Transparent milk beverage, preparation method thereof and gel prepared from transparent milk beverage

Abstract

The invention discloses a transparent milk beverage, a preparation method thereof and a gel prepared from the transparent milk beverage, the milk beverage comprises water, more than 1.0% of isolated whey protein, 0.20-1.00% of hydrosol and 0.03-0.40% of buffer salt based on the weight of the milk beverage; wherein the milk beverage is colorless transparent liquid, and the pH of the milk beverage at room temperature is 6-8. According to the technical scheme provided by the invention, the milk beverage meets the standard of GB / T21732-2008 milk beverage, is colorless transparent liquid, is kept stable in shelf life, and can be gelatinized by simply adding acid, so that the application scene of the milk beverage is enriched.

Description

Technical Field

[0001] The present invention relates to the field of milk beverages, in particular to a transparent milk beverage and a preparation method thereof, and a gel prepared therefrom. Background Art

[0002] Currently, traditional commercially available liquid beverages mainly include the following types: 1) shelf-stable transparent liquids made from whey but without protein, which mainly contain lactose, such as Rivela and local competitors; 2) shelf-stable transparent solutions with a pH value below 4.5, which are mainly made of whey protein isolate (WPI) and other ingredients; 3) shelf-stable translucent or opaque drinks made from whey protein isolate or whey protein concentrate and other ingredients, such as protein drinks; and 4) bottled beverages containing jelly, which is formed during the production process and remains unchanged during storage during the shelf life.

[0003] These protein-containing beverages generally have low protein content, a sour taste, and cannot provide consumers with a more attractive appearance. Therefore, there is still a need to develop new protein-containing beverages to meet consumers' diverse demands for beverage taste, appearance, applications, etc. Summary of the Invention

[0004] In light of this, the present invention provides a transparent milk beverage, a method for preparing the same, and a gel prepared therefrom. The milk beverage meets the GB / T 21732-2008 standard for milk beverages, is a colorless, transparent liquid, remains shelf-stable, and can be gelled simply by adding acid, enriching its application scenarios.

[0005] The present invention provides the following technical solutions:

[0006] A milk beverage comprises water, more than 1.0% isolated whey protein, 0.20-1.00% hydrosol and 0.03-0.40% buffer salt, based on the weight of the milk beverage; wherein the milk beverage is a colorless transparent liquid with a pH of 6-8 at room temperature.

[0007] Optionally, the hydrosol comprises carrageenan.

[0008] Optionally, the hydrosol further comprises at least one other gum selected from one or more of xanthan gum, alginate, agar, furcellaran, tamarind gum, locust bean gum, pectin, konjac gum, curdlan, guar gum, gellan gum and gelatin.

[0009] Optionally, the weight ratio of the other gum to carrageenan is (0-50):100.

[0010] Optionally, the cations in the buffer salt include one or more of potassium ions, sodium ions, calcium ions, and magnesium ions; the anions in the buffer salt include one or more of citrate, lactate, phosphate, hydrogen phosphate, dihydrogen phosphate, and bicarbonate.

[0011] Optionally, the buffer salt includes one or more of potassium citrate, sodium citrate, calcium citrate, potassium phosphate, sodium phosphate, and magnesium phosphate.

[0012] Optionally, the pH of the milk beverage at room temperature is 7.2-8.0.

[0013] Optionally, the shear viscosity of the milk beverage at 20° C. is 8-50 mPa·s.

[0014] Optionally, the milk beverage further comprises 4-20% carbohydrates, based on the weight of the milk beverage.

[0015] The present invention also provides a method for preparing the milk beverage, which comprises mixing water, whey protein, hydrosol and buffer salt to obtain the milk beverage.

[0016] The present invention also provides a gel, which is prepared by mixing the milk beverage with an acidic substance.

[0017] Optionally, the pH of the acidic substance at room temperature is lower than 4.0.

[0018] According to the technical solution of the present invention, the milk beverage of the present invention contains greater than 1.0% whey protein, a specific content of hydrosol and buffer salt; so that the milk beverage meets the standard of GB / T 21732-2008 milk beverages, and is a neutral, colorless, transparent liquid that remains stable during the shelf life and can be gelled by simply adding acid, enriching the application scenarios of the milk beverage. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] For purposes of illustration and not limitation, the present invention will now be described in terms of embodiments thereof and with reference to the accompanying drawings, in which:

[0020] Figure 1 is an image of the milk beverage according to Example 1 of the present invention;

[0021] Figure 2 is an image of a gel formed by the milk beverage of Example 1 of the present invention; and

[0022] Figure 3 This is an image of a mixture of the beverage of Comparative Example 1 without WPI and an acidic substance. DETAILED DESCRIPTION

[0023] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the examples. Preferred embodiments of the present invention are provided in the examples. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present invention.

[0024] Some traditional liquid beverages have relatively low protein content or even contain no protein at all, failing to meet the GB / T 21732-2008 standard for milk beverages and, therefore, cannot be called "milk (or milk)." Some protein-containing liquid beverages are translucent or opaque, which reduces their appeal to consumers. Other products, while transparent and protein-containing, have a low pH, resulting in a strong sour taste, which significantly limits their ability to be mixed with other beverages, such as coffee or tea. Traditional liquid beverages can only maintain one form during shelf life and use and cannot be gelled simply by adding acid. The milk beverage of the present invention is a mixture of whey protein, a hydrosol, and buffer salts; it is a stable liquid that does not gel during production and storage; it can form a jelly-like gel with a moderate hardness when mixed with an acidic substance (such as an acidic beverage); it can also form a stratified gel with common beverages, such as coffee or tea; and it can be made into a sparkling beverage using common household tools. Therefore, the milk beverage of the present invention has a wide range of applications and can meet the diverse needs of consumers.

[0025] The present invention provides a milk beverage comprising water, greater than 1.0%, such as 1.0-10.0%, of whey protein isolate (WPI), 0.20-1.00% of a hydrosol, and 0.03-0.40% of a buffer salt, based on the weight of the milk beverage; wherein the milk beverage is a colorless, transparent liquid having a pH of 6-8, such as 7.2-8.0, at room temperature. The term "room temperature" is generally understood by those skilled in the art, such as a temperature typically in the range of 20-25°C. Optionally, the milk beverage comprises 70-90%, such as 85-90%, such as 87.5-88.5% water, 1.0-10.0%, such as 1.0-6.0%, such as 1.0-1.5% whey protein isolate, 0.20-1.00%, such as 0.30-0.40%, such as 0.35-0.40%, such as 0.35-0.38% hydrosol, and 0.03-0.40%, such as 0.03-0.1%, such as 0.05-1.0%, such as 0.07-0.95%, such as 0.07-0.085% buffer salts, based on the weight of the milk beverage. The sum of the weight percentages of the components in the milk beverage is 100%, based on the weight of the milk beverage.

[0026] In the milk beverage of the present invention, water may include one or more of drinking water, deionized water, ultrafiltered water, reverse osmosis water, etc. Water is used as the balance in the milk beverage to make up the sum of the weight percentages of the components of the milk beverage to 100%.

[0027] The content of isolated whey protein in the milk beverage of the present invention is greater than 1.0%, meeting the standard of GB / T21732-2008 milk beverage. The whey protein content of the isolated whey protein is not less than 88%, and the milk beverage is colorless and transparent.

[0028] Hydrocolloids may include carrageenan. Carrageenan, also known as chondrus crispus, is a linear polysaccharide composed of D-galactose and 3,6-anhydro-D-galactose residues. Depending on the position of the half-ester sulfate group attached to the galactose, carrageenan primarily includes iota, lambda, and kappa carrageenan, with iota and kappa carrageenan being preferred. The carrageenan content is 0.10-0.60%, such as 0.2-0.5%, or 0.25-0.40%, based on the weight of the milk beverage.

[0029] In addition to carrageenan, the hydrosol further comprises at least one other gum selected from one or more of xanthan gum, alginate, agar, furcellaran, tamarind gum, locust bean gum (LBG), pectin, konjac gum, curdlan, guar gum, gellan gum, and gelatin, for example, one or more selected from locust bean gum, konjac gum, xanthan gum, and gellan gum, such as xanthan gum and gellan gum, with an average particle size of 60-100 mesh. The content of the other gum is 0-0.4%, such as 0-0.2%, such as 0-0.15%, such as 0.01-0.06%, such as 0.02-0.03%, based on the weight of the milk beverage.

[0030] The use of carrageenan and other gums together can produce a synergistic effect, which can improve the elasticity and water retention of the gel. The weight ratio of the other gums to carrageenan is (0-50):100, such as (0-20):100, such as (0-10):100, such as (4-6.7):100, such as 5.7:100.

[0031] The buffer salt may be any commonly used buffer salt known to those skilled in the art. The cations in the buffer salt include one or more of potassium ions, sodium ions, calcium ions, and magnesium ions; the anions in the buffer salt include one or more of citrate, lactate, phosphate, hydrogen phosphate, dihydrogen phosphate, and bicarbonate. Alternatively, the buffer salt includes one or more of potassium citrate, sodium citrate, calcium citrate, potassium phosphate (i.e., tripotassium phosphate), sodium phosphate (i.e., trisodium phosphate), and magnesium phosphate. Alternatively, the cations in the buffer salt include potassium ions or sodium ions, and the anions include citrate or phosphate.

[0032] The milk beverage also contains 4-20%, such as 8-12%, such as 9-11%, such as 10%, of carbohydrates, based on the weight of the milk beverage. The carbohydrates may include sugars, sweeteners, and fibers. The sugars may include non-reducing sugars or reducing sugars, the non-reducing sugars including one or more of trehalose and sucrose, and the reducing sugars including one or more of maltose and fructose. The sweeteners may include one or two of maltitol, xylitol, erythritol, sucralose, acesulfame potassium, and steviol glycosides. The fibers may include one or more of polydextrose and inulin. The carbohydrates may be non-reducing sugars such as trehalose, which can minimize the Maillard reaction between whey protein and sugar to prevent discoloration of the milk beverage.

[0033] Milk beverages may also include one or more other additives commonly used in the art, such as flavorings, coloring agents, vitamins, mineral substances, amino acids, prebiotics, probiotics, preservatives, fats, stabilizers, etc. These other additives may be selected and added as needed by those skilled in the art. For example, vitamins may include vitamin C and vitamin B. Vitamins may also include other vitamins, including ascorbic acid, ascorbic acid, palmitate, vitamin A, D, E, and K, and acidic vitamins such as pantothenic acid, folic acid, and biotin.

[0034] The pH of milk beverages at room temperature is not less than 6, and can be 6-8 or 7.2-8.0. The density of milk beverages is greater than 1.0g / cm 3 For example, 1.04 g / cm 3 , so it can form a layering effect with coffee and tea. The milk beverage is a transparent, colorless liquid and remains stable during shelf life, i.e., there are no visible lumps or aggregates during shelf life. The milk beverage has a shear viscosity of 8-50 mPa·s, such as 8-30 mPa·s, such as 8-15 mPa·s at 20°C; and an absorbance of 0.2 or less, such as 0.1 or less, such as 0.05 or less, measured using an ultraviolet and visible spectrophotometer at a wavelength of 600 nm.

[0035] The present invention also provides a method for preparing the milk beverage as described above, which comprises mixing water, isolated whey protein, hydrosol and buffer salt to obtain the milk beverage.

[0036] Alternatively, the method comprises mixing water, whey protein isolate, carbohydrates, a hydrosol and a buffer salt, sterilizing and filtering to obtain a milk beverage. Sterilization may be ultra-high temperature sterilization commonly used in the art, such as direct steam sterilization (DSI). Filtration may be performed by techniques known in the art, such as through a filter screen.

[0037] Optionally, the method is carried out at a temperature of 40-70°C, for example, 50-60°C, under normal pressure. In one embodiment, the method comprises mixing the hydrosol and water at 55°C, then adding the carbohydrate and buffer salt and mixing for 10-20 minutes; then adding the whey protein isolate and mixing for 20-40 minutes; and then sterilizing and filtering to obtain the milk beverage. The order of the above-mentioned steps of adding the components can be adjusted as needed. The above embodiment is merely for illustration of the preparation method of the present invention.

[0038] The milk beverage of the present invention can be mixed with an acidic substance to produce a liquid-solid phase transition, thereby forming a jelly-like gel with appropriate hardness and softness. The acidic substance can include a commercially available acidic beverage or a consumer-prepared acidic substance. The pH of the acidic substance at room temperature can be below 4.0. Consumers can adjust the ratio of the milk beverage to the acidic substance as needed, for example, to a weight ratio of 1:(1-6), such as 1:1, 1:2, or 1:3.5.

[0039] Under neutral conditions, the hydrosol (e.g., carrageenan) and whey protein in a transparent milk beverage are negatively charged, repelling each other and maintaining a stable transparent state. When an acidic substance, such as fruit juice, is added to the milk beverage, the pH drops below the isoelectric point of the whey protein, causing the positively charged proteins to aggregate with the negatively charged hydrosol, thereby forming a gel. The cations (e.g., potassium ions) in the buffer salt further react with the hydrosol, increasing the hardness and elasticity of the gel, thereby improving the mouthfeel of the gel, for example, making it harder.

[0040] Therefore, the present invention also provides a gel prepared by mixing the above-described milk beverage with an acidic substance. The gel has a peak force of 100-200 g, as measured using a texture analyzer, where a greater peak force indicates a greater relative hardness. The gel can be consumed directly, exhibits good hardness and elasticity, and has a firm mouthfeel. The gel can be obtained by simply mixing a milk beverage containing a low concentration of buffer salts with an acidic beverage, without the need for heating or the addition of high concentrations of cations.

[0041] Unless otherwise indicated, all percentages in the specification are by weight where applicable.

[0042] Unless otherwise defined, all techniques and terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0043] Example

[0044] The present invention is described below by way of specific examples. The examples described below are illustrative and are intended only to explain the present invention and are not to be construed as limiting the present invention. Where specific techniques or conditions are not specified in the examples, the methods described in the literature in the art or the product specifications were used. Where the manufacturer of the reagents or instruments used is not specified, they are all commercially available conventional products.

[0045] raw material

[0046] Water: Reverse osmosis water (RO water)

[0047] Xanthan gum: average particle size 80 mesh, model HT-80N

[0048] Carrageenan: Refined kappa carrageenan BV71 INS407

[0049] Carbohydrate: Trehalose crystalline powder

[0050] Buffer salt: Potassium citrate, purity 99%, model INS332ii

[0051] Sodium phosphate, purity 97%, model INS339iii

[0052] WPI: purchased from Arla Foods Ingredients.

[0053] Performance Testing

[0054] Absorbance of milk beverages

[0055] The measurements were made using an ultraviolet and visible spectrophotometer at a wavelength of 600 nm, zeroed with reverse osmosis water.

[0056] Viscosity of milk beverages

[0057] The shear viscosity of the samples was measured using an Anton Paar rheometer at a temperature of 20°C with a shear force of 10 1 / s.

[0058] Stability of milk beverages

[0059] The prepared milk beverage was allowed to stand at 4° C. for 48 hours, then poured out to observe the fluidity of the liquid. If lumps were found, the milk beverage was considered unstable.

[0060] Peak force of gel

[0061] A TA.XT.Plus texture analyzer was used in compression mode. The sample was compressed 35 mm at a speed of 120 mm / min and returned at a speed of 600 mm / min. A trigger force of 5.0 g was used to measure the peak force of the sample in g, which is used to characterize the relative hardness of the sample.

[0062] The color and gel form of milk beverages were classified by visual inspection.

[0063] Example 1

[0064] Carrageenan, xanthan gum and water were added to a beaker at 55°C and mixed thoroughly for 10 minutes.

[0065] Trehalose and potassium citrate were then added and mixed for 15 minutes.

[0066] Then WPI was added and mixed for 30 min.

[0067] The resulting mixture was then sterilized at 145°C for 5 seconds using a UHT ultra-high temperature sterilization device through direct steam sterilization, and filtered through a 200-mesh sieve to obtain a milk beverage.

[0068] The types and amounts of the components are summarized in Table 1, wherein the amounts are based on the weight of the milk beverage.

[0069] The absorbance of the obtained milk beverage measured at a wavelength of 600 nm was 0.019. Other properties are summarized in Table 2. The morphology is shown in Figure 1 .

[0070] Examples 2-9

[0071] The preparation steps of Example 1 were repeated, except for the amounts and types of the components, as detailed in Table 1. The properties of the resulting milk beverage are summarized in Table 2.

[0072] Comparative Example 1

[0073] The preparation steps of Example 1 were repeated, except that the amount of potassium citrate was 0.5%. The types and amounts of the components are summarized in Table 1. The final product obtained by mixing the components does not need to be mixed with an acidic substance and is a transparent jelly-like gel rather than a transparent liquid milk beverage.

[0074] The properties of the obtained products are summarized in Table 2.

[0075] Comparative Example 2

[0076] The preparation steps of Example 1 were repeated except that WPI was not added. The types and amounts of the components are summarized in Table 1, where the amounts are based on the weight of the beverage.

[0077] The properties of the resulting beverages are summarized in Table 2.

[0078] Table 1 Composition of milk beverages of various embodiments and comparative examples

[0079]

[0080] *The weight ratio of the two gums is the ratio of xanthan gum to carrageenan.

[0081] Gel preparation

[0082] The milk beverages or drinks prepared in Examples 1-9 and Comparative Example 2 were refrigerated at 4°C overnight. After the temperature was raised to room temperature, they were thoroughly mixed with water-soluble C100 purchased from Nongfu Spring Company in a beaker at a ratio of 1:1 (w / w) to form a gel. The pH of the water-soluble C100 used was 2.99 at room temperature.

[0083] The gel properties are summarized in Table 2.

[0084] The gel prepared from the milk beverage of Example 1 is shown in FIG. Figure 2 .

[0085] The product obtained by mixing the beverage of Comparative Example 2 with water-soluble C100 is shown in FIG. Figure 3 .

[0086] Table 2 Properties of milk beverages and gels formed in various examples and comparative examples

[0087]

[0088] According to the above embodiments and comparative examples, it can be seen that the milk beverage of the present invention is a transparent colorless liquid that can remain stable during the shelf life. At the same time, it can be simply mixed with an acidic substance to obtain a gel. The obtained gel has good hardness, thereby obtaining a better taste.

[0089] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may occur depending on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A milk beverage, characterized in that The invention comprises water, more than 1.0% isolated whey protein, 0.20-1.00% hydrosol and 0.03-0.40% buffer salt, based on the weight of the milk beverage; wherein the milk beverage is a colorless transparent liquid with a pH of 6-8 at room temperature.

2. The milk beverage according to claim 1, characterized in that The hydrosol comprises carrageenan.

3. The milk beverage according to claim 2, characterized in that The hydrosol further comprises at least one other gum selected from one or more of xanthan gum, alginate, agar, furcellaran, tamarind gum, locust bean gum, pectin, konjac gum, curdlan, guar gum, gellan gum and gelatin.

4. The milk beverage according to claim 3, characterized in that The weight ratio of the other gums to carrageenan is (0-50):

100.

5. The milk beverage according to any one of claims 1 to 4, characterized in that The cations in the buffer salt include one or more of potassium ions, sodium ions, calcium ions, and magnesium ions; the anions in the buffer salt include one or more of citrate, lactate, phosphate, hydrogen phosphate, dihydrogen phosphate, and bicarbonate.

6. The milk beverage according to claim 5, characterized in that The buffer salt includes one or more of potassium citrate, sodium citrate, calcium citrate, potassium phosphate, sodium phosphate, and magnesium phosphate.

7. The milk beverage according to any one of claims 1 to 6, characterized in that The pH of the milk beverage at room temperature is 7.2-8.

0.

8. The milk beverage according to any one of claims 1 to 7, characterized in that The shear viscosity of the milk beverage at 20° C. is 8-50 mPa·s.

9. The milk beverage according to any one of claims 1 to 8, characterized in that The milk beverage also comprises 4-20% carbohydrates, based on the weight of the milk beverage.

10. A method for preparing a milk beverage according to any one of claims 1 to 9, characterized in that: The method comprises mixing water, whey protein, hydrosol and buffer salt to obtain the milk beverage.

11. A gel prepared by mixing the milk beverage according to any one of claims 1 to 9 with an acidic substance.

12. The gel according to claim 11, characterized in that The pH of the acidic substance at room temperature is lower than 4.0.

Images