Composition for foamed milk and method for producing same

Abstract

To provide a composition for readily preparing foamed milk and a method for producing the composition; or preferably, provide a composition for readily preparing foamed milk that shows good foaming, kept for a long time, and a method for producing the composition.SOLUTION: A liquid composition for foamed milk at least contains water of 80 mass% or more, protein of 0.5 mass% or more, and lipids. The total content of divalent ions is 1 mmol or less relative to 1 g of the protein.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a composition for preparing frothed milk (foamed milk) and to a method for preparing said composition. [Background technology]

[0002] Foamed milk is milk that has been foamed while incorporating air, and is often used in cafe lattes and cappuccinos. By foaming the milk finely, you can create foamed milk that is smooth and delicious. Foamed milk can be prepared by frothing milk using, for example, a commercially available espresso machine or milk frother, but it requires careful adjustment of the milk temperature and stirring time, making it difficult to prepare easily at home.

[0003] In view of the above circumstances, various milk frothers have been developed. For example, Patent Document 1 describes a milk frother comprising a cylinder, a pump connected to the first end for pumping air into the cylinder, and a spout provided at the second end for discharging the contents in the cylinder, the spout having a second spout end that extends substantially inside the cylinder and is open for putting the contents in the cylinder, a first spout end that is outside the cylinder and has a hole that is sized and positioned for dispersing the contents in the cylinder that exit through the spout, and a discharge valve that controls the release of the contents in the cylinder through the spout. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2019-126707 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, various devices for preparing foamed milk have been developed, but compositions for easily preparing foamed milk have not previously been considered. In view of the above circumstances, an object of the present invention is to provide a composition for easily preparing foamed milk and a method for producing the composition, preferably a composition for easily preparing foamed milk that foams well and has good foam retention, and a method for producing the composition. [Means for solving the problem]

[0006] The present invention, which solves the above problem, is a liquid composition for foamed milk, which contains at least 80% by mass or more of water, 0.5% by mass or more of protein, and lipids, and which has a total content of divalent ions per 1 g of protein of 1 mmol or less. According to the present invention, a liquid composition for foamed milk can be provided that can easily prepare foamed milk that foams well and has a good foam-retention property.

[0007] In a preferred embodiment of the present invention, the total amount of monovalent ions per gram of protein is 1.5 mmol or more. According to the present invention, a liquid composition for foamed milk can be provided that can easily prepare foamed milk that foams well and has a good foam-retention property.

[0008] In a preferred embodiment of the present invention, the proportion of the protein relative to the total solid content of the liquid composition for foamed milk is 5% by mass or more. According to the present invention, a liquid composition for foamed milk can be provided that can easily prepare foamed milk that foams well and has a good foam-retention property.

[0009] The present invention, which solves the above problem, provides a composition for foamed milk, which contains at least 0.5% by mass of protein and lipids, and is used to prepare the liquid composition for foamed milk. According to the present invention, it is possible to provide a composition for preparing a liquid composition for foamed milk, which can prepare foamed milk that foams well and has a good foam retention.

[0010] In a preferred embodiment of the present invention, the composition for foamed milk contains the protein in an amount of 5 mass % or more relative to the total solid content. According to the present invention, a liquid composition for foamed milk can be prepared that can produce foamed milk that is foamy and has good foam retention.

[0011] The present invention, which solves the above-mentioned problems, is a method for preparing the above-mentioned liquid composition for foamed milk, which comprises an ion-exchanged skim milk preparation step in which ion-exchanged skim milk is prepared by exchanging the skim milk so that the pH of the skim milk is 7.0 or higher, and a mixing step in which the prepared ion-exchanged skim milk, water, and lipids are mixed at least together. By subjecting skim milk to ion exchange, the amounts of monovalent ions and divalent ions contained in the skim milk can be adjusted, thereby preparing a liquid composition for foamed milk that can produce foamed milk with good foamability and foam retention.

[0012] In a preferred embodiment of the present invention, the total content of divalent ions per gram of protein in the ion-exchanged skim milk is 1 mmol or less. According to the present invention, a liquid composition for foamed milk can be prepared that can prepare foamed milk that foams well and has a good foam-retention property.

[0013] The present invention, which solves the above problem, is a method for producing foamed milk, which includes the steps of preparing a liquid composition for foamed milk by adding water to the above-mentioned composition for foamed milk so that the water content is 80% by mass or more and stirring the mixture, and frothing the prepared liquid composition for foamed milk. According to the present invention, foamed milk that foams well and maintains its foam quality can be easily produced. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a composition for easily preparing foamed milk that foams well and retains its foam, and a method for producing the composition. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a diagram showing the evaluation of foaming of foamed milk in Test Example 1. In Fig. 1, the solid lines indicate the boundary between the foam and liquid portions and the point where the foam reaches, and the arrows between the solid lines indicate the points where the foam height was measured. [Figure 2] This is a diagram showing the evaluation of foaming of foamed milk in Test Example 2. In Fig. 2, the solid lines indicate the boundary between the foam and liquid parts and the point where the foam reaches, and the arrows between the solid lines indicate the points where the foam height was measured. DETAILED DESCRIPTION OF THE INVENTION

[0016] In the present invention, "foamed milk" refers to a milk composition that has been foamed. Here, in the present invention, the term "milk composition" refers to a composition containing 0.5% by mass or more of milk solids, and includes the liquid composition for foamed milk according to the present invention. In the present invention, the term "monovalent ions" refers to sodium ions and potassium ions, and the term "divalent ions" refers to calcium ions and magnesium ions. In the present invention, the mass content (mass%) of each of sodium ions, potassium ions, calcium ions, and magnesium ions is determined by inductively coupled plasma (ICP) atomic emission spectroscopy, and the content (mmol) can be determined from the mass content (mass%) and the molar mass of each ion.

[0017] <1> Liquid composition for foamed milk and method for producing same The liquid composition for foamed milk of the present invention contains at least 80% by mass or more of water, 0.5% by mass or more of protein, and lipids, and the total content of calcium ions and magnesium ions per 1 g of protein is 1 mmol or less. According to the present invention, foamed milk that foams well and maintains its foam quality can be easily prepared.

[0018] In the present invention, the protein content is 0.5% by mass or more, preferably 1% by mass or more, and more preferably 3% by mass or more. In addition, in the present invention, the protein content is not particularly limited as long as it does not affect the foaming or foam retention when the liquid composition for foamed milk of the present invention is foamed, but it can be, for example, 10% by mass or less, preferably 6% by mass or less, and more preferably 5% by mass or less. According to the present invention, foamed milk that foams well and maintains its foam quality can be easily prepared. In the present invention, the protein content is the content measured by a combustion method.

[0019] In a preferred embodiment of the present invention, the proportion of protein relative to the total solid content of the liquid composition for foamed milk is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, and even more preferably 25% by mass or more. The proportion of protein relative to the total solid content of the liquid composition for foamed milk can be, for example, 35% by mass or less, and can be 30% by mass or less. By setting the ratio of protein to the total solids of the liquid composition for foamed milk within the above numerical range, a liquid composition for foamed milk can be provided that can prepare foamed milk with good foaming.

[0020] In the present invention, the lipid content in the liquid composition for foamed milk is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more. In the present invention, the mass content of lipids in the liquid composition for foamed milk is preferably 5% by mass or less, and more preferably 4% by mass or less. By including lipids in the liquid composition for foamed milk, the foaming and foam retention properties can be improved when preparing foamed milk. By setting the lipid mass content within the above numerical range, a liquid composition for foamed milk can be provided that can prepare foamed milk that foams well and has good foam retention. In the present invention, the lipid content is the content measured by the Roese-Gottlieb method.

[0021] In the present invention, the ratio of lipids to the total solid content of the liquid composition for foamed milk can be 5% by mass or more, preferably 10% by mass or more, and more preferably 15% by mass or more. Furthermore, the ratio of lipids to the total solid content of the liquid composition for foamed milk may be 45% by mass or less, 35% by mass or less, or 30% by mass or less. By setting the ratio of lipids to the total solids of the liquid composition for foamed milk within the above numerical range, a liquid composition for foamed milk can be provided that can prepare foamed milk that foams well and has good foam retention.

[0022] In the present invention, the total content (mmol) of divalent ions per 1 g of protein in the liquid composition for foamed milk is 1 mmol or less, preferably 0.75 mmol or less, more preferably 0.5 mmol or less, even more preferably 0.4 mmol or less, and even more preferably 0.35 mmol. In the present invention, the total content (mmol) of divalent ions per 1 g of protein in the liquid composition for foamed milk can be 0.1 mmol or more, and preferably 0.2 mmol or more. By setting the total content (mmol) of divalent ions per 1 g of protein in the liquid composition for foamed milk within the above numerical range, a liquid composition for foamed milk can be provided that can prepare foamed milk that foams well and has good foam retention.

[0023] In a preferred embodiment of the present invention, the total content (% by mass) of divalent ions in the liquid composition for foamed milk is preferably 0.03% by mass or less, and more preferably 0.02% by mass or less. The total content of divalent ions in the liquid composition for foamed milk can be 0.005% by mass or more.

[0024] In a preferred embodiment of the present invention, the total content (mmol) of monovalent ions per gram of protein in the liquid composition for foamed milk is 1.5 mmol or more, more preferably 1.8 mmol or more, even more preferably 2 mmol or more, and even more preferably 2.5 mmol or more. In addition, the total content (mmol) of monovalent ions per 1g of protein in the liquid composition for foamed milk can be 5mmol or less, preferably 3mmol or less, and more preferably 2.9mmol or less. By setting the total content (mmol) of monovalent ions per 1 g of protein in a liquid composition for foamed milk within the above numerical range, a liquid composition for foamed milk can be provided that can prepare foamed milk that foams well and has good foam retention.

[0025] In a preferred embodiment of the present invention, the total content (mass %) of monovalent ions in the liquid composition for foamed milk is preferably 0.3 mass % or less, and more preferably 0.25 mass % or less. The total content (mass %) of monovalent ions in the liquid composition for foamed milk is preferably 0.2 mass % or more, and more preferably 0.21 mass % or more.

[0026] In a preferred embodiment of the present invention, when the total content (mmol) of divalent ions per 1g of protein in the liquid composition for foamed milk is taken as 1, the total content (mmol) of monovalent ions per 1g of protein is 7 or more, in a more preferred embodiment it is 7.5 or more, and in an even more preferred embodiment it is 8 or more. In a preferred embodiment of the present invention, when the total content (mmol) of divalent ions per 1g of protein in the liquid composition for foamed milk is taken as 1, the total content (mmol) of monovalent ions per 1g of protein is 11 or less, and in a more preferred embodiment, it is 10.99 or less. According to the present invention, a liquid composition for foamed milk can be provided that can prepare foamed milk that foams well and has a good foam retention.

[0027] In a preferred embodiment of the present invention, when the ratio (mass%) of the total content of divalent ions per 1 g of protein in the liquid composition for foamed milk is taken as 1, the ratio (mass%) of the total content of monovalent ions per 1 g of protein in the liquid composition for foamed milk is preferably 4 or more, more preferably 5 or more, and even more preferably 5.5 or more. Furthermore, when the ratio (mass %) of the total content of divalent ions per 1 g of protein in the liquid composition for foamed milk is taken as 1, the ratio of the total content of monovalent ions per 1 g of protein in the liquid composition for foamed milk is preferably 8 or less, and more preferably 7.99 or less. According to the present invention, a liquid composition for foamed milk can be provided that can prepare foamed milk that has good foam retention and foams well.

[0028] The content (mmol), content (mmol) ratio, and content ratio (mass%) of the above monovalent ions and divalent ions can be adjusted by adjusting the blending balance of raw materials containing minerals or by ion-exchanging raw materials such as skim milk, but adjustment by ion-exchange is preferred. When adjusting by ion exchange, for example, when skim milk is ion-exchanged with a cation exchange resin, divalent ions (calcium ions and magnesium ions) are removed and replaced with monovalent ions (sodium ions and potassium ions). That is, the ion exchange reduces the amount of divalent ions in the skim milk and increases the amount of monovalent ions. This allows the amounts of monovalent and divalent ions to be adjusted. The extent to which skim milk is ion-exchanged (e.g., the time required for ion exchange) can be determined using the pH of the skim milk after ion exchange as an indicator. Specifically, when skim milk is ion-exchanged using a cation exchange resin, the protons in the skim milk decrease, and the pH of the resulting ion-exchanged skim milk increases. Therefore, the pH of the ion-exchanged skim milk can be used as an indicator to determine the degree of ion exchange of the skim milk. Note that the ion exchange efficiency can be appropriately adjusted depending on the type of ion-exchange group bound to the matrix of the ion exchange carrier, the surface area (porosity) of the matrix, and the mechanical and chemical strength.

[0029] The liquid composition for foamed milk of the present invention may contain other known ingredients, such as, but not limited to, carbohydrates, preservatives, antiseptics, flavoring agents, pH adjusters, etc. When carbohydrates are contained as other known ingredients, lactose, powdered sugar, dextrin, etc. can be used as the carbohydrate source.

[0030] The liquid composition for foamed milk of the present invention can be produced by a method comprising: an ion-exchanged skim milk preparation step in which ion-exchanged skim milk is prepared by ion-exchanging skim milk so that the pH of the skim milk is 7.0 or higher; and a mixing step in which the prepared ion-exchanged skim milk is mixed with water and lipids. As described above, the degree to which skim milk is ion-exchanged can be determined using the pH of the skim milk as an indicator. Therefore, by adjusting the pH of the skim milk to the above-mentioned range in the ion-exchange skim milk preparation step, the amount of divalent ions (preferably divalent ions and monovalent ions) in the ion-exchange skim milk can be adjusted, thereby adjusting the amount of monovalent ions and divalent ions in the liquid composition for foamed milk. This makes it possible to prepare a liquid composition for foamed milk that can produce foamed milk with good foamability and foam retention.

[0031] The skim milk may be generally available skim milk, or may be skim milk prepared by removing milk fat from generally available cow's milk using a known method. Also, generally available skim milk powder dissolved in water at a concentration such that the protein content falls within the above-mentioned range may be used.

[0032] Ion exchange of skim milk can be carried out using a cation exchange resin, the details of which are described in the Examples. In the ion-exchanged skim milk preparation step, skim milk is subjected to ion exchange to prepare ion-exchanged skim milk so that the pH of the skim milk is 7.0 or higher, preferably 7.3 or higher. The upper limit of the pH is not particularly limited, but may be 9.0 or lower, 8.7 or lower, or 8.5 or lower. As described above, the degree of ion exchange in skim milk can be adjusted using the pH of the ion-exchanged skim milk as an indicator. By adjusting the pH of the ion-exchanged skim milk to fall within the above-mentioned range, it is possible to prepare ion-exchanged skim milk such that the divalent ion content (mmol, mass %) of the liquid composition for foamed milk falls within the above-mentioned range. It is also possible to prepare ion-exchanged skim milk such that the divalent ion and monovalent ion contents (mmol, mass %) of the liquid composition for foamed milk fall within the above-mentioned range. This allows the preparation of a liquid composition for foamed milk that can produce foamed milk with good foaming and foam retention.

[0033] In the mixing step, at least the ion-exchanged skim milk prepared in the ion-exchanged skim milk preparation step, water, and lipids are mixed.

[0034] As the lipid, any known lipid source can be used without any particular limitation, for example, commonly available butter, margarine, shortening, etc.

[0035] In the mixing step, ion-exchanged skim milk, water, and lipids are mixed so that the water content is 80% by mass or more and the protein content is 0.5% by mass or more. This allows the above-mentioned liquid composition for foamed milk to be prepared.

[0036] In the mixing step, other known ingredients may be mixed in addition to ion-exchanged skim milk, water, and lipids, including, but not limited to, carbohydrates, preservatives, antiseptics, flavorings, and pH adjusters. When carbohydrates are contained as other known ingredients, lactose, powdered sugar, dextrin, etc. can be used as the carbohydrate source.

[0037] As described above, in the present invention, the degree of ion exchange of skim milk can be determined using the pH of the ion-exchanged skim milk as an indicator. As described above, by performing ion exchange so that the pH of the ion-exchanged skim milk is 7.0 or higher, preferably 7.3 or higher, it is possible to prepare a liquid composition for foamed milk such that when the skim milk is mixed with lipids and other ingredients to prepare the liquid composition for foamed milk, the content (mmol, mass %) of divalent ions (preferably divalent ions and monovalent ions) falls within the above numerical range. In other words, when the liquid composition for foamed milk is prepared, the divalent ions and monovalent ions are present in the raw material, ion-exchanged skim milk, in amounts such that the content of each component in the liquid composition for foamed milk falls within the above-mentioned numerical ranges. The amount of each ion in the composition for foamed milk can be measured by the method described above.

[0038] In the present invention, the above-mentioned ion-exchanged skim milk may be used alone as the protein source, or a protein source other than the above-mentioned ion-exchanged skim milk (for example, skim milk, etc.) may be used in combination as the protein source. In this case, the proportion of ion-exchanged skim milk in the protein source is preferably 85% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. By adjusting the proportion of ion-exchanged skim milk in the protein source to fall within the above range, the content of divalent ions in the liquid composition for foamed milk can be adjusted to fall within the above range, and preferably the content of monovalent ions in the liquid composition for foamed milk can be adjusted to fall within the above range. This allows the preparation of a liquid composition for foamed milk that can produce foamed milk with good foaming and foam retention.

[0039] In addition to the above steps, the present invention may include other steps known in the art, such as, but not limited to, a step of filling the liquid composition for foamed milk and a step of heat sterilization.

[0040] <2> Composition for foamed milk The present invention also relates to a composition for foaming milk. The composition for foamed milk of the present invention is a composition for preparing the above-mentioned liquid composition for foamed milk, and contains at least 0.5% by mass or more of protein and lipids. According to the present invention, the above-mentioned liquid composition for foamed milk can be prepared. Furthermore, the liquid composition for foamed milk prepared using the composition for foamed milk of the present invention can easily prepare foamed milk that is good in foaming and retains its foam.

[0041] The protein content in the composition for foamed milk is preferably 0.5% by mass or more, 1% by mass or more, 2.5% by mass or more, or 3% by mass or more. In the present invention, the protein content in the composition for foamed milk is not particularly limited as long as it does not affect the foaming or foam retention of the foamed milk, but can be, for example, 30% by mass or less, preferably 20% by mass or less, and more preferably 10% by mass or less. By frothing a liquid composition for frothed milk prepared using the composition for frothed milk of the present invention, frothed milk that is foamy and has a good foam retention can be prepared.

[0042] In a preferred embodiment of the present invention, the proportion of protein in the total solid content of the composition for foamed milk is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, and even more preferably 25% by mass or more. The proportion of protein relative to the total solid content of the composition for foamed milk can be, for example, 35% by mass or less, and can be 30% by mass or less. By setting the ratio of protein to the total solids of the composition for foamed milk within the above numerical range, a liquid composition for foamed milk can be prepared that can produce foamed milk with good foaming.

[0043] The lipid content in the composition for foamed milk is preferably 3% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more. The lipid content in the composition for foamed milk may be 35% by mass or less, and may be 30% by mass or less. By setting the lipid content in the composition for foamed milk within the above range, the lipid content in the liquid composition for foamed milk becomes appropriate. Therefore, according to the present invention, it is possible to prepare a liquid composition for foamed milk that can prepare foamed milk with good foaming and foam retention.

[0044] The composition for foamed milk of the present invention may contain other known ingredients in addition to proteins and lipids, such as, but not limited to, carbohydrates, preservatives, antiseptics, flavorings, pH adjusters, etc. When carbohydrates are contained as other known ingredients, lactose, powdered sugar, dextrin, etc. can be used as the carbohydrate source.

[0045] The content (mmol) of each monovalent ion (sodium and potassium) and each divalent ion (calcium and magnesium) in the composition for foamed milk, the total content (mmol), the content ratio (mmol) of sodium ion to potassium ion, and the content ratio (mmol) of calcium ion to magnesium ion are as follows: <1> The matters stated for each numerical value in the above can be applied.

[0046] The composition for foamed milk of the present invention can be, for example, <1> The composition for foamed milk can be prepared by converting the liquid composition for foamed milk described in 1. above into a concentrate or powder. A known method can be appropriately used as a method for preparing a composition for foamed milk by converting the liquid composition for foamed milk into a concentrate or powder. For example, a concentrated composition for foamed milk can be obtained by evaporating the water content of the liquid composition for foamed milk by heating or concentrating it using an osmotic membrane using known equipment. Alternatively, a powdered composition for foamed milk can be prepared by spray-drying or freeze-drying the liquid composition for foamed milk using known equipment. If necessary, the composition may be granulated using known equipment after spray-drying or freeze-drying.

[0047] The composition for foamed milk of the present invention is <1> 1. A composition for preparing the liquid composition for foamed milk described in 1. Specifically, water is added to the composition for foamed milk of the present invention so that the water content is 80% by mass or more, and the mixture is stirred, whereby the above-mentioned <1> The liquid composition for foamed milk described in the above can be prepared. As described above, the composition for foamed milk of the present invention is mixed with water to prepare a liquid composition for foamed milk, so it is preferably in the form of a concentrated liquid or powder, and particularly preferably in the form of a powder.

[0048] <3> How foamed milk is made The present invention also relates to a method for producing foamed milk. The method for producing foamed milk of the present invention comprises the steps of: <2> The method includes the steps of preparing a liquid composition for foamed milk by adding water to the composition for foamed milk described above so that the water content is 80% by mass or more and stirring the mixture, and frothing the prepared liquid composition for foamed milk. According to the present invention, foamed milk that foams well and maintains its foam quality can be easily prepared.

[0049] The production method of the present invention can be carried out in an ordinary home or store using commercially available equipment. For example, first, water is added to a powdered composition for foamed milk so that the water content is 80% by mass or more, and the mixture is stirred to prepare a liquid composition for foamed milk. At this time, the composition for foamed milk and water can be measured using a commonly available scale or measuring cup. Next, the obtained liquid composition for foamed milk is frothed using a commonly available milk frother or espresso machine. The milk frother or espresso machine is not particularly limited as long as it can froth the liquid composition for foamed milk to prepare foamed milk. [Example]

[0050] The present invention will be described in more detail below based on examples, but the technical scope of the present invention is not limited to the following examples.

[0051] <Test Example 1> Examination of liquid composition for foamed milk In this test example, the foaming and foam retention of a liquid composition for foamed milk using ion-exchanged skim milk, a liquid composition for foamed milk using non-ion-exchanged skim milk, and a liquid composition for foamed milk without skim milk were evaluated.

[0052] Test Example 1 was carried out in the following manner. (1) Skim milk obtained by dissolving skim milk powder in water at a concentration of 10% by mass was heated and passed through a sodium-type cation exchange resin column to prepare ion-exchanged skim milk. (2) Various protein sources were used to prepare liquid compositions for foamed milk in Example 1 and Comparative Examples 1 to 3. As the protein source, Example 1 used the ion-exchanged skim milk prepared in (1) above, while Comparative Examples 1 to 3 used non-ion-exchanged skim milk, a combination of sodium caseinate and whey powder (mixed so that 80% of the total protein was casein and 20% was whey protein), and sodium caseinate, respectively. All liquid compositions for foamed milk used commercially available butter as the lipid source and commercially available lactose as the carbohydrate source. The liquid solution obtained by mixing and dissolving the ingredients was heated to 80°C, homogenized using a homogenizer (manufactured by Sanmaru Machinery Co., Ltd.), and then cooled to prepare each liquid composition for foamed milk. The protein, fat, carbohydrate, ash and moisture contents of each liquid composition for foamed milk are shown in Table 1 below. (3) The temperature of each of the prepared liquid compositions for foamed milk was adjusted to 80°C. The liquid compositions for foamed milk adjusted to 80°C were frothed for 30 seconds to prepare foamed milk. The pH of each of the prepared liquid compositions for foamed milk was measured at a product temperature of 25°C using a pH meter (manufactured by Horiba, Ltd.). (4) The foaming and foam retention of each foamed milk product was evaluated.

[0053] The amount of protein in each of the prepared liquid compositions for foamed milk was measured by a combustion method.

[0054] The lipid content in each of the prepared liquid compositions for foamed milk was measured by the Roese-Gottlieb method.

[0055] The amount of carbohydrates in each liquid composition for foamed milk was calculated by subtracting the fat, protein, moisture, and ash contents from 100%, where the total ash content was measured by the direct ashing method.

[0056] The water content in each of the prepared liquid compositions for foamed milk was measured by the atmospheric pressure drying method.

[0057] The amount of each mineral (i.e., calcium, magnesium, sodium, and potassium) in each of the prepared liquid compositions for foamed milk was measured by inductively coupled plasma (ICP) emission spectroscopy.

[0058] [Table 1]

[0059] To evaluate foaming, the height of the foam portion (i.e., the height of the foam measured from the boundary between the liquid and the foam) of the foamed milk prepared in (3) above was measured immediately after preparation (see Figure 1). In the evaluation of foam retention, the time for which the foam portion of the foamed milk prepared in (3) above retained the foam height measured in the foaming evaluation above was measured, and if the retention time was 1 hour or more, the foam retention was judged to be good. The results are shown in Table 2 and FIG.

[0060] [Table 2]

[0061] As shown in Table 2 and FIG. 1, Example 1, which was prepared using ion-exchanged skim milk, had better foaming properties when whipped (i.e., when foamed milk was prepared) than Comparative Example 1, which used skim milk, Comparative Example 2, which used a combination of sodium caseinate and whey powder, and Comparative Example 3, which used sodium caseinate. The foam retention was also good, with the foam state being maintained for more than 1.5 hours.

[0062] Furthermore, when a panel tasted the foamed milk prepared in Example 1 and Comparative Examples 1 to 3, a distinctive odor clearly derived from casein was detected in Comparative Examples 2 and 3. On the other hand, Example 1 and Comparative Example 1 had almost the same flavor, and neither had the unnatural odor derived from casein that was detected in Comparative Examples 2 and 3, and both had a good, natural flavor derived from milk.

[0063] From the above, it was revealed that the liquid composition for foamed milk (Example 1) using ion-exchanged skim milk as a protein source can prepare foamed milk with good foaming, compared to the liquid composition for foamed milk (Comparative Example 1) using skim milk as a protein source. Furthermore, it was found that the liquid composition for foamed milk (Example 1) using ion-exchanged skim milk as a protein source had a superior flavor when consumed compared to liquid compositions for foamed milk using sodium caseinate or whey powder.

[0064] <Test Example 2> Examination of the composition of liquid compositions for foamed milk In this test example, the composition of a liquid composition for foamed milk that can prepare foamed milk with good foaming and foam retention was investigated.

[0065] In Test Example 2, the starting point was the time when the ion-exchanged skim milk was replaced with water in the ion-exchange resin column, and the protein sources were the initial ion-exchanged skim milk immediately after the start (obtained quickly after all the water in which the ion-exchange resin had been immersed had been replaced with skim milk), the middle ion-exchanged skim milk (obtained 1.5 hours after the start of ion exchange), and the late ion-exchanged skim milk (obtained 3 hours after the start of ion exchange), respectively. The liquid compositions for foamed milk of Examples 2 to 4 were prepared in the same manner as in Test Example 1. Furthermore, the amounts of protein, lipid, carbohydrate, and ash in each liquid composition for foamed milk were measured in the same manner as in Test Example 1. The composition of each liquid composition for foamed milk is shown in Table 3.

[0066] [Table 3]

[0067] For Example 1, Comparative Examples 1 to 3, and Examples 2 to 4 prepared in Test Example 1, the total mass content (mass%) of monovalent ions and divalent ions per 1 g of protein in the liquid composition for foamed milk, the molar content (mmol) of monovalent ions and divalent ions, the mass content ratio (mass%) of monovalent ions to divalent ions, and the molar content ratio (mmol) were measured and calculated. In addition, in the same manner as in Test Example 1, the liquid compositions for foamed milk of Examples 2 to 4 were whipped to prepare foamed milk, and the foaming and foam retention of each composition was evaluated. The results are shown in FIG. 2 and Tables 4 to 7.

[0068] [Table 4]

[0069] [Table 5]

[0070] [Table 6]

[0071] [Table 7]

[0072] As shown in Figure 2 and Table 4, whether the ion-exchanged skim milk was obtained at the early, middle, or late stage of ion exchange, it had better foaming properties than Comparative Examples 1 to 3 evaluated in Test Example 1. In addition, the foam state was maintained for 1.5 hours or more, and foam retention was also good.

[0073] Tables 2, 4 and 5 suggest that the total content (mass %) of divalent ions in the liquid composition for foamed milk is preferably 0.03% by mass or less.

[0074] Tables 2, 4 and 6 suggest that when the ratio (mass%) of the total content of divalent ions per 1 g of protein in the liquid composition for foamed milk is taken as 1, it is preferable that the ratio (mass%) of the total content of monovalent ions per 1 g of protein in the liquid composition for foamed milk be 4 or more.

[0075] Tables 2, 4 and 7 suggest that by setting the total content (mmol) of divalent ions per 1 g of protein in the liquid composition for foamed milk to 1 mmol or less, a liquid composition for foamed milk with good foaming and foam retention can be prepared.

[0076] Furthermore, it was suggested that when the total content (mmol) of divalent ions per 1g of protein in the liquid composition for foamed milk is taken as 1, the total content (mmol) of monovalent ions per 1g of protein is 7 or more.

[0077] Furthermore, as described above, it was suggested that the content (mmol) and content ratio (molar ratio) of each ion in the ion-exchanged skim milk can be adjusted so that the content (mmol) and content ratio of each ion in the liquid composition for foamed milk are within the above numerical ranges.

[0078] <Test Example 3> pH of ion-exchanged skim milk In this test example, the effect of the pH of ion-exchanged skim milk on the foaming and foam retention of foamed milk was tested.

[0079] A pH adjuster was added to a liquid composition for foamed milk prepared in the same manner as in Example 1 to adjust the pH to the values ​​shown in Table 8 below, thereby preparing liquid compositions for foamed milk (Examples 5 to 7). The liquid compositions for foamed milk prepared in Examples 5 to 7 were frothed to prepare foamed milk in the same manner as in Test Example 1, and the foaming and foam retention properties were evaluated in the same manner as in Test Example 1. The pH and evaluation results of each ion-exchanged skim milk are shown in Table 8 below.

[0080] [Table 8]

[0081] As shown in Table 8, in all of Examples 5 to 7, the foaming was 1.4 cm or more, which was better than that of Comparative Example 1, which had a foaming of 0.8 cm. From the above, it was revealed that the pH of ion-exchanged skim milk is preferably 7.0 or higher. [Industrial Applicability]

[0082] According to the present invention, it is possible to provide a composition for easily preparing foamed milk that foams well and retains its foam, and a method for producing the composition.

Claims

1. A liquid composition for foamed milk, comprising at least 80% by mass or more of water, 0.5% by mass or more of protein, and lipids, A liquid composition for foamed milk, having a total content of divalent ions per 1 g of protein of 0.5 mmol or less.

2. 2. A liquid composition for foamed milk according to claim 1, wherein the total content of monovalent ions per 1 g of protein is 2 mmol or more.

3. 3. A liquid composition for foaming milk according to claim 1, wherein the proportion of said protein relative to the total solid content of said liquid composition for foaming milk is 5% by mass or more.

4. A composition for foamed milk for preparing the liquid composition for foamed milk according to any one of claims 1 to 3, comprising at least 0.5% by mass of protein and lipids.

5. 5. The composition for foamed milk according to claim 4, wherein the protein is contained in an amount of 5% by mass or more relative to the total solid content of the composition for foamed milk.

6. A method for preparing a liquid composition for foamed milk according to any one of claims 1 to 3, comprising: an ion-exchanged skim milk preparation step of preparing ion-exchanged skim milk by ion-exchanging the skim milk so that the pH of the skim milk is 7.0 or higher; A method for preparing a liquid composition for foamed milk, comprising a mixing step of at least mixing the prepared ion-exchanged skim milk, water, and lipid.

7. 7. The method for preparing a liquid composition for foamed milk according to claim 6, wherein the total content of divalent ions per gram of protein in the ion-exchanged skim milk is 1 mmol or less.

8. A step of preparing a liquid composition for foamed milk by adding water to the composition for foamed milk according to claim 4 or 5 so that the water content is 80% by mass or more and stirring the mixture; and a step of frothing the prepared liquid composition for frothed milk.

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