Double-protein functional layered yoghourt and preparation method thereof

Abstract

The invention belongs to the technical field of dairy products, particularly relates to double-protein functional layered yoghurt and further discloses a preparation method of the double-protein functional layered yoghurt. According to the double-protein functional layered yoghurt disclosed by the invention, by arranging the edible protein film between the yoghurt base material and the functional base material, the yoghurt base material and the functional base material are effectively separated, so that a good layering effect is achieved; the method ensures that the yogurt base material and the functional base material are not in contact in the shelf life so as not to influence the stability and the eating taste of the product, and ensures that stable layering is realized in the shelf life of the normal-temperature yogurt, so that the stability of the functional components is ensured, the yogurt category is innovated, and a new product type is formed.

Description

Technical Field

[0001] The invention belongs to the technical field of dairy products, and in particular relates to a double-protein functional layered yogurt, and further discloses a preparation method thereof. Background Art

[0002] Yogurt and other dairy products have become popular products as a healthy food. With the continuous increase in the types of yogurt products, consumers have more and more requirements for the taste of yogurt. Room temperature yogurt is favored by consumers because it can be stored at room temperature and is rich in nutrition, especially those who do not like cold food. With the high quality development of yogurt itself, more and more functional ingredients will bring higher added value and premium to yogurt.

[0003] However, due to the long shelf life of room temperature yogurt (about 6 months), the functional ingredients are immersed in the yogurt material for a long time, which is prone to oxidation, penetration, and attenuation, which seriously affects the quality of the yogurt product. Layered yogurt products have emerged. For example, a layered yogurt disclosed in Chinese patent CN109619186A includes a yogurt base layer formed by a yogurt base and a nutrient layer formed by a nutrient material, that is, by layering and pouring the yogurt material and the nutrient material, the mixing of the two is avoided to ensure the stability of the yogurt. However, the layering of the yogurt product mainly depends on the viscosity-to-gravity difference between the yogurt base layer and the nutrient layer. Not only is the quality difficult to control, but also during the long shelf life of room temperature yogurt, there is a problem of poor layering effect or even mixing, which makes it difficult to ensure the quality stability of the product.

[0004] Therefore, there is an urgent need in the art to develop room temperature yogurt products with more stable stratification during the shelf life, so as to ensure the stability of functional ingredients and the taste of the product. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present invention is to provide a double-protein functional layered yogurt to solve the problem that the functional ingredients of yogurt products in the prior art are unstable during the shelf life;

[0006] The second technical problem to be solved by the present invention is to provide a method for preparing the above-mentioned double-protein functional layered yogurt.

[0007] In order to solve the above technical problems, the present invention discloses a double-protein functional layered yogurt, which comprises a yogurt base and a functional base contained in a packaging container, and an edible protein film is arranged between the yogurt base and the functional base.

[0008] Specifically, in the double-protein functional layered yogurt, the yogurt base includes a fermentation base and a yogurt starter;

[0009] The fermentation base material comprises the following raw material components by weight based on the total amount: 75-95wt% of milk raw material, 0.1-1wt% of protein powder, 0.1-7wt% of dietary fiber, 2-10wt% of sweetener, and 1-5wt% of stabilizer;

[0010] The amount of the yogurt starter is 0.02-0.2 wt % of the fermentation base.

[0011] Preferably, in the double-protein functional layered yogurt, the fermentation base comprises the following raw material components by weight, calculated on the total amount: 80-90wt% of milk raw material, 0.2-0.7wt% of protein powder, 0.5-6wt% of dietary fiber, 6-9wt% of sweetener, and 1.5-2wt% of stabilizer;

[0012] The amount of the yogurt starter is 0.04-0.1wt% of the fermentation base.

[0013] Specifically, the double-protein functional layered yogurt:

[0014] The milk raw material includes one or a mixture of milk, cow's milk, milk powder, cream, hydrolyzed protein, whey powder; and / or,

[0015] The protein powder comprises high-lactose protein powder; preferably, the lactose content in the protein powder is ≥5wt%; and / or,

[0016] The dietary fiber is insoluble dietary fiber, preferably including one or a mixture of soybean fiber, citrus fiber, cellulose, hemicellulose, lignin, etc.; and / or,

[0017] The sweetener includes one or a mixture of white sugar, fructose syrup, maltose, erythritol or steviol glycoside; and / or,

[0018] The yogurt starter comprises one or a mixture of several of Lactobacillus bulgaricus, Streptococcus thermophilus, Lactobacillus plantarum, Lactobacillus casei, Lactococcus lactis subsp. lactis or Lactococcus lactis subsp. cremoris; and / or,

[0019] The stabilizer comprises one or a mixture of starch, pectin, gelatin, agar or konjac gum.

[0020] Specifically, in the double-protein functional layered yogurt, the edible protein film is an edible plant protein film;

[0021] Preferably, the edible protein film comprises raw material components in the following mass ratio: soy protein: gelatin: endopeptidase: water = 30-50: 10-20: 2-4: 100-200.

[0022] Preferably, the edible protein film comprises raw material components in the following mass ratio: soy protein: gelatin: endopeptidase: water = 35-45: 12-18: 2.5-3.5: 150-180.

[0023] Specifically, in the double-protein functional layered yogurt, the endopeptidase includes one or a mixture of trypsin, chymotrypsin or elastase.

[0024] Specifically, in the double-protein functional layered yogurt, the functional base material includes fruits and vegetables, grains, nuts or popping pearls;

[0025] Preferably, the functional base material comprises explosive beads formed by embedding a cross-linked material;

[0026] Preferably, the popping beads may also contain juice or fruit pieces;

[0027] Preferably, the cross-linking material includes one or a mixture of gamma-aminobutyric acid, hyaluronic acid, collagen peptide or sodium hyaluronate.

[0028] In the double-protein functional layered yogurt of the present invention, the functional base material can be selected from conventional materials, and the preparation method of the selected base materials such as popping beads or fruits, vegetables, and cereal particles does not affect the performance of the layered yogurt.

[0029] The present invention provides a method for preparing the double-protein functional layered yogurt, comprising the following steps:

[0030] (1) according to the raw material ratio of the yogurt base, taking a selected amount of the milk raw material, protein powder, dietary fiber, sweetener and stabilizer for mixing, homogenizing, and sterilizing, adding a selected amount of the yogurt starter for fermentation, collecting the fermentation product, breaking the emulsion, and secondary pasteurization to obtain the desired yogurt base, and filling it into a selected packaging container;

[0031] (2) according to the raw material ratio of the edible protein film, taking a selected amount of the soy protein and gelatin and dispersing them in water, then adding endopeptidase for enzymolysis, collecting the enzymolysis solution and pouring it into the upper layer of the yogurt base, and aseptically cooling it until a film is formed;

[0032] (3) Aseptically filling the functional base material into the upper layer of the edible protein film and packaging the film.

[0033] Specifically, in the method for preparing the double-protein functional layered yogurt, in the step (1):

[0034] The temperature of the mixing step is 40-55°C and the mixing time is 10-40 minutes; and / or,

[0035] The temperature of the homogenization step is 45-75°C and the total homogenization pressure is 120-200 bar; and / or,

[0036] The temperature of the sterilization step is 75-105°C and the sterilization time is 200-300s; and / or,

[0037] The temperature of the fermentation step is 25-45° C., and the fermentation time is 5-20 hours.

[0038] Specifically, in the preparation method of the double-protein functional layered yogurt, in the step (2), the temperature of the enzymatic hydrolysis step is 30-60° C.;

[0039] Preferably, the step (2) further comprises the step of cooling the enzymatic hydrolysate to 20°C-25°C.

[0040] Specifically, in the preparation method of the double-protein functional layered yogurt, in the step (2), the aseptic cooling step includes blowing in 4°C-10°C aseptic gas to cool and form a film;

[0041] Preferably, the cooling film forming time is 8-10 minutes;

[0042] Preferably, the sterile gas includes one or a mixture of nitrogen, helium or argon.

[0043] The double-protein functional layered yogurt of the present invention provides an edible protein film between the yogurt base and the functional base, so that the yogurt base and the functional base are effectively separated to achieve a good layering effect, thereby ensuring that the yogurt base and the functional base will not come into contact with each other during the shelf life and affect the product stability and edible taste, and ensuring stable layering during the shelf life of the room temperature yogurt, thereby ensuring the stability of the functional ingredients, while innovating the yogurt category and forming a new product type.

[0044] The double-protein functional layered yogurt of the present invention achieves the texture requirements of a delicate and thick yogurt product by optimizing the screening of high-lactose gel protein, insoluble dietary fiber and stabilizer in the processing system of the yogurt base, and by adjusting the types and ratios of proteins and colloids. The high-textured yogurt system has a stable supporting function, which can "support" the upper protein film to ensure continuous stability and achieve a good layering effect. The insoluble dietary fiber side chains can also absorb water precipitation caused by interfacial tension pressure of the protein film, effectively ensuring the continuous stability of the yogurt product.

[0045] The double-protein functional layered yogurt of the present invention is a layer of plant protein-based edible film poured on the upper layer of the yogurt, which is an innovative layering form. Its purpose is to be able to layer the yogurt and the functional ingredients, which can be pierced with the tip of a spoon when eating. At the same time, soy protein belongs to plant protein, and the final product can achieve the application effect of "double protein". The product rich in plant and animal double protein can maximize the nutritional value by reasonably matching plant protein and animal protein.

[0046] The double-protein functional layered yogurt of the present invention has an edible protein film made of soy protein, gelatin, glycerol and transglutaminase to form a texture with good pressure resistance and tensile resistance, and ensures that it has good toughness and hardness while taking into account the taste, and can resist the pressure of the infusion functional ingredients and the gravity of the material on the film during the shelf life. Since the soy protein in the film has a certain hydrophobicity, it can ensure that the film will not penetrate into the yogurt on the one hand, and on the other hand, ensure the stability of the material on the film.

[0047] The double-protein functional layered yogurt of the present invention embeds the functional ingredients or fruit particles and juices rich in functional ingredients in the upper layer of the edible protein film, and adopts an aseptic docking system to aseptically add them to the soy protein-based edible film, thereby achieving good stratification of the functional ingredients and the yogurt. The aseptic docking system is used to infuse the functional bursting beads, which effectively avoids the secondary heating of the functional ingredients and the damage of the bursting beads, thereby ensuring the stability of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0049] Figure 1 The rheological viscosity test results of the yogurt product prepared in Example 1;

[0050] Figure 2 The rheological viscosity test results of the yogurt product prepared in Example 2;

[0051] Figure 3 The rheological viscosity test results of the yogurt product prepared in Example 3;

[0052] Figure 4 The rheological viscosity test results of the yogurt product prepared in Comparative Example 1;

[0053] Figure 5 Comparison of centrifugal water loss rates of yogurt products of Examples 1-3 and Comparative Example 1. From left to right, the samples are respectively Examples 1-3 and Comparative Example 1;

[0054] Figure 6 The figure shows a comparison of particle breakage of yogurt products prepared in Examples 1-3 and Comparative Example 3. DETAILED DESCRIPTION

[0055] Example 1

[0056] The present embodiment provides a double-protein functional layered yogurt, the preparation method of which comprises the following steps:

[0057] (1) 891 kg of milk was heated to 45° C. and then the materials were dissolved. 5 kg of high lactose protein powder, 6 kg of soybean fiber, 80 kg of white sugar, and 18 kg of stabilizer (including 1.8 kg of agar, 1.8 kg of pectin, 5 kg of gelatin, 0.3 kg of gellan gum, and 9.1 kg of starch) were added to the milk in sequence. The stirring speed was controlled to 40 rpm and the mixture was stirred for 20 min to allow the raw materials to be fully dissolved.

[0058] The mixed mixture is homogenized at a temperature of 55° C. and a total pressure of 160 bar to obtain a homogenized product;

[0059] The homogenized product was sterilized at 85°C for 300s, and then the sterilized product was cooled to 43°C;

[0060] Add 0.35 kg of fermentation agent containing Lactobacillus bulgaricus and Streptococcus thermophilus in conventional proportions to the cooled sterilized product, ferment in a fermentation tank at 43° C. until the acidity of the fermentation liquid is greater than 70° and the pH is less than 4.6, then stir and break the emulsion, and at the same time lower the temperature of the yogurt to 15° C.;

[0061] The obtained yogurt base is evenly filled to the bottom of the packaging container according to 80% of the packaging container volume, and set aside;

[0062] (2) 40 kg of soy protein and 15 kg of gelatin were uniformly dispersed in 150 kg of water, and 3 kg of trypsin was added. After being enzymatically hydrolyzed at 45° C. with constant temperature stirring, the mixture was cooled to 20° C.-25° C., and poured into the upper layer of the yogurt base in the above container. The amount poured was twice the surface area of ​​the upper layer of the yogurt.

[0063] Blow 5°C sterile nitrogen into the container for about 10 minutes, and wait for the film to cool down to form an edible protein film;

[0064] (3) After adding calcium salt to hyaluronic acid, the mixture is dripped into a mixed solution of pectin, sodium alginate and water to encapsulate the popping beads, and the resulting popping beads are poured into the upper layer of the edible protein film through an aseptic filling system to obtain the dual-protein functional layered yogurt.

[0065] Example 2

[0066] The present embodiment provides a double-protein functional layered yogurt, the preparation method of which comprises the following steps:

[0067] (1) 890 kg of milk was heated to 40° C. and then the materials were dissolved. 4 kg of high lactose protein powder, 5 kg of soybean fiber, 85 kg of white sugar, and 16 kg of stabilizer (including 1.6 kg of agar, 1.5 kg of pectin, 6 kg of gelatin, 0.2 kg of gellan gum, and 6.7 kg of starch) were added to the milk in sequence. The stirring speed was 40 rpm and the stirring was performed for 20 min to allow the raw materials to be fully dissolved.

[0068] The obtained mixture is subjected to a homogenization treatment, wherein the homogenization temperature is 60° C. and the total homogenization pressure is 180 bar, to obtain a homogenous product;

[0069] The homogenized product was sterilized at 90°C for 200s, and then the sterilized product was cooled to 43°C;

[0070] Add 0.25 kg of fermentation agent containing Lactobacillus bulgaricus and Streptococcus thermophilus in a conventional ratio to the cooled sterilized product, and ferment in a fermentation tank at 43°C until the acidity of the fermentation liquid is greater than 70° and the pH is less than 4.6, breaking the emulsion and stirring, and at the same time lowering the temperature of the yogurt to 10°C;

[0071] The obtained yogurt base is evenly filled to the bottom of the packaging container according to 80% of the packaging container volume, and set aside;

[0072] (2) 30 kg of soy protein and 20 kg of gelatin were uniformly dispersed in 100 kg of water, and 3 kg of chymotrypsin was added. After enzymolysis at 55° C. with stirring, the mixture was cooled to 20° C.-25° C. and poured into the upper layer of the yogurt base in the container. The amount poured was twice the surface area of ​​the upper layer of the yogurt.

[0073] Blow 3°C sterile nitrogen into the container for about 10 minutes, wait for the film to cool, and form an edible protein film;

[0074] (3) γ-aminobutyric acid is added with calcium salt and then dripped into a mixed solution of pectin, sodium alginate and water to be embedded in the popping beads, and the obtained popping beads are poured into the upper layer of the above-mentioned edible protein film through a sterile filling system to obtain the dual-protein functional layered yogurt.

[0075] Example 3

[0076] The present embodiment provides a double-protein functional layered yogurt, the preparation method of which comprises the following steps:

[0077] (1) 906 kg of milk was heated to 50° C. and then the materials were dissolved. 2 kg of high lactose protein powder, 2 kg of citrus fiber, 70 kg of white sugar, and 20 kg of stabilizer (including 2.0 kg of agar, 0.5 kg of pectin, 3 kg of gelatin, 0.2 kg of gellan gum, and 14.3 kg of starch) were added to the milk in sequence. The stirring speed was 40 rpm and the stirring was continued for 20 min to allow the raw materials to be fully dissolved.

[0078] The mixed mixture is homogenized at a temperature of 60° C. and a total pressure of 180 bar to obtain a homogenized product;

[0079] The homogenized product was sterilized at 90°C for 200s, and then the sterilized product was cooled to 43°C;

[0080] Add 0.25 kg of fermentation agent containing Lactobacillus bulgaricus, Streptococcus thermophilus, Lactobacillus plantarum and Lactobacillus casei in conventional proportions to the cooled sterilized product, ferment in a fermentation tank at 43° C. until the acidity of the fermentation liquid is greater than 70° and the pH is less than 4.6, and the emulsion is broken and stirred, while the temperature of the yogurt is reduced to 10° C.;

[0081] The obtained yogurt base material is evenly filled to the bottom of several selected packaging containers according to an appropriate filling amount, and is set aside; the obtained yogurt base material is evenly filled to the bottom of the packaging container according to 80% of the packaging container volume, and is set aside;

[0082] (2) 50 kg of soy protein and 10 kg of gelatin are uniformly dispersed in 200 kg of water, and 2 kg of elastase is added. After enzymolysis at 35° C. with constant stirring, the mixture is cooled to 20° C.-25° C. and poured into the upper layer of the yogurt base in the container. The amount poured is twice the surface area of ​​the upper layer of the yogurt.

[0083] Blow 2°C sterile nitrogen into the container for about 10 minutes, and wait for the film to cool down to form an edible protein film;

[0084] (3) taking collagen peptides, adding calcium salt and dripping into a mixed solution of pectin, sodium alginate and water to embed the popping beads, and pouring the obtained popping beads into the upper layer of the above-mentioned edible protein film through a sterile filling system to obtain the dual-protein functional layered yogurt.

[0085] Example 4

[0086] The preparation method of the double-protein functional layered yogurt described in this embodiment is the same as that in Embodiment 1, the only difference being that the raw material ratio of the yogurt base is different.

[0087] In this embodiment, the yogurt base includes the following raw material components: 869 kg of milk, 1 kg of high lactose protein powder, 60 kg of citrus fiber, 20 kg of white sugar, and 50 kg of stabilizer (the ingredients and proportions are the same as in Example 1).

[0088] In this embodiment, the edible protein film includes the following raw material components: 40 kg of soy protein, 150 kg of water, 10 kg of gelatin, and 2 kg of endopeptidase.

[0089] Example 5

[0090] The preparation method of the double-protein functional layered yogurt described in this embodiment is the same as that in Embodiment 1, the only difference being that the raw material ratio of the yogurt base is different.

[0091] In this embodiment, the yogurt base includes the following raw material components: 869 kg of milk, 10 kg of high lactose protein powder, 1 kg of citrus fiber, 100 kg of white sugar, and 20 kg of stabilizer (the ingredients and proportions are the same as those in Example 1).

[0092] In this embodiment, the edible protein film includes the following raw material components: 40 kg of soy protein, 150 kg of water, 20 kg of gelatin, and 4 kg of endopeptidase.

[0093] Comparative Example 1

[0094] The ingredients and preparation method of the layered yogurt described in this comparative example are the same as those in Example 1, the only difference being that, in the yogurt base, ordinary protein powder (lactose content 1%-4%) is used instead of the high lactose protein powder, and soluble dietary fiber (polydextrose) is selected to replace the insoluble dietary fiber (soy fiber).

[0095] Comparative Example 2

[0096] The ingredients and preparation method of the layered yogurt in this comparative example are the same as those in Example 1, the only difference being that egg white liquid is used instead of soy protein, and agar is used instead of gelatin in the protein film ingredients.

[0097] Comparative Example 3

[0098] The ingredients and preparation method of the layered yogurt in this comparative example are the same as those in Example 1, the only difference being that the filling step of the functional base material adopts a tubular heat treatment sterilization method instead of an aseptic filling system.

[0099] Experimental example

[0100] 1. Product viscosity analysis

[0101] The viscosity corresponding to the shear rate of 75 1 / s was measured using an Anton Paar MCR302 rheometer. The viscosity of the yogurt obtained in Examples 1-3 and Comparative Example 1 was tested respectively. The results are as follows: Figure 1-4 In the curve shown:

[0102] ● represents viscosity (i.e., the right ordinate, mPa.s), ● viscosity. From the two flow curves, it can be seen that the sample becomes thinner after shearing, where the right ordinate corresponding to the shear rate of the abscissa is 75 1 / s is the corresponding viscosity value;

[0103] ▲ represents shear stress (i.e. the left vertical axis, Pa), and the area composed of ▲ represents the thixotropic area of ​​the product. The size of this area can represent the thixotropy of the sample. The larger the area, the slower the structural recovery speed of the sample, and the smaller the area, the faster the structural recovery speed of the sample. This parameter is not the focus of the discussion of the technical effects of this application.

[0104] Depend on Figure 1-4 It can be seen from the results that when the shear rate is 75 1 / s, the viscosities of the products of Examples 1-3 are 1.6119 Pa.s, 1.4963 Pa.s, and 1.421 Pa.s, respectively, and the viscosity of the product of Comparative Example 1 is 0.46198 Pa.s, indicating that high lactose protein powder + insoluble dietary fiber can increase the viscosity of the product compared to ordinary protein powder + soluble dietary fiber, so that the product has high texture characteristics, can have a certain supporting effect on the upper protein film, and can help to achieve a good stratification effect.

[0105] 2. Product stability analysis

[0106] The centrifugal water loss rate can reflect the stability of the sample. The higher the water loss rate, the more unstable the product is, and the water-emulsion separation phenomenon is likely to occur during the shelf life. The centrifugal water loss rate was used to analyze the stability of the yogurt products prepared in Examples 1-3 and Comparative Example 1. The results are shown in Table 1 below. The centrifugal water loss of each yogurt product is shown in the attached table. Figure 5 As shown, from left to right, the samples are respectively Examples 1-3 and Comparative Example 1 。

[0107] Table 1 Centrifugal water loss rate

[0108] serial number Centrifugal water loss rate Example 1 0％ Example 2 0％ Example 3 0.8％ Comparative Example 1 17％

[0109] As shown in Table 1, the centrifugal water loss rates of the yogurt products in Examples 1-3 were all 0%-0.8%, which was much lower than the 17% water loss rate of the product in Comparative Example 1. This was because insoluble dietary fiber had many more synapses than soluble dietary fiber, and could adsorb water due to the interfacial tension and gravity of the upper membrane and functional components.

[0110] 3. Product stratification effect

[0111] The layered effect of the double-protein functional layered room temperature yogurt prepared in Examples 1-5 and Comparative Examples 1-2 was evaluated, and the specific method was as follows: 20 randomly selected tasters evaluated the visual layered effect of the product. The evaluation adopted a scoring method: the scoring method is a method of using digital scoring to evaluate products or product characteristics, and finally the quality is determined by the average score. The scoring rule is based on an interval of 0-10 points, 0-2 points are considered poor, 3-5 points are considered fair, 6-8 points are considered good, and 9-10 points are considered excellent.

[0112] The evaluation results are shown in Table 2 below.

[0113] Table 2 Stratification effect scoring table

[0114] serial number Layered effect score Example 1 9 Example 2 8 Example 3 8 Example 4 7 Example 5 7 Comparative Example 1 3 Comparative Example 2 2

[0115] The above results show that compared with the products of comparative examples 1-2, the organizational state of examples 1-5 is better, the yogurt under the membrane is thick and smooth, the functional bursting beads are on the membrane, and the stratification boundaries are obvious and clear.

[0116] It can be seen that in the preparation system of edible protein film, replacing soy protein with egg white liquid has poor barrier properties compared to soy protein with good barrier properties, and will gradually penetrate during the shelf life, affecting the effect of the film and then affecting the stratification effect; and replacing gelatin with agar will affect the texture of the film and harden it, making it hard and brittle, which is easily affected by the injection pressure of the material on the perfusion membrane or the bumps during transportation, causing breakage, thereby affecting the stratification effect and product stability.

[0117] 4. Particle breakage

[0118] In this experimental example, the particle breakage degree of the yogurt products in Examples 1-3 and Comparative Example 3 was tested respectively.

[0119] Stack two standard sieves of 10 mesh and 40 mesh together, with the 10 mesh standard sieve on top and the 40 mesh standard sieve on the bottom. Randomly select 4-6 packages of samples and pour them into the 10 mesh standard sieve. Put the two standard sieves into water, shake horizontally for 60 seconds, remove the yogurt, weigh the 40 mesh and 10 mesh standard sieves respectively, and record the results as shown in the attached Figure 6 shown.

[0120] The calculation formula for the breakage degree R (%) of particles in the finished product is: the weight of the 40-mesh standard sieve / the weight of the 40-mesh + 10-mesh standard sieve.

[0121] It can be seen that the particle breakage of Examples 1-3 fluctuates between 5.1% and 12.7%, while the particle breakage of the product in Comparative Example 3 is 25.2% to 28%, which is much higher than that of Examples 1-3. It can be seen that the particles perfused by the aseptic docking system are relatively intact, while the particles sterilized by heat treatment such as tubular and plate treatment have higher losses and poorer integrity.

[0122] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the present invention.

Claims

1. A double-protein functional layered yogurt, characterized in that: The yogurt comprises a yogurt base material and a functional base material contained in a packaging container, and an edible protein film is arranged between the yogurt base material and the functional base material.

2. The double-protein functional layered yogurt according to claim 1, characterized in that: The yogurt base material comprises a fermentation base material and a yogurt starter; The fermentation base material comprises the following raw material components by weight based on the total amount: 75-95wt% of milk raw material, 0.1-1wt% of protein powder, 0.1-7wt% of dietary fiber, 2-10wt% of sweetener, and 1-5wt% of stabilizer; The amount of the yogurt starter is 0.02-0.2 wt % of the fermentation base.

3. The double-protein functional layered yogurt according to claim 2, characterized in that: The milk raw material includes one or a mixture of milk, cow's milk, milk powder, cream, hydrolyzed protein, whey powder; and / or, The protein powder comprises high-lactose protein powder; preferably, the lactose content in the protein powder is ≥5wt%; and / or, The dietary fiber is insoluble dietary fiber, preferably including one or a mixture of soybean fiber, citrus fiber, cellulose, hemicellulose, lignin, etc.; and / or, The sweetener includes one or a mixture of white sugar, fructose syrup, maltose, erythritol or steviol glycoside; and / or, The yogurt starter comprises one or a mixture of several of Lactobacillus bulgaricus, Streptococcus thermophilus, Lactobacillus plantarum, Lactobacillus casei, Lactococcus lactis subsp. lactis or Lactococcus lactis subsp. cremoris; and / or, The stabilizer comprises one or a mixture of starch, pectin, gelatin, agar or konjac gum.

4. The double-protein functional layered yogurt according to any one of claims 1 to 3, characterized in that: The edible protein film is an edible plant protein film; Preferably, the edible protein film comprises raw material components in the following mass ratio: soy protein: gelatin: endopeptidase: water = 30-50: 10-20: 2-4: 100-200.

5. The double-protein functional layered yogurt according to claim 4, characterized in that: The endopeptidase includes one or a mixture of trypsin, chymotrypsin or elastase.

6. The double-protein functional layered yogurt according to any one of claims 1 to 5, characterized in that: The functional base material includes fruits and vegetables, grains, nuts or popping pearls; Preferably, the functional base material comprises explosive beads formed by embedding a cross-linked material; Preferably, the cross-linking material includes one or a mixture of gamma-aminobutyric acid, hyaluronic acid, collagen peptide or sodium hyaluronate.

7. A method for preparing the double-protein functional layered yogurt according to any one of claims 1 to 6, characterized in that: The steps include: (1) according to the raw material ratio of the yogurt base, taking a selected amount of the milk raw material, protein powder, dietary fiber, sweetener and stabilizer for mixing, homogenizing and sterilizing, adding a selected amount of the yogurt starter for fermentation, collecting the fermentation product, breaking the emulsion and performing secondary pasteurization to obtain the desired yogurt base, and filling it into a selected packaging container; (2) according to the raw material ratio of the edible protein film, taking a selected amount of the soy protein and gelatin and dispersing them in water, then adding the endopeptidase for enzymolysis, collecting the enzymolysis solution and pouring it into the upper layer of the yogurt base, and aseptically cooling it until a film is formed; (3) Aseptically filling the functional base material into the upper layer of the edible protein film to obtain the product.

8. The method for preparing the double-protein functional layered yogurt according to claim 7, characterized in that: In the step (1): The temperature of the mixing step is 40-55°C and the mixing time is 10-40 minutes; and / or, The temperature of the homogenization step is 45-75°C and the total homogenization pressure is 120-200 bar; and / or, The temperature of the sterilization step is 75-105°C and the sterilization time is 200-300s; and / or, The temperature of the fermentation step is 25-45° C., and the fermentation time is 5-20 hours.

9. The method for preparing the double-protein functional layered yogurt according to claim 7 or 8, characterized in that: In the step (2), the temperature of the enzymatic hydrolysis step is 30-60°C; Preferably, the step (2) further comprises the step of cooling the enzymatic hydrolysate to 20°C-25°C.

10. The method for preparing the double-protein functional layered yogurt according to any one of claims 7 to 9, characterized in that: In the step (2), the aseptic cooling step includes blowing in 4°C-10°C aseptic gas to cool and form a film; Preferably, the cooling film forming time is 8-10 minutes; Preferably, the sterile gas includes one or a mixture of nitrogen, helium or argon.

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