Embedded particles and preparation method thereof and application in yogurt preparation

Abstract

The present invention relates to the technical field of embedded particle preparation, and specifically discloses an embedded particle and a preparation method thereof and an application thereof in yogurt preparation. The embedded particle of the present invention comprises: an inner core and a rubber layer, the inner core comprises bacterial powder and grease; the rubber layer is solidified by a rubber liquid; the rubber liquid comprises a first colloid component, a second colloid component and sodium alginate; the first colloid component comprises konjac gum and xanthan gum in a mass ratio of (1-1.9):1; the second colloid component comprises gelatin and carrageenan in a mass ratio of (1.25-1.6):1; the mass ratio of the first colloid component to the second colloid component is 1:(0.25-1); the final mass ratio of the inner core and the rubber layer is 1:(0.5-0.6). The embedded particle of the present invention can ensure the content / activity of the active substance in the inner core, has strong acid resistance and shear resistance, is light in weight, and is conducive to suspension.

Description

Technical Field

[0001] The invention relates to the technical field of embedded particle preparation, in particular to an embedded particle and a preparation method thereof and application thereof in yogurt preparation. Background Art

[0002] There are two ways to add particles to yogurt. First, add particles directly. This method requires the development of a customized particle aseptic addition system based on the properties of the particles to control the mixing accuracy and asepticity of solid particles and liquid. Second, use liquid (such as jam) as a carrier for particles, sterilize at high temperature and pump them into yogurt together (see the process flow diagram for details). Figure 1 ); This is a common method for preparing yogurt containing fruit particles / particles. It can achieve a high sterilization effect and reduce the microbial risk of the product. However, after high-temperature sterilization, the particles containing active substances are prone to reducing the content / activity of active substances. In addition, the shear resistance of live bacteria particles under high-temperature sterilization is also weakened, and they are easy to break. In addition, because the jam is too viscous, the amount of particles added cannot be too much, otherwise it will be difficult to disperse and will cause the risk of pipe clogging, which makes the number of live bacteria particles in the product generally small. Moreover, the conventionally prepared live bacteria particles are larger and heavier, and are not easy to be stably suspended in yogurt, which affects the taste of the product.

[0003] Specifically, Chinese patent CN200710079314.5 discloses that the sterilization of fruit particles adopts a single sleeve or tube sterilizer, the sterilization temperature is 100-120℃, and the sterilization time is 25-35s. Disadvantages: The sterilization temperature is high, and if it is applied to live bacteria particles, it will affect the bacterial activity. CN211076424U discloses online addition of particles to contain a material cylinder in a magnetic stirring system to solve the problem of uneven addition of jam and fruit particles. Disadvantages: Customized equipment is required, and high-temperature sterilization is required after the particles are mixed with the jam. CN202210271878.3 discloses a fruit particle suspension solidification type yogurt and a preparation method thereof, and CN102812999B discloses a fruit particle solidification type yogurt and a preparation method thereof. They prepare solidification type yogurt, which is easy for fruit particles to suspend, and the method is not suitable for stirred yogurt (such as yogurt with a viscosity in the range of 400-1000mPa·s). CN115997821B discloses a popping bead yogurt and its preparation method. The yogurt is prepared by using a certain proportion of stabilizer, which can keep the popping beads (with a diameter of 8-12 mm) more stable in the entire popping bead yogurt system. Disadvantages: The stabilizer ingredients are relatively large, including starch, pectin, agar, gelatin, gellan gum and microcrystalline cellulose. There are also existing technologies that use smaller fruit particles (1-3 mm 3) to solve the suspension problem, but it is difficult to prepare embedded particles to such a small size, and even if the reverse dripping of the dripping pill can be successfully made, the inner core will inevitably be small (containing less active substance) or the outer skin will be thin (easy to break). Therefore, it is necessary to develop a new active substance particle and its application method. Summary of the invention

[0004] One of the purposes of the present invention is to provide an embedded particle which is not easy to break, light in weight, easy to suspend, and has a good effect of maintaining the number of viable bacteria, and its application.

[0005] The invention provides an embedded particle, comprising: an inner core and a rubber layer, wherein the inner core comprises bacterial powder and grease; the rubber layer is formed by solidifying a rubber liquid; the rubber liquid comprises a first colloid component, a second colloid component and sodium alginate; the first colloid component comprises konjac gum and xanthan gum in a mass ratio of (1-1.9):1; the second colloid component comprises gelatin and carrageenan in a mass ratio of (1.25-1.6):1; the mass ratio of the first colloid component to the second colloid component is 1:(0.25-1); and the final mass ratio of the inner core and the rubber layer is 1:(0.5-0.6).

[0006] The present invention has found that when bacterial powder is embedded in a specific rubber layer, embedded particles with good protection performance and light overall weight can be obtained, thereby meeting the requirements of shear resistance and acid resistance when added to food later, and are suitable for being added to liquid food systems as suspended particles to achieve stable suspension.

[0007] Specifically, the present invention has found that konjac gum and xanthan gum in the rubber liquid of the present invention are used in combination at a specific ratio, and the double helix structure of the xanthan gum molecule is easily interlocked with the β-1,4 bond of konjac gum, thereby improving the protective performance. In addition, the present invention has also found that the gelatin molecules are linked by hydrogen bonds, but are not enough to form a continuous spatial network structure, and when they are compounded with carrageenan in a specific ratio, the spatial network structure can be strengthened. When the specific combination of konjac gum and xanthan gum is matched with the specific combination of gelatin and carrageenan, it can provide an ideal protective effect for the bacterial powder in the embedded particles under the premise that the overall mass of the particles is relatively light, and expand the application mode of the embedded particles.

[0008] Preferably, the first colloidal component comprises konjac gum and xanthan gum in a mass ratio of (1-1.86):1 (more preferably (1.85-1.86):1); the second colloidal component comprises gelatin and carrageenan in a mass ratio of (1.25-1.54):1 (more preferably (1.53-1.54):1).

[0009] The embedded particles of the present invention can be prepared by a pellet method, and the mass ratio of the inner core to the rubber layer in the prepared wet pellets (wet pellets) is 1: (4-7), preferably 1: (4-5), and after drying (the moisture content of the pellet surface is less than 3%), the final mass ratio of the inner core to the rubber layer is 1: (0.5-0.6).

[0010] In the embedded particles of the present invention, the concentration of sodium alginate in the glue liquid is 5-15‰ (preferably 5-10‰); the viscosity of the glue liquid is 200-300mPa·s (under the viscosity and material composition of the glue liquid of the present invention, the total concentration of the first colloid and the second colloid is 15-25‰).

[0011] And / or, curing is achieved by contacting the rubber liquid with a calcium salt solution.

[0012] The sodium alginate in the rubber liquid of the present invention can react with calcium ions in the calcium salt solution to achieve solidification of the particles. In the rubber liquid of the present invention, with the cooperation of other rubber liquid components, sodium alginate is added in a relatively low amount to achieve an ideal protective effect.

[0013] In the present invention, the viscosity is tested by using a rotational rheometer (DV2T, VISCOMETER), using a rotor LV-1 (61), setting the temperature to 25 degrees, and setting the shear rate to 50s -1 The degree of esterification of low-ester pectin is 30%-35%.

[0014] Preferably, the calcium salt solution is a calcium chloride solution or a calcium lactate solution with a concentration of 15-40‰; more preferably, the calcium salt solution is a 15-20‰ calcium chloride solution, so as to shorten the curing time and save the amount of calcium salt.

[0015] In the present invention, the content of calcium ions in the calcium salt solution (curing solution) should be able to react completely with the sodium alginate in the rubber solution.

[0016] In the embedded particles of the present invention, the mass percentage of the bacterial powder in the inner core is 5-20% (preferably 10-20%);

[0017] The bacterial powder includes one or more of Bifidobacterium animalis, Bifidobacterium adolescentis, Bifidobacterium bifidum, Bifidobacterium breve, Bifidobacterium infantis, Bifidobacterium longum, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus crispatus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus delbrueckii lactis subsp. lactis, Lactobacillus fermentum, Lactobacillus gasseri, Lactobacillus helveticus, Lactobacillus johnsonii, Lactobacillus paracasei, Lactobacillus plantarum, Lactobacillus reuteri, Lactobacillus rhamnosus, Lactobacillus salivarius, and Bacillus coagulans;

[0018] The oil comprises one or more of corn oil, palm oil, linseed oil, rapeseed oil and sunflower oil.

[0019] The bacterial powder of the present invention may be a known probiotic powder, preferably a probiotic powder with good heat resistance.

[0020] The present invention preferably uses oils with longer carbon chains and more unsaturated fatty acids, which take into account both healthiness and oil fluidity, so as to facilitate the dispersion of bacterial powder and the subsequent preparation of drop pills.

[0021] The diameter of the embedded particles of the present invention is 3-4 mm.

[0022] The embedded particles of the present invention have an appropriate size, which is conducive to taking into account both the amount of bacterial powder added and the shear resistance of the particles, and reduces shear crushing while embedding more bacterial powder.

[0023] The present invention also provides a method for preparing the embedded particles, wherein the inner core is wrapped in the rubber liquid in a pellet manner, and then solidified in a calcium salt solution and dried.

[0024] Those skilled in the art can set specific operating parameters of the dropping pills according to common sense, and use conventional methods in the art to solidify the particles to achieve the mass ratio of the inner core and the rubber layer defined in the present invention.

[0025] As a specific implementation, the core liquid tank temperature can be 30-40°C, the core liquid pump speed can be 100-150r / min, the glue tank temperature can be 85-90°C, the glue pump speed can be 400-500r / min, the dripper temperature can be 85-90°C, and the refrigeration temperature can be 8-10°C.

[0026] The solidification time of the embedded particles can be 30-60 minutes. Stir for 5-15 seconds every 10 minutes, then soak, sieve and wash with water. Transfer to the rotary drying equipment and dry for 4-8 hours, so that the water activity of the outer layer of the particles after drying is less than 3%.

[0027] The present invention also provides the use of the embedded particles or the embedded particles prepared by the method in preparing food.

[0028] The present invention also provides a method for preparing yogurt, which comprises the step of adding the above-mentioned embedded particles or the embedded particles prepared by the method.

[0029] The method for preparing yoghurt of the present invention comprises:

[0030] (1) animal milk is fermented with a starter and a slime-producing fungus to prepare a liquid 1, wherein the fermentation substrate comprises animal milk, a sweetener and a stabilizer; the stabilizer comprises agar, citrus fiber, flaxseed gum and low-ester pectin; the agar accounts for 50-65% (preferably 50-55%) of the total mass of the stabilizer; the mass ratio of the citrus fiber, flaxseed gum and low-ester pectin is 1:(0.4-0.6):(1.4-1.6);

[0031] The protein content in the fermentation substrate is 4.0-4.5%; the mass ratio of the stabilizer to the protein is 1:(1.8-2.5);

[0032] The ratio of the number of live bacteria of the slime-producing mold to the fermentation agent is 1:(0.5-1.5); the viscosity of the feed liquid 1 is 550-650 mPa·s;

[0033] (2) mixing high-ester pectin with water to prepare liquid 2; the mass concentration of the high-ester pectin in the liquid 2 is 2-4% (preferably 2.8-3.2%);

[0034] (3) mixing the embedded particles with the feed solution 2 to obtain the feed solution 2 containing the embedded particles, wherein the mass concentration of the embedded particles in the feed solution 2 containing the embedded particles is 10-15%;

[0035] (4) The liquid 1 and the liquid 2 containing embedded particles are mixed in a mass ratio of (8-9): (1-2).

[0036] The invention studies the formula of yogurt and the adding method of embedded particles, and finally prepares a live bacteria yogurt (non-coagulated type) containing active substances and with stable suspended particles.

[0037] Specifically, in order to allow the embedded particles to be suspended in yogurt with a viscosity of 550-650 mPa·s, the present invention has conducted a lot of research on the fermentation link and the formulation link, and finally found that in the presence of a specific stabilizer, after fermenting animal milk with a certain protein content with a starter and a slime-producing fungus, the obtained liquid 1 can be combined with the specific liquid 2. When less stabilizer is added, the stable suspension of the embedded particles and the stability of the system are guaranteed, and a yogurt product with a high content of viable bacteria and relatively stable is obtained.

[0038] In the present invention, a suitable protein content is helpful for the fermentation process of the present invention to proceed and for obtaining a feed liquid 1 with a specific viscosity.

[0039] In the present invention, the esterification degree of the high-ester pectin is 64%-68%.

[0040] The protein in the fermentation substrate of the present invention can be provided only by animal milk after concentration (such as RO membrane concentration). Preferably, in the method for preparing yogurt of the present invention, the fermentation substrate also includes a protein supplement, and the protein supplement includes one or more of milk protein powder, isolated whey protein powder, concentrated whey protein powder, micronized whey protein, casein powder, sweet whey protein, and acid whey protein.

[0041] The use of protein supplements to supplement the required protein content of the substrate can save the cost of animal milk concentrate. It is preferred to use a protein supplement with a certain viscosity (such as isolated whey protein powder), so that the target viscosity of the feed solution 1 can be obtained while appropriately reducing the amount of slime-producing mold or shortening the fermentation time.

[0042] In the present invention, animal milk refers to the milk of mammals such as cow's milk, goat's milk, horse's milk, camel's milk, deer's milk, and donkey's milk.

[0043] Preferably, the protein content of animal milk can be concentrated to 3.6-3.8% by RO membrane, and then a protein supplement is additionally added to obtain the target protein content.

[0044] In the method for preparing yogurt of the present invention, the sweetener comprises one or more of white sugar, xylitol, maltitol and erythritol.

[0045] Those skilled in the art may use a variety of known sweeteners, and the present invention is not limited thereto.

[0046] As a specific embodiment, the fermentation substrate preparation method of the present invention comprises: heating RO membrane concentrated milk to 42-46°C, maintaining stirring (300-500r / min), adding protein supplement, sweetener, stabilizer, maintaining stirring for 5-10min to ensure uniform dispersion. Then homogenizing (60-65°C, 150-200bar) and high temperature sterilization (121-125°C, time is 5-10s), cooling and using for fermentation.

[0047] In the method for preparing yogurt of the present invention, the starter comprises one or more of Lactobacillus bulgaricus, Streptococcus thermophilus, Lactobacillus acidophilus, Bifidobacterium lactis, and Bifidobacterium longum. Preferably, the starter comprises Streptococcus thermophilus and Lactobacillus bulgaricus with a bacterial activity ratio of (6.8-7.2):3;

[0048] And / or, the slime-producing fungi include two or more of Lactobacillus bulgaricus 5L6 (Food Biotechnology Center of Jiangnan University), Lactobacillus bulgaricus OLL1073R-1 (Meiji Dairy Company), Lactobacillus reuteri CCFM1175 (Food Biotechnology Center of Jiangnan University), Lactobacillus paracasei F-19 (Chr. Hansen), Lactococcus lactis LL O224 (Chr. Hansen), Lactobacillus helveticus BCRC14030 (Biological Resources Conservation and Research Center, Taiwan, China), and Lactobacillus casei 01 (Chr. Hansen), and the slime-producing fungi do not include Lactococcus lactis LL O224 and Lactobacillus reuteri CCFM1175 at the same time.

[0049] The present invention selects specific slime-producing fungi and fermenting bacteria for co-fermentation, which not only ensures that the fermentation processes of the two bacteria will not have a negative impact on each other, but also improves the final viscosity of the yogurt, so that a product with a stable system can be obtained when less stabilizer is added.

[0050] Preferably, in the method for preparing yogurt of the present invention, the slime-producing bacteria are Lactobacillus bulgaricus, Lactobacillus reuteri CCFM1175 and Lactobacillus paracasei F-19 with a live cell count ratio of 3:(1.5-2):(1.5-2); the Lactobacillus bulgaricus is Lactobacillus bulgaricus 5L6 or Lactobacillus bulgaricus OLL1073R-1;

[0051] Alternatively, the slime-producing fungi are Lactococcus lactis LL O224 and Lactobacillus helveticus BCRC14030 with a live cell count ratio of 1:(0.8-1.2);

[0052] Alternatively, the slime-producing fungi are Lactococcus lactis LL O224 and Lactobacillus casei 01 with a live cell count ratio of 1:(0.8-1.2);

[0053] Alternatively, the slime-producing mold includes Lactococcus lactis LL O224, and the starter includes Streptococcus thermophilus; the ratio of the number of live bacteria of Lactococcus lactis LL O224 to that of Streptococcus thermophilus is 1:(1.8-2.3).

[0054] The present invention has found that a better fermentation effect can be obtained by using a preferred combination of slime-producing molds. Further preferably, when the slime-producing molds contain lactic acid streptococci, it is more conducive to the fermentation of thermophilic streptococci.

[0055] Preferably, in the method for preparing yogurt of the present invention, the fermentation substrate comprises, by weight: 90-100 parts of animal milk having a protein content of 3.6-3.8% after concentration, 0.8-1 part of protein supplement, 5-7 parts of sweetener, and 1.5-2.0 parts of stabilizer; during fermentation, the starter and slime-producing fungi are both added at 0.5×10 11 ~1.5×10 11 CFU addition;

[0056] In the method for preparing yogurt of the present invention, in step (1), the fermentation temperature is 38-45° C., the fermentation time is 8-10 hours, and when the pH value of the fermentation reaches 4.4-4.5, demulsification is performed (25-30 r / min, 2-3 min).

[0057] A person skilled in the art can select a combination of conditions within the scope of the present invention based on the common sense in the art, on the premise of achieving the target viscosity of the liquid 1. For example, if the amount of stabilizer is reduced, the amount of starter can be appropriately reduced and the fermentation time can be extended to increase the polysaccharide yield of the slime-producing fungus and avoid excessive acidification of the fermentation product, so as to achieve the final target viscosity value of the liquid 1.

[0058] In step (3) of the method for preparing yogurt of the present invention, when the embedded particles are mixed with the liquid 2, the liquid 2 is first sterilized at high temperature, then cooled to 85-95°C, the embedded particles are added, and the temperature is maintained at 85-95°C for sterilization for 3-5 minutes and then rapidly cooled (e.g., 18°C); the temperature of the high temperature sterilization is 121-125°C and the time is 5-10s.

[0059] At present, most factories use jam as a carrier to add particles, but the number of live bacteria particles that can be transported is small, and the overall sterilization temperature is high, which reduces the bacterial activity. The present invention changes the carrier used in conventional particle addition and adopts a separate sterilization method, which not only takes into account the convenience of addition, but also reduces the loss of active substances.

[0060] As a specific embodiment, the step of preparing liquid 2 of the present invention includes: heating water to 60-65°C, maintaining stirring (300-500r / min), adding high-ester pectin, maintaining stirring for 5-10min to ensure uniform dispersion. Then homogenizing (60-65°C, 150-200bar) and high-temperature sterilization (121-125°C, time is 5-10s), and then cooling to 85-95°C.

[0061] In the method for preparing yogurt of the present invention, the yogurt also includes jam. In step (4), the liquid 1, the liquid 2 containing embedded particles and the jam are mixed together. The mass ratio of the liquid 1, the liquid 2 containing embedded particles and the jam is (8-9): (1-2): (1-2).

[0062] The method of the present invention can be used to prepare plain yogurt, and various fruity yogurts can also be obtained by adding jam (pH 3.8-4.0, consistency 12-16). The consistency test method of the jam is: using a consistency meter (MZ-25CD flow consistency meter), 40 ml of jam is heated to 37°C and poured into the sample tank, and the spring door is pressed to make the jam flow naturally, and the stopwatch is pressed at the same time. The scale at the end point of the flow of the jam after 30 seconds is recorded, which is characterized as the consistency of the jam.

[0063] The method for preparing yogurt of the present invention further comprises the steps of low-pressure homogenization and pasteurization after step (4); the homogenization pressure is 25-40 bar, the pasteurization temperature is 73-77° C., and the time is 22-28 s. Preferably, the homogenization pressure is 30 bar, the pasteurization temperature is 75° C., and the time is 25 s.

[0064] As a specific preferred embodiment, the schematic diagram of the preparation process of the yogurt (live bacteria finished product) of the present invention is shown in Figure 2 Wherein, stabilizer 1 refers to agar, citrus fiber, flaxseed gum and low-ester pectin in liquid 1, and stabilizer 2 refers to high-ester pectin in liquid 2.

[0065] The invention also provides yogurt, which is prepared by the method.

[0066] The yogurt of the present invention contains a large number of live bacteria embedded particles, which can be suspended in the yogurt when a small amount of stabilizer is added. In addition, the live bacteria embedded particles have a good protective effect, which can make the overall live bacteria content of the product ideal.

[0067] The beneficial effects of the present invention are at least:

[0068] The embedded particles of the present invention can ensure the content / activity of the active substance in the inner core, have strong acid resistance and shear resistance, are light in weight, and are conducive to suspension.

[0069] The yogurt containing the embedded particles of the present invention can still make the embedded particles stably suspended in the yogurt system without sinking to the bottom when a small amount of stabilizer is added, and the yogurt has a stable texture. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Figure 1 The figure is a schematic diagram of the process flow of adding particles in the prior art.

[0071] Figure 2 The figure is a schematic diagram of the process for preparing the live bacteria finished product (yogurt) of the present invention. DETAILED DESCRIPTION

[0072] The preferred embodiments of the present invention will be described in detail below in conjunction with examples. It should be understood that the following examples are provided only for the purpose of illustration and are not intended to limit the scope of the present invention. Those skilled in the art may make various modifications and substitutions to the present invention without departing from the purpose and spirit of the present invention.

[0073] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples, unless otherwise specified, can be obtained from commercial sources or prepared according to conventional methods in the art. In the specific embodiments of the present invention, high-ester pectin and low-ester pectin were purchased from DSM.

[0074] Example 1

[0075] This embodiment provides a live bacteria granule and a room temperature yogurt containing the live bacteria granule, in which the live bacteria granule can be stably suspended, which specifically includes the following steps:

[0076] S1: Prepare particles containing live bacteria and prepare pellets according to the pellet formula and titration parameters recorded in Table 1.

[0077] Table 1

[0078]

[0079] Mix the wet pellets with the solidifying liquid in a mass ratio of 1:1 and solidify for 45 minutes. Stir for 5-15 seconds every 10 minutes, sieve and wash after soaking. The size of the live bacteria wet pellets is 5.4-5.6mm in diameter and weighs 0.17-0.18g. The weight ratio of the inner core and the rubber layer of the wet pellets is about 1:5. Transfer the wet pellets to the rotary drying equipment. After drying, the water activity of the outer layer of the pellets is less than 3%; the diameter of the dried pellets is 3-4mm and the weight is 0.02-0.03g. The final weight ratio of the inner core and the rubber layer is 1: (0.5-0.6).

[0080] S2: Preparation of live bacteria yogurt:

[0081] 1. Preparation of liquid 1 (based on 1 ton):

[0082] Formula: RO membrane concentrated raw milk (raw milk concentrated with RO membrane to a protein content of 3.6%) 912kg, isolated whey protein powder 10kg, white sugar 60kg, stabilizer (agar 9.9kg, citrus fiber 2.7kg, flaxseed gum 1.35kg, low-ester pectin 4.05kg), starter 10 11 CFU (purchased from Chr. Hansen, the bacterial activity ratio of thermophilic Streptococcus: bulgaricus Lactobacillus = 7:3), slime-producing mold 10 11 CFU (bacterial activity ratio of Lactobacillus bulgaricus 5L6: Lactobacillus reuteri CCFM1175: Lactobacillus paracasei F-19 = 3:1.75:1.75).

[0083] Preparation steps: Heat the RO membrane concentrated raw milk to 45°C, maintain stirring (350r / min), add isolated whey protein powder, white sugar, and stabilizer, maintain stirring for 7 minutes, ensure uniform dispersion, and then homogenize (62°C, 150bar) and sterilize at high temperature (122°C, time for 7s). Cool to 40°C, add starter and slime-producing mold, ferment at 40°C for 8h, demulsify (30r / min, 2min) when the pH reaches 4.4-4.5, cool to 18°C, and obtain liquid 1 with a viscosity of 633.3mPa·s.

[0084] 2. Preparation of liquid 2 (500 kg):

[0085] Formula: 15kg high ester pectin, 485kg water.

[0086] Preparation steps: Heat the water to 62°C, maintain stirring (350r / min), add high-ester pectin, maintain stirring for 7 minutes, ensure uniform dispersion, then homogenize (62°C, 150bar) and sterilize at high temperature (122°C, time is 7s), and then cool to 95°C.

[0087] 3. After the temperature of liquid 2 drops to 95°C, add live bacteria granules, maintain the temperature at 95°C for 5 minutes, and then quickly cool to 18°C. The amount of live bacteria granules added is 75kg (about 13%).

[0088] 4. Mix liquid 1, liquid 2 containing live bacteria granules, and jam (pH 4.0, consistency 14) in a mass ratio of 8:2:1 (i.e., mix 800 kg of liquid 1, 200 kg of liquid 2 containing live bacteria granules, and 100 kg of jam), then perform low-pressure homogenization (30 bar), and then undergo a secondary pasteurization process (75°C, 25s), cool to 20°C, and perform aseptic filling.

[0089] Example 2

[0090] This embodiment provides live bacteria particles and room temperature yogurt containing the same. The live bacteria particles in the yogurt can be stably suspended. The specific preparation method is basically the same as that in Example 1, except that: (1) when preparing the particles containing live bacteria, corn oil is replaced with an equal amount of palm oil, and 12% of BC99 Bacillus coagulans is replaced with 20% of BB12 Bifidobacterium powder (1.3×10 9 CFU / g), the formula of the rubber solution was modified to: konjac gum 6.11‰, xanthan gum 3.29‰, gelatin 5.7‰, carrageenan 3.7‰, sodium alginate 10‰, and water was made up to 1000‰. The viscosity of the rubber solution is 259.1mPa·s. When making pellets, the core liquid pump speed is set to 120r / min and the glue pump speed is set to 410r / min, so that the weight ratio of the inner core and the rubber layer of the wet pill is about 1:4. The wet pill particles are mixed with the curing liquid in a mass ratio of 1:1 and cured for 45min. Stir for 5-15s every 10min, sieve and wash after soaking. The size of the live bacteria wet pill particles is 5.3-5.5mm in diameter and weighs 0.15-0.16g. The wet pellets are transferred to the tumble drying equipment. After drying, the water activity of the outer layer of the pellets is less than 3%. The diameter of the pellets after drying is 3-4mm and the weight is 0.02-0.03g. The final weight ratio of the inner core to the rubber layer is 1: (0.5-0.6).

[0091] (2) When liquid 1 is fermented, the slime-producing mold is replaced by 10 11 CFU (Lactobacillus bulgaricus OLL1073R-1: Lactobacillus reuteri CCFM1175: Lactobacillus paracasei F-19 strain activity ratio = 3:2:2). The viscosity of the obtained feed solution 1 was 624.7 mPa·s.

[0092] Example 3

[0093] This embodiment provides a live bacteria granule and room temperature yogurt containing the same. The live bacteria granule in the yogurt can be stably suspended. The specific preparation method is basically the same as that in Example 1, except that: (1) when preparing the granule containing live bacteria, the formula of the rubber solution is modified to: 9.5‰ konjac gum, 9.5‰ xanthan gum, 2.675‰ gelatin, 2.135‰ carrageenan, 5‰ sodium alginate, and water is added to 1000‰. The viscosity of the rubber solution is 235.1mPa·s. (2) When the liquid 1 is fermented, the slime-producing fungi are replaced by Lactococcus lactis LL O224 and Lactobacillus helveticus BCRC14030 (total live bacteria count 7×10 10 CFU, bacterial activity ratio = 1:1.2). The viscosity of the feed solution 1 is 562.4 mPa·s.

[0094] Example 4

[0095] This embodiment provides a live bacteria granule and room temperature yogurt containing the same. The specific preparation method is basically the same as that of Example 1, except that during the fermentation of liquid 1, the slime-producing bacteria are replaced by Lactococcus lactis LL O224 and Lactobacillus helveticus BCRC14030 (total live bacteria count 7×10 10 CFU, bacterial activity ratio = 3.88:3.19). The viscosity of the feed solution 1 is 559.6 mPa·s.

[0096] Example 5

[0097] The present embodiment provides a live bacteria particle and a room temperature yogurt containing the live bacteria particle. The live bacteria particle in the yogurt can be stably suspended. The specific preparation method is basically the same as that in Example 1, except that when the feed liquid 1 is fermented, the formula is: RO membrane concentrated raw milk (raw milk is concentrated by RO membrane to a protein content of 3.6%) 912 kg, micronized whey protein (purchased from Arla Foods Ingredients) 10 kg, xylitol 60 kg, stabilizer (agar 11.89 kg, citrus fiber 3.97 kg, flaxseed gum 1.89 kg, low-ester pectin 5.94 kg), starter 10 kg. 11 CFU (Streptococcus thermophilus: Lactobacillus bulgaricus strain activity ratio = 7:3), slime-producing mold 1.5×10 11CFU (Lactococcus lactis LL O224: Lactobacillus casei 01 bacterial strain activity ratio = 1:1). The viscosity of the feed solution 1 is 629.5 mPa·s.

[0098] Comparative Example 1

[0099] This comparative example provides a live bacteria granule and room temperature yogurt containing the same. The specific preparation method is basically the same as that in Example 1, the only difference is that when preparing the granule containing live bacteria, the konjac gum in the rubber liquid is replaced by an equal amount of xanthan gum.

[0100] Comparative Example 2

[0101] This comparative example provides a live bacteria granule and room temperature yogurt containing the same. The specific preparation method is basically the same as that of Example 1, except that when preparing the granule containing live bacteria, the xanthan gum in the rubber liquid is replaced by an equal amount of konjac gum.

[0102] Comparative Example 3

[0103] This comparative example provides a live bacteria granule and room temperature yogurt containing the same. The specific preparation method is basically the same as that of Example 1, except that when preparing the granule containing live bacteria, the xanthan gum in the rubber liquid is replaced by an equal amount of locust bean gum.

[0104] Comparative Example 4

[0105] This comparative example provides a live bacteria granule and room temperature yogurt containing the same. The specific preparation method is basically the same as that in Example 1, the only difference is that when preparing the granule containing live bacteria, the amount of konjac gum in the rubber liquid is changed to 7.1‰, and the amount of xanthan gum is changed to 7.9‰.

[0106] Comparative Example 5

[0107] This comparative example provides a live bacteria granule and room temperature yogurt containing the same. The specific preparation method is basically the same as that in Example 1, the only difference is that when preparing the granule containing live bacteria, the amount of gelatin in the rubber liquid is changed to 2.03‰, and the amount of carrageenan is changed to 1.77‰.

[0108] Comparative Example 6

[0109] This comparative example provides a live bacteria granule and room temperature yogurt containing the same. The specific preparation method is basically the same as that in Example 1, the only difference is that when preparing the granules containing live bacteria, the amount of konjac gum in the rubber liquid is changed to 9.93‰, the amount of xanthan gum is changed to 5.35‰, the amount of gelatin in the rubber liquid is changed to 2.13‰, and the amount of carrageenan is changed to 1.39‰.

[0110] Comparative Example 7

[0111] This comparative example provides a live bacteria granule and room temperature yogurt containing the same. The specific preparation method is basically the same as that of Example 1, except that, when preparing the live bacteria yogurt, the preparation of the liquid 1 is carried out by fermenting the fermentation bacteria and the slime-producing mold separately. The specific steps are as follows:

[0112] Two portions of fermentation substrate were prepared, each of which was prepared as follows: RO membrane concentrated raw milk (protein content = 3.6%, 456 kg) was heated to 45 °C, maintained in a stirring state (350 r / min), and whey protein isolate powder (5 kg), white sugar (30 kg), and stabilizer (agar 4.95 kg, citrus fiber 1.35 kg, flaxseed gum 0.675 kg, low-ester pectin 2.025 kg) were added, and stirring was maintained for 7 min to ensure uniform dispersion, followed by homogenization (62 °C, 150 bar) and high-temperature sterilization (122 °C, time 7 s).

[0113] The two fermentation substrates were respectively pumped into two fermentation tanks and cooled to 40°C. 5×10 10 CFU (Streptococcus thermophilus: Lactobacillus bulgaricus strain activity ratio = 7:3), 5×10 slime-producing bacteria were added to fermenter 2. 10 CFU (bacterial activity ratio of Lactobacillus bulgaricus 5L6: Lactobacillus reuteri CCFM1175: Lactobacillus paracasei F-19 = 3:1.75:1.75).

[0114] After fermentation at 40°C for about 8 hours, when the pH of fermenter 1 reaches 4.4-4.5, demulsification (30r / min, 2min) is performed, and at the same time, demulsification (30r / min, 2min) is performed in fermenter 2. The liquid in fermenter 2 is pumped into fermenter 1, and after mixing evenly at a low speed (30r / min, 2min), it is cooled to 18°C ​​to obtain liquid 1 with a viscosity of 473.9mPa·s.

[0115] Comparative Example 8

[0116] This comparative example provides a live bacteria granule and room temperature yogurt containing the same. The specific preparation method is basically the same as that of Example 1, except that, when preparing the live bacteria yogurt, the stabilizer of liquid 1 is changed to include: 9.9 kg agar, 3.1 kg citrus fiber, 0.9 kg flaxseed gum, and 4.1 kg low-ester pectin. Finally, liquid 1 with a viscosity of 582.9 mPa·s is obtained.

[0117] Comparative Example 9

[0118] This comparative example provides a live bacteria granule and room temperature yogurt containing the same. The specific preparation method is basically the same as that of Example 1, except that, when preparing the live bacteria yogurt, the citrus fiber in the stabilizer is replaced by an equal amount of modified starch. Finally, a feed solution 1 with a viscosity of 592.0 mPa·s is obtained.

[0119] Comparative Example 10

[0120] This comparative example provides a live bacteria granule and room temperature yogurt containing the same. The specific preparation method is basically the same as that of Example 1, except that, when preparing the live bacteria yogurt, the flaxseed gum in the stabilizer is replaced with an equal amount of locust bean gum. Finally, a feed solution 1 with a viscosity of 587.3 mPa·s is obtained.

[0121] Comparative Example 11

[0122] This comparative example provides a live bacteria granule and room temperature yogurt containing the same. The specific preparation method is basically the same as that of Example 1, except that, when preparing the live bacteria yogurt, the high ester pectin in the feed solution 2 is replaced by 25 kg of sodium carboxymethyl cellulose.

[0123] Experimental example

[0124] The particle breakage rates of different embodiments and comparative examples in the laboratory shear simulation experiment were compared. The method is: weigh 150 dried live bacteria embedded particles, add 50 ml of high ester pectin solution (3%, 95±2℃). Maintain the temperature at 95±2℃, shear at a high speed of 700r / min for 5 minutes, and observe the breakage rate of live bacteria embedded particles, breakage rate = number of breakages / 150×100%; the results are shown in Table 2 below.

[0125] Table 2

[0126]

[0127] 2. Determine the stability of the yogurt base in the final product of live bacteria yogurt, and characterize it by centrifugal water loss rate. The test method is: take out 5ml of the yogurt base (without particles) in the live bacteria yogurt and put it in a 13ml centrifuge tube. The test condition is 4000r / min and centrifuge for 15min. The centrifugal water loss rate is obtained by comparing the mass of the yogurt base after centrifugation after the water is separated and the mass of the original product:

[0128]

[0129] The results are shown in Table 3 below.

[0130] Table 3

[0131]

[0132] 3. During the storage period (25°C) of the finished yogurt product with live bacteria-embedded particles at 0 (offline), 1, 3, 5, and 6 months, observe the particle sinking to the bottom of the product and test the live bacteria count and hardness of the particles.

[0133] 3.1 Particle suspension:

[0134] The particles of Examples 1-5 can be stably and evenly dispersed in the yogurt system without sinking to the bottom. In Comparative Examples 1-6, due to the poor rubber solution, several particles were broken during storage, but no sinking occurred. In Comparative Examples 7-11, due to the insufficient stability of the yogurt system during storage, the particles all sank to the bottom within 1 month after being offline.

[0135] 3.2 Viable bacteria count:

[0136] The method for determining the number of viable bacteria in the granules is as follows: take out 5 embedded granules from the product, clean the surface, soak them in distilled water for 1-2 minutes, and then crush them. After gradient dilution with physiological saline (containing 5% Tween 80), the total colony count is determined in accordance with GB4789.2-2022, and finally converted to the number of viable bacteria contained in each granule. The results are shown in Table 4, and the unit of viable bacteria count is cfu / granule.

[0137] Table 4

[0138]

[0139] 3.3 Texture characteristics test: The particles separated from the yogurt were collected and their hardness was measured by TPA test of Texture Analyser Plus (UK): a cylindrical flat-bottom probe (P / 36R) was used, the trigger force was set to 2g, the measuring speed was 1mm / s, and the compression deformation was 80%. The particle hardness (g, definition: the force corresponding to the compression breaking point) was calculated on the obtained time-force curve. Six particles were taken from each sample for testing and the average value was taken. The results are shown in Table 5.

[0140] Table 5

[0141]

[0142] Although the present invention has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto based on the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A method for preparing yogurt, characterized in that: include: (1) Fermenting animal milk with a starter and a slime-producing fungus to prepare a liquid 1, wherein the fermentation substrate includes animal milk, a sweetener and a stabilizer; the stabilizer includes agar, citrus fiber, flaxseed gum and low-ester pectin; the agar accounts for 50-65% of the total weight of the stabilizer; the mass ratio of the citrus fiber, flaxseed gum and low-ester pectin is 1:(0.4-0.6):(1.4-1.6); The protein content in the fermentation substrate is 4.0%-4.5%; the mass ratio of the stabilizer to the protein is 1:(1.8-2.5); The ratio of the number of live bacteria of the slime-producing fungus to the starter is 1:(0.5-1.5); the viscosity of the liquid 1 is 550-650 mPa·s; the starter includes one or more of Lactobacillus bulgaricus, Streptococcus thermophilus, Lactobacillus acidophilus, Bifidobacterium lactis, and Bifidobacterium longum; The slime-producing bacteria include two or more of Lactobacillus bulgaricus 5L6, Lactobacillus bulgaricus OLL1073R-1, Lactobacillus reuteri CCFM1175, Lactobacillus paracasei F-19, Lactococcus lactis LL O224, Lactobacillus helveticus BCRC14030, and Lactobacillus casei 01, and the slime-producing bacteria do not include Lactococcus lactis LL O224 and Lactobacillus reuteri CCFM1175 at the same time; (2) mixing high-ester pectin with water to prepare liquid 2; the mass concentration of the high-ester pectin in the liquid 2 is 2-4%; (3) mixing the embedded particles with the feed solution 2 to obtain the feed solution 2 containing the embedded particles, wherein the mass concentration of the embedded particles in the feed solution 2 containing the embedded particles is 10-15%; (4) mixing the liquid 1 and the liquid 2 containing embedded particles in a mass ratio of (8-9): (1-2); The embedded particles include: an inner core and a rubber layer, wherein the inner core includes bacterial powder and oil; the rubber layer is solidified by a rubber liquid; the rubber liquid includes a first colloid component, a second colloid component and sodium alginate; the first colloid component includes konjac gum and xanthan gum in a mass ratio of (1-1.9):1; the second colloid component includes gelatin and carrageenan in a mass ratio of (1.25-1.6):1; the mass ratio of the first colloid component to the second colloid component is 1:(0.25-1); the final mass ratio of the inner core and the rubber layer is 1:(0.5-0.6); The method for preparing the embedded particles comprises: wrapping the inner core in the rubber liquid in a pellet manner, solidifying in a calcium salt solution, and then drying.

2. The method for preparing yogurt according to claim 1, characterized in that: The concentration of sodium alginate in the rubber liquid is 5-15‰; the viscosity of the rubber liquid is 200-300mPa·s; And / or, the mass percentage of the bacterial powder in the inner core is 5-20%; And / or, the bacterial powder includes one or more of Bifidobacterium animalis, Bifidobacterium adolescentis, Bifidobacterium bifidum, Bifidobacterium breve, Bifidobacterium infantis, Bifidobacterium longum, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus crispatus, Lactobacillus delbrueckii subsp. bulgaricus, Lactobacillus delbrueckii subsp. lactis, Lactobacillus fermentum, Lactobacillus gasseri, Lactobacillus helveticus, Lactobacillus johnsonii, Lactobacillus paracasei, Lactobacillus plantarum, Lactobacillus reuteri, Lactobacillus rhamnosus, Lactobacillus salivarius, and Bacillus coagulans; And / or, the oil comprises one or more of corn oil, palm oil, linseed oil, rapeseed oil, and sunflower oil; And / or, the diameter of the embedded particles is 3-4 mm.

3. The method for preparing yogurt according to claim 1, characterized in that: The fermentation substrate further comprises a protein supplement, and the protein supplement comprises one or more of milk protein powder, isolated whey protein powder, concentrated whey protein powder, micronized whey protein, casein powder, sweet whey protein, and acid whey protein; And / or, the sweetener includes one or more of white sugar, xylitol, maltitol, and erythritol.

4. The method for preparing yogurt according to claim 3, characterized in that: The fermentation substrate comprises, by weight: 90-100 parts of animal milk with a protein content of 3.6-3.8% after concentration, 0.8-1 part of protein supplement, 5-7 parts of sweetener, and 1.5-2.0 parts of stabilizer; during fermentation, the fermentation agent and slime-producing mold are both 0.5×10 11 ~1.5×10 11 CFU addition; And / or, the slime-producing bacteria are Lactobacillus bulgaricus, Lactobacillus reuteri CCFM1175 and Lactobacillus paracasei F-19 with a live cell count ratio of 3:(1.5-2):(1.5-2); the Lactobacillus bulgaricus is Lactobacillus bulgaricus 5L6 or Lactobacillus bulgaricus OLL1073R-1; Alternatively, the slime-producing fungi are Lactococcus lactis LL O224 and Lactobacillus helveticus BCRC14030 with a live cell count ratio of 1:(0.8-1.2); Alternatively, the slime-producing fungi are Lactococcus lactis LL O224 and Lactobacillus casei 01 with a live cell count ratio of 1:(0.8-1.2); Alternatively, the slime-producing mold includes Lactococcus lactis LL O224, and the starter includes Streptococcus thermophilus; the ratio of the number of live bacteria of Lactococcus lactis LL O224 to that of Streptococcus thermophilus is 1:(1.8-2.3).

5. The method for preparing yogurt according to claim 3 or 4, characterized in that: In step (1), the fermentation temperature is 38-45°C, the fermentation time is 8-10 hours, and the emulsion is broken when the pH value reaches 4.4-4.5; And / or, in step (3), when the embedded particles are mixed with the liquid 2, the liquid 2 is first sterilized at high temperature, then cooled to 85-95°C, the embedded particles are added, and the temperature is maintained at 85-95°C for sterilization for 3-5 min and then rapidly cooled; the temperature of the high temperature sterilization is 121-125°C and the time is 5-10s; And / or, the yogurt further comprises jam, and in step (4), the liquid 1, the liquid 2 containing the embedded particles and the jam are mixed together, and the mass ratio of the liquid 1, the liquid 2 containing the embedded particles and the jam is (8-9): (1-2): (1-2); And / or, after step (4), the method further comprises the steps of low-pressure homogenization and pasteurization; the homogenization pressure is 25-40 bar, the pasteurization temperature is 73-77° C., and the time is 22-28 s.

6. A yogurt, characterized in that: The method is prepared by any one of claims 1 to 5.

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