JP7628008B2 - Dairy beverages - Google Patents

Description

The present invention relates to a beverage containing dairy ingredients.

Conventionally, a wide variety of dairy-containing beverages, such as milk coffee and milk tea, have been commercialized and distributed on the market. These dairy-containing beverages have problems such as quality deterioration due to the germination and proliferation of heat-resistant flat sour bacteria spores, so bacteriostatic emulsifiers, such as polyglycerol fatty acid esters and sucrose fatty acid esters, which have bacteriostatic effects, are added to them.

In addition, dairy-containing beverages have the problem that the milk components, such as milk fat and milk protein, are prone to separation and aggregation during distribution in the market. Therefore, a method has been proposed for producing dairy-containing beverages that contain a bacteriostatic emulsifier and also a food-grade emulsifier to suppress separation and aggregation of the milk components.

Examples of such technologies include a stabilizer for milk beverages in sealed containers, characterized by containing a polyglycerol monopalmitate ester having a degree of polymerization of 3, a polyglycerol fatty acid ester having a degree of polymerization of 5 to 10, and an organic acid monoglyceride (Patent Document 1); a polyglycerol fatty acid ester (a) which is an ester of polyglycerol having an average degree of polymerization of 2 to 3 and a fatty acid, the ester having a monoester content of 50% by mass or more, a thickening stabilizer (b), and water (c), in which the content of (a) is 10 to 40% by mass in 100% by mass of the improver, and the content of (b) is 100% by mass of the improver. Disclosed are a food product that is characterized by the addition of 0.01 to 30% by weight of a food preservability improver per 100% by weight (Patent Document 2), and an emulsifier composition for milk coffee that contains 50 to 250 parts by weight of sucrose fatty acid ester (B) whose constituent fatty acids are 60% by weight or more of stearic acid and whose monoester content is 20 to 35% by weight, per 100 parts by weight of sucrose fatty acid ester (A) whose constituent fatty acids are 70% by weight or more of palmitic acid and less than 30% by weight of stearic acid and whose monoester content is 70% by weight or more (Patent Document 3).

However, even with the above methods, separation and aggregation of the milk ingredients may occur when the dairy-containing beverage is placed in an environment with drastic temperature changes. For this reason, there has been a demand for a dairy-containing beverage that contains a bacteriostatic emulsifier and in which separation and aggregation of the milk ingredients is suppressed in an environment with drastic temperature changes.

JP 2007-306865 A JP 2006-280386 A Japanese Patent Application Publication No. 07-289164

The present invention aims to provide a beverage containing dairy ingredients in which separation and aggregation of dairy ingredients is suppressed in an environment with rapid temperature changes.

As a result of intensive research into the above-mentioned problems, the inventors discovered that the above-mentioned problems could be solved by using a combination of specific emulsifiers, and based on this knowledge, they developed the present invention.

That is, the present invention provides the following components (A) to (D):
(A) a bacteriostatic emulsifier,
(B) a polyglycerol fatty acid ester in which the main constituent fatty acid is stearic acid and the average polymerization degree of the polyglycerol is 3.5 to 5.0;
(C) glycerin organic acid fatty acid ester,
(D) a dairy beverage containing a glycerin mono fatty acid ester.

The dairy beverage of the present invention suppresses the occurrence of white floating matter in environments with drastic temperature changes.

[Component (A)]
The dairy component-containing beverage of the present invention contains a bacteriostatic emulsifier as component (A). The bacteriostatic emulsifier is a food emulsifier that is effective against heat-resistant flat sour bacteria, which is the cause of deterioration in the quality of beverages. Any food emulsifier that has this effect can be used without particular limitation, and examples thereof include diglycerol monomyristate, diglycerol monopalmitate, triglycerol monopalmitate, and sucrose palmitate. Among these, triglycerol monopalmitate and sucrose palmitate are preferred from the viewpoint of bacteriostatic strength. As the bacteriostatic emulsifier, a food emulsifier that is effective against heat-resistant flat sour bacteria and is contained in a commercially manufactured and sold product can be used, and a commercially manufactured and sold product can be used as a bacteriostatic emulsifier.

[Component (B)]
The dairy component-containing beverage of the present invention contains, as component (B), a polyglycerol fatty acid ester in which the main constituent fatty acid is stearic acid and the average degree of polymerization of the polyglycerol is 3.5 to 5.0 (preferably 3.6 to 4.8).

Regarding component (B), the "main constituent fatty acid" refers to a fatty acid that accounts for 50% by mass or more, preferably 60% by mass or more, of the total fatty acids that constitute the polyglycerol fatty acid ester (100% by mass). Therefore, in the component (B) of the present invention, stearic acid accounts for 50% by mass or more of the constituent fatty acids, and the remainder contains other fatty acids. The other fatty acids are not particularly limited as long as they are fatty acids (excluding stearic acid) originating from edible animal and vegetable fats and oils, and examples thereof include linear saturated fatty acids having 6 to 24 carbon atoms (e.g., caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, arachidic acid, behenic acid, lignoceric acid, etc.) or unsaturated fatty acids (e.g., palmitoleic acid, oleic acid, elaidic acid, linoleic acid, γ-linolenic acid, α-linolenic acid, arachidonic acid, ricinoleic acid, etc.), and preferably saturated or unsaturated fatty acids having 14 to 22 carbon atoms (e.g., myristic acid, palmitic acid, arachidic acid, behenic acid, oleic acid, linoleic acid, linolenic acid, erucic acid, etc.). These fatty acids may be used alone or in any combination of two or more types.

In addition, when the average degree of polymerization of the polyglycerin constituting component (B) is 3.5 to 5.0, the effect of suppressing separation and aggregation of milk components in a milk component-containing beverage is sufficiently exhibited.

Here, the average degree of polymerization is determined by analyzing the composition of the polyglycerin (i.e., the polyol composition) that constitutes the polyglycerin fatty acid ester. The method is shown in the following steps (1) to (3).

(1) Preparation of sample First, the test sample is decomposed into fatty acid and polyol by saponification decomposition treatment. Specifically, 2.0 g of the test sample is weighed into a saponification flask, 30 mL of 0.5 mol/L potassium hydroxide-ethanol standard solution is added to it, a condenser is attached to the flask, and the temperature is adjusted within the range of about 70 to 80 ° C. so that the refluxing ethanol does not reach the top of the condenser while shaking occasionally, and the mixture is gently heated for about 1 hour, and then the flask is transferred to a separatory funnel while washing it with 40 to 50 mL of hot water, 40 to 50 mL of water, and 100 mL of hexane in order. About 5 mL of 10% by volume hydrochloric acid is added to this separatory funnel, the separatory funnel is shaken, 50 mL of hexane is added to it, and the mixture is further shaken and then left to stand. The separated lower layer is taken in a beaker, the pH is adjusted with 0.5 mol/L potassium hydroxide solution to neutralize it, and the beaker is left to stand in a ventilated dryer at 60 ° C. to dehydrate it. Once completely dehydrated, add 5-10 mL of methanol in 2-3 portions, stir the contents, and allow to naturally filter. The filtrate is transferred to a flask and the methanol is removed using an evaporator.

(2) Measurement method Next, 50 mg of the obtained concentrate is weighed out, and 1 to 2 mg of pyridine (special grade reagent; Fujifilm Wako Pure Chemical Industries, Ltd.) is added to it, mixed and dissolved. 0.5 mL of 1,1,1,3,3,3,-hexamethyldisilazane (Tokyo Chemical Industry Co., Ltd.) is added to it and mixed, and further 0.1 mL of trifluoroacetic acid (Wako special grade; Fujifilm Wako Pure Chemical Industries, Ltd.) is added and mixed. After leaving it for about 1 minute, polyol composition analysis is performed using GC (gas chromatography) under the following conditions.
<GC analysis conditions>
Equipment: Gas chromatogram (model: GC-2010Plus; manufactured by Shimadzu Corporation)
Data processing software (model: GCsolution version 2.4; manufactured by Shimadzu Corporation)
Column (Model: Ultra ALLOY-TRG; P/N: UATRG-30M-0.1F; manufactured by Frontier Labs)
Column oven conditions: initial temperature 100° C. (1 min); heating rate 15° C./min; final temperature 365° C. (11 min)
Sample injection volume: 1.0 μL
Carrier gas: Nitrogen

(3) Quantitative After the analysis, the peak areas of the peaks corresponding to each component of the test sample recorded on the chromatogram by the data processing software are measured using an integrator, and the polyol composition is determined as an area percentage based on the measured peak areas. The weight average value of the polymerization degree of each component is calculated to obtain the average polymerization degree.

A preferred method for producing component (B) is as follows. For example, a polyglycerol having an average degree of polymerization of 3.5 to 5.0 and a fatty acid composition having a stearic acid content of 50% by mass or more (preferably 60% by mass or more) are charged in a molar ratio of 1:0.1 to 1:2.0, preferably 1:0.2 to 1:1.5, in a normal reaction vessel equipped with a stirrer, a heating jacket, a baffle plate, etc., sodium hydroxide is added as a catalyst, the mixture is stirred and mixed, and the mixture is heated at a predetermined temperature under a nitrogen gas atmosphere while removing water generated by the esterification reaction from the system. The reaction temperature is in the range of 180 to 260°C, preferably 200 to 250°C. The reaction pressure conditions are reduced pressure or normal pressure, and the reaction time is 0.5 to 15 hours, preferably 1 to 3 hours. The end point of the reaction is usually determined by measuring the acid value of the reaction mixture and setting the acid value at 2 or less as a guideline. After the reaction is complete, an acid is added to the resulting reaction liquid to neutralize the catalyst, and the liquid is cooled to 120°C or higher but lower than 180°C. If any unreacted polyol separates, it is removed. Next, the liquid is distilled under reduced pressure to remove the remaining polyol, yielding a polyglycerol fatty acid ester that can be used as component (B).

The polyglycerin used as a raw material in the above manufacturing method may be appropriately selected so that the average degree of polymerization of the polyglycerin constituting the resulting polyglycerin fatty acid ester is 3.5 to 5.0. Only one type of such polyglycerin may be used, or two or more types of polyglycerins may be used in combination.

If desired, the polyglycerol fatty acid ester used as component (B) may be melted and mixed with a glycerol monofatty acid ester (i.e., component (D) described below) by heating at 70 to 100°C, and then cooling and solidifying the resulting melt to form a one-component composition containing components (B) and (D). By forming the composition into a one-component in this manner, the handleability of the sticky polyglycerol fatty acid ester can be improved, making it easier to handle.

[Component (C)]
The dairy component-containing beverage of the present invention contains a glycerin organic acid fatty acid ester as component (C). The glycerin organic acid fatty acid ester is an ester of glycerin with an organic acid and a fatty acid, and is produced by a method known per se, such as by reacting a glycerin monofatty acid ester with an organic acid (or a reactive derivative of an organic acid, such as an acid anhydride of an organic acid), or by reacting glycerin with an organic acid and a fatty acid.

Examples of organic acids that make up glycerin organic acid fatty acid esters include succinic acid, diacetyl tartaric acid, lactic acid, citric acid, and acetic acid. Of these organic acids, succinic acid is preferably used.

The fatty acids constituting the glycerin organic acid fatty acid ester are not particularly limited as long as they are fatty acids originating from edible animal and vegetable fats and oils, and examples thereof include linear saturated fatty acids having 6 to 24 carbon atoms (e.g., caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, etc.) or unsaturated fatty acids (e.g., palmitoleic acid, oleic acid, elaidic acid, linoleic acid, γ-linolenic acid, α-linolenic acid, arachidonic acid, ricinoleic acid, etc.), and preferably saturated or unsaturated fatty acids having 14 to 22 carbon atoms (e.g., myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, oleic acid, linoleic acid, linolenic acid, erucic acid, etc.). These fatty acids may be used alone or in any combination of two or more types. The molar ratio of the organic acid and fatty acid (organic acid: fatty acid) that constitute the glycerin organic acid fatty acid ester is preferably 1:0.5 to 1:2.

In addition, products that are commercially manufactured and sold as glycerin organic acid fatty acid esters often contain unreacted glycerin mono-fatty acid esters that were used as raw materials, and some products are made by adding glycerin mono-fatty acid esters to reaction products. In the present invention, such glycerin mono-fatty acid esters are not included in component (C) but are included in component (D) described below.

Here, the content of glycerin mono fatty acid ester in the glycerin organic acid fatty acid ester product is determined by analysis using HPLC (high performance liquid chromatography). Specifically, a sample is analyzed under the analysis conditions shown below, and after the analysis, the peak areas corresponding to each component of the test sample recorded on a chromatogram by data processing software are measured using an integrator. Based on the measured peak areas, the content of each component can be calculated as an area percentage. The HPLC analysis conditions are shown below.
<HPLC analysis conditions>
Apparatus: Shimadzu high-performance liquid chromatograph data processing software (model: LCsolution ver. 1.25; manufactured by Shimadzu Corporation)
Pump (Model: LC-20AD; manufactured by Shimadzu Corporation)
Column oven (Model: CTO-20A; manufactured by Shimadzu Corporation)
Autosampler (Model: SIL-20A; Shimadzu Corporation)
Detector: RI detector (Model: RID-10A; manufactured by Shimadzu Corporation)
Column: GPC column (model: SHODEX KF-801; manufactured by Showa Denko)
Column: GPC column (model: SHODEX KF-802; manufactured by Showa Denko)
Two connected mobile phases: THF (tetrahydrofuran)
Flow rate: 1.0mL/min
Column temperature: 40°C
Sample concentration: 0.01 g/1 mL THF
Sample injection volume: 20 μL (in THF)

[Component (D)]
The dairy component-containing beverage of the present invention contains a glycerin mono-fatty acid ester as component (D). The glycerin mono-fatty acid ester is a compound in which a fatty acid is ester-bonded to any one of the hydroxyl groups of glycerin, and the number of ester bonds is one.

The fatty acids constituting the glycerin mono fatty acid ester are not particularly limited as long as they are fatty acids originating from edible animal and vegetable fats and oils, and examples thereof include linear saturated fatty acids having 6 to 24 carbon atoms (e.g., caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, etc.) or unsaturated fatty acids (e.g., palmitoleic acid, oleic acid, elaidic acid, linoleic acid, γ-linolenic acid, α-linolenic acid, arachidonic acid, ricinoleic acid, etc.), and preferably saturated or unsaturated fatty acids having 14 to 22 carbon atoms (e.g., myristic acid, palmitic acid, stearic acid, arachidic acid, behenic acid, oleic acid, linoleic acid, linolenic acid, erucic acid, etc.). These fatty acids may be used alone or in any combination of two or more types.

As the glycerin mono-fatty acid ester, those contained in commercially manufactured and sold glycerin organic acid fatty acid ester products can be used, as well as products commercially manufactured and sold as glycerin mono-fatty acid esters. Examples of such products include Emulgy P-100 (trade name: glycerin monopalmitic acid ester; manufactured by Riken Vitamin Co., Ltd.) and Emulgy MS (trade name: glycerin monostearate ester; manufactured by Riken Vitamin Co., Ltd.).

The dairy beverage of the present invention contains components (A) to (D). The content of components (A) to (D) relative to the total amount of the dairy beverage of the present invention is as follows: component (A) is 10 to 3000 ppm, preferably 50 to 1500 ppm, and more preferably 100 to 1000 ppm; component (B) is 5 to 1000 ppm, preferably 10 to 500 ppm, and more preferably 15 to 200 ppm; component (C) is 10 to 2000 ppm, preferably 20 to 1000 ppm, and more preferably 30 to 500 ppm; and component (D) is 15 to 2500 ppm, preferably 30 to 1500 ppm, and more preferably 40 to 750 ppm.

In the present invention, a beverage containing a dairy component refers to a beverage containing milk and/or a dairy product, and examples thereof include milk coffee, milk tea, milk cocoa, and matcha milk. Examples of the milk include raw milk, cow's milk, special cow's milk, raw goat's milk, pasteurized goat's milk, raw sheep's milk, ingredient-adjusted milk, low-fat milk, non-fat milk, and processed milk, as specified in the "Ministry of Health, Labour and Welfare Ordinance on the Ingredient Standards of Milk and Dairy Products" (Ministry of Health, Labour and Welfare Ordinance No. 52, December 27, 1951). Examples of the dairy products include cream, butter, butter oil, cheese, concentrated whey, ice cream, concentrated milk, skim concentrated milk, unsweetened condensed milk, unsweetened condensed skim milk, sweetened condensed milk, sweetened condensed skim milk, whole milk powder, skim milk powder, cream powder, whey powder, protein-concentrated whey powder, buttermilk powder, sweetened milk powder, modified milk powder, and fermented milk, as specified in the ministerial ordinance.

There is no particular limitation on the method for producing the dairy component-containing beverage of the present invention, but for example, the outline of the method for producing a coffee milk beverage is as follows. For example, coffee extract (including coffee extract in which polysaccharides have been subjected to low molecular weight processing using mannan decomposition enzymes, etc.) extracted from roasted coffee beans with purified water at 90 to 98°C is dissolved by adding milk and/or dairy products, sugar, components (A) to (D), sodium bicarbonate (sodium bicarbonate), sodium caseinate, etc., and homogenized using a high-pressure homogenizer. Examples of high-pressure homogenizers include the APV Gaulin Homogenizer (APV), Microfluidizer (Microfluidex), Ultimizer (Sugino Machine), Nanomizer (Yamato Can), and HV-OA-07-1.5S (Izumi Food Machinery). The homogenization conditions vary depending on the specifications of the device, but can be, for example, 5 to 50 MPa.

The homogenized milk beverage is preferably subsequently subjected to heat sterilization. As a method of heat sterilization, retort sterilization is preferred for canned beverages, and UHT (Ultra High Temperature) sterilization is preferred for PET (polyethylene terephthalate) bottled beverages. Retort sterilization can be carried out by filling the milk beverage into a can and sealing it, and heating it in a retort sterilizer at 121 to 124°C for 20 to 40 minutes. UHT sterilization methods include direct heating methods such as the steam injection method in which steam is directly blown into the milk beverage and the steam infusion method in which the milk beverage is heated by injecting it into steam, and indirect heating methods using a surface heat exchanger such as a plate or tube, and is preferably a method using a plate-type sterilizer. UHT sterilization using a plate-type sterilizer can be carried out at 130 to 150°C under heating conditions equivalent to a sterilization value (F0) of 10 to 50 at 121°C. The UHT sterilized milk beverage is preferably aseptically filled into PET bottles and tightly sealed.

The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these.

[Production of polyglycerol fatty acid ester (prototype 1)]
A 1L four-neck flask equipped with a stirrer, a thermometer, a gas inlet tube and a water separator was charged with 300 g of polyglycerin (trade name: R-PG3; manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.) and 300 g of stearic acid (trade name: Stearic Acid 65; stearic acid content 65% by mass; manufactured by Miyoshi Oil & Fat Co., Ltd.), 0.48 g of sodium hydroxide was added as a catalyst, and the esterification reaction was carried out for about 3 hours at 240 ° C. in a nitrogen gas stream until the acid value became 2 or less. 0.96 g of phosphoric acid (85% by mass) was added to the resulting reaction mixture to neutralize the catalyst, and the mixture was left at 150 ° C. for about 1 hour, and about 35 g of polyol containing unreacted triglycerin and tetraglycerin was removed. Next, the remaining polyol was distilled under reduced pressure at about 1 Pa using a centrifugal distiller to distill off the remaining polyol, and about 550 g of polyglycerin fatty acid ester (prototype 1) in which the main constituent fatty acid was stearic acid was obtained. The average degree of polymerization of the polyglycerol constituting the obtained polyglycerol fatty acid ester was 3.65.

[Production of polyglycerol fatty acid ester (prototype 2)]
A 1L four-neck flask equipped with a stirrer, a thermometer, a gas inlet tube and a water separator was charged with 150 g of polyglycerin (trade name: R-PG3; manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.), 150 g of polyglycerin (trade name: T-GR; manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.), and 300 g of stearic acid (trade name: Stearic Acid 65; stearic acid content 65% by mass; manufactured by Miyoshi Oil & Fat Co., Ltd.), 0.48 g of sodium hydroxide was added as a catalyst, and the mixture was subjected to an esterification reaction for about 3 hours at 240 ° C. in a nitrogen gas stream until the acid value was 2 or less. 0.96 g of phosphoric acid (85% by mass) was added to the resulting reaction mixture to neutralize the catalyst, and the mixture was left at 150 ° C. for about 1 hour, and about 35 g of polyol containing unreacted triglycerin and tetraglycerin that had been separated was removed. Next, the remaining polyol was removed by vacuum distillation at about 1 Pa using a centrifugal distiller, and about 550 g of a polyglycerol fatty acid ester (trial product 2) whose main constituent fatty acid was stearic acid was obtained. The average degree of polymerization of the polyglycerol constituting the obtained polyglycerol fatty acid ester was 4.69.

[Preparation of a composition containing a polyglycerol fatty acid ester and a glycerol mono fatty acid ester (Prototype 3)]
The same procedure as in Production Example 1 was carried out to obtain about 550 g of a polyglycerol fatty acid ester in which the main constituent fatty acid was stearic acid and the average degree of polymerization of polyglycerol was 3.65. 550 g of this polyglycerol fatty acid ester and 296 g of Emulgy P-100 (product name: glycerol monopalmitic acid ester; manufactured by Riken Vitamin Co., Ltd.) were placed in a 1000 mL glass beaker, heated to 90°C in a thermostatic bath, and melt-mixed by stirring with a glass rod. The resulting melt was dropped onto aluminum foil with a plastic dropper so as to form granules, and cooled and solidified at room temperature for 30 minutes to obtain about 846 g of a composition (trial product 3) containing a polyglycerol fatty acid ester in which the average degree of polymerization of polyglycerol was 3.65 and a glycerol mono fatty acid ester.

[Preparation of a composition containing a polyglycerol fatty acid ester and a glycerol mono fatty acid ester (Prototype 4)]
The same procedure as in Production Example 3 was repeated, except that 296 g of Emulgy MS (trade name: glycerin monostearate; manufactured by Riken Vitamin Co., Ltd.) was used instead of 296 g of Emulgy P-100 (trade name: glycerin monopalmitate; manufactured by Riken Vitamin Co., Ltd.), to obtain approximately 846 g of a composition (Prototype 4) containing a polyglycerin fatty acid ester having an average degree of polymerization of polyglycerin of 3.65 and a glycerin monofatty acid ester.

[Test Example]
[Evaluation test for canned milk coffee]
(1) Test Emulsifiers 1) Triglycerol monopalmitate (product name: Poem TRP-97RF; manufactured by Riken Vitamin Co., Ltd.)
2) Sucrose palmitate (product name: Ryoto Sugar Ester P-1670; powder form; manufactured by Mitsubishi Chemical Foods Corporation)
3) Prototypes 1 to 4
4) Polyglycerol fatty acid ester 1 (product name: TR-40S; main constituent fatty acid: stearic acid; average degree of polymerization of polyglycerol: 3.04; manufactured by Riken Vitamin Co., Ltd.)
5) Polyglycerol fatty acid ester 2 (trade name: Sunsoft A-181E; main constituent fatty acid: stearic acid; average degree of polymerization of polyglycerol: 6.55; manufactured by Taiyo Kagaku Co., Ltd.)
6) Glycerin succinic acid fatty acid ester (product name: Poem B-25KV; content of glycerin mono fatty acid ester: 48.2% by mass; manufactured by Riken Vitamin Co., Ltd.)
7) Glycerin monopalmitate (product name: Emulgy P-100; manufactured by Riken Vitamin Co., Ltd.)

(2) Amounts of Test Emulsifiers and Components (A) to (D) Added The amounts of test emulsifiers added and the amounts of components (A) to (D) added due to the addition of these emulsifiers for canned milk coffees 1 to 10 prepared using the above test emulsifiers are shown in Tables 1 and 2. Of these, canned milk coffees 1 to 7 in Table 1 are examples according to the present invention, and canned milk coffees 8 to 10 in Table 2 are comparative examples.

(3) Preparation of canned milk coffee 500 g of roasted coffee beans were extracted with 5000 g of purified water at 95 ° C. to obtain a coffee extract (Brix 3 mass %). 3200 g of the coffee extract, 960 g of milk (milk fat 3.5 mass % or more, non-fat milk solids 8.3 mass % or more), and 384 g of granulated sugar were blended, and purified water was added to make a total amount of 6400 g, and further, 9.6 g of an emulsifier shown in Table 1 or 2, sodium bicarbonate (sodium bicarbonate), and 3.2 g of sodium caseinate were added. After reaching a temperature of 70 ° C. using a water bath, stirring was performed for 10 minutes to confirm that there was no residual dissolution. Using a high-pressure homogenizer (model: HV-OA-07-1.5S; manufactured by Izumi Food Machinery Co., Ltd.), homogenization was performed under the conditions of a liquid temperature of about 60 to 70 ° C., a first stage pressure of about 15 MPa, and a second stage pressure of 5 MPa. The homogenized milk coffee was filled into beverage cans (190 g each), sealed, and retort sterilized at about 123° C. for 20 minutes to obtain canned milk coffees 1 to 10.

(4) Stability test After storing the canned milk coffee for 2 weeks at 37°C, it was alternately stored twice in a low-temperature incubator (model: IN804; manufactured by Yamato Scientific Co., Ltd.) at 37°C for 12 hours and at -4°C for 24 hours. After that, the can was opened at -4°C, and the white floating matter that rose to the surface of the beverage due to solidification of liberated fat was observed and coded according to the following criteria. The results are shown in Table 3.

<Symbolization Standards>
-: No white floating matter ±: Very small amount of white floating matter +: Small amount of white floating matter ++: Noticeable white floating matter partially scattered on the liquid surface +++: Noticeable white floating matter scattered over the entire liquid surface

As is clear from the results in Table 3, canned milk coffees 1 to 7, which are examples of the present invention, achieved results of "+" or higher, and therefore had excellent effects in suppressing white floating matter. In contrast, canned milk coffees 8 to 10, which are comparative examples, achieved results of "++" or lower, and were inferior to those of the present invention.

Claims (1)

The following components (A) to (D):
(A) a bacteriostatic emulsifier which is triglycerol monopalmitate or sucrose palmitate ;
(B) a polyglycerol fatty acid ester in which the main constituent fatty acid is stearic acid and the average polymerization degree of the polyglycerol is 3.5 to 4.8 ;
(C) glycerin succinic acid fatty acid ester,
(D) A dairy beverage containing a glycerin mono-fatty acid ester.