Whey protein hydrolysate, brown active lactic acid bacteria beverage and preparation method thereof

Abstract

The present application provides a whey protein enzymatic hydrolysate, a brown active lactic acid bacteria beverage and a preparation method thereof. The whey protein enzymatic hydrolysate prepared by a specific formula and a specific process is applied to the production of the brown active lactic acid bacteria beverage, the acid production rate of the lactic acid bacteria is accelerated, the fermentation time is significantly reduced, the viable count and stability of the product in the shelf life are higher, and the increasing demand of consumers for healthy products is met.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of fermented milk preparation, and particularly relates to a whey protein enzymatic hydrolysate, a brown active lactic acid bacteria beverage and a preparation method thereof. BACKGROUND

[0002] The brown active lactic acid bacteria beverage has a sour-sweet refreshing taste, a unique caramel flavor and a high number of lactic acid bacteria, and the lactic acid bacteria have many physiological functions such as regulating intestinal flora, improving immunity and reducing cholesterol. Therefore, such products are favored by the majority of young people. At present, the production process of the brown active lactic acid bacteria beverage is generally as follows: defatted milk powder and glucose are subjected to a Maillard reaction, and then are subjected to a long-time fermentation of more than 72 hours by Lactobacillus casei or Lactobacillus paracasei to prepare the active lactic acid bacteria beverage. Due to the long fermentation time, the energy consumption of the factory is seriously affected and the production cost of the product is increased. The number of live bacteria and stability are key indicators for measuring the lactic acid bacteria beverage.

[0003] At present, there are many studies on the influence of additional components on yogurt fermentation, mainly focusing on the influence of soy protein and casein hydrolysate on yogurt fermentation and the influence of milk protein hydrolysate on the growth of probiotics in yogurt and the quality characteristics of yogurt. There are few reports on the influence of whey protein enzymatic hydrolysate on yogurt fermentation and its mechanism. Whey protein has high nutritional value and is an important component of milk protein. Moreover, it contains various bioactive peptide sequences, and its enzymatic hydrolysate has been widely used as an additive with biological activity and nutritional function in food. SUMMARY

[0004] In order to solve the above problems, the purpose of the present application is to provide a whey protein enzymatic hydrolysate, a brown active lactic acid bacteria beverage and a preparation method thereof. The prepared brown active lactic acid bacteria beverage has the characteristics of fast acid production speed and short fermentation time, and the number of live bacteria and stability of the product are high during the shelf life.

[0005] In order to achieve the above purpose, the present application provides a preparation method of a whey protein enzymatic hydrolysate, which comprises the following steps:

[0006] The concentrated whey protein powder WPC80 is hydrated and then cathepsin is added, and the mixture is hydrolyzed at a constant temperature of 45±2℃, and then the enzyme is inactivated and centrifuged to obtain the whey protein enzymatic hydrolysate;

[0007] The cathepsin comprises one or a combination of two or more of cathepsin B, cathepsin F, cathepsin H, cathepsin K, cathepsin L, cathepsin S and cathepsin V;

[0008] The addition amount of the cathepsin is 1.2%-1.6% based on 100% of the mass of the whey protein enzymatic hydrolysate;

[0009] Based on the mass of the whey protein hydrolysate being 100%, the added amount of the concentrated whey protein powder WPC80 is 4%-6%.

[0010] According to a specific embodiment of the present invention, preferably, the above preparation method specifically comprises the following steps:

[0011] (1) Heat water to 45-50°C, add concentrated whey protein powder WPC80, add cathepsin after the material is dissolved, stir and hydrolyze at a constant temperature of 45±2°C for 90-120 minutes;

[0012] (2) After inactivating the enzyme at 95±2° C. for 8-12 minutes, centrifuge at 4-6° C. and 4000-8000 RPM for 20-30 minutes, and collect the supernatant to obtain the whey protein hydrolysate.

[0013] In the prior art, most of the methods are to directly perform enzymatic hydrolysis on the reconstituted skim milk. The present invention uses concentrated whey protein powder WPC80 to perform enzymatic hydrolysis first to form a whey protein hydrolysate, and then performs mixing and other processes to prepare fermented milk. The obtained whey protein hydrolysate contains a variety of bioactive peptide sequences, which have biological activity and nutritional functions. It can be fully utilized by lactic acid bacteria as non-protein nitrogen, thereby promoting its proliferation and fermentation to the greatest extent. Milk or reconstituted milk is mainly composed of casein, and protease is directly added. The types and quantities of peptides, especially bioactive peptides, in the casein hydrolysate are relatively small, and its effect on the proliferation of lactic acid bacteria is relatively poor. Compared with other proteases, in the present invention, tissue protease has a higher enzymatic hydrolysis efficiency, and the number of bioactive peptides and amino acids in its hydrolysate is greater, which can better promote the proliferation and fermentation of lactic acid bacteria, and the hydrolysate does not have bitter peptides and odor, so that the product maintains a good flavor.

[0014] The present invention also provides whey protein hydrolysate prepared by the above preparation method.

[0015] The present invention also provides the use of the whey protein hydrolysate in the preparation of a lactic acid bacteria beverage or in lactic acid bacteria fermentation.

[0016] According to a specific embodiment of the present invention, preferably, in the above application, when preparing the lactic acid bacteria beverage, the whey protein hydrolysate is added as a raw material before fermentation.

[0017] The present invention also provides a brown active lactic acid bacteria beverage, which, based on 100% by weight of the lactic acid bacteria beverage, comprises the following raw materials:

[0018] 2.2%-5.0% of skim milk powder, 1.2%-1.8% of the whey protein hydrolysate of the present invention, 0.02%-0.5% of an acidity regulator, 0.001%-0.01% of lactic acid bacteria and water.

[0019] According to a specific embodiment of the present invention, preferably, the added amount of the whey protein hydrolysate is 1.5%.

[0020] According to a specific embodiment of the present invention, preferably, the viable bacteria count of the brown active lactic acid bacteria beverage within a 25-day shelf life reaches 1.0×10 9 CFU / mL or above.

[0021] According to a specific embodiment of the present invention, preferably, the raw material further comprises 4%-15% of a sweetener.

[0022] According to a specific embodiment of the present invention, preferably, the raw materials further include 0.03%-0.15% edible flavoring.

[0023] According to a specific embodiment of the present invention, preferably, the sweetener includes one or a combination of two or more of white sugar, glucose, fructose syrup, crystalline fructose, xylose, xylitol, erythritol, maltose, maltitol, sucralose, acesulfame potassium, steviol glycosides, and mogrosides, which can adjust the flavor and taste of the product.

[0024] According to a specific embodiment of the present invention, preferably, the added amount of the acidity regulator is 0.05%-0.3%.

[0025] According to a specific embodiment of the present invention, preferably, the acidity regulator includes one or a combination of two or more of lactic acid, citric acid, sodium citrate, and malic acid.

[0026] According to a specific embodiment of the present invention, preferably, the acidity regulator comprises lactic acid.

[0027] According to a specific embodiment of the present invention, preferably, the added amount of the lactic acid bacteria is 0.002%-0.004%.

[0028] According to a specific embodiment of the present invention, preferably, the lactic acid bacteria include one or a combination of two or more of Lactobacillus casei, Lactobacillus plantarum, Lactobacillus acidophilus, Lactobacillus rhamnosus, Lactobacillus bulgaricus, Streptococcus thermophilus, Lactobacillus helveticus, Lactobacillus paracasei, Lactobacillus salivarius, Lactobacillus gestatum, Lactobacillus fermentum, Lactobacillus reuteri, Bifidobacterium longum, Bifidobacterium animalis, Bifidobacterium infantis, Bifidobacterium breve, Bifidobacterium adolescentis, and Bifidobacterium bifidum.

[0029] According to a specific embodiment of the present invention, preferably, the lactic acid bacteria is Lactobacillus paracasei.

[0030] The present invention also provides a method for preparing the brown active lactic acid bacteria beverage, which comprises the following steps:

[0031] The skimmed milk powder, reducing sugar and water are mixed, left to stand for hydration and homogenized once to obtain homogenized reconstituted milk;

[0032] browning the homogenized reconstituted milk, and then cooling it to obtain browning reconstituted milk;

[0033] adding fermentation bacteria and whey protein hydrolysate to the browning reduced milk for fermentation, stopping the fermentation when the fermentation ends, breaking the milk, homogenizing, and cooling to obtain brown fermented milk;

[0034] adding an acidity regulator to the brown fermented milk and homogenizing the milk twice to obtain the brown active lactic acid bacteria beverage;

[0035] The reducing sugar includes one or a combination of two or more of glucose, fructose, xylose, galactose, ribose, deoxyribose, lactose and maltose.

[0036] According to a specific embodiment of the present invention, preferably, the above preparation method specifically comprises the following steps:

[0037] (1) Heat water to 45-50°C, add skim milk powder and reducing sugar, stir and hydrate, let stand for 30-40 minutes, and homogenize at 30-50 / 180-200 bar and 65-68°C to obtain homogenized reconstituted milk;

[0038] (2) keeping the homogenized reconstituted milk at 95±2°C for browning for 180-270 minutes, and cooling it to 37±1°C to obtain browning reconstituted milk;

[0039] (3) adding the fermentation bacteria and the whey protein hydrolysate to the browning reduced milk, mixing and fermenting, stopping the fermentation when the acidity reaches 180-190°T, breaking the emulsion at 30-50 / 180-200 bar, and cooling to below 10°C to obtain brown fermented milk;

[0040] (4) adding an acidity regulator to water, mixing, and sterilizing to obtain an acidity regulating solution;

[0041] (5) The acidity regulating liquid is used to adjust the acidity of the brown fermented milk to 50-55°T, and secondary homogenization is performed at a pressure of 30-50 / 180-200 bar to obtain the brown active lactic acid bacteria beverage.

[0042] According to a specific embodiment of the present invention, preferably, the acidity regulating liquid in step (4) may further include edible flavors and sweeteners to form a sugar solution.

[0043] According to a specific embodiment of the present invention, the preparation method of the brown active lactic acid bacteria beverage specifically comprises the following steps:

[0044] (1) Preparation of whey protein hydrolysate:

[0045] (1) Add RO water, heat to 45-50 ° C, add concentrated whey protein powder WPC80 and stir for 15 minutes to complete the mixing;

[0046] (2) Add cathepsin and stir for 15 minutes, then hydrolyze at 45 ± 2°C for 90-120 minutes;

[0047] (3) inactivating the enzyme at 95 ± 2°C for 10 min, centrifuging at 4°C and 5000 RPM for 20 min, and collecting the supernatant to obtain the whey protein hydrolysate;

[0048] (2) Preparation of fermented milk:

[0049] (1) Add RO water to the batching tank and heat it to 45-50°C. Add skim milk powder and glucose to the mixing tank and stir for 20 minutes. After the mixing is completed, let it stand for 30 minutes and then homogenize at 30 / 180 bar and 65°C to obtain homogenized reconstituted milk.

[0050] (2) heat-browning the homogenized reconstituted milk at 95° C. for 180 min to 270 min;

[0051] (3) The reconstituted milk after browning is cooled to 37±1℃;

[0052] (4) adding the fermentation bacteria and whey protein hydrolysate to the reconstituted milk under aseptic conditions, stirring for 20 minutes, and fermenting. When the acidity reaches 180-190°T, the fermentation is stopped, and the milk is broken at 30 / 150 bar to obtain brown fermented milk, which is then cooled to below 10°C for later use;

[0053] (3) Preparation of sugar solution:

[0054] (1) Add RO water to the batching tank, add sweetener, acidity regulator and edible flavoring while stirring the water, and use a high-speed blender to stir and dissolve evenly;

[0055] (2) sterilizing at 95°C for 300 seconds to obtain a sugar solution (acidity adjustment solution);

[0056] (3) Refrigerate the sugar solution to below 10°C for later use;

[0057] (4) Allocation:

[0058] (1) Mix brown fermented milk and sugar solution in a certain proportion so that the acidity of the base reaches 50-55°T;

[0059] (2) Homogenization at 30 / 180 bar pressure;

[0060] (3) Cool down to below 10℃ for aseptic filling.

[0061] Milk contains only a very small amount of non-protein nitrogen. Lactobacillus casei or Lactobacillus paracasei have a weak ability to hydrolyze milk protein, resulting in a slow fermentation and acid production rate. Therefore, milk is not an ideal nitrogen source for the growth of Lactobacillus paracasei. The present invention applies a whey protein hydrolysate prepared by a specific formula and process to the production of a brown active lactic acid bacteria beverage. The low-molecular-weight peptides and amino acids in the whey protein hydrolysate can increase the proliferation of lactic acid bacteria, accelerate the acid production rate of lactic acid bacteria, significantly reduce fermentation time, and increase the viable count and stability of the product during its shelf life, meeting consumers' growing demand for healthy products. DETAILED DESCRIPTION

[0062] In order to have a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be understood as limiting the scope of implementation of the present invention.

[0063] The cathepsin B used in the following examples and comparative examples of the present invention was purchased from Novozymes Biotech Ltd.

[0064] Example 1

[0065] This embodiment provides a brown active lactic acid bacteria beverage, which is prepared by the following steps:

[0066] (1) Raw material formula (based on 1000g):

[0067] Fermented milk: 250g; White sugar: 130g; Lactic acid: 0.5g; Edible flavoring: 1g; Pure water to 1000g;

[0068] Among them, fermented milk formula (based on 1000g):

[0069] 125g skim milk powder, 20g anhydrous glucose, 60g whey protein hydrolysate, 10.1g Lactobacillus paracasei L.casei43, make up to 1000g with purified water;

[0070] Among them, the whey protein hydrolysate formula (based on 1000g):

[0071] Concentrated whey protein powder WPC80 50g, cathepsin B14g, make up to 1000g with pure water.

[0072] (2) Preparation method:

[0073] 1. Preparation of whey protein hydrolysate

[0074] (1) Add RO water, heat to 45-50 ° C, add concentrated whey protein powder WPC80 and stir for 15 minutes to complete the mixing;

[0075] (2) Add cathepsin B and stir for 15 min, then hydrolyze at 45 ± 2 °C for 100 min;

[0076] (3) Inactivate the enzyme at 95 ± 2°C for 10 min;

[0077] (4) Centrifuge at 4°C and 5000 RPM for 20 min and collect the supernatant to obtain the whey protein hydrolysate.

[0078] 2. Preparation of fermented milk

[0079] (1) Add RO water to the batching tank and heat it to 45-50°C. Add skim milk powder and glucose to the mixing tank and stir for 20 minutes. After the mixing is completed, let it stand for 30 minutes for hydration.

[0080] (2) Homogenize at 30 / 180 bar and 65°C;

[0081] (3) heat-browning at 95°C for 180-270 min;

[0082] (4) cooling to 37±1°C to obtain browning reconstituted milk;

[0083] (5) Add the fermentation bacteria and whey protein hydrolysate to the browned reconstituted milk under aseptic conditions, stir for 20 minutes, and ferment. Stop the fermentation when the acidity reaches 185°T, break the emulsion at 30 / 150 bar, and cool to below 10°C for later use.

[0084] 3. Preparation of sugar solution

[0085] (1) Add RO water to the batching tank, add white sugar, lactic acid and edible flavoring while stirring the water, and use a high-speed mixer to stir and dissolve evenly;

[0086] (2) sterilizing at 95°C for 300 seconds to obtain a sugar solution;

[0087] (3) Refrigerate the sugar solution to below 10°C for later use.

[0088] 4. Allocation

[0089] (1) Mixing fermented milk and sugar solution in a certain proportion so that the acidity of the base reaches 50-55°T;

[0090] (2) Homogenization at 30 / 180 bar pressure;

[0091] (3) Cool down to below 10℃ for aseptic filling.

[0092] Example 2

[0093] This embodiment provides a brown active lactic acid bacteria beverage, which is prepared by the following steps:

[0094] (1) Raw material formula (based on 1000g):

[0095] Fermented milk: 250g; White sugar: 55g; Crystallized fructose: 50g; Lactic acid: 0.5g; Edible flavoring: 1g; Pure water to 1000g;

[0096] Among them, fermented milk formula (based on 1000g):

[0097] 125g skim milk powder, 20g anhydrous glucose, 60g whey protein hydrolysate, 10.1g Lactobacillus paracasei L.casei43, make up to 1000g with pure water.

[0098] Among them, the whey protein hydrolysate formula (based on 1000g):

[0099] Concentrated whey protein powder WPC80 50g, cathepsin B14g, make up to 1000g with pure water.

[0100] (2) The preparation method is the same as that of Example 1.

[0101] Example 3

[0102] This embodiment provides a brown active lactic acid bacteria beverage, which is prepared by the following steps:

[0103] (1) Raw material formula (based on 1000g):

[0104] Fermented milk: 265g; White sugar: 130g; Lactic acid: 0.5g; Edible flavoring: 1g; Pure water to 1000g;

[0105] Among them, fermented milk formula (based on 1000g):

[0106] 125g skim milk powder, 20g anhydrous glucose, 60g whey protein hydrolysate, 1000.1g Lactobacillus paracasei LPC, make up to 1000g with purified water;

[0107] Among them, the whey protein hydrolysate formula (based on 1000g):

[0108] Concentrated whey protein powder WPC80 50g, cathepsin B14g, make up to 1000g with pure water.

[0109] (2) The preparation method is the same as that of Example 1.

[0110] Comparative Example 1

[0111] The present comparative example provides a brown active lactic acid bacteria beverage prepared by the following steps:

[0112] (I) Raw material formula (in 1000g):

[0113] Fermented milk: 250g; white granulated sugar: 130g; lactic acid: 0.5g; food flavoring: 1g; pure water to: 1000g;

[0114] Among them, the fermented milk formula (in 1000g):

[0115] Skim milk powder 125g, anhydrous glucose 20g, L. casei 431 0.1g, and pure water to 1000g.

[0116] (II) The preparation method is the same as Example 1.

[0117] Comparative Example 2

[0118] The present comparative example provides a brown active lactic acid bacteria beverage prepared by the following steps:

[0119] (I) Raw material formula (in 1000g):

[0120] Fermented milk: 250g; white granulated sugar: 130g; lactic acid: 0.5g; food flavoring: 1g; pure water to: 1000g;

[0121] Among them, the fermented milk formula (in 1000g):

[0122] Skim milk powder 125g, anhydrous glucose 20g, whey protein enzymatic hydrolysate 20g, L. casei 431 0.1g, and pure water to 1000g;

[0123] Among them, the whey protein enzymatic hydrolysate formula (in 1000g):

[0124] Concentrated whey protein powder WPC80 50g, tissue proteinase B 14g, and pure water to 1000g.

[0125] (II) The preparation method is the same as Example 1.

[0126] Comparative Example 3

[0127] The present comparative example provides a brown active lactic acid bacteria beverage prepared by the following steps:

[0128] Fermented milk: 250g; white granulated sugar: 130g; lactic acid: 0.5g; food flavoring: 1g; pure water to: 1000g;

[0129] Among them, fermented milk formula (based on 1000g):

[0130] 125g skim milk powder, 20g anhydrous glucose, 40g whey protein hydrolysate, 10.1g Lactobacillus paracasei L.casei43, make up to 1000g with purified water;

[0131] Among them, the whey protein hydrolysate formula (based on 1000g):

[0132] Concentrated whey protein powder WPC80 50g, cathepsin B14g, make up to 1000g with pure water.

[0133] (2) The preparation method is the same as that of Example 1.

[0134] Comparative Example 4

[0135] This comparative example provides a brown active lactic acid bacteria beverage, which is prepared by the following steps:

[0136] (1) Raw material formula (based on 1000g):

[0137] Fermented milk: 250g; White sugar: 130g; Lactic acid: 0.5g; Edible flavoring: 1g; Pure water to 1000g;

[0138] Among them, fermented milk formula (based on 1000g):

[0139] 125g skim milk powder, 20g anhydrous glucose, 80g whey protein hydrolysate, 10.1g Lactobacillus paracasei L.casei43, make up to 1000g with purified water;

[0140] Among them, the whey protein hydrolysate formula (based on 1000g):

[0141] Concentrated whey protein powder WPC80 50g, cathepsin B14g, make up to 1000g with pure water.

[0142] (2) The preparation method is the same as that of Example 1.

[0143] Comparative Example 5

[0144] This comparative example provides a brown active lactic acid bacteria beverage, which is prepared by the following steps:

[0145] (1) Raw material formula (based on 1000g):

[0146] Fermented milk: 250g; White sugar: 130g; Lactic acid: 0.5g; Edible flavoring: 1g; Pure water to 1000g;

[0147] Among them, fermented milk formula (based on 1000g):

[0148] 125g skim milk powder, 20g anhydrous glucose, 100g whey protein hydrolysate, 10.1g Lactobacillus paracasei L.casei43, make up to 1000g with purified water;

[0149] Among them, the whey protein hydrolysate formula (based on 1000g):

[0150] Concentrated whey protein powder WPC80 50g, cathepsin B14g, make up to 1000g with pure water.

[0151] (2) The preparation method is the same as that of Example 1.

[0152] Comparative Example 6

[0153] This comparative example provides a brown active lactic acid bacteria beverage, which is prepared by the following steps:

[0154] (1) Raw material formula (based on 1000g):

[0155] Fermented milk: 250g; White sugar: 130g; Lactic acid: 0.5g; Edible flavoring: 1g; Pure water to 1000g;

[0156] Among them, fermented milk formula (based on 1000g):

[0157] 125g skim milk powder, 20g anhydrous glucose, 60g whey protein hydrolysate, 10.1g Lactobacillus paracasei L.casei43, make up to 1000g with purified water;

[0158] Among them, the whey protein hydrolysate formula (based on 1000g):

[0159] 50g concentrated whey protein powder WPC80, 14g papain, make up to 1000g with pure water.

[0160] (2) The preparation method is the same as that of Example 1.

[0161] Comparative Example 7

[0162] This comparative example provides a brown active lactic acid bacteria beverage, which is prepared by the following steps:

[0163] (1) Raw material formula (based on 1000g):

[0164] Fermented milk: 250g; White sugar: 130g; Lactic acid: 0.5g; Edible flavoring: 1g; Pure water to 1000g;

[0165] Among them, fermented milk formula (based on 1000g):

[0166] 125g skim milk powder, 20g anhydrous glucose, 60g whey protein hydrolysate, 10.1g Lactobacillus paracasei L.casei43, make up to 1000g with purified water;

[0167] Among them, the whey protein hydrolysate formula (based on 1000g):

[0168] 50g concentrated whey protein powder WPC80, 14g pepsin, make up to 1000g with pure water.

[0169] (2) The preparation method is the same as that of Example 1.

[0170] Comparative Example 8

[0171] This comparative example provides a brown active lactic acid bacteria beverage, which is prepared by the following steps:

[0172] (1) Raw material formula (based on 1000g):

[0173] Fermented milk: 250g; White sugar: 130g; Lactic acid: 0.5g; Edible flavoring: 1g; Pure water to 1000g;

[0174] Among them, fermented milk formula (based on 1000g):

[0175] 125g skim milk powder, 20g anhydrous glucose, 0.3g cathepsin B, 10.1g Lactobacillus paracasei L.casei43, make up to 1000g with pure water.

[0176] (2) Preparation method:

[0177] 1. Preparation of fermented milk

[0178] (1) Add RO water to the batching tank and heat it to 45-50°C. Add skim milk powder and glucose to the mixing tank and stir for 20 minutes. After the mixing is completed, let it stand for 30 minutes for hydration.

[0179] (2) Homogenize at 30 / 180 bar and 65°C;

[0180] (3) heat-browning at 95°C for 180-270 min;

[0181] (4) Cool to 45 ± 1°C, add cathepsin B under sterile conditions, stir for 15-20 minutes, and let stand for 100 minutes for hydrolysis;

[0182] (5) Cool down to 37±1°C, add fermentation bacteria under sterile conditions, stir for 20 minutes, and ferment. Stop fermentation when the acidity reaches 185°T, break the emulsion at 30 / 150 bar, and cool to below 10°C for use.

[0183] 2. Preparation of sugar solution

[0184] (1) Add ingredient RO water in ingredient tank, under the condition of stirring ingredient water, add white sugar, lactic acid and food flavor, use high speed blender to stir and dissolve uniformly;

[0185] (2) Perform sterilization under the condition of 95°C, 300s, to obtain sugar solution;

[0186] (3) Cool sugar solution to below 10°C for standby.

[0187] 3. Formulation

[0188] (1) Mix fermented milk and sugar solution according to certain proportion, to make base material acidity reach 50-55°T;

[0189] (2) Perform homogenization under the condition of 30 / 180 bar pressure;

[0190] (3) Cool to below 10°C for sterile filling.

[0191] Comparative Example 9

[0192] This comparative example provides a brown active lactic acid bacteria beverage, which is prepared by the following steps:

[0193] (I) Raw material formula (1000g):

[0194] Fermented milk: 250g; white sugar: 130g; lactic acid: 0.5g; food flavor: 1g; pure water: 1000g;

[0195] Among them, the formula of fermented milk (1000g):

[0196] Defatted milk powder 125g, anhydrous glucose 20g, trypsin 0.3g, L. casei 431 0.1g, and pure water to 1000g.

[0197] (II) Preparation method is the same as comparative example 8.

[0198] Test Example 1, verification result of fermented milk fermentation time

[0199] The time required for the end point acidity of fermented milk in the sample of the embodiment and the comparative example to reach 185°T was determined, and the results are shown in Table 1.

[0200] Table 1

[0201]

[0202] The results in Table 1 show that compared to Comparative Example 1 in which no enzymolyte was added, the addition of whey protein hydrolysate can accelerate the acid production rate of fermented milk and shorten the fermentation time; the greater the amount of enzymolyte added, the faster the acid production rate and the shorter the fermentation time. Comparative Example 2 (0.5% addition) and Comparative Example 3 (1% addition) shortened the fermentation time by 6.6% and 9.3% respectively, while Examples 1-3 (1.5% addition) can shorten the fermentation time by about 15%, and their fermentation speed is significantly better than Comparative Examples 1 to 3. The fermentation time of Comparative Example 4 (2% addition) and Comparative Example 5 (2.5% addition) is not significantly different from that of Examples 1-3, indicating that the difference in fermentation time of samples with an enzymolyte addition amount greater than 1.5% is not significant. Comparative Examples 6 (papain, enzymolyte addition 1.5%) and Comparative Examples 7 (pepsin, enzymolyte addition 1.5%) can shorten fermentation time only about 5%, and its reason is that the peptide section and amino acid quantity that the characteristic of above two kinds of protease determines that its whey protein hydrolysate produces are less, so the lifting to fermentation speed is limited. Comparative Examples 8 and Comparative Examples 9 can shorten fermentation time about 3.5%, owing to directly adding protease and carrying out enzymolysis in reconstituted milk, the main component of reconstituted milk is casein, and the active peptides and amino acid whose kind and quantity of generation after the enzymolysis are less, so relatively poor to the proliferation effect of lactic acid bacteria, fermentation speed is slower than adding lactolyte of the present invention.So selecting to use the lactolyte that adds cathepsin and its reasonable addition is that 1.5% effect is better.

[0203] Test Example 2: Sample Shelf Life Stability Verification Results

[0204] Samples from the Examples and Comparative Examples were used as test samples and stored refrigerated at 2-6°C. The water separation and tissue state were visually observed during shelf life, and the centrifugal sedimentation rate was measured. Water separation refers to the height of the precipitated water layer, which was measured with a ruler. The centrifugal rate was determined by placing a certain amount of sample into a centrifuge tube and centrifuging at 3500 rpm for 15 minutes at 20°C. After the sample was centrifuged, the supernatant was slowly discarded and the tube was inverted until no supernatant flowed out. The mass of the precipitate was weighed and the centrifugal rate was calculated by dividing the mass of the precipitate by the mass of the sample. The results are shown in Table 2.

[0205] Table 2

[0206]

[0207]

[0208]

[0209] The results in Table 2 show that the hydrolysis, centrifugation rate and precipitation of the samples in Examples 1-3, Comparative Examples 4 and 5 are significantly lower than those in the other comparative examples, indicating that the peptides and amino acids in the whey protein hydrolysate can be fully utilized by Lactobacillus paracasei, maximizing the proliferation of lactic acid bacteria, thereby allowing the lactic acid bacteria to hydrolyze more casein to form a large number of small molecular weight peptides and amino acids, thereby increasing product stability. Comparative Example 1 does not add enzymolysis liquid, and because Lactobacillus paracasei has a lower casein decomposition rate, the small-molecule peptides produced are minimum, which has a great impact on product stability, and elutriation and centrifugation are obviously higher, and more sediments are on the bottom, and its stability is the worst; the enzymolysis liquid addition of Comparative Examples 2 and 3 is less, and the peptides and amino acids that Lactobacillus paracasei can utilize are limited, which promotes lactic acid bacteria proliferation to a certain extent, but the small-molecule peptides quantity produced by its decomposition is relatively small, and product elutriation and centrifugation are obviously lower than Comparative Example 1, and stability is improved; Comparative Examples 6 and 7 add papain and pepsin enzymolysis liquid respectively, and their enzymolysis efficiency is lower than cathepsin. Under the same addition condition, the small-molecule peptides and amino acid quantity produced by their enzymolysis are obviously less than cathepsin, and the proliferation effect of lactic acid bacteria is relatively poor, so the small-molecule peptides produced by casein hydrolysis are also less, and stability is close to Comparative Examples 2 and 3. Comparative Examples 8 and 9 mainly hydrolyze casein directly by protease. Since the molecular weight of casein itself is relatively large, the molecular weight of the peptides produced by enzymatic hydrolysis is also relatively large, so the product stability is poorer than the effect of adding whey protein hydrolysate.

[0210] Test Example 3: Verification results of viable bacteria count during shelf life of samples

[0211] The samples of the embodiment and the comparative example were used as test samples, and the number of viable bacteria during the shelf life was determined according to GB 4789.35-2010 "National Food Safety Standard - Microbiological Examination of Food - Lactic Acid Bacteria". The results are shown in Table 3.

[0212] Table 3

[0213]

[0214]

[0215] As shown in Table 3, the shelf life validation results of the samples show that the initial viable counts of the samples in Examples 1-3, Comparative Examples 4 and 5 were the highest, reaching 12.0×10 8 The trend of viable bacteria count during shelf life is similar, and the viable bacteria count can reach 1.0×10 9 CFU / mL or above, the number of viable bacteria at room temperature reaches 5.0×10 8CFU / mL or more. The reason is that the whey enzymatic hydrolysate in the above samples contains the largest number of small molecule peptides and amino acids, which can promote the proliferation of lactic acid bacteria to the greatest extent; in Comparative Example 1, since no enzymatic hydrolysate was added, Lactobacillus paracasei had poor ability to hydrolyze casein, and the available small molecule peptides and amino acids were the least, so the number of viable bacteria was the lowest, with an initial viable bacteria count of 6.85×10 8 CFU / mL, at the end of the shelf life, the viable bacterial counts at refrigerated and room temperature were 4.12×10 8 CFU / mL and 2.36×10 8 CFU / mL; the amount of enzymatic hydrolysate added in Comparative Examples 2 and 3 was lower than that in Examples 1-3. The amount of small molecule peptides and amino acids in the enzymatic hydrolysate was relatively small, which could promote the proliferation of lactic acid bacteria to a certain extent. Therefore, the number of viable bacteria was lower than that in Examples 1-3 but higher than that in Comparative Example 1. The initial number of viable bacteria was 9×10 8 CFU / mL, at the end of the shelf life, the number of viable bacteria under refrigeration and room temperature was 6.5×10 8 CFU / mL and 4.0×10 8 CFU / mL; the protease in the enzymatic hydrolysate of the samples of Comparative Examples 6 and 7 is a non-optimal protease, so the number of peptides and amino acids in the enzymatic hydrolysate is also small, which promotes the proliferation of lactic acid bacteria to a certain extent, but the number of viable bacteria is significantly lower than that of Examples 1-3, and is close to that of Comparative Examples 2 and 3. Comparative Examples 8 and 9 use enzymatic hydrolysis by directly adding protease to the reconstituted milk. Because the types and quantities of active peptides and amino acids in the casein hydrolysate are small, the effect on the proliferation of lactic acid bacteria is not obvious, and the number of viable bacteria is lower than that of the sample with added whey enzyme hydrolysate, but it is better than Comparative Example 1 without adding protease.

[0216] Test Example 4: Taste Test Results

[0217] Tasting method: 60 people anonymously rated the taste, evaluating the freshness, sweet-sour ratio, flavor, and overall evaluation. Each indicator scored out of 10 points, with higher scores indicating better results. The tasting results were statistically analyzed, as shown in Table 4:

[0218] Table 4 Taste test results of different samples

[0219]

[0220] The sample taste test results show that the freshness, the sweet-sour ratio, the flavor and the comprehensive evaluation indexes of the samples of Examples 1-3, Comparative Examples 1-3 have no significant difference and the scores are high. It is shown that the cathepsin enzyme solution has no obvious influence on the flavor and taste of the brown lactic acid bacteria beverage in the range of less than 2% of the addition amount. The taste of Comparative Examples 4 and 5 has an odor, and the odor of Comparative Example 5 is more obvious than that of Comparative Example 4, which shows that the addition amount of the enzyme solution is greater than 2% and an odor is produced, which is caused by the taste of the enzyme solution itself, and the odor is more obvious with the increase of the enzyme solution, so the flavor and the comprehensive evaluation are low. Comparative Example 6 uses papain enzyme solution, and the flavor meets the requirements. Comparative Example 7 has a bitter taste, and the reason is that the bitter polypeptide is produced by the pepsin enzyme solution of whey protein, so the product flavor and the comprehensive evaluation are also low. Comparative Example 8 uses cathepsin to enzymatically hydrolyze the reduced milk, and each index is close to that of Examples 1-3 and is high. Comparative Example 9 uses trypsin to enzymatically hydrolyze the reduced milk, but the enzymatic product has a slight bad flavor, which has a certain influence on the flavor and the comprehensive evaluation.

[0221] The present application adds a specific amount of cathepsin to the concentrated whey protein solution and prepares an enzyme solution through an optimized enzyme hydrolysis process, and then adds it to the browned reduced milk for fermentation and preparation to produce an active lactic acid bacteria beverage. The small molecular peptide segments and amino acids in the whey protein enzyme solution can be fully utilized by lactic acid bacteria to proliferate and accelerate the acid production speed, so that the fermentation time of the fermented milk is reduced by about 15%, and the product energy consumption and production cost are significantly reduced. At the same time, the number of live bacteria in the product can reach more than 1x10 9 CFU / mL within 25 days of shelf life, and has good stability and flavor.

Claims

1. A brown active lactic acid bacteria beverage, which is composed of the following raw materials, calculated based on 100% by weight of the lactic acid bacteria beverage: Skim milk powder 2.2%-5.0%, whey protein hydrolysate 1.2-1.8%, acidity regulator 0.02%-0.5%, lactic acid bacteria 0.001%-0.01%, sweetener 4%-15%, edible flavor 0.03%-0.15% and water; Wherein, the preparation method of the whey protein hydrolysate comprises the following steps: The concentrated whey protein powder WPC80 is dissolved in water and cathepsin is added, and the mixture is hydrolyzed at a constant temperature of 45±2° C., followed by enzyme inactivation and centrifugation to obtain the whey protein hydrolyzate; Wherein, the cathepsin includes one or a combination of two or more of cathepsin B, cathepsin F, cathepsin H, cathepsin K, cathepsin L, cathepsin S, and cathepsin V; Based on the mass of the whey protein hydrolysate being 100%, the added amount of the cathepsin is 1.2%-1.6%; Calculated based on the mass of the whey protein hydrolysate being 100%, the added amount of the concentrated whey protein powder WPC80 is 4%-6%.

2. The brown active lactic acid bacteria beverage according to claim 1, wherein The cathepsin is cathepsin B.

3. The brown active lactic acid bacteria beverage according to claim 1, wherein The preparation method of the whey protein hydrolysate comprises the following steps: (1) Heat water to 45-50°C, add concentrated whey protein powder WPC80, add cathepsin after the material is dissolved, stir and hydrolyze at a constant temperature of 45±2°C for 90-120 minutes; (2) After inactivating the enzyme at 95±2°C for 8-12 minutes, centrifuge at 4-6°C and 4000-8000 RPM for 20-30 minutes, and collect the supernatant to obtain the whey protein hydrolysate.

4. The brown active lactic acid bacteria beverage according to claim 1, wherein The added amount of the whey protein hydrolysate is 1.5%.

5. The brown active lactic acid bacteria beverage according to claim 1, wherein The brown active lactic acid bacteria beverage has a viable bacterial count of 1.0×10 9 CFU / mL or above.

6. The brown active lactic acid bacteria beverage according to claim 1, wherein The sweetener includes one or a combination of two or more of white sugar, glucose, fructose syrup, crystalline fructose, xylose, xylitol, erythritol, maltose, maltitol, sucralose, acesulfame potassium, steviol glycosides, and mogrosides.

7. The brown active lactic acid bacteria beverage according to claim 1, wherein The added amount of the acidity regulator is 0.05%-0.3%.

8. The brown active lactic acid bacteria beverage according to claim 1, wherein The acidity regulator includes one or a combination of two or more of lactic acid, citric acid, sodium citrate, and malic acid.

9. The brown active lactic acid bacteria beverage according to claim 1, wherein The acidity regulator includes lactic acid.

10. The brown active lactic acid bacteria beverage according to claim 5, wherein The added amount of the lactic acid bacteria is 0.002%-0.004%.

11. The brown active lactic acid bacteria beverage according to claim 1, wherein The lactic acid bacteria include one or a combination of two or more of Lactobacillus casei, Lactobacillus plantarum, Lactobacillus acidophilus, Lactobacillus rhamnosus, Lactobacillus bulgaricus, Streptococcus thermophilus, Lactobacillus helveticus, Lactobacillus paracasei, Lactobacillus salivarius, Lactobacillus gestatum, Lactobacillus fermentum, Lactobacillus reuteri, Bifidobacterium longum, Bifidobacterium animalis, Bifidobacterium infantis, Bifidobacterium breve, Bifidobacterium adolescentis, and Bifidobacterium bifidum.

12. The brown active lactic acid bacteria beverage according to claim 1, wherein The lactic acid bacteria is Lactobacillus paracasei.

13. The method for preparing the brown active lactic acid bacteria beverage according to any one of claims 1 to 12, comprising the following steps: The skimmed milk powder, reducing sugar and water are mixed, left to stand for hydration and homogenized once to obtain homogenized reconstituted milk; browning the homogenized reconstituted milk, and then cooling it to obtain browning reconstituted milk; adding fermentation bacteria and whey protein hydrolysate to the browning reduced milk for fermentation, stopping the fermentation when the fermentation ends, breaking the milk, homogenizing, and cooling to obtain brown fermented milk; An acidity regulator is added to the brown fermented milk, and the mixture is homogenized twice to obtain the brown active lactic acid bacteria beverage.

14. The preparation method according to claim 13, wherein The reducing sugar includes one or a combination of two or more of glucose, fructose, xylose, galactose, ribose, deoxyribose, lactose and maltose.

15. The preparation method according to claim 13, wherein The above preparation method comprises the following specific steps: (1) Heat water to 45-50°C, add skim milk powder and reducing sugar, stir and hydrate, let it stand for 30-40 minutes, and homogenize once at 30-50 / 180-200 bar and 65-68°C to obtain homogenized reconstituted milk; (2) The homogenized reconstituted milk is kept at 95±2°C for browning for 180 min to 270 min, and then cooled to 37±1°C to obtain browning reconstituted milk; (3) adding the fermentation bacteria and the whey protein hydrolysate to the browned reduced milk, mixing and fermenting, stopping the fermentation when the acidity reaches 180-190°T, breaking the emulsion at 30-50 / 180-200 bar, and cooling to below 10°C to obtain brown fermented milk; (4) Adding the acidity regulator to water, mixing and sterilizing to obtain an acidity regulating solution; (5) The acidity of the brown fermented milk is adjusted to 50-55°T using the acidity regulating liquid, and secondary homogenization is performed at a pressure of 30-50 / 180-200 bar to obtain the brown active lactic acid bacteria beverage.

16. The preparation method according to claim 13, wherein The acidity regulating liquid in step (4) further comprises edible flavorings and sweeteners.

Images