heat-resistant spore-forming bacteria to the beverage.

[0081] Experimental Example 2: Evaluation of the bacteriostatic effect of sorbitan palmitate fatty acid ester (Part 2) Various milk-containing beverages (beverages before filling into retort cans) were prepared according to the instructions in Manufacturing Example 2 using the emulsifiers listed in Tables 7-10. The prepared milk-containing 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 5 samples (n=5) were determined to be negative (0 / 5), it was determined that there was a bacteriostatic effect; otherwise (1 / 5 to 5 / 5), it was determined that there was no bacteriostatic effect.

[0082] [Table 7]

[0083] [Table 8]

[0084] [Table 9]

[0085] [Table 10]

[0086] As shown in Tables 7-10, sorbitan palmitate was confirmed to have a high bacteriostatic effect against anaerobic, heat-resistant spore-forming bacteria in milk-containing beverages. In particular, it was confirmed that by incorporating sorbitan palmitate at a ratio of 0.0015 parts by mass or more per 1 part by mass of milk solids in milk-containing beverages, an effective bacteriostatic effect against anaerobic, heat-resistant spore-forming bacteria can be imparted to milk-containing beverages.

[0087] Experimental Example 3: Evaluation of bacteriostatic effect by combining sorbitan palmitate and sucrose fatty acid ester. Using the emulsifiers listed in Tables 11-16, various coffee beverages containing milk components (beverages before filling into retort cans) were prepared according to the instructions in Manufacturing Example 1. The prepared coffee beverages containing milk components were placed in medium bottles, and the bacteriostatic test described above (heat treatment at 124.2°C followed by storage at 55°C for 4 weeks) was performed. If all of the 5 samples (n=5) were determined to be negative (0 / 5), it was determined that there was a bacteriostatic effect; otherwise (1 / 5 to 5 / 5), it was determined that there was 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 11-16, it was confirmed that combining sucrose fatty acid esters and sorbitan fatty acid esters enhances the bacteriostatic effect against anaerobic, heat-resistant spore-forming bacteria in milk-containing beverages, which was less effective with sucrose fatty acid esters alone. Sucrose fatty acid esters are known to degrade the flavor of beverages depending on the amount used. The results of this experiment revealed that combining sucrose fatty acid esters with sorbitan fatty acid esters allows for a high bacteriostatic effect while reducing the amount of sucrose fatty acid esters used, which is a concern due to its potential impact on flavor depending on the amount added.

[0095] Experimental Example 4: Evaluation of the bacteriostatic effect of sorbitan palmitate fatty acid ester (Part 3) Using the emulsifiers listed in Tables 17-19, various coffee beverages containing milk components (beverages before filling into retort cans) were prepared according to the instructions in Manufacturing Example 1. The prepared coffee beverages containing milk components were placed in medium bottles, and the bacteriostatic test described above (heat treatment at 124.2°C followed by storage at 55°C for 4 weeks) was performed. If all of the 5 samples (n=5) were determined to be negative (0 / 5), it was determined that there was a bacteriostatic effect; otherwise (1 / 5 to 5 / 5), it was determined that there was no bacteriostatic effect.

[0096] [Table 17]

[0097] [Table 18]

[0098] [Table 19]

[0099] As shown in Tables 17-19, sorbitan palmitate was confirmed to have a high bacteriostatic effect against anaerobic, heat-resistant spore-forming bacteria in milk-containing beverages. In particular, it was confirmed that by incorporating sorbitan palmitate at a ratio of 0.0015 parts by mass or more per 1 part by mass of milk solids in milk-containing beverages, an effective bacteriostatic effect against anaerobic, heat-resistant spore-forming bacteria can be imparted to milk-containing beverages.

[0100] Experimental Example 5: Evaluation of the bacteriostatic effect of sorbitan palmitate fatty acid ester (Part 4) Various milk-containing beverages (beverages before filling into retort cans) were prepared according to the instructions in Manufacturing Example 2 using the emulsifiers listed in Tables 20-22. The prepared milk-containing beverages were placed in medium bottles, and the bacteriostatic test described above (heat treatment at 124.2°C followed by storage at 55°C for 4 weeks) was performed. If all of the 5 samples (n=5) were determined to be negative (0 / 5), it was determined that there was a bacteriostatic effect; otherwise (1 / 5 to 5 / 5), it was determined that there was no bacteriostatic effect.

[0101] [Table 20]

[0102] [Table 21]

[0103] [Table 22]

[0104] As shown in Tables 20-22, sorbitan palmitate exhibits high bacteriostatic activity against anaerobic, heat-resistant spore-forming bacteria in milk-containing beverages. It was confirmed that by incorporating sorbitan palmitate at a ratio of 0.0015 parts by mass or more per 1 part by mass of milk solids in milk-containing beverages, effective bacteriostatic activity against anaerobic, heat-resistant spore-forming bacteria can be imparted to milk-containing beverages.

Claims

1. A beverage containing milk components that has bacteriostatic properties against anaerobic heat-resistant spore-forming bacteria, The bacteriostatic component that exhibits the aforementioned bacteriostatic properties contains sorbitan palmitate, The proportion of sorbitan palmitate ester per 1 part by mass of milk solids in a beverage containing milk ingredients is 0.0015 parts by mass or more. The aforementioned beverage containing milk ingredients.

2. The milk-containing beverage according to claim 1, wherein the milk-containing beverage contains milk solids in a proportion of 0.5 to 11.5% by mass.

3. A milk-containing beverage according to claim 1 or 2, wherein the proportion of sorbitan palmitate ester in 100% by mass of the milk-containing beverage is 0.001 to 0.5% by mass.

4. A milk-containing beverage according to claim 1 or 2, further containing sucrose fatty acid ester.

5. A milk-containing beverage according to claim 4, wherein the ratio of sucrose fatty acid ester to 100 parts by mass of sorbitan palmitate ester is 1 to 300 parts by mass.

6. A method for producing a beverage containing milk components to impart bacteriostatic properties against anaerobic heat-resistant spore-forming bacteria to the beverage containing milk components, The process involves adding sorbitan palmitate ester as a bacteriostatic component to a milk-containing beverage, such that the proportion per 1 part by mass of milk solids in the milk-containing beverage is 0.0015 parts by mass or more. A method for manufacturing a beverage containing milk ingredients.

7. The manufacturing method according to claim 6, wherein the milk-containing beverage contains milk solids in a proportion of 0.5 to 11.5% by mass.

8. The manufacturing method according to claim 6 or 7, wherein sorbitan palmitate is blended so that its concentration in 100% by mass of a milk-containing beverage is 0.001 to 0.5% by mass.

9. The manufacturing method according to claim 6 or 7, further comprising the step of blending in sucrose fatty acid ester.

10. The manufacturing method according to claim 9, wherein the ratio of sucrose fatty acid ester to 100 parts by mass of sorbitan palmitate ester is 1 to 300 parts by mass.

11. The manufacturing method according to claim 6 or 7, further comprising a heat sterilization step.

12. An emulsifying stabilizer for a milk-containing beverage, used to impart bacteriostatic properties against anaerobic heat-resistant spore-forming bacteria to a milk-containing beverage, The beverage containing milk components contains sorbitan palmitate as an active ingredient for imparting the aforementioned bacteriostatic properties. It is used such that the proportion of sorbitan palmitate ester per 1 part by mass of milk solids in a milk-containing beverage is 0.0015 parts by mass or more. Emulsifying stabilizer for beverages containing milk ingredients.

13. Furthermore, the emulsifying stabilizer for milk-containing beverages according to claim 12 further contains sucrose fatty acid ester.

14. The emulsifying stabilizer for milk-containing beverages according to claim 13, wherein the ratio of sucrose fatty acid ester to 100 parts by mass of sorbitan palmitate ester is 1 to 300 parts by mass.

15. A method for imparting bacteriostatic properties against anaerobic heat-resistant spore-forming bacteria to a milk-containing beverage, characterized in that sorbitan palmitate ester is added to the milk-containing beverage as a bacteriostatic component to impart the bacteriostatic properties, such that the proportion of sorbitan palmitate ester per 1 part by mass of milk solids in the milk-containing beverage is 0.0015 parts by mass or more.

16. The method according to claim 15, wherein the milk-containing beverage contains milk solids in a proportion of 0.5 to 11.5% by mass.

17. The method according to claim 15 or 16, characterized in that a milk-containing beverage is further blended with sucrose fatty acid ester.

18. The method according to claim 17, wherein the ratio of sucrose fatty acid ester to 100 parts by mass of sorbitan palmitate ester is 1 to 300 parts by mass.

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