Milk for promoting calcium absorption and preparation method thereof

Abstract

The invention relates to milk capable of promoting calcium absorption and a preparation method thereof, and the preparation method comprises the following steps: (1) degreasing raw milk to obtain skimmed milk and single cream; (2) performing membrane treatment on the skimmed milk obtained in the step (1) to obtain membrane-treated milk; (3) mixing the membrane-treated milk obtained in the step (2) with the single cream obtained in the step (1) to obtain fat backfill milk; (4) mixing the sodium hyaluronate and the calcium beta-hydroxy-beta-methyl butyrate to obtain a premix; and mixing the premix with the fat backfill milk obtained in the step (3), and then performing homogenization treatment and sterilization treatment to obtain the milk capable of promoting calcium absorption. According to the preparation method provided by the invention, the technical effects of improving the stability of the milk and improving the mouth feel under the condition of not containing any food thickening agent and edible essence are realized, and the obtained milk has the functional effects of promoting calcium absorption and improving the bone mineral density at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of dairy products, and in particular to milk for promoting calcium absorption and a preparation method thereof. Background Art

[0002] The main problems of the middle-aged and elderly people are as follows: First, the hidden hunger problem of the middle-aged and elderly people: People aged 18-59 have hidden hunger, among which 98% of the middle-aged and elderly people are seriously deficient in calcium, and their daily calcium intake accounts for only 41% of the recommended amount. Second, the problem of muscle loss in the middle-aged and elderly people: From about the age of 40, the muscle mass of the human body begins to gradually decrease. Between the ages of 40 and 70, the muscle mass is lost at a rate of about 8% every decade, so the daily dietary protein intake of the elderly needs to be supplemented. Third, the problem of joint degeneration in the middle-aged and elderly people: After entering middle age, all tissues and organs of the body will age and degenerate, and the joints of bones and tissues will also undergo senile degenerative changes. If fractures occur and the meniscus and soft tissues of the joints are worn, it will also cause premature degeneration and aging.

[0003] Milk and dairy products are rich in calcium and have a high absorption rate. They are the best source of dietary calcium and can effectively solve the problem of insufficient dietary calcium intake in the country and promote bone health. At the same time, the addition of calcium β-hydroxy-β-methylbutyrate (CaHMB) can prevent muscle loss and increase muscle protein synthesis. However, when this raw material is combined with protein-containing products, protein precipitation will occur.

[0004] CN114568515A discloses a method for preparing a protein solution containing calcium β-hydroxy-β-methylbutyrate, wherein the pH of the CaHMB raw material aqueous solution is adjusted to a weak acidity (6.5-7.0) by adding an acid-base regulator (citric acid, malic acid, lactic acid, tartaric acid, ascorbic acid), and then the protein solution + acid-base regulator (KOH, KOH, NaOH, sodium bicarbonate) are added to the aqueous solution to adjust the pH to 6.7-6.9, thereby solving the denaturation problem of CaHMB in the protein solution (reconstituted milk), and the addition amount is 1-6%. However, this method requires the use of acid-base additives, which does not conform to the concept of green, low-carbon, and healthy life.

[0005] Therefore, based on the objective nutritional gaps such as insufficient dietary calcium intake and joint and muscle degeneration among the middle-aged and elderly people, as well as the subjective needs of middle-aged and elderly consumers, the design and development of native high-calcium activity-fortified milk for middle-aged and elderly people, while avoiding the use of additives, has practical significance for promoting healthy aging. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a milk that promotes calcium absorption and a preparation method thereof. The preparation method provided by the present invention achieves the technical effect of improving the stability of milk and enhancing the taste without any food thickener or edible flavor, and the obtained milk also has the functional effect of promoting calcium absorption and improving bone density.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a method for preparing milk for promoting calcium absorption, the preparation method comprising the following steps:

[0009] (1) Degreasing raw milk to obtain skimmed milk and cream;

[0010] (2) subjecting the skimmed milk obtained in step (1) to membrane treatment to obtain membrane-treated milk;

[0011] (3) mixing the membrane-treated milk obtained in step (2) with the cream obtained in step (1) to obtain fat-filled milk;

[0012] (4) Mixing sodium hyaluronate and calcium β-hydroxy-β-methylbutyrate to obtain a premix; mixing the premix with the fat-filled milk obtained in step (3), and then homogenizing and sterilizing to obtain the milk that promotes calcium absorption.

[0013] In the prior art, neutral room temperature milk products that achieve native high calcium, native high index protein, and promote bone, muscle and joint health without food additives such as stabilizers, acid-base regulators, emulsifiers or food flavors have the following problems:

[0014] First, the product stability is poor:

[0015] (1) Milk with native protein ≥5.6 g / 100 mL and native calcium ≥160 mg / 100 mL is prone to tube sticking and protein denaturation during ultra-high temperature instantaneous sterilization (UHT sterilization), which affects the stability of the product within the 6-month shelf life. During storage, fat will float or protein will precipitate, and it may even be impossible to continuously produce and complete filling.

[0016] (2) The functional raw material calcium β-hydroxy-β-methylbutyrate (CaHMB) is alkaline, with a pH of 7.2-7.5 for a 1% aqueous solution. It has poor water solubility and thermal stability in cow's milk. When added to neutral milk and heated, it causes local protein denaturation, thus affecting the stability of the system during the shelf life of the product. The reason is that CaHMB exists in milk in the form of ions, which can easily form calcium bridges between protein molecules, leading to protein precipitation.

[0017] Second, the product tastes bad:

[0018] (1) During the processing of native high-nutrition milk (native protein ≥5.6 g / 100 mL, native high calcium ≥160 mg / 100 mL), the fat, protein and lactose molecules will be concentrated, broken and heated, resulting in a rough taste and astringent taste of the product;

[0019] (2) CaHMB has a bitter taste. If added directly to milk, it will cause an unpleasant flavor and will not be accepted by consumers.

[0020] Based on the above defects, the present invention provides a new method for preparing milk. From the aspect of formula, the present invention introduces sodium hyaluronate and adopts a process of premixing with CaHMB. Since sodium hyaluronate has a water-retaining effect similar to a thickener, it can increase the Ca content of CaHMB. 2+ The ions are wrapped to form a water film to prevent the protein from forming a calcium bridge with calcium, thereby causing protein denaturation; on the other hand, the ionic wrapping effect of sodium hyaluronate on CaHMB will change the triple helix structure of sodium hyaluronate, thereby solving its solubility problem in liquid milk to a certain extent; in addition, sodium hyaluronate also synergizes with CaHMB to enhance the effect of promoting calcium absorption and improving bone density function.

[0021] From the process aspect, the present invention adjusts the content ratio of β-lactoglobulin and α-lactalbumin in the background of bovine milk through a membrane filtration treatment process, which is manifested in the macroscopic view as locking the heat-sensitive protein whey protein in neutral milk, and the structures of α-lactalbumin and β-lactoglobulin unfold and decompose into monomers, exposing hydrophobic residues, and finally adding a premix of sodium hyaluronate and CaHMB to attach its linear non-sulfated structure to the hydrophobic residues of milk protein, forming a hydrophilic carrier so that sodium hyaluronate is dissolved in liquid milk and improves solubility; at the same time, the formed hydrophilic carrier can effectively avoid the denaturation of milk protein caused by thermal processing, and encapsulate the free calcium ions of CaHMB, thereby effectively ensuring the subsequent thermal stability during sterilization. The bovine colostrum after membrane treatment forms a stable hydrophilic carrier structure with sodium hyaluronate and CaHMB, and at the same time, sodium hyaluronate can selectively bind to the Ca of CaHMB. 2+ A water film is formed to wrap the stable neutral small units, thereby realizing the preparation of room temperature sodium hyaluronate milk that maintains a good tissue state within a shelf life of 6 months without any thickener or stabilizer, and the milk can maintain a non-oxidative and non-enzymatic browning effect under a 37°C insulation condition. In addition, the membrane treatment process used in the present invention can increase the smooth taste of the product by adjusting the lactose content and combining the addition of sodium hyaluronate, thereby solving the astringency of the original high-nutrition milk.

[0022] Preferably, the materials in step (4) include, by weight: 990-1000 parts of fat backfilled milk (for example, 990 parts, 992 parts, 994 parts, 996 parts, 998 parts, 1000 parts, etc.), 0.1-2 parts of sodium hyaluronate (for example, 0.1 parts, 0.2 parts, 0.5 parts, 0.8 parts, 1 parts, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts, etc.), and 0.05-1 parts of calcium β-hydroxy-β-methylbutyrate (for example, 0.05 parts, 0.1 parts, 0.2 parts, 0.5 parts, 0.8 parts, 1 parts, etc.).

[0023] Preferably, the molecular weight of the sodium hyaluronate is 80,000-400,000 Da (for example, 80,000, 100,000, 150,000, 200,000, 250,000, 300,000, 350,000, 400,000 Da, etc.), preferably 80,000-200,000 Da.

[0024] In the present invention, by preparing the formula ratio of fat backfilled milk, sodium hyaluronate and calcium β-hydroxy-β-methylbutyrate in the raw materials, a better effect of improving stability and product taste can be achieved.

[0025] Preferably, the fat content of the skimmed milk in step (1) is 0.5-0.8% (for example, it may be 0.5%, 0.55%, 0.6%, 0.65%, 0.7%, 0.75%, 0.8%, etc.).

[0026] Preferably, in step (2), the membrane is treated to obtain a protein content of 5.5-6.0% by mass in the retentate (for example, 5.5%, 5.6%, 5.7%, 5.8%, 5.9%, 6.0%, etc.).

[0027] In the present invention, when the protein content in the retentate is within the above-defined range, the ratio of β-lactoglobulin to α-lactalbumin in raw milk can reach 1.6-3.3. The raw milk system at this ratio can form a more stable hydrophilic carrier structure with CaHMB and sodium hyaluronate, thereby further improving the stability of milk.

[0028] Preferably, the membrane treatment in step (2) comprises reverse osmosis membrane treatment and ultrafiltration membrane treatment performed sequentially.

[0029] Preferably, the reverse osmosis membrane is used for treatment until the protein content in the retentate is 3.6-4.0% by mass (eg, 3.6%, 3.7%, 3.8%, 3.9%, 4.0%, etc.).

[0030] Preferably, the ultrafiltration membrane is used to treat the retentate until the protein content is 5.5-6.0% by mass (eg, 5.5%, 5.6%, 5.7%, 5.8%, 5.9%, 6.0%, etc.).

[0031] In the present invention, the lactose content is first adjusted by reverse osmosis (RO) membrane concentration, and then concentrated by ultrafiltration (UF) membrane to filter out part of the lactose and Na + At the same time, the ratio of β-lactoglobulin and α-lactalbumin in raw cow's milk is adjusted, and sodium hyaluronate with properties similar to emulsifier is added on this basis to increase the smooth taste of the product and solve the astringency of native high-nutrition milk.

[0032] Preferably, the fat content of the fat backfilled milk in step (3) is 4.0-4.5% (for example, 4%, 4.1%, 4.2%, 4.3%, 4.4%, 4.5%, etc.).

[0033] Preferably, the mixing temperature of the premix in step (4) is 40-65°C (for example, it may be 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, etc.), and the mixing speed is ≤1 kg / min (for example, it may be 0.1 kg / min, 0.2 kg / min, 0.3 kg / min, 0.4 kg / min, 0.8 kg / min, 0.9 kg / min, etc.).

[0034] In the present invention, at the above-mentioned adding temperature and adding speed, a better material transformation effect can be achieved, thereby ensuring the stability and taste of the milk.

[0035] Preferably, the adding of the premix in step (4) comprises: mixing the premix with 100-120 times (for example, 100 times, 105 times, 110 times, 115 times, 120 times, etc.) the mass of the fat backfilling milk obtained in step (3) to form a liquid feed; and then mixing the liquid feed with the remaining fat backfilling milk in step (3).

[0036] Preferably, the homogenization and sterilization treatments in step (4) include a first homogenization treatment, a pasteurization treatment, a second homogenization treatment and an ultra-high temperature sterilization treatment performed in sequence.

[0037] Preferably, the temperature of the first homogenization treatment is 50-80°C (for example, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, etc.), and the pressure is 150-270 bar (for example, 150 bar, 180 bar, 200 bar, 220 bar, 240 bar, 270 bar, etc.).

[0038] Preferably, the temperature of the second homogenization treatment is 60-90°C (for example, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C, 90°C, etc.), and the pressure is 220-240 bar (for example, 220 bar, 225 bar, 230 bar, 235bar, 240 bar, etc.).

[0039] Preferably, the pasteurization temperature is 70-75°C (for example, 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, etc.), and the time is 10-20 s (for example, 10 s, 12 s, 14 s, 16 s, 18 s, 20 s, etc.).

[0040] Preferably, the ultra-high temperature sterilization treatment temperature is 135-140°C (for example, it can be 135°C, 136°C, 137°C, 138°C, 139°C, 140°C, etc.), and the time is 4-6 s (for example, it can be 4 s, 4.5 s, 5 s, 5.5 s, 6 s, etc.).

[0041] Preferably, the preparation method further comprises adding a bone health aid.

[0042] Preferably, the added amount of the bone health aid is 0.0012-0.5% of the mass of the fat backfilled milk (for example, it can be 0.0012%, 0.005%, 0.01%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, etc.).

[0043] Preferably, the bone health aid includes any one or a combination of at least two of vitamin D, bovine colostrum basic protein, casein phosphopeptide, milk basic protein, magnesium, phosphorus, chondroitin sulfate, N-acetylglucosamine, glucosamine or lactase.

[0044] Preferably, the bone health aid is added after the premix is ​​mixed with the fat backfill milk in step (4).

[0045] Preferably, the adding is performed at a temperature of 40-50°C (eg, 40°C, 42°C, 44°C, 46°C, 48°C, 50°C, etc.).

[0046] Step (4) further comprises the step of adding lactase; after the addition of lactase, an enzymolysis process is further comprised, wherein the enzymolysis temperature is 50-60°C (for example, 50°C, 52°C, 54°C, 56°C, 58°C, 60°C, etc.), and the enzymolysis time is 25-35 min (for example, 25 min, 26 min, 28 min, 30 min, 32 min, 34 min, 35 min, etc.).

[0047] Preferably, the added amount of lactase is 0.001-0.1% (for example, 0.001%, 0.005%, 0.01%, 0.02%, 0.05%, 0.08%, 0.1%, etc.) of the mass of the fat backfilled milk.

[0048] Preferably, the preparation method comprises the following steps:

[0049] (1) skimming raw milk to obtain skimmed milk and cream with a fat content of 0.5-0.8% by mass;

[0050] (2) treating the skimmed milk obtained in step (1) with a reverse osmosis membrane until the protein content in the retentate is 3.6-4.0% by mass, and then treating the skimmed milk with an ultrafiltration membrane until the protein content in the retentate is 5.5-6.0% by mass, thereby obtaining membrane-treated milk;

[0051] (3) mixing the membrane-treated milk obtained in step (2) with the cream obtained in step (1) to obtain fat-filled milk having a fat content of 4.0-4.5% by mass;

[0052] (4) Sodium hyaluronate and calcium β-hydroxy-β-methylbutyrate are mixed to obtain a premix; the premix is ​​mixed with the fat backfilled milk obtained in step (3) at 40-65° C. and at a rate of ≤1 kg / min, and then a first homogenization treatment is performed at 50-80° C. and 150-270 bar, a pasteurization treatment is performed at 70-75° C. for 10-20 s, a second homogenization treatment is performed at 60-90° C. and 220-240 bar, and an ultra-high temperature sterilization treatment is performed at 135-140° C. for 4-6 s to obtain the milk that promotes calcium absorption.

[0053] The materials in step (4) include, by weight: 990-1000 parts of fat backfill milk, 0.1-2 parts of sodium hyaluronate and 0.05-1 parts of calcium β-hydroxy-β-methylbutyrate.

[0054] In a second aspect, the present invention provides milk for promoting calcium absorption, prepared according to the method for preparing milk for promoting calcium absorption described in the first aspect.

[0055] Compared with the prior art, the present invention has at least the following beneficial effects:

[0056] The preparation method provided by the present invention introduces the functional raw materials sodium hyaluronate and CaHMB, and through specific membrane treatment and premixing processes, the obtained milk protein content is ≥5.0 g / 100 mL, and the native calcium content is ≥160 mg / 100 mL, achieving the technical effect of improving the stability of milk and enhancing the taste without any food thickeners or edible flavors, and the obtained milk also has the functional effects of promoting calcium absorption and improving bone density. DETAILED DESCRIPTION

[0057] For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0058] The sources of materials used in the following examples and comparative examples are as follows:

[0059] Raw milk: in accordance with GB 19301;

[0060] Sodium hyaluronate: purity ≥95%;

[0061] Bovine colostrum basic protein: the manufacturer is Keytone Enterprises of New Zealand;

[0062] Casein phosphopeptide: The manufacturer is Shanghai Daoyan Trading Co., Ltd.;

[0063] Milk alkaline protein: The manufacturer is Xi'an Enpeptideyuan Biotechnology Co., Ltd.

[0064] Example 1

[0065] This embodiment provides a method for preparing milk that promotes calcium absorption, wherein the raw materials for preparation include, by weight: 999.2 parts of fat backfilled milk, 0.2 parts of sodium hyaluronate (molecular weight 130000 Da), 0.1 parts of calcium β-hydroxy-β-methylbutyrate, and 0.5 parts of N-acetylglucosamine;

[0066] The preparation method comprises the following steps:

[0067] (1) skimming raw milk to obtain skimmed milk and cream with a fat content of 0.7% by mass;

[0068] (2) The skimmed milk was treated with a reverse osmosis membrane until the protein content in the retentate was 3.6%, and then treated with an ultrafiltration membrane until the protein content in the retentate was 5.68%, thereby obtaining membrane-treated milk. The results showed that the ratio of β-lactoglobulin to α-lactalbumin in the membrane-treated milk was 1.8:1.

[0069] (3) adding cream to the membrane-treated milk to obtain fat-filled milk with a fat content of 4.21% by mass;

[0070] (4) Sodium hyaluronate and calcium β-hydroxy-β-methylbutyrate are mixed to obtain a premix; the premix is ​​added to a portion of the fat backfilled milk (the amount is 100 times the total mass of sodium hyaluronate, calcium β-hydroxy-β-methylbutyrate and N-acetylglucosamine) at 50°C and 0.5 kg / min, and stirred for 10 minutes to dissolve; then N-acetylglucosamine is added at 40°C and stirred for 3 minutes to dissolve, to obtain a liquid feed; the liquid feed is added to the remaining fat backfilled milk to complete the mixing;

[0071] (5) performing a first homogenization treatment at 70°C and 200 bar, performing a pasteurization treatment at 72°C for 15 s, performing a second homogenization treatment at 80°C and 230 bar, and performing an ultra-high temperature sterilization treatment at 135°C for 6 s to obtain the milk that promotes calcium absorption.

[0072] Example 2

[0073] This embodiment provides a method for preparing milk that promotes calcium absorption, wherein the raw materials include, by weight: 999.787 parts of fat backfilled milk, 0.125 parts of sodium hyaluronate (molecular weight 154000 Da), 0.050 parts of calcium β-hydroxy-β-methylbutyrate, 0.02 parts of vitamin D, and 0.018 parts of lactase;

[0074] The preparation method comprises the following steps:

[0075] (1) skimming raw milk to obtain skimmed milk and cream with a fat content of 0.5% by mass;

[0076] (2) The skimmed milk was treated with a reverse osmosis membrane until the protein content in the retentate was 3.8%, and then treated with an ultrafiltration membrane until the protein content in the retentate was 5.95%, thereby obtaining membrane-treated milk. The results showed that the ratio of β-lactoglobulin to α-lactalbumin in the membrane-treated milk was 3:1.

[0077] (3) adding cream to the membrane-treated milk to obtain fat-filled milk having a fat content of 4% by mass;

[0078] (4) Sodium hyaluronate and calcium β-hydroxy-β-methylbutyrate are mixed to obtain a premix; the premix is ​​added to a portion of the fat-filled milk (the amount is 100 times the total mass of sodium hyaluronate, calcium β-hydroxy-β-methylbutyrate and vitamin D, and lactase) at 48°C and 0.3 kg / min, and stirred for 10 minutes to dissolve; vitamin D is then added at 45°C and stirred for 3 minutes to dissolve, to obtain a liquid feed; the liquid feed is added to the remaining fat-filled milk to complete the mixing;

[0079] (5) Performing a first homogenization treatment at 50°C and 150 bar, and then pasteurizing at 70°C for 20 s, and then performing a second homogenization treatment at 60°C and 220 bar, and ultra-high temperature sterilization at 136°C for 5 s, adding lactase to each package in a sterile online enzyme adding machine, and leaving the package at room temperature of 25°C for 5 days to complete lactase hydrolysis, thereby obtaining the zero-lactose milk that promotes calcium absorption.

[0080] Example 3

[0081] This embodiment provides a method for preparing milk that promotes calcium absorption, wherein the raw materials for preparation include, by weight: 996.9 parts of fat backfill milk, 1 part of sodium hyaluronate (molecular weight 159000 Da), 1 part of calcium β-hydroxy-β-methylbutyrate, 0.1 part of bovine colostrum alkaline protein, and 1 part of lactase;

[0082] The preparation method comprises the following steps:

[0083] (1) skimming raw milk to obtain skimmed milk and cream with a fat content of 0.8% by mass;

[0084] (2) The skimmed milk was treated with a reverse osmosis membrane until the protein content in the retentate was 3.8%, and then treated with an ultrafiltration membrane until the protein content in the retentate was 5.89%, thereby obtaining membrane-treated milk. The results showed that the ratio of β-lactoglobulin to α-lactalbumin in the membrane-treated milk was 2.3:1.

[0085] (3) adding cream to the membrane-treated milk to obtain fat-filled milk with a fat content of 4.43% by mass;

[0086] (4) Sodium hyaluronate and calcium β-hydroxy-β-methylbutyrate are mixed to obtain a premix; the premix is ​​added to a portion of the fat backfill milk (the amount is 120 times the total mass of sodium hyaluronate, calcium β-hydroxy-β-methylbutyrate, bovine colostrum alkaline protein and lactase) at 55°C and 0.7 kg / min, and stirred for 10 minutes to dissolve; then, bovine colostrum alkaline protein is added at 40°C and stirred for 5 minutes to dissolve, to obtain a liquid feed; the liquid feed is added to the remaining fat backfill milk to complete the mixing;

[0087] (5) Performing a first homogenization treatment at 80°C and 270 bar, and then pasteurizing at 72°C for 10 s, adding lactase, and performing enzymatic hydrolysis at 57°C for 30 min, followed by a second homogenization treatment at 80°C and 240 bar, and then ultra-high temperature sterilization at 139°C for 4 s to obtain the zero-lactose milk that promotes calcium absorption.

[0088] Example 4

[0089] This embodiment provides a method for preparing milk that promotes calcium absorption, wherein the preparation raw materials include, by weight: 997.8 parts of fat backfilled milk, 2 parts of sodium hyaluronate (molecular weight 80000 Da), and 0.2 parts of calcium β-hydroxy-β-methylbutyrate;

[0090] The preparation method comprises the following steps:

[0091] (1) skimming raw milk to obtain skimmed milk and cream with a fat content of 0.7% by mass;

[0092] (2) The skimmed milk was treated with a reverse osmosis membrane until the protein content in the retentate was 4% by weight, and then treated with an ultrafiltration membrane until the protein content in the retentate was 6% by weight, thereby obtaining membrane-treated milk. The results showed that the content ratio of β-lactoglobulin to α-lactalbumin in the membrane-treated milk was 3.3:1.

[0093] (3) adding cream to the membrane-treated milk to obtain fat-filled milk having a fat content of 4.5% by mass;

[0094] (4) Mixing sodium hyaluronate and calcium β-hydroxy-β-methylbutyrate to obtain a premix; adding the premix to a portion of the fat-filled milk (the amount used is 100 times the mass of sodium hyaluronate and calcium β-hydroxy-β-methylbutyrate) at 60° C. and 1 kg / min, stirring for 10 minutes to dissolve the mixture, and obtaining a liquid feed; adding the liquid feed to the remaining fat-filled milk to complete the mixing;

[0095] (5) performing a first homogenization treatment at 70°C and 200 bar, performing a pasteurization treatment at 72°C for 15 s, performing a second homogenization treatment at 90°C and 230 bar, and performing an ultra-high temperature sterilization treatment at 138°C for 6 s to obtain the milk that promotes calcium absorption.

[0096] Example 5

[0097] This embodiment provides a method for preparing milk that promotes calcium absorption, wherein the raw materials for preparation include, by weight: 997.988 parts of fat backfilled milk, 1.5 parts of sodium hyaluronate (molecular weight 400000 Da), 0.5 parts of calcium β-hydroxy-β-methylbutyrate, and 0.012 parts of casein phosphopeptide;

[0098] The preparation method comprises the following steps:

[0099] (1) skimming raw milk to obtain skimmed milk and cream with a fat content of 0.6% by mass;

[0100] (2) The skimmed milk was treated with a reverse osmosis membrane until the protein content in the retentate was 4%, and then treated with an ultrafiltration membrane until the protein content in the retentate was 5.98%, thereby obtaining membrane-treated milk. The results showed that the ratio of β-lactoglobulin to α-lactalbumin in the membrane-treated milk was 3.1:1.

[0101] (3) adding cream to the membrane-treated milk to obtain fat-filled milk with a fat content of 4.16% by mass;

[0102] (4) Sodium hyaluronate and calcium β-hydroxy-β-methylbutyrate are mixed to obtain a premix; the premix is ​​added to a portion of the fat backfilled milk (the amount is 120 times the total mass of sodium hyaluronate, calcium β-hydroxy-β-methylbutyrate and casein phosphopeptide) at 45°C and 0.5 kg / min, and stirred for 10 minutes to dissolve; then casein phosphopeptide is added at 40°C and stirred for 5 minutes to dissolve, to obtain a liquid feed; the liquid feed is added to the remaining fat backfilled milk to complete the mixing;

[0103] (5) performing a first homogenization treatment at 70°C and 200 bar, performing a pasteurization treatment at 72°C for 15 s, performing a second homogenization treatment at 80°C and 230 bar, and performing an ultra-high temperature sterilization treatment at 137°C for 4 s to obtain the milk that promotes calcium absorption.

[0104] Example 6

[0105] This embodiment provides a method for preparing milk that promotes calcium absorption, wherein the raw materials for preparation include, by weight: 993.08 parts of fat backfilled milk, 1.8 parts of sodium hyaluronate (200000 Da), 0.1 parts of calcium β-hydroxy-β-methylbutyrate, 5 parts of milk alkaline protein, and 0.02 parts of lactase;

[0106] The preparation method comprises the following steps:

[0107] (1) skimming raw milk to obtain skimmed milk and cream with a fat content of 0.7% by mass;

[0108] (2) The skimmed milk was treated with a reverse osmosis membrane until the protein content in the retentate was 3.5% by mass, and then treated with an ultrafiltration membrane until the protein content in the retentate was 5.5% by mass, thereby obtaining membrane-treated milk. The results showed that the content ratio of β-lactoglobulin to α-lactalbumin in the membrane-treated milk was 1.6:1.

[0109] (3) adding cream to the membrane-treated milk to obtain fat-filled milk with a fat content of 4.15% by mass;

[0110] (4) Sodium hyaluronate and calcium β-hydroxy-β-methylbutyrate are mixed to obtain a premix; the premix is ​​added to a portion of the fat backfilled milk (the amount is 100 times the total mass of sodium hyaluronate, calcium β-hydroxy-β-methylbutyrate, milk alkaline protein and lactase) at 50°C and 0.5 kg / min, and stirred for 10 minutes to dissolve; then milk alkaline protein is added at 45°C and stirred for 3 minutes to dissolve, to obtain a liquid feed; the liquid feed is added to the remaining fat backfilled milk to complete the mixing;

[0111] (5) Performing a first homogenization treatment at 50°C and 150 bar, and then pasteurizing at 70°C for 20 s, adding lactase, and performing enzymatic hydrolysis at 50°C for 35 min, followed by a second homogenization treatment at 60°C and 220 bar, and then ultra-high temperature sterilization at 137°C for 4 s to obtain the milk that promotes calcium absorption.

[0112] Example 7

[0113] This embodiment provides a method for preparing milk that promotes calcium absorption. The only difference between this method and Example 1 is that the raw materials used in the preparation include 0.05 parts of sodium hyaluronate and 1.2 parts of calcium β-hydroxy-β-methylbutyrate. The rest is based on Example 1.

[0114] Example 8

[0115] This embodiment provides a method for preparing milk that promotes calcium absorption. The only difference between this method and Example 1 is that the raw materials used in the preparation include 2.2 parts of sodium hyaluronate and 0.03 parts of calcium β-hydroxy-β-methylbutyrate. The rest is based on Example 1.

[0116] Example 9

[0117] This embodiment provides a method for preparing milk that promotes calcium absorption. The difference between this method and embodiment 1 is that in step (2), ultrafiltration membrane treatment is performed until the protein content in the retentate is 5.3% by mass, thereby obtaining membrane-treated milk. Detection shows that the content ratio of β-lactoglobulin to α-lactalbumin in the membrane-treated milk is 1.4:1. The rest is referred to embodiment 1.

[0118] Example 10

[0119] This embodiment provides a method for preparing milk that promotes calcium absorption. The difference between this method and embodiment 1 is that in step (2), ultrafiltration membrane treatment is performed until the protein content in the retentate is 6.5% by mass, thereby obtaining membrane-treated milk. Detection shows that the content ratio of β-lactoglobulin to α-lactalbumin in the membrane-treated milk is 3.5:1. The rest is referred to embodiment 1.

[0120] Comparative Example 1

[0121] This comparative example provides a method for preparing milk that promotes calcium absorption. The only difference between the comparative example and Example 1 is that sodium hyaluronate is not added. The rest is for reference to Example 1.

[0122] The results showed that the direct addition of calcium β-hydroxy-β-methylbutyrate in step (4) caused some milk proteins to denature, and after ultra-high temperature sterilization in step (5), the milk tube became sticky and particles precipitated in the product, making it impossible to carry out sensory testing and product function verification.

[0123] Comparative Example 2

[0124] This comparative example provides a method for preparing milk that promotes calcium absorption. The difference between the comparative example and Example 1 is that in step (4), no premix is ​​prepared, and sodium hyaluronate and calcium β-hydroxy-β-methylbutyrate are directly added to the fat backfilled milk in sequence. The rest is as in Example 1.

[0125] The results showed that after the product was left at room temperature for 3 days after filling, protein precipitation was found at the bottom of the package when it was cut, making it impossible to carry out subsequent evaluation and verification.

[0126] Comparative Example 3

[0127] This comparative example provides a method for preparing milk that promotes calcium absorption. The difference between the comparative example and Example 1 is that steps (1) to (3) are not performed, and in step (4), the fat backfill milk is replaced with an equal amount of raw cow's milk (the ratio of β-lactoglobulin to α-lactalbumin in the raw cow's milk is 1.2:1). The rest is with reference to Example 1.

[0128] The results showed that the direct addition of calcium β-hydroxy-β-methylbutyrate in step (4) caused some milk proteins to denature, and scaling occurred during ultra-high temperature sterilization in step (5), making it impossible to fill the product and conduct subsequent product evaluation and verification.

[0129] Test Case

[0130] Quality control indicators:

[0131] (1) Stability indicators (lower-line indicators): clarification index ≤ 0.030, median particle size ≤ 0.30 μm, centrifugal sedimentation rate ≤ 2.5%.

[0132] (2) Stability indicators for 6-month shelf life:

[0133] Δ clarification index (sample stored at room temperature for 6 months - offline sample, absolute value) ≤ 0.1;

[0134] Δ particle size median diameter (sample stored at room temperature for 6 months - offline sample, absolute value) ≤ 0.1 μm;

[0135] ΔCentrifugal sedimentation rate (sample stored at room temperature for 6 months - offline sample, absolute value) ≤1.0%.

[0136] (3) Microorganisms: Commercially sterile.

[0137] (4) Sensory evaluation: sensory score ≥ 85 points.

[0138] (5) Bone density function evaluation: If the bone calcium content or bone density is significantly higher than that of the low-calcium control group and not lower than that of the calcium carbonate control group at the corresponding dose, and the calcium absorption rate is not lower than that of the calcium carbonate control group, it can be determined that the test sample has the effect of helping to improve bone density.

[0139] Test method:

[0140] (1) Clarification index: tested using LUMiSizer X65 stability analyzer, light factor 1.00, rotation speed 4000 rpm, temperature 25°C, profile 300, time interval 10 s.

[0141] (2) Particle size analysis: Median diameter (μm): LA 960 laser particle size analyzer was used for testing, with a transmittance of 70-90%, and the D50 median diameter index was obtained.

[0142] (3) Centrifugal sedimentation rate (%): Weigh 50 g of sample and place it in a centrifuge tube. Centrifuge at 3500 rpm for 15 min. Remove the supernatant from the centrifuge tube and place it in a 37°C incubator to dry for 2 min. Calculate the amount of sedimentation xg. Centrifugal sedimentation rate = (x / 50)*100%.

[0143] (4) Determination of microorganisms (commercial sterility): Take one sample from each batch and store it in a refrigerator at 2-5℃ as a control. Keep the remaining samples at 36℃±1℃ for 10 days and then perform sensory, pH and smear staining microscopy examinations. If there is no sign of microbial proliferation, it is judged to be commercially sterile. For details of the detection method, please refer to GB 4789.26.

[0144] (5) α-lactalbumin content: refer to T / CSIQ 77001-2020 Determination of α-lactalbumin content in dairy products-High performance liquid chromatography;

[0145] β-lactoglobulin content: refer to NY / T 1663-2008 Determination of β-lactoglobulin in milk and dairy products-polyacrylamide gel electrophoresis method.

[0146] (6) Sensory evaluation: A team of professionally trained sensory personnel (n = 30 people), who were in good health and had no lactose intolerance and who drank milk on a regular basis, were organized to conduct a sensory evaluation of commercially sterile products. The full score was 100 points. The evaluation criteria were shown in Table 1, and the final score was the average.

[0147] Table 1

[0148]

[0149] (7) Bone density function evaluation method: refer to the "Health Food Function Testing and Evaluation Methods (2023)".

[0150] Test results:

[0151] The sensory evaluation results of each embodiment and comparative example are shown in Table 2.

[0152] Table 2

[0153]

[0154] The bone density index results of each embodiment and comparative example are shown in Table 3.

[0155] Table 3

[0156]

[0157] The results of the calcium absorption rates of the embodiments and comparative examples for promoting calcium absorption are shown in Table 4.

[0158] Table 4

[0159]

[0160] The evaluation results of the immune enhancement functions of the embodiments and comparative examples are shown in Table 5.

[0161] Table 5

[0162]

[0163] The above test results and stability data are summarized in Table 6.

[0164] Table 6

[0165]

[0166] The test results show that:

[0167] (1) It can be seen from Examples 1 to 10 that the present invention adjusts the content ratio of β-lactoglobulin and α-lactalbumin in raw cow milk through a membrane treatment process, and introduces sodium hyaluronate in combination with a premixing process to synergistically solve the problem of CaHMB causing milk denaturation and bitter taste due to alkalinity, thereby effectively achieving the preparation of milk with good stability, good taste, and the function of promoting calcium absorption and improving bone density.

[0168] (2) By comparing Example 1 with Examples 7-10, it can be seen that the present invention has the advantages of further optimizing the product formula and adopting the membrane treatment process, which further improves the product stability of no precipitation, no protein denaturation, uniform tissue state, etc. during the shelf life of 6 months at room temperature, and has a good taste without astringency or blandness. At the same time, the technical effect of sodium hyaluronate:N-acetylglucosamine=2:5 can significantly promote calcium absorption.

[0169] (3) By comparing Example 1 with Comparative Example 1, it can be seen that when hyaluronic acid is not added, the stability of the obtained milk decreases. Even if the ratio of milk α-lactalbumin and β-lactoglobulin is adjusted, the problem of denaturation of calcium β-hydroxy-β-methylbutyrate in the milk protein system cannot be solved. After ultra-high temperature sterilization, the tube becomes sticky and particles precipitate in the product.

[0170] By comparing Example 1 and Comparative Example 2, it can be seen that when the premixing process is not adopted, protein precipitation occurs in the obtained milk after being placed at room temperature for 3 days, and the shelf life stability is poor, and the stability of the product with a shelf life of 6 months cannot be guaranteed.

[0171] By comparing Example 1 and Comparative Example 3, it can be seen that when the raw milk is not subjected to membrane treatment, the stability of the obtained milk decreases: the functional raw materials sodium hyaluronate, N-acetylglucosamine, and calcium β-hydroxy-β-methylbutyrate react with proteins to cause protein denaturation, resulting in instability of the product system, scaling and tube sticking during the ultra-high temperature sterilization stage, and the product cannot be filled.

[0172] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing milk that promotes calcium absorption, characterized in that: The preparation method comprises the following steps: (1) Degreasing raw milk to obtain skimmed milk and cream; (2) subjecting the skimmed milk obtained in step (1) to membrane treatment to obtain membrane-treated milk; (3) mixing the membrane-treated milk obtained in step (2) with the cream obtained in step (1) to obtain fat-filled milk; (4) Mixing sodium hyaluronate and calcium β-hydroxy-β-methylbutyrate to obtain a premix; mixing the premix with the fat-filled milk obtained in step (3), and then homogenizing and sterilizing to obtain the milk that promotes calcium absorption.

2. The preparation method according to claim 1, characterized in that: The materials in step (4) include, by weight: 990-1000 parts of fat backfill milk, 0.1-2 parts of sodium hyaluronate and 0.05-1 parts of calcium β-hydroxy-β-methylbutyrate.

3. The preparation method according to claim 1, characterized in that: The fat content of the skimmed milk in step (1) is 0.5-0.8%; The membrane is treated in step (2) until the protein content in the retentate is 5.5-6.0%.

4. The preparation method according to claim 1, characterized in that: The membrane treatment in step (2) includes reverse osmosis membrane treatment and ultrafiltration membrane treatment performed sequentially; The reverse osmosis membrane is used to treat the retentate until the protein content is 3.6-4.0% by mass; the ultrafiltration membrane is used to treat the retentate until the protein content is 5.5-6.0% by mass.

5. The preparation method according to claim 1, characterized in that: The fat content of the fat backfilled milk in step (3) is 4.0-4.5%.

6. The preparation method according to claim 1, characterized in that: The mixing temperature of the premix in step (4) is 40-65°C, and the mixing speed is ≤1 kg / min; The homogenization and sterilization treatments in step (4) include a first homogenization treatment, a pasteurization treatment, a second homogenization treatment, and an ultra-high temperature sterilization treatment performed in sequence; The temperature of the first homogenization treatment is 50-80°C and the pressure is 150-270 bar; The temperature of the second homogenization treatment is 60-90°C and the pressure is 220-240 bar; The pasteurization treatment is performed at a temperature of 70-75°C and a time of 10-20 seconds; The ultra-high temperature sterilization treatment is carried out at a temperature of 135-140° C. and a time of 4-6 s.

7. The preparation method according to claim 1, characterized in that: The preparation method further comprises adding a bone health aid; The bone health aid comprises any one or a combination of at least two of vitamin D, bovine colostrum basic protein, casein phosphopeptide, milk basic protein, magnesium, phosphorus, chondroitin sulfate, N-acetylglucosamine, glucosamine or lactase; The bone health enhancer is added after the premix is ​​mixed with the fat backfill milk in step (4), and the addition is carried out at a temperature of 40-50°C.

8. The preparation method according to claim 1, characterized in that: Step (4) further comprises the step of adding lactase; after the addition of lactase, an enzymolysis process is also included, wherein the enzymolysis temperature is 50-60° C. and the enzymolysis time is 25-35 min.

9. The preparation method according to claim 1, characterized in that: The preparation method comprises the following steps: (1) skimming raw milk to obtain skimmed milk and cream with a fat content of 0.5-0.8% by mass; (2) treating the skimmed milk obtained in step (1) with a reverse osmosis membrane until the protein content in the retentate is 3.6-4.0% by mass, and then treating the skimmed milk with an ultrafiltration membrane until the protein content in the retentate is 5.5-6.0% by mass, thereby obtaining membrane-treated milk; (3) mixing the membrane-treated milk obtained in step (2) with the cream obtained in step (1) to obtain fat-filled milk having a fat content of 4.0-4.5% by mass; (4) Sodium hyaluronate and calcium β-hydroxy-β-methylbutyrate are mixed to obtain a premix; the premix is ​​mixed with the fat backfilled milk obtained in step (3) at 40-65° C. and at a rate of ≤1 kg / min, and then a first homogenization treatment is performed at 50-80° C. and 150-270 bar, a pasteurization treatment is performed at 70-75° C. for 10-20 s, a second homogenization treatment is performed at 60-90° C. and 220-240 bar, and an ultra-high temperature sterilization treatment is performed at 135-140° C. for 4-6 s to obtain the milk that promotes calcium absorption; The materials in step (4) include, by weight: 990-1000 parts of fat backfill milk, 0.1-2 parts of sodium hyaluronate and 0.05-1 parts of calcium β-hydroxy-β-methylbutyrate.

10. Milk for promoting calcium absorption prepared according to the method for preparing milk for promoting calcium absorption according to any one of claims 1 to 9.

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