Hydrolysis method of casein

Abstract

The invention relates to the technical field of biological products, in particular to a casein hydrolysis method. According to the method provided by the invention, a casein solution with the mass concentration of 4%-9% is used as an enzymolysis substrate, the casein solution with the total volume of 16%-84% is placed at the constant temperature of 50-60 DEG C for enzymolysis for 15-100 min, then the remaining casein solution is supplemented and added into an enzymolysis system, and enzymolysis continues for 30-90 min. According to the method, a batch feeding means is adopted, the raw material casein is added into an enzymolysis system in two times, the enzyme amount in the enzymolysis process has relative advantages, finally, the hydrolysis degree of the casein is improved under the condition that the enzyme amount is small, the reaction of the casein is more sufficient, and the content of small molecule peptide in the obtained product is higher.

Description

Technical Field

[0001] The invention relates to the technical field of biological products, and in particular to a method for hydrolyzing casein. Background Art

[0002] Hydrolyzed casein refers to a protein that has been enzymatically or heated to change the molecular structure of casein, reduce its molecular weight, and thus increase its solubility and bioavailability. Hydrolyzed casein contains a large amount of antioxidants, which can neutralize free radicals, delay aging, and protect cell health. Compared with ordinary casein, hydrolyzed casein usually contains shorter protein peptide chains and amino acid sequences, which are easier to be absorbed by the intestine, and are also easier to be used by intestinal cells, and have better nutritional value. Hydrolyzed casein has a wide range of applications in the production of functional peptides and the improvement of protein digestibility. Based on the production needs of hydrolyzed casein, it is of great significance to study the hydrolysis method of casein. Chinese patent CN103923964A discloses a method for preparing casein hydrolysate, which can be adjusted according to different production conditions to ensure the stability of the product. U.S. Patent US20100151080A1 discloses a production process of fermented milk and fermented milk beverage / food, which also involves the hydrolysis of casein. However, the above-mentioned disclosed casein hydrolysis methods are all to add the substrate to the reaction system at one time, and there are problems such as slow hydrolysis reaction and low hydrolysis efficiency. In view of this, the present invention is proposed. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a casein hydrolysis method, which utilizes a batch feeding method to hydrolyze casein, thereby reducing the amount of enzyme used and improving the casein hydrolysis efficiency.

[0004] Specifically, the technical solution of the present invention is as follows: In a first aspect, the present invention provides a method for hydrolyzing casein, using a casein solution with a mass concentration of 4%-9% as an enzymatic substrate, first placing 16%-84% of the total volume of the casein solution under a constant temperature condition of 50-60°C for enzymatic hydrolysis for 15-100 minutes, and then adding the remaining casein solution as a feed to the enzymatic hydrolysis system, and continuing the enzymatic hydrolysis for 30-90 minutes.

[0005] Preferably, the present invention uses at least one of neutral protease, alkaline protease and flavor protease for enzymatic hydrolysis.

[0006] Preferably, the added amount of the neutral protease, alkaline protease or flavor protease of the present invention is 1.5%-3% of the casein mass.

[0007] Preferably, the present invention uses neutral protease, alkaline protease and flavor protease for enzymolysis; and the added amount of neutral protease is 2.0%±0.1% of the casein mass; the added amount of alkaline protease is 2.0%±0.1% of the casein mass; and the added amount of flavor protease is 2.0%±0.1% of the casein mass.

[0008] Preferably, the enzymatic substrate of the present invention is obtained by hydrating casein and distilled water at a temperature of 40-65°C.

[0009] Preferably, the present invention firstly places 50%±10% of the total volume of the casein solution under a constant temperature condition of 55±1° C. for enzymolysis for 60-90 min, then adds the remaining casein solution as a feed to the enzymolysis system, and continues the enzymolysis for 30-90 min.

[0010] Preferably, the present invention further comprises an enzyme inactivation step, and the enzyme inactivation method is: heating to 95±5°C and keeping warm for 10±5 minutes.

[0011] The hydrolysis degree of the hydrolysis method provided by the invention is ≥16.4.

[0012] The peptide content in the hydrolyzate obtained by the hydrolysis method provided by the invention is ≥5.32.

[0013] In the hydrolysis product obtained by the hydrolysis method provided by the invention, the proportion of substances with a relative molecular mass of ≤500 is ≥65.48%.

[0014] In the hydrolysis product obtained by the hydrolysis method provided by the invention, the proportion of substances with a relative molecular mass of ≤2000 is ≥92.01%.

[0015] Beneficial effects: The present invention provides a method for hydrolyzing casein, wherein a casein solution with a mass concentration of 4%-9% is used as an enzymatic substrate, and a casein solution with a total volume of 16%-84% is first placed under a constant temperature of 50-60°C for enzymatic hydrolysis for 15-100 minutes, and then the remaining casein solution is added to the enzymatic hydrolysis system for 30-90 minutes. The present invention adopts a batch feeding method, and the raw casein is added to the enzymatic hydrolysis system twice. The amount of enzyme has a relative advantage during the enzymatic hydrolysis process, and finally the degree of hydrolysis of casein is improved at a relatively low enzyme dosage, so that the reaction of casein is more complete, and the content of small molecule peptides in the obtained product is relatively higher. DETAILED DESCRIPTION

[0016] The currently disclosed casein hydrolysis method is to add the substrate to the reaction system at one time. The enzymatic reaction is a two-way reversible reaction. During the reaction, as the products (peptides and amino acids) accumulate, the reaction equilibrium will be pushed toward the reverse reaction of hydrolysis. However, due to the high water content in the casein hydrolysis system, the synthesis reaction basically does not occur. Despite this, the product will bind to the enzyme in large quantities, reducing the catalytic effect, causing the overall hydrolysis reaction to slow down and the hydrolysis efficiency to decrease. At the same time, during the fermentation enzymatic hydrolysis process, the initial substrate concentration and viscosity are too high, which may produce too many by-products or inhibit the activity of the enzyme. At the same time, at a lower enzyme-to-substrate ratio, the hydrolysis efficiency and the final product will be affected.

[0017] The invention provides a casein hydrolysis method, which utilizes a batch feeding method to hydrolyze casein, avoids substrate accumulation or inhibition, and improves casein hydrolysis efficiency while reducing enzyme dosage.

[0018] In one or more preferred and specific embodiments, the technical solution provided by the present invention is as follows: (1) Take casein and heat it to 40-65°C with 2-4L distilled water to hydrate it so that the final mass concentration of casein is 4%-9% (preferably 7%±1%).

[0019] (2) Add the casein solution into the fermentation tank in batches according to the ratio of 1:5, 1:2, 1:1, 2:1, and 5:1, and control the temperature at 50-60°C. After the temperature becomes constant, add neutral protease, alkaline protease, and flavor protease. The amount of each protease added is 1.5%-3% of the casein mass.

[0020] (3) After 15-100 minutes, add the remaining casein solution as feed.

[0021] (4) Hydrolysis in the fermentation tank for 2 hours (total time 2 hours).

[0022] (5) Maintain at 95°C for 10 min to inactivate the enzyme.

[0023] (6) Detect molecular weight and protein concentration.

[0024] (7) OPA method to measure the degree of hydrolysis.

[0025] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] The endpoints and any values ​​of the ranges disclosed in this specification are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0027] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "specific implementations", or "some specific implementations" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0028] In the examples provided in this specification, if no specific techniques or conditions are specified, the techniques or conditions described in the literature in this field or the product instructions are used. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased through regular channels.

[0029] In the following examples: The OPA method controls the hydrolysis reaction and calculates the degree of hydrolysis according to the following formulas (1), (2) and (3).

[0030] Formula (1): .

[0031] Wherein: Serine-NH2 is the amount of serine-NH2 per gram of protein, meqv / g; X is the sample mass, which is 1.0g; P is the protein content of the sample, %; V is the sample volume, which is 0.1L.

[0032] Formula (2): .

[0033] Where: serine-NH2 is the amount of serine-NH2 per gram of protein, meqv / g; β and α are constants, corresponding to 0.383 and 1.039 for casein respectively.

[0034] Formula (3): .

[0035] Where: DH is the degree of protein hydrolysis, %; h is the number of peptide bonds hydrolyzed in milk protein, meqv / g; h tot The total number of peptide bonds in casein is 8.2, meqv / g.

[0036] Determination of peptide content: refer to GB / T 22492-2008.

[0037] Determination of molecular weight distribution: refer to GB / T 22492-2008.

[0038] Example 1 This embodiment provides a casein hydrolysis method.

[0039] The casein hydrolysis method provided in this embodiment comprises the following steps: (1) Take 210 g of casein and hydrate it with 3 L of distilled water, heating it to 55°C to make the final mass concentration of casein 7%.

[0040] (2) Place 1.5 L of casein solution into a fermentation tank and control the temperature at 55°C. Add neutral protease, alkaline protease, and flavor protease into the fermentation tank. The amount of each protease added is 2% of the casein mass.

[0041] (3) After 30 min, add 1.5 L of casein solution as feed.

[0042] (4) The fermenter was hydrolyzed for 2 h (total duration was 2 h, and hydrolysis continued for 90 min after feeding).

[0043] (5) Maintain at 95°C for 10 min to inactivate the enzyme.

[0044] (6) Detect molecular weight and protein concentration.

[0045] (7) OPA method to measure the degree of hydrolysis.

[0046] Example 2 This embodiment provides a casein hydrolysis method.

[0047] The casein hydrolysis method provided in this embodiment comprises the following steps: (1) Take 210 g of casein and hydrate it with 3 L of distilled water, heating it to 55°C to make the final mass concentration of casein 7%.

[0048] (2) Place 1.5 L of casein solution into a fermentation tank and control the temperature at 55°C. Add neutral protease, alkaline protease, and flavor protease into the fermentation tank. The amount of each protease added is 2% of the casein mass.

[0049] (3) After 60 min, add 1.5 L of casein solution as feed.

[0050] (4) The fermentation tank was hydrolyzed for 2 h (total duration was 2 h, and hydrolysis continued for 60 min after feeding).

[0051] (5) Maintain at 95°C for 10 min to inactivate the enzyme.

[0052] (6) Detect molecular weight and protein concentration.

[0053] (7) OPA method to measure the degree of hydrolysis.

[0054] Example 3 This embodiment provides a casein hydrolysis method.

[0055] The casein hydrolysis method provided in this embodiment comprises the following steps: (1) Take 210 g of casein and hydrate it with 3 L of distilled water, heating it to 55°C to make the final mass concentration of casein 7%.

[0056] (2) Place 1.5 L of casein solution into a fermentation tank and control the temperature at 55°C. Add neutral protease, alkaline protease, and flavor protease into the fermentation tank. The amount of each protease added is 2% of the casein mass.

[0057] (3) After 90 min, add 1.5 L of casein solution as feed.

[0058] (4) The fermenter was hydrolyzed for 2 h (total time was 2 h, and hydrolysis continued for 30 min after feeding).

[0059] (5) Maintain at 95°C for 10 min to inactivate the enzyme.

[0060] (6) Detect molecular weight and protein concentration.

[0061] (7) OPA method to measure the degree of hydrolysis.

[0062] Example 4 This embodiment provides a casein hydrolysis method.

[0063] The casein hydrolysis method provided in this embodiment comprises the following steps: (1) Take 210 g of casein and hydrate it with 3 L of distilled water, heating it to 55°C to make the final mass concentration of casein 7%.

[0064] (2) Place 0.5 L of casein solution into a fermentation tank and control the temperature at 55°C. Add neutral protease, alkaline protease, and flavor protease into the fermentation tank. The amount of each protease added is 2% of the casein mass.

[0065] (3) After 60 min, add 2.5 L of casein solution as feed.

[0066] (4) The fermentation tank was hydrolyzed for 2 h (total duration was 2 h, and hydrolysis continued for 60 min after feeding).

[0067] (5) Maintain at 95°C for 10 min to inactivate the enzyme.

[0068] (6) Detect molecular weight and protein concentration.

[0069] (7) OPA method to measure the degree of hydrolysis.

[0070] Example 5 This embodiment provides a casein hydrolysis method.

[0071] The casein hydrolysis method provided in this embodiment comprises the following steps: (1) Take 210 g of casein and hydrate it with 3 L of distilled water, heating it to 55°C to make the final mass concentration of casein 7%.

[0072] (2) Place 1 L of casein solution in a fermentation tank and control the temperature at 55°C. Add neutral protease, alkaline protease and flavor protease into the fermentation tank. The amount of each protease added is 2% of the casein mass.

[0073] (3) After 60 min, add 2 L of casein solution as feed.

[0074] (4) The fermentation tank was hydrolyzed for 2 h (total duration was 2 h, and hydrolysis continued for 60 min after feeding).

[0075] (5) Maintain at 95°C for 10 min to inactivate the enzyme.

[0076] (6) Detect molecular weight and protein concentration.

[0077] (7) OPA method to measure the degree of hydrolysis.

[0078] Example 6 This embodiment provides a casein hydrolysis method.

[0079] The casein hydrolysis method provided in this embodiment comprises the following steps: (1) Take 210 g of casein and hydrate it with 3 L of distilled water, heating it to 55°C to make the final mass concentration of casein 7%.

[0080] (2) Place 2 L of casein solution in a fermentation tank and control the temperature at 55°C. Add neutral protease, alkaline protease and flavor protease into the fermentation tank. The amount of each protease added is 2% of the casein mass.

[0081] (3) After 60 min, add 1 L of casein solution as feed.

[0082] (4) The fermentation tank was hydrolyzed for 2 h (total duration was 2 h, and hydrolysis continued for 60 min after feeding).

[0083] (5) Maintain at 95°C for 10 min to inactivate the enzyme.

[0084] (6) Detect molecular weight and protein concentration.

[0085] (7) OPA method to measure the degree of hydrolysis.

[0086] Example 7 This embodiment provides a casein hydrolysis method.

[0087] The casein hydrolysis method provided in this embodiment comprises the following steps: (1) Take 210 g of casein and hydrate it with 3 L of distilled water, heating it to 55°C to make the final mass concentration of casein 7%.

[0088] (2) Place 2.5 L of casein solution into a fermentation tank and control the temperature at 55°C. Add neutral protease, alkaline protease, and flavor protease into the fermentation tank. The amount of each protease added is 2% of the casein mass.

[0089] (3) After 60 min, add 0.5 L of casein solution as feed.

[0090] (4) The fermentation tank was hydrolyzed for 2 h (total duration was 2 h, and hydrolysis continued for 60 min after feeding).

[0091] (5) Maintain at 95°C for 10 min to inactivate the enzyme.

[0092] (6) Detect molecular weight and protein concentration.

[0093] (7) OPA method to measure the degree of hydrolysis.

[0094] Example 8 This embodiment provides a casein hydrolysis method.

[0095] The casein hydrolysis method provided in this embodiment comprises the following steps: (1) Take 210 g of casein and hydrate it with 3 L of distilled water, heating it to 55°C to make the final mass concentration of casein 7%.

[0096] (2) Place 1.5 L of casein solution into a fermentation tank and control the temperature at 50°C. Add neutral protease, alkaline protease, and flavor protease into the fermentation tank. The amount of each protease added is 2% of the casein mass.

[0097] (3) After 60 min, add 1.5 L of casein solution as feed.

[0098] (4) The fermentation tank was hydrolyzed for 2 h (total duration was 2 h, and hydrolysis continued for 60 min after feeding).

[0099] (5) Maintain at 95°C for 10 min to inactivate the enzyme.

[0100] (6) Detect molecular weight and protein concentration.

[0101] (7) OPA method to measure the degree of hydrolysis.

[0102] Example 9 This embodiment provides a casein hydrolysis method.

[0103] The casein hydrolysis method provided in this embodiment comprises the following steps: (1) Take 210 g of casein and hydrate it with 3 L of distilled water, heating it to 55°C to make the final mass concentration of casein 7%.

[0104] (2) Place 1.5 L of casein solution into a fermentation tank and control the temperature at 60°C. Add neutral protease, alkaline protease, and flavor protease into the fermentation tank. The amount of each protease added is 2% of the casein mass.

[0105] (3) After 60 min, add 1.5 L of casein solution as feed.

[0106] (4) The fermentation tank was hydrolyzed for 2 h (total duration was 2 h, and hydrolysis continued for 60 min after feeding).

[0107] (5) Maintain at 95°C for 10 min to inactivate the enzyme.

[0108] (6) Detect molecular weight and protein concentration.

[0109] (7) OPA method to measure the degree of hydrolysis.

[0110] Example 10 This embodiment provides a casein hydrolysis method.

[0111] The casein hydrolysis method provided in this embodiment comprises the following steps: (1) Take 210 g of casein and hydrate it with 3 L of distilled water, heating it to 55°C to make the final mass concentration of casein 7%.

[0112] (2) Place 1.5 L of casein solution into a fermentation tank and control the temperature at 55°C. Add neutral protease, alkaline protease, and flavor protease into the fermentation tank. The amount of each protease added is 1.5% of the casein mass.

[0113] (3) After 60 min, add 1.5 L of casein solution as feed.

[0114] (4) The fermentation tank was hydrolyzed for 2 h (total duration was 2 h, and hydrolysis continued for 60 min after feeding).

[0115] (5) Maintain at 95°C for 10 min to inactivate the enzyme.

[0116] (6) Detect molecular weight and protein concentration.

[0117] (7) OPA method to measure the degree of hydrolysis.

[0118] Embodiment 11 This embodiment provides a casein hydrolysis method.

[0119] The casein hydrolysis method provided in this embodiment comprises the following steps: (1) Take 210 g of casein and hydrate it with 3 L of distilled water, heating it to 55°C to make the final mass concentration of casein 7%.

[0120] (2) Place 1.5 L of casein solution into a fermentation tank and control the temperature at 55°C. Add neutral protease, alkaline protease, and flavor protease into the fermentation tank. The amount of each protease added is 3% of the casein mass.

[0121] (3) After 60 min, add 1.5 L of casein solution as feed.

[0122] (4) The fermentation tank was hydrolyzed for 2 h (total duration was 2 h, and hydrolysis continued for 60 min after feeding).

[0123] (5) Maintain at 95°C for 10 min to inactivate the enzyme.

[0124] (6) Detect molecular weight and protein concentration.

[0125] (7) OPA method to measure the degree of hydrolysis.

[0126] Comparative Example 1 This comparative example provides a casein hydrolysis method.

[0127] The casein hydrolysis method provided in this comparative example comprises the following steps: (1) Take 210 g of casein and hydrate it with 3 L of distilled water, heating it to 55°C to make the final mass concentration of casein 7%.

[0128] (2) Place 3 L of casein solution in a fermentation tank and control the temperature at 55°C. Add neutral protease, alkaline protease and flavor protease into the fermentation tank. The amount of each protease added is 2% of the casein mass.

[0129] (3) Hydrolyze in the fermentation tank for 2 hours.

[0130] (4) Maintain at 95°C for 10 min to inactivate the enzyme.

[0131] (5) Detect molecular weight and protein concentration.

[0132] (6) OPA method to measure the degree of hydrolysis.

[0133] Comparative Example 2 This comparative example provides a casein hydrolysis method.

[0134] The casein hydrolysis method provided in this comparative example comprises the following steps: (1) Take 210 g of casein and hydrate it with 3 L of distilled water, heating it to 55°C to make the final mass concentration of casein 7%.

[0135] (2) Place 1.5 L of casein solution into a fermentation tank and control the temperature at 55°C. Add neutral protease, alkaline protease, and flavor protease into the fermentation tank. The amount of each protease added is 0.1% of the casein mass.

[0136] (3) After 60 min, add 1.5 L of casein solution as feed.

[0137] (4) The fermentation tank was hydrolyzed for 2 h (total duration was 2 h, and hydrolysis continued for 60 min after feeding).

[0138] (5) Maintain at 95°C for 10 min to inactivate the enzyme.

[0139] (6) Detect molecular weight and protein concentration.

[0140] (7) OPA method to measure the degree of hydrolysis.

[0141] Comparative Example 3 This comparative example provides a casein hydrolysis method.

[0142] The casein hydrolysis method provided in this comparative example comprises the following steps: (1) Take 210 g of casein and hydrate it with 3 L of distilled water, heating it to 55°C to make the final mass concentration of casein 7%.

[0143] (2) Place 1.5 L of casein solution into a fermentation tank and control the temperature to 55°C. Add neutral protease, alkaline protease and flavor protease into the fermentation tank. The amount of each protease added is 0.5% of the casein mass.

[0144] (3) After 60 min, add 1.5 L of casein solution as feed.

[0145] (4) The fermentation tank was hydrolyzed for 2 h (total duration was 2 h, and hydrolysis continued for 60 min after feeding).

[0146] (5) Maintain at 95°C for 10 min to inactivate the enzyme.

[0147] (6) Detect molecular weight and protein concentration.

[0148] (7) OPA method to measure the degree of hydrolysis.

[0149] Comparative Example 4 This comparative example provides a casein hydrolysis method.

[0150] The casein hydrolysis method provided in this comparative example comprises the following steps: (1) Take 210 g of casein and hydrate it with 3 L of distilled water, heating it to 55°C to make the final mass concentration of casein 7%.

[0151] (2) Place 1.5 L of casein solution into a fermentation tank and control the temperature at 55°C. Add neutral protease, alkaline protease, and flavor protease into the fermentation tank. The amount of each protease added is 1% of the casein mass.

[0152] (3) After 60 min, add 1.5 L of casein solution as feed.

[0153] (4) The fermentation tank was hydrolyzed for 2 h (total duration was 2 h, and hydrolysis continued for 60 min after feeding).

[0154] (5) Maintain at 95°C for 10 min to inactivate the enzyme.

[0155] (6) Detect molecular weight and protein concentration.

[0156] (7) OPA method to measure the degree of hydrolysis.

[0157] Comparative Example 5 This comparative example provides a casein hydrolysis method.

[0158] The casein hydrolysis method provided in this comparative example comprises the following steps: (1) Take 210 g of casein and hydrate it with 3 L of distilled water, heating it to 55°C to make the final mass concentration of casein 7%.

[0159] (2) Place 1.5 L of casein solution into a fermentation tank and control the temperature at 55°C. Add neutral protease, alkaline protease, and pepsin into the fermentation tank. The amount of each protease added is 2% of the casein mass.

[0160] (3) After 60 min, add 1.5 L of casein solution as feed.

[0161] (4) The fermentation tank was hydrolyzed for 2 h (total duration was 2 h, and hydrolysis continued for 60 min after feeding).

[0162] (5) Maintain at 95°C for 10 min to inactivate the enzyme.

[0163] (6) Detect molecular weight and protein concentration.

[0164] (7) OPA method to measure the degree of hydrolysis.

[0165] The hydrolysis degree, peptide content and proportion of substances with different relative molecular weights of each embodiment and comparative example are shown in Table 1.

[0166] Table 1

[0167] It can be seen from Table 1 that compared with the enzymatic hydrolysate without batch feeding treatment, the hydrolysis degree of the enzymatic hydrolysate of batch feeding at the same enzyme addition amount is increased, and the proportion of substances with a relative molecular mass of ≤500 is increased. Therefore, the batch feeding method improves the hydrolysis efficiency of the enzymatic hydrolysis process. The higher the enzyme addition amount, the higher the hydrolysis degree and peptide content of the enzymatic hydrolysate when other conditions are the same. However, based on cost and other considerations, the enzyme addition amount of 2% is the best choice. Therefore, after comparing the hydrolysis degree and peptide content, the optimal enzymatic hydrolysis conditions are to add the substrate after 60 minutes, the feed volume is 1:1, the enzyme addition amount is 2%, and the temperature is 55°C.

[0168] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for hydrolyzing casein, characterized in that: A casein solution with a mass concentration of 4%-9% is used as an enzymatic substrate, and 16%-84% of the total volume of the casein solution is first placed at a constant temperature of 50-60°C for enzymatic hydrolysis for 15-100 minutes, and then the remaining casein solution is added to the enzymatic hydrolysis system as a feed, and the enzymatic hydrolysis is continued for 30-90 minutes; neutral protease, alkaline protease and flavor protease are selected for enzymatic hydrolysis; and the added amount of neutral protease is 2.0%±0.1% of the casein mass; the added amount of alkaline protease is 2.0%±0.1% of the casein mass; the added amount of flavor protease is 2.0%±0.1% of the casein mass; the proportion of substances with a relative molecular mass ≤500 in the hydrolysate is ≥65.48%.

2. The hydrolysis method according to claim 1, characterized in that The enzymatic substrate is obtained by hydrating casein and distilled water at a temperature of 40-65°C.

3. The hydrolysis method according to claim 1, characterized in that First, place 50%±10% of the total volume of the casein solution at a constant temperature of 55±1°C for enzymatic hydrolysis for 60-90 minutes, then add the remaining casein solution feed to the enzymatic hydrolysis system and continue enzymatic hydrolysis for 30-90 minutes.

4. The hydrolysis method according to claim 1, characterized in that The method also includes an enzyme inactivation step, wherein the enzyme inactivation method is: heating to 95±5° C. and keeping the temperature for 10±5 minutes.

5. The hydrolysis method according to any one of claims 1 to 4, characterized in that Degree of hydrolysis ≥16.

4.

6. The hydrolysis method according to any one of claims 1 to 4, characterized in that The peptide content in the hydrolysate was ≥5.

32.

7. The hydrolysis method according to any one of claims 1 to 4, characterized in that The proportion of substances with relative molecular mass ≤2000 in the hydrolysis products is ≥92.01%.

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