Embedding microbial inoculum, feed, native ARA-rich milk and preparation method of embedding microbial inoculum, feed and native ARA-rich milk

Abstract

The invention relates to the technical field of pure milk, in particular to an embedding fungicide, a feed, native ARA-rich milk and a preparation method of the embedding fungicide, the feed and the native ARA-rich milk. The embedding bacterial agent provided by the invention comprises dry thalli of mortierella alpina; the embedding layer is coated outside the dry thallus of the mortierella alpina; the embedding layer comprises a first component and a second component in a mass ratio of (5.5-7.0): (3.0-4.5); the first component is selected from one or more of inulin, soluble soybean polysaccharide, beta-glucan and chitosan; the second component is selected from one or more of pectin, gelatin and Arabic gum. The embedded dry thallus for producing the native ARA-rich milk, provided by the invention, can be converted into natural ARA through cow milk metabolism, so that a native natural ARA-rich pure milk product is obtained, the pure natural and additive-free consumption trend is met, and the effect of promoting the human health of consumers drinking milk is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of pure milk, and in particular to an embedded bacterial agent, feed, native ARA-rich milk and a preparation method thereof. Background Art

[0002] Nowadays, consumers' pursuit of food nutrition has reached a new height. As an important daily source of nutrition, milk has high requirements for the nutrition that milk can provide. Exogenously added food nutrients can meet consumers' needs for diversified nutritional intake, but more consumers are beginning to pursue natural milk without external additives, so milk produced by bio-enrichment technology came into being.

[0003] ARA is a nutrient that is beneficial to the human body. Its scientific name is eicosatetraenoic acid, also known as arachidonic acid, which belongs to the Omega6 family long-chain polyunsaturated fatty acid. In early childhood, ARA belongs to essential fatty acids. The lack of ARA may have serious adverse effects on the development of human tissues and organs, especially the development of the brain and nervous system. ARA can improve intelligence, enhance vision, soften blood vessels, regulate blood cell function, prevent cardiovascular diseases, and enhance immune function. For ruminants, ARA plays an important role in connecting cell membranes and maintaining the toughness of membranes. It is also a precursor of prostaglandins, and can also be converted into leukotrienes, thromboxanes, etc., which is very important for the blood circulation system and immune system. ARA plays an important role in promoting survival, growth and lipid metabolism, and can regulate the antioxidant capacity and immune response of animals. Regarding the edible products of ARA, there is currently a preparation method of arachidonic acid soft capsules (CN103340846A), but there is no connection between ARA and dairy cows and milk. The current implementation method is to add exogenous nutrients in milk, and providing a method that can produce native natural ARA-rich antioxidant milk is an important issue to be solved in this area. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides an embedded bacterial agent, feed and native ARA-rich milk and a preparation method thereof.

[0005] In a first aspect, the present invention provides an embedded bacterial agent for producing native ARA-rich milk, the embedded bacterial agent comprising:

[0006] Dried thallus of Mortierella alpina; and,

[0007] An embedding layer coated outside the dried fungus of Mortierella alpina;

[0008] The embedding layer comprises a first component and a second component in a mass ratio of (5.5-7.0):(3.0-4.5):

[0009] The first component is selected from one or more of inulin, soluble soybean polysaccharide, β-glucan, and chitosan;

[0010] The second component is selected from one or more of pectin, gelatin, and gum arabic.

[0011] The encapsulated bacterial agent of the feed for feeding dairy cows provided by the present invention, namely the encapsulated dried bacterial cells, since the bacterial cells themselves produce ARA, which is metabolized and converted into natural ARA through milk, improving the ARA content in milk and obtaining a pure milk product rich in ARA natively. The milk produced by feeding the feed containing the encapsulated dried bacterial cells has the same stability and taste as pure milk, conforms to the consumption trend of being pure natural and additive-free, and can have a role in promoting human health for consumers who drink milk.

[0012] The present invention unexpectedly discovers through experiments that the selection of a specific combination of the first component and the second component for the encapsulation material of the present invention can form good protection for Mortierella alpina bacterial cells and reduce oxidation. The encapsulation material adopted by the present invention does not contain components that are adverse to dairy cows and milk production. Most of the existing encapsulation materials use chemical source components such as acrylic resin and ethyl cellulose, and are not as good as the food-source materials in the present invention in having a positive impact on the health of cattle. At the same time, the above dietary fiber raw materials have solubility, emulsifying property, and gelling property. Especially when a certain proportion of the above specific combination of the first and second components is adopted, a more stable gel network structure is formed during the encapsulation process, the core material and the wall material are tightly combined, so that it shrinks or remains stable under the low pH value of the gastric juice of dairy cows; and a stable glassy matrix or protective film is formed to encapsulate the core material to form a capsule protection barrier to block the erosion of the gastric juice of dairy cows and reduce the damage of the core material in adverse environments such as oxygen and high temperature, so that the Mortierella alpina bacterial cells are greatly protected before reaching the rumen, and thus more ARA is contained in raw milk and milk products. When the encapsulation material adopts the specific combination method of the present invention, the encapsulation effect can also be greatly improved.

[0013] Preferably, the first component is selected from one or more of inulin, β-glucan, and chitosan; and / or, the second component is selected from pectin and / or gum arabic; and / or, the mass ratio of the Mortierella alpina dried bacterial cells to the encapsulation layer is 5:4 to 5.

[0014] Preferably, the encapsulation layer is a mixture of inulin and pectin with a mass ratio of (5.5 to 7.0):(3.0 to 4.5); or, a mixture of β-glucan, chitosan, and gum arabic with a mass ratio of (2.5 to 3.5):(3.0 to 4.5):(3.0 to 4.5); or, the encapsulation layer is a mixture of inulin, soluble soybean polysaccharide, and gelatin with a mass ratio of (3.0 to 3.5):(2.5 to 3.5):(3.0 to 4.5).

[0015] Further preferably, the embedding layer is a mixture of inulin and pectin in a mass ratio of (6.0-6.5):(3.5-4.0); or, a mixture of β-glucan, chitosan and gum arabic in a mass ratio of (2.8-3.2):(3.4-4.0):(3.2-3.4); or, the embedding layer is a mixture of inulin, soluble soybean polysaccharides and gelatin in a mass ratio of (3.2-3.4):(2.8-3.2):(3.4-4.0).

[0016] The present invention optimizes and screens the combination mode and dosage ratio of the embedding layer, and the specific raw material combination adopted can significantly improve the embedding effect.

[0017] Preferably, in the embedded bacterial agent, ARA accounts for 23-25% of the dry matter content.

[0018] In a second aspect, the present invention provides a preparation method for the embedded dry bacteria for producing native ARA-rich milk, comprising: mixing and dissolving the embedding layer raw materials with an alcohol reagent to obtain a packaging material, and encapsulating the dry bacteria of Mortierella alpina with the packaging material by electrostatic spraying or electrostatic spinning.

[0019] Existing encapsulation technology generally adopts spray drying, but high inlet temperature and instant dehydration will cause thermal damage to the dry cells of Mortierella alpina, resulting in a deepening of the degree of ARA oxidation, resulting in a loss of ARA content, and subsequently reducing the antioxidant capacity of the cow itself and the antioxidant capacity of the produced milk. In the present invention, electrospinning and electrospraying are used to encapsulate the dry cells of Mortierella alpina in the above packaging materials. This process uses an electric field to quickly dry the dispersion without applying high temperature, thereby reducing the oxidation of ARA and maximizing the intake of ARA raw materials, thereby increasing the native ARA content in milk, and increasing the antioxidant capacity of the cow itself and the antioxidant capacity of the produced milk.

[0020] Preferably, the conditions for the electrostatic spraying include: a gas flow rate of 30 to 35 Nm 3 / h, the inlet air temperature is 70-80℃, the material pump flow rate is 20-30r / min, the static voltage is 20-25kV, and the atomization pressure is 220-230kPa.

[0021] Preferably, the electrospinning conditions include: receiving distance of 15 to 17 cm, propulsion speed of 0.002 to 0.004 mm / s, applied voltage of 10 to 35 kV, temperature of 30 to 35° C., humidity of 37.5% to 40%, and time of 12 to 24 h.

[0022] More preferably, the mass ratio of the raw material of the embedding layer to the alcohol reagent is 1:6-12; and the alcohol reagent is (95%) ethanol or polyethylene glycol.

[0023] More preferably, stirring and dissolving are carried out at a rate of 80 - 250 rpm / min.

[0024] In a third aspect, the present invention provides a feed for producing milk rich in ARA natively, which contains the encapsulated microbial agent or the encapsulated microbial agent obtained by the preparation method of the encapsulated microbial agent.

[0025] According to the present invention, ARA has antioxidant ability. The intake of ARA raw materials by dairy cows has a positive effect on the health of dairy cows themselves, improves the antioxidant ability of dairy cows themselves, resists diseases, enhances the antioxidant ability of dairy cows, and has a positive impact on the health of dairy cows. Moreover, the antioxidant ability in the milk produced by dairy cows is also enhanced, which can play a role in promoting human health for consumers who drink the milk, and at the same time can increase the contents of catalase (CAT) and superoxide dismutase (SOD) in the serum and milk of dairy cows.

[0026] Preferably, the feed comprises encapsulated dried bacterial cells, concentrate feed and roughage in a mass ratio of 10 - 15:25 - 35:45 - 65; wherein, the concentrate feed is preferably selected from at least one of yeast powder, vitamins, minerals, corn flour and soybean meal; the roughage is preferably selected from at least one of silage corn, oat grass, alfalfa grass and pasture grass.

[0027] In a fourth aspect, the present invention provides a preparation method of the feed for producing milk rich in ARA natively, comprising: mixing the encapsulated microbial agent, concentrate feed and roughage in proportion.

[0028] Preferably, the encapsulated microbial agent is mixed with the concentrate feed in proportion to obtain a mixture, and then the mixture is subjected to TMR mixing with the roughage. According to the present invention, TMR is the abbreviation of the English Total Mixed Rations (total mixed ration). The so-called total mixed ration (TMR) is a feeding technology that fully mixes roughage, concentrate feed, minerals, vitamins and other additives and can provide sufficient nutrition to meet the needs of dairy cows. The total mixed ration (TMR) is a nutritionally relatively balanced ration obtained by fully stirring and mixing chopped (kneaded) roughage, concentrate feed and various nutritional additives in a certain ratio according to the nutritional needs of ruminants at different physiological stages.

[0029] In yet another aspect, the present invention further provides a preparation method of the milk rich in ARA natively, which is produced and processed by dairy cows fed with the feed obtained by using the feed for producing milk rich in ARA natively or the preparation method of the feed for producing milk rich in ARA natively.

[0030] Preferably, the method for preparing the native ARA-rich milk includes a sterilization process using direct steam sterilization. In the present invention, this method can avoid the significant thermal damage to milk caused by existing milk processing methods and reduce the antioxidant capacity of milk. The direct steam sterilization used in the milk processing method reduces the heating intensity of milk and further better retains the antioxidant capacity of milk.

[0031] More preferably, the direct steam sterilization is carried out by steam immersion or steam injection. The treatment temperature of the direct steam sterilization is 130 - 139 °C, preferably 131 - 135 °C, and the treatment time is 0.09 - 5 s.

[0032] According to the present invention, the sterilization process generally used for commercially available long-shelf-life pure milk is tubular UHT sterilization at high temperature for 4 - 6 s. Although the sterilization intensity is high and the shelf life of the product can be extended, severe heat treatment results in serious loss of nutrients in milk, especially the functional active substances, and the milk will produce a cooked flavor, destroying the original flavor. The UHT ultra-high temperature instantaneous sterilization used in the existing method can extend the product shelf life, but the retention of active substances is poor, resulting in a very low retention rate of active substances. The shelf life of pasteurization is too short for long-distance transportation and requires cold chain transportation and a strong supply chain capacity, so the sales radiation range of the product is small. The milk processing method of the present invention uses direct steam sterilization treatment, which can overcome the existing problems. By combining the direct steam sterilization treatment method and optimizing its treatment temperature, the heating intensity of milk can be reduced, the ARA content in milk can be further increased by about 10%, and the contents of catalase and superoxide dismutase are also further increased, better retaining the antioxidant capacity of milk.

[0033] Preferably, the method for preparing the native ARA-rich milk includes: clarifying the raw milk produced by the cows fed with the feed, removing impurities, concentrating by RO membrane, then separating fat, subjecting the cream to high-temperature sterilization, double-effect sterilization, then carrying out the direct steam sterilization, homogenization and aseptic filling.

[0034] Further preferably, the concentration ratio of RO membrane concentration is 1.25, and the temperature is 4-7 °C. Through the RO membrane concentration process, the ARA content in milk can be increased; the temperature of fat separation is 45-60 °C, and the fat content of skim milk is ≤0.5 g / 100 g; the sterilization temperature of the cream in high-temperature sterilization is 135-154 °C for 0.09-3 s; the two-stage sterilization preferably uses two centrifugal sterilizers in series to sterilize the skim milk. The set parameters of the two centrifugal sterilizers are the same, with the set parameters being 45-60 °C, 4000-6000 r / min, and the running time being 40-80 s. Through this physical sterilization method, 95%-99% of the spores in milk can be removed; the steam direct sterilization adopts steam immersion or steam injection, and homogenization is carried out after sterilization to make the fat disperse evenly and ensure the stability of the product system during the shelf life. The milk provided by the present invention can be stored at room temperature for 6-12 months after aseptic filling, and the original ARA content is greater than 15 mg / 100 g.

[0035] In the present invention, the feed is continuously fed to dairy cows, and the dairy cows are dairy cows in the lactation period of 10-210 days, and are continuously fed for 15-25 days. The intake of the encapsulated Mortierella alpina dry cells is 250 g / day / head. Feeding is carried out according to the feeding gradient of 50, 100, 150, 200, 250 g / day / head of the encapsulated Mortierella alpina dry cells, and each gradient is fed for 3-5 days to reach the feeding amount of 250 g of the encapsulated Mortierella alpina dry cells within two weeks.

[0036] On the other hand, the native ARA-rich milk provided by the present invention is obtained by the method for preparing ARA-rich milk described above.

[0037] The beneficial effects of the present invention are at least as follows: ARA is the main precursor of eicosanoids, can participate in the regulation and activation of bioactive components in the antioxidant system, and has antioxidant ability. The present invention optimizes the encapsulation of raw materials containing ARA with encapsulating materials, optimizes the encapsulation process according to the properties of the raw materials, feeds dairy cows with ARA-containing feed, significantly increases the original ARA content in milk, improves the antioxidant function of milk through the optimization of encapsulation and the improvement of the processing method of ARA-containing milk, and produces milk that is a native natural ARA antioxidant milk rich in more various antioxidant substances, which can promote the health of consumers who drink milk, and has the same stability and taste as pure milk, meeting the consumption trend of pure natural and no additives. Detailed implementation mode

[0038] In order to make the objectives, technical solutions, and advantages of the embodiments of the invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts fall within the scope of protection of the present invention.

[0039] Unless otherwise specified, the raw materials and reagents used in the following embodiments are all commercially available products, or can be prepared by known methods. For those embodiments where specific techniques or conditions are not indicated, they are all conventional methods or are carried out according to the techniques or conditions described in the literature in this field, or according to the product instructions. For those reagents and instruments etc. where the manufacturer is not indicated, they are all conventional products that can be obtained through regular channels.

[0040] The present invention will be further described below in conjunction with embodiments.

[0041] Example 1

[0042] This example provides an encapsulated Mortierella alpina dry cell, and the preparation method is as follows:

[0043] 1) Use inulin and pectin with a mass ratio of 6.0:4.0, and dissolve them in 95% ethanol at a mass ratio of 1:6, and stir and dissolve at 80 rpm / min to serve as the coating film.

[0044] 2) Weigh the Mortierella alpina dry cell and the embedding layer at a mass ratio of 5:5, and send it into the electrospinning equipment. In the encapsulated microbial agent, ARA accounts for 23% of the dry matter content. Set the electrospinning equipment conditions: the receiving distance is 15 cm, the advancing speed is 0.002 mm / s, apply a voltage of 10 kV, the ambient temperature is 30 °C, the humidity is 37.5% (RH), and the time is 12 h.

[0045] Example 2

[0046] This example provides an encapsulated Mortierella alpina dry cell, and the preparation method is as follows:

[0047] 1) Use a mixture of β-glucan, chitosan, and arabic gum with a mass ratio of 3.0:3.7:3.3, and dissolve them in 95% ethanol at a ratio of 1:12, and stir and dissolve at 250 rpm / min to serve as the coating film.

[0048] 2) Weigh the Mortierella alpina dry cell and the embedding layer at a mass ratio of 5:4, and send it into the electrostatic spraying equipment. In the encapsulated microbial agent, ARA accounts for 24% of the dry matter content. Set the electrostatic spraying equipment conditions: the gas flow rate is 30 Nm 3 / h, inlet air temperature 70 °C, material pump flow rate 20 r / min, static voltage 20 kV, atomization pressure 220 kPa.

[0049] Example 3

[0050] This example provides a method for encapsulating dried Mortierella alpina cells, and the preparation method is as follows:

[0051] 1) Use inulin, soluble soybean polysaccharide, and gelatin with a mass ratio of 3.2:2.8:4.0, and dissolve them in 95% ethanol at a mass ratio of 1:6, and stir and dissolve at 80 rpm / min as the coating film.

[0052] 2) Weigh dried Mortierella alpina cells and the embedding layer at a mass ratio of 5:5, and send them into the electrospinning equipment. In the encapsulated microbial agent, ARA accounts for 25% of the dry matter content. Set the electrospinning equipment conditions: receiving distance 17 cm, advancing speed 0.004 mm / s, applying a voltage of 35 kV, ambient temperature 35 °C, humidity 40.0% (RH), and time 24 h.

[0053] Example 4

[0054] This example provides a method for encapsulating dried Mortierella alpina cells, and the preparation method is as follows:

[0055] 1) Use a mixture of β-glucan, chitosan, and arabic gum with a mass ratio of 2.5:3.0:4.5, and dissolve them in 95% polyethylene glycol at a ratio of 1:10, and stir and dissolve at 250 rpm / min as the coating film.

[0056] 2) Weigh dried Mortierella alpina cells and the embedding layer at a mass ratio of 5:4, and send them into the electrostatic spraying equipment. In the encapsulated microbial agent, ARA accounts for 24% of the dry matter content. Set the electrostatic spraying equipment conditions: gas flow rate 30 Nm 3 / h, inlet air temperature 70 °C, material pump flow rate 20 r / min, static voltage 20 kV, atomization pressure 220 kPa.

[0057] Example 5

[0058] This example provides a method for encapsulating dried Mortierella alpina cells, and the preparation method is as follows:

[0059] 1) Use a combination of inulin, soluble soybean polysaccharide, and gelatin with a mass ratio of 3.4:3.0:3.6, and dissolve them in 95% ethanol at a ratio of 1:6, and stir and dissolve at 80 rpm / min as the coating film.

[0060] 2) Weigh the dry mycelium of Mortierella alpina and the embedding layer at a mass ratio of 5:5, and feed it into the spray drying equipment. In the embedded microbial agent, ARA accounts for 25% of the dry matter content. Set the conditions of the spray drying equipment: flow rate 2 L / min, inlet air temperature 70 °C, outlet air temperature 25 °C, time 3 h.

[0061] Comparative Example 1

[0062] This comparative example provides an embedded dry mycelium of Mortierella alpina, and the preparation method is as follows:

[0063] 1) Use cyclodextrin and carrageenan with a mass ratio of 6.0:4.0, and dissolve them in 95% ethanol at a mass ratio of 1:6, and stir and dissolve at 80 rpm / min as the coating film.

[0064] 2) Weigh the dry mycelium of Mortierella alpina and the embedding layer at a mass ratio of 5:5, and feed it into the electrospinning equipment. In the embedded microbial agent, ARA accounts for 23% of the dry matter content. Set the conditions of the electrospinning equipment: receiving distance 15 cm, advancing speed 0.002 mm / s, applying a voltage of 10 kV, environmental temperature 30 °C, humidity 37.5% (RH), time 12 h.

[0065] Comparative Example 2

[0066] This comparative example provides an embedded dry mycelium of Mortierella alpina, and the preparation method is as follows:

[0067] 1) Use a mixture of cyclodextrin, polydextrose and carrageenan with a mass ratio of 3.0:3.7:3.3, and dissolve it in 95% ethanol at a ratio of 1:12, and stir and dissolve at 250 rpm / min as the coating film.

[0068] 2) Weigh the dry mycelium of Mortierella alpina and the embedding layer at a mass ratio of 5:4, and feed it into the electrostatic spraying equipment. In the embedded microbial agent, ARA accounts for 24% of the dry matter content. Set the conditions of the electrostatic spraying equipment: gas flow rate 30 Nm 3 / h, inlet air temperature 70 °C, material pump flow rate 20 r / min, static voltage 20 kV, atomization pressure 220 kPa.

[0069] For Examples 1 - 5 and Comparative Examples 1 - 2, the rumen passage rate of the embedded dry mycelium of Mortierella alpina was detected. The detection results are shown in Table 1

[0070] Table 1 Detection results of the rumen passage rate of the embedded dry mycelium of Mortierella alpina

[0071] Rumen passage rate Example 1 93％ Example 2 95％ Example 3 92％ Example 4 88％ Example 5 76％ Comparative Example 1 52％ Comparative Example 2 55％

[0072] The rumen passage rate of polyunsaturated fatty acids was calculated as follows: the polyunsaturated fatty acid content in the sample after 24 hours in the rumen / the polyunsaturated fatty acid content in the sample before feeding. The content of polyunsaturated fatty acids was determined according to GB 5009.168 "National Food Safety Standard - Determination of Fatty Acids in Food".

[0073] Example 6

[0074] This embodiment provides a feed containing embedded Mortierella alpina dry cells, and the preparation method is as follows:

[0075] 1) The embedded Mortierella alpina dry cells of Example 1, concentrated feed and roughage were fully mixed in a mass ratio of 10:25:65.

[0076] 2) The concentrated feed includes a mixture of yeast powder, vitamins and minerals. The roughage includes silage corn.

[0077] 3) Mix the embedded dried thallus of Mortierella alpina with concentrated feed to obtain a mixture. The mixture is mixed with roughage by TMR to obtain feed. TMR is the abbreviation of Total Mixed Rations in English. The so-called total mixed ration (TMR) is a feeding technology that fully mixes roughage, concentrate, minerals, vitamins and other additives to provide sufficient nutrition to meet the needs of dairy cows. A total mixed ration (TMR) is a relatively balanced diet obtained by fully stirring and mixing roughage, concentrated feed and various nutritional additives chopped (kneaded) to appropriate lengths according to the nutritional needs of ruminants at different physiological stages.

[0078] The present embodiment also provides a native ARA-rich milk and a preparation method thereof, wherein the feed containing the embedded Mortierella alpina dry thalli of the present embodiment is continuously fed to dairy cows (the dairy cows are in the lactation period of 10 days, and are continuously fed for 25 days. The intake of the embedded Mortierella alpina dry thalli is 250 g / day / cow. The embedded Mortierella alpina dry thalli is fed in a feeding gradient of 50, 100, 150, 200, and 250 g / day / cow. Each gradient is fed for 3 to 5 days, and the feeding amount of 250 g of the embedded Mortierella alpina dry thalli is reached within two weeks). After the feeding period, the milk produced by the fed dairy cows is processed, and the following process is adopted:

[0079] 1) Raw milk is purified and impurities removed.

[0080] 2) After the treatment in step 1), the RO membrane concentration process is used, with a concentration ratio of 1.25 and a temperature of 4°C;

[0081] 3) After the treatment in step 2), fat separation is carried out at a temperature of 45°C, and the fat content of skim milk is ≤0.5 g / 100 g; high-temperature sterilization of cream is carried out at a sterilization temperature of 135°C for 3 s;

[0082] 4) After the treatment in step 3), double-effect sterilization is adopted. Two centrifugal sterilizers are connected in series to sterilize the skim milk. The set parameters of the two centrifugal sterilizers are the same, and the set parameters are 45°C, 4000 r / min, and the running time is 40 s;

[0083] 5) After the treatment in step 4), steam direct sterilization is adopted, steam immersion type, 131°C, 5 s;

[0084] 6) The raw materials in step 3) and step 5) are mixed evenly;

[0085] 7) After the treatment in step 6), homogenization is carried out;

[0086] 8) After the treatment in step 7), aseptic filling is carried out.

[0087] Detect the ARA content in the produced milk. Collect cow blood samples and detect antioxidant indexes - catalase (CAT), superoxide dismutase (SOD); detect antioxidant indexes - catalase (CAT), superoxide dismutase (SOD) in the produced milk. The detection is carried out using a commercial kit from Nanjing Jiancheng Bioengineering Research Institute and operated according to the product instruction manual. The detection results are shown in Table 2.

[0088] Example 7

[0089] This example provides a feed containing encapsulated dried cells of Mortierella alpina, and the preparation method is as follows:

[0090] 1) The encapsulated dried cells of Mortierella alpina, concentrate feed, and roughage in Example 2 are fully mixed according to a mass ratio of 15:35:50.

[0091] 2) The concentrate feed includes a mixture of yeast powder, vitamins, and minerals. The roughage contains silage corn.

[0092] 3) Mix the encapsulated dried cells of Mortierella alpina with the concentrate feed to obtain a mixed material. Mix the mixed material with the roughage by TMR to obtain the feed.

[0093] This embodiment also provides a native ARA-rich milk and its preparation method. The feed containing encapsulated Mortierella alpina dry cells of this embodiment is continuously fed to dairy cows (the dairy cows are in the 10th day of lactation period and are continuously fed for 25 days. The intake of encapsulated Mortierella alpina dry cells is 250 g / day / head. Feeding is carried out according to the feeding gradient of 50, 100, 150, 200, 250 g / day / head of encapsulated Mortierella alpina dry cells, and each gradient is fed for 3 - 5 days to reach the feeding amount of 250 g of encapsulated Mortierella alpina dry cells within two weeks). After the feeding period ends, the milk produced by the fed dairy cows is processed using the following process:

[0094] 1) The raw milk is clarified and impurities are removed.

[0095] 2) After the treatment in step 1), it is processed using an RO membrane concentration process with a concentration ratio of 1.25 and a temperature of 4°C;

[0096] 3) After the treatment in step 2), fat separation is carried out at a temperature of 60°C, and the fat content of the skim milk is ≤0.5 g / 100 g; the cream is subjected to high-temperature sterilization at a sterilization temperature of 154°C for 0.09 s;

[0097] 4) After the treatment in step 3), double-effect sterilization is adopted, with two centrifugal sterilizers connected in series to sterilize the skim milk. The set parameters of the two centrifugal sterilizers are the same, with the set parameters being 60°C, 6000 r / min, and the running duration being 80 s;

[0098] 5) After the treatment in step 4), steam direct sterilization is adopted, steam immersion type, 131°C, 5 s;

[0099] 6) The raw materials in step 3) and step 5) are mixed evenly;

[0100] 7) After the treatment in step 6), homogenization is carried out;

[0101] 8) After the treatment in step 7), aseptic filling is carried out.

[0102] The detection is carried out using the method of Example 6, and the detection results are shown in Table 2.

[0103] Example 8

[0104] This embodiment provides a feed containing encapsulated Mortierella alpina dry cells, and the preparation method is as follows:

[0105] 1) The encapsulated Mortierella alpina dry cells, concentrate feed, and roughage of Example 3 are fully mixed according to a mass ratio of 12:30:58.

[0106] 2) The concentrate feed includes a mixture of yeast powder, vitamins, and minerals. The roughage contains silage corn.

[0107] 3) Mix the encapsulated Mortierella alpina dry cells with the concentrate feed to obtain a mixed material. Mix the said mixed material with the roughage by TMR to obtain the feed.

[0108] This example also provides a native ARA-rich milk and its preparation method. Feed the cows continuously with the feed containing the encapsulated Mortierella alpina dry cells of this example (the cows are cows in the 10th day of lactation period, and are fed continuously for 25 days. The intake of the encapsulated Mortierella alpina dry cells is 250 g / day / head. Feed according to the feeding gradient of the encapsulated Mortierella alpina dry cells of 50, 100, 150, 200, 250 g / day / head, and each gradient is fed for 3 - 5 days, and the feeding amount of the encapsulated Mortierella alpina dry cells reaches 250 g within two weeks). After the feeding period ends, use the milk produced by the fed cows for processing, and adopt the following process:

[0109] 1) The raw milk is clarified and defatted.

[0110] 2) After the treatment in step 1), adopt the RO membrane concentration process for treatment, with a concentration ratio of 1.25 and a temperature of 4°C;

[0111] 3) After the treatment in step 2), conduct fat separation, with a temperature of 50°C and the fat content of the skim milk ≤ 0.5 g / 100 g; conduct high-temperature sterilization of the cream, with a sterilization temperature of 150°C and 2 s;

[0112] 4) After the treatment in step 3), adopt double-effect sterilization, with two centrifugal sterilizers connected in series to sterilize the skim milk. The set parameters of the two centrifugal sterilizers are the same, and the set parameters are 50°C, 5000 r / min, and the running duration is 60 s;

[0113] 5) After the treatment in step 4), adopt steam direct sterilization, steam immersion type, 132°C, 3 s;

[0114] 6) Mix the raw materials in step 3) and step 5);

[0115] 7) After the treatment in step 6), conduct homogenization;

[0116] 8) After the treatment in step 7), conduct aseptic filling.

[0117] Adopt the method of Example 6 for detection, and the detection results are shown in Table 2.

[0118] Example 9

[0119] This example provides a feed containing encapsulated Mortierella alpina dry cells, and the preparation method is as follows:

[0120] 1) The encapsulated Mortierella alpina dry cells, concentrate feed, and roughage in Example 4 are fully mixed according to the mass ratio of 15:32:53.

[0121] 2) The concentrate feed includes a mixture of yeast powder, vitamins, and minerals. The roughage contains silage corn.

[0122] 3) Mix the encapsulated Mortierella alpina dry cells with the concentrate feed to obtain a mixed material. Perform TMR mixing on the mixed material and the roughage to obtain the feed.

[0123] This embodiment also provides a native ARA-rich milk and its preparation method. Continuously feed the cows with the feed containing encapsulated Mortierella alpina dry cells of this embodiment (the cows are cows in the 10th day of lactation period and are continuously fed for 25 days. The intake of encapsulated Mortierella alpina dry cells is 250 g / day / head. Feed according to the feeding gradient of 50, 100, 150, 200, 250 g / day / head of encapsulated Mortierella alpina dry cells, and each gradient is fed for 3 - 5 days to reach the feeding amount of 250 g of encapsulated Mortierella alpina dry cells within two weeks). After the feeding period ends, use the milk produced by the fed cows for processing, and adopt the following process:

[0124] 1) The raw milk is subjected to milk clarification and impurity removal.

[0125] 2) After the treatment in step 1), adopt the RO membrane concentration process for treatment, with a concentration ratio of 1.25 and a temperature of 4°C;

[0126] 3) After the treatment in step 2), perform fat separation at a temperature of 55°C, and the fat content of the skim milk is ≤0.5 g / 100 g; perform high-temperature sterilization on the cream at a sterilization temperature of 140°C for 2.5 s;

[0127] 4) After the treatment in step 3), adopt double-effect sterilization. Two centrifugal sterilizers are connected in series to sterilize the skim milk. The set parameters of the two centrifugal sterilizers are the same, and the set parameters are 55°C, 4500 r / min, and the running duration is 50 s;

[0128] 5) After the treatment in step 4), adopt direct steam sterilization, steam injection type, 132°C, 4 s;

[0129] 6) Mix the raw materials in step 3) and step 5);

[0130] 7) After the treatment in step 6), perform homogenization;

[0131] 8) After the treatment in step 7), perform aseptic filling.

[0132] Detect by the method of Example 6, and the detection results are shown in Table 2.

[0133] Example 10

[0134] Adopt the method of Example 6, the difference is only that the encapsulated Mortierella alpina dry cells in Example 1 are changed to the encapsulated Mortierella alpina dry cells in Example 5.

[0135] Comparative Example 3

[0136] The method of Example 6 was adopted, and the difference was only that the embedded dried cells of Mortierella alpina were not added to the feed.

[0137] Table 2 ARA content in milk and contents of CAT and SOD in cow serum and milk

[0138]

[0139] It can be seen from the detected values of the indexes that the catalase (CAT) and superoxide dismutase (SOD) in the cow serum and milk of the embodiments of the present invention are both increased. The spray-drying embedding method has a higher heating intensity compared with the electrospinning and electrospraying embedding methods, resulting in the loss of ARA content in milk. The ARA content is significantly lower than that in the milk of the embodiments, and the contents of catalase (CAT) and superoxide dismutase (SOD) in cow serum and milk are also lower than those in the embodiments. The embedded dried cells of Mortierella alpina were not added to the feed in Comparative Example 3, so ARA was not detected in the milk. In addition, the milk itself and the produced milk were detected and analyzed from the perspective of antioxidant capacity, so as to infer that the milk produced by the present invention has the effect of enhancing the antioxidant capacity of the human body.

[0140] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A kind of embedded microbial agent, characterized in that, The encapsulated microbial agent includes: Mortierella alpina dry cells; and, An encapsulation layer coated on the outside of the Mortierella alpina dry cells; The encapsulation layer includes a first component and a second component with a mass ratio of (5.5 - 7.0):(3.0 - 4.5): The first component is selected from one or more of inulin, soluble soybean polysaccharide, β-glucan, and chitosan; The second component is selected from one or more of pectin, gelatin, and arabic gum.

2. The embedded microbial agent according to claim 1, wherein The first component is selected from one or more of inulin, β-glucan, and chitosan; and / or, the second component is selected from pectin and / or arabic gum; and / or, the mass ratio of the Mortierella alpina dry cells to the encapsulation layer is 5:4 - 5.

3. The embedded microbial agent according to claim 2, characterized in that, The encapsulation layer is a mixture of inulin and pectin with a mass ratio of (5.5 - 7.0):(3.0 - 4.5); or, a mixture of β-glucan, chitosan, and arabic gum with a mass ratio of (2.5 - 3.5):(3.0 - 4.5):(3.0 - 4.5); or, the encapsulation layer is a mixture of inulin, soluble soybean polysaccharide, and gelatin with a mass ratio of (3.0 - 3.5):(2.5 - 3.5):(3.0 - 4.5).

4. The preparation method of the embedded microbial agent according to any one of claims 1 to 3, characterized in that Including: Mix and dissolve the encapsulation layer raw materials with an alcohol reagent to obtain a packaging material, and encapsulate the Mortierella alpina dry cells with the packaging material by means of electrostatic spraying or electrospinning.

5. The preparation method of the embedded microbial agent according to claim 4, wherein, The conditions for the electrostatic spraying include: the gas flow rate is 30 - 35 Nm 3 / h, the inlet air temperature is 70 - 80 °C, the flow rate of the material pump is 20 - 30 r / min, the static voltage is 20 - 25 kV, and the atomization pressure is 220 - 230 kPa; And / or, the conditions of the electrospinning include: the receiving distance is 15 - 17 cm, the advancing speed is 0.002 - 0.004 mm / s, the applied voltage is 10 - 35 kV, the temperature is 30 - 35 °C, the humidity is 37.5% - 40%, and the time is 12 - 24 h.

6. Feed for producing native ARA-rich milk, characterized in that, Containing the encapsulated microbial agent described in any one of claims 1 - 3 or the encapsulated microbial agent obtained by the preparation method of the encapsulated microbial agent described in claim 4 or 5.

7. The feed for producing native ARA-rich milk according to claim 6, characterized in that, The feed includes an encapsulated microbial agent, concentrate feed, and roughage with a mass ratio of (10 - 15):(25 - 35):(45 - 65); the concentrate feed is preferably selected from at least one of yeast powder, vitamins, minerals, corn flour, and soybean meal; the roughage is preferably selected from at least one of silage corn, oat grass, alfalfa, and pasture grass.

8. A method for preparing a native ARA-rich milk, characterized in that, Produced and processed from dairy cows fed with the feed for producing milk rich in ARA described in claim 6 or 7.

9. The preparation method of the native ARA-rich milk according to claim 8, characterized in that, Including direct steam sterilization, the treatment temperature of the direct steam sterilization is 130 - 139 °C, preferably 131 - 135 °C, and the treatment time is 0.09 - 5 s.

10. A native ARA-rich milk, characterized in that, Obtained by the preparation method of milk rich in ARA described in claim 8 or 9.

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