A prepared milk containing dha algal oil capsules and a method of making the same

Abstract

The application discloses a kind of DHA algal oil capsule-containing modulated milk and its preparation method.The preparation method of modulated milk provided by the application comprises the following steps: 1) dissolving DHA algal oil and hydroxylated polycaprolactone at both ends in ethanol;2) quickly injecting the mixed solution obtained in step 1) into water to obtain DHA algal oil capsule mixture A;3) drying the mixture A to obtain DHA algal oil capsules;4) mixing the DHA algal oil capsules with water to obtain mixture B;5) mixing the mixture B with raw cow milk to obtain mixture C;6) homogenizing;7) UHT ultra-high temperature instantaneous sterilization;8) cooling to room temperature and then aseptically filling.The application solves the problem of instability of DHA algal oil in modulated milk by encapsulating DHA algal oil with hydroxylated polycaprolactone at both ends, so that DHA algal oil maintains good flavor in the product, is not oxidized, reduces the generation of fishy smell, and makes the product system more stable.

Description

Technical Field

[0001] This invention relates to modified milk and its production method, specifically to a modified milk containing DHA algal oil capsules and its preparation method. Background Technology

[0002] Flavored milk is a popular dairy product among consumers. To enrich the variety of flavored milk, various nutrients are often added to improve its nutritional content and taste. Among them, DHA (docosahexaenoic acid) is an essential polyunsaturated fatty acid for the human body. It is an important component of brain cell membranes, participates in the formation and development of brain cells, plays an important role in the extension of nerve cell axons and the formation of new protrusions, maintains the normal physiological activities of nerve cells, and participates in the process of brain thinking and memory formation.

[0003] However, DHA is an unsaturated fatty acid, characterized by instability and easy oxidation. If the environment is not properly controlled during production or storage, a fishy odor can develop. Furthermore, the longer the product is stored after leaving the factory, the more severe the oxidation becomes, seriously affecting product quality. Adding DHA algal oil directly to liquid milk results in poor product stability and a tendency for stratification. While adding DHA algal oil powder to liquid milk avoids stratification, it is still susceptible to oxidation and the development of a fishy odor during production or storage. Therefore, adding DHA to liquid milk faces significant technological barriers. Summary of the Invention

[0004] To address the DHA oxidation problem, this invention proposes a solution that encapsulates DHA algal oil within hydroxylated polycaprolactone particles to form nanocapsules, thereby improving the stability of DHA in milk.

[0005] This invention first provides a method for preparing a modified milk containing DHA algal oil capsules, comprising the following steps:

[0006] 1) Dissolve DHA algal oil and hydroxylated polycaprolactone at both ends in ethanol to obtain a mixed solution;

[0007] 2) Inject the mixed solution obtained in step 1) into water to obtain DHA algal oil capsule mixture A, and dry it to obtain DHA algal oil capsules;

[0008] 3) Mix the DHA algal oil capsules with water to obtain mixture B;

[0009] 4) Mix mixture B with raw milk and then homogenize to obtain mixture C;

[0010] 5) The mixture C was subjected to UHT ultra-high temperature instantaneous sterilization, and after cooling, a modified milk containing DHA algal oil capsules was obtained.

[0011] As a preferred embodiment of the present invention, in step 1), the weight ratio of DHA algal oil to polycaprolactone with hydroxylation at both ends is 1:3-1:1000.

[0012] As a preferred embodiment of the present invention, step 2) specifically involves: injecting the obtained mixed solution into water through a microchannel. Since ethanol and water are miscible, as ethanol diffuses, the solubility of DHA algal oil and hydroxylated polycaprolactone in the water and ethanol mixture decreases and they precipitate together. Furthermore, DHA algal oil is embedded in the hydroxylated polycaprolactone matrix to form nanoparticles encapsulating DHA algal oil. Afterward, the water and ethanol are removed by drying to obtain DHA algal oil capsules.

[0013] As a preferred embodiment of the present invention, in step 2), the diameter of the microchannel is 0.1 mm-2 mm, and the volumetric flow rate when injecting the mixture is 50-2000 mL / min.

[0014] As a preferred embodiment of the present invention, the DHA algal oil capsules obtained in step 2) have a size of 100nm-400nm and a wall thickness of 10nm-100nm.

[0015] As a preferred embodiment of the present invention, in step 3), the weight ratio of DHA algal oil capsules to water is 1:(1-20).

[0016] As a preferred embodiment of the present invention, in step 4), the weight ratio of mixture B to raw milk is 1:(4-99).

[0017] In a preferred embodiment of the present invention, in step 4), the homogenization pressure is 15-25 MPa, more preferably 20-25 MPa, and most preferably 20 MPa; the homogenization temperature is 50℃-75℃, more preferably 60-65℃, and most preferably 62℃.

[0018] As a preferred embodiment of the present invention, in step 5), the sterilization temperature of the UHT ultra-high temperature instantaneous sterilization is 135℃-150℃, more preferably 135-140℃, and most preferably 137℃; the sterilization time is 2-8s, more preferably 3-5s, and most preferably 4s.

[0019] The present invention also provides a modified milk containing DHA algal oil capsules prepared according to the above preparation method.

[0020] The reagents and raw materials used in this invention are all commercially available.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] This invention extends the shelf life of DHA by making DHA algal oil into nanocapsules, overcoming the problem in existing technologies where adding DHA to milk results in a fishy smell that affects product quality. The DHA algal oil is encapsulated in nanoparticles, preventing DHA oxidation and ensuring its stable presence in the milk, thus maintaining the product's good flavor and avoiding a fishy smell that could affect its quality.

[0023] This invention can also effectively control the size and wall thickness of nanocapsules by regulating the solution formulation and the microfluidic shearing process, thereby further preventing the oxidation of DHA algal oil. Attached Figure Description

[0024] Figure 1 A flowchart illustrating the method for preparing a modified emulsion containing DHA algal oil capsules as shown in this invention;

[0025] Figure 2 This is a schematic diagram showing the dispersion of DHA algal oil capsules in milk. Detailed Implementation

[0026] The present invention will be further described and illustrated below with reference to specific embodiments. The embodiments described are merely examples of the content of this disclosure and do not limit the scope of the invention. The technical features of each embodiment in the present invention can be combined accordingly, provided that there is no mutual conflict.

[0027] like Figure 1 As shown, this invention provides a method for preparing a modified milk containing DHA algal oil capsules, comprising the following steps:

[0028] 1) Dissolve DHA algal oil and hydroxylated polycaprolactone at both ends in ethanol to obtain a mixed solution; wherein the weight ratio of DHA algal oil to hydroxylated polycaprolactone is 1:(3-1000);

[0029] 2) The mixed solution obtained in step 1) is injected into water through microchannels with a diameter of 0.1 mm to 2 mm at a volumetric flow rate of 50-2000 mL / min. Since ethanol and water are miscible, as ethanol diffuses, the solubility of DHA algal oil and hydroxylated polycaprolactone in the water and ethanol mixture decreases and they precipitate together. DHA algal oil is embedded in the hydroxylated polycaprolactone matrix to form nanoparticles that encapsulate DHA algal oil. After drying, water and ethanol are removed to obtain DHA algal oil capsules.

[0030] 3) Mix DHA algal oil capsules with water to obtain mixture B; wherein the weight ratio of DHA algal oil capsules to water is 1:(1-20);

[0031] 4) Mix mixture B with raw milk and then homogenize to obtain mixture C; wherein the weight ratio of mixture B to raw milk is 1:(4-99), the homogenization pressure is 15-25MPa, and the homogenization temperature is 50℃-75℃.

[0032] 5) The mixture C was subjected to UHT ultra-high temperature instantaneous sterilization, and after cooling, the following was obtained: Figure 2 The image shows a modified milk containing DHA algal oil capsules.

[0033] Example 1

[0034] Table 1 Raw material formula for Example 1

[0035] raw material Amount added (%) Raw buffalo milk 90 DHA algal oil capsules (DHA algal oil: hydroxylated polycaprolactone = 1:100) 1 water 9

[0036] Production steps:

[0037] 1) Dissolve 50g of DHA algal oil and 5kg of hydroxylated polycaprolactone in 1000ml of ethanol;

[0038] 2) The mixed solution obtained in step 1) is rapidly injected into 1000ml of water through a microchannel with a diameter of 0.2mm at a flow rate of 60ml / min to obtain DHA algal oil capsule mixture A;

[0039] 3) The mixture A was dried to remove ethanol and water, yielding DHA algal oil capsules;

[0040] 4) Mix 100g of DHA algal oil capsules with 900g of water to obtain mixture B;

[0041] 5) Mix 1 kg of mixture B with 9 kg of raw milk to obtain mixture C;

[0042] 6) Homogenize the mixture C at a pressure of 20 MPa and a temperature of 60 °C;

[0043] 7) The mixture obtained in step 6) is subjected to UHT ultra-high temperature instantaneous sterilization. In this embodiment, the sterilization temperature is 137°C and the sterilization time is 4 seconds.

[0044] 8) Cool the mixture obtained in step 7) to 28°C and then perform aseptic filling;

[0045] 9) Packaging and inspection; products are shipped after passing inspection.

[0046] Example 2

[0047] Table 2 Raw material formula for Example 2

[0048] raw material Amount added (%) Raw buffalo milk 85 DHA algal oil capsules (DHA algal oil: hydroxylated polycaprolactone = 1:200) 5 water 10

[0049] Production steps:

[0050] 1) Dissolve 50g of DHA algal oil and 10kg of hydroxylated polycaprolactone in 1500ml of ethanol;

[0051] 2) The mixed solution obtained in step (1) is rapidly injected into 1500ml of water through a microchannel with a diameter of 0.1mm at a flow rate of 50ml / min to obtain DHA algal oil capsule mixture A;

[0052] 3) The mixture A was dried to remove ethanol and water, yielding DHA algal oil capsules;

[0053] 4) Mix 500g of DHA algal oil capsules with 1000g of water to obtain mixture B;

[0054] 5) Mix 15 kg of mixture B with 85 kg of raw milk to obtain mixture C;

[0055] 6) Homogenize the mixture C at a pressure of 22 MPa and a temperature of 65℃;

[0056] 7) The mixture obtained in step 6) is subjected to UHT ultra-high temperature instantaneous sterilization. In this embodiment, the sterilization temperature is 138°C and the sterilization time is 5 seconds.

[0057] 8) Cool the mixture obtained in step 7) to 29°C and then perform aseptic filling;

[0058] 9) Packaging and inspection; products are shipped after passing inspection.

[0059] Example 3

[0060] Table 3 Raw material formula for Example 3

[0061] raw material Amount added (%) Raw buffalo milk 80 DHA algal oil capsules (DHA algal oil: hydroxylated polycaprolactone = 1:200) 4 water 16

[0062] Production steps:

[0063] 1) Dissolve 50g of DHA algal oil and 1000g of hydroxylated polycaprolactone in 1500ml of ethanol;

[0064] 2) The mixed solution obtained in step 1) is rapidly injected into 1500ml of water through a microchannel with a diameter of 0.2mm at a flow rate of 70ml / min to obtain DHA algal oil capsule mixture A;

[0065] 3) The mixture A was dried to remove ethanol and water, yielding DHA algal oil capsules;

[0066] 4) Mix 400g of DHA algal oil capsules with 1600g of water to obtain mixture B;

[0067] 5) Mix 20 kg of mixture B with 80 kg of raw milk to obtain mixture C;

[0068] 6) Homogenize the mixture C at a pressure of 22 MPa and a temperature of 65℃;

[0069] 7) The mixture obtained in step 6) is subjected to UHT ultra-high temperature instantaneous sterilization. In this embodiment, the sterilization temperature is 138°C and the sterilization time is 5 seconds.

[0070] 8) Cool the mixture obtained in step 7) to 29°C and then perform aseptic filling;

[0071] 9) Packaging and inspection; products are shipped after passing inspection.

[0072] Comparative Example 1

[0073] Production steps:

[0074] 1) Mix 7.2g of DHA in the form of DHA algal oil powder with 1600g of water to obtain mixture A;

[0075] 2) Mix mixture A with raw milk to prepare a total of 100 kg of mixture B;

[0076] 3) Homogenize the mixture B at a pressure of 22 MPa and a temperature of 65°C;

[0077] 4) The mixture obtained in step 3) is subjected to UHT ultra-high temperature instantaneous sterilization. In this embodiment, the sterilization temperature is 138°C and the sterilization time is 5 seconds.

[0078] 5) Cool the mixture obtained in step 4) to 29°C and then perform aseptic filling;

[0079] 6) Packaging and inspection; products are shipped after passing inspection.

[0080] Comparative Example 2

[0081] Production steps:

[0082] 1) Mix 7.2g of DHA algal oil with 1600g of water to obtain mixture A;

[0083] 2) Mix mixture A with raw milk to prepare a total of 100 kg of mixture B;

[0084] 3) Homogenize the mixture B at a pressure of 22 MPa and a temperature of 65°C;

[0085] 4) The mixture obtained in step 3) is subjected to UHT ultra-high temperature instantaneous sterilization. In this embodiment, the sterilization temperature is 138°C and the sterilization time is 5 seconds.

[0086] 5) Cool the mixture obtained in step 4) to 29°C and then perform aseptic filling;

[0087] 6) Packaging and inspection; products are shipped after passing inspection.

[0088] Example 1

[0089] To evaluate the differences between the examples and the comparative examples, the flavor, texture, color, and state of the modified milk prepared in Examples 1-3 and Comparative Examples 1-2 were evaluated after three months. The flavor evaluation used normal milk as a reference for difference assessment. The relevant evaluation results are shown in Table 4.

[0090] Table 4 Evaluation Tables for Examples 1-3 and Comparative Examples 1-2

[0091]

[0092] The evaluation was based on "GB / T 12315-2008";

[0093] Table 4 leads to the following conclusions: the embodiments exhibit significant advantages, producing products with pure and uniform color, moderate sweetness, rich and harmonious milky aroma, and uniform consistency. Furthermore, the preparation process is green and efficient. In summary, this invention has positive and effective significance.

[0094] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. Those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A method for preparing a modified milk containing DHA algal oil capsules, characterized in that, Includes the following steps: 1) Dissolve DHA algal oil and hydroxylated polycaprolactone at both ends in ethanol to obtain a mixed solution; the weight ratio of DHA algal oil to hydroxylated polycaprolactone at both ends in step 1) is 1:(3-1000). 2) Inject the mixed solution obtained in step 1) into water to obtain DHA algal oil capsule mixture A, and dry it to obtain DHA algal oil capsules; Step 2) specifically involves injecting the obtained mixed solution into water through a microchannel. Since ethanol and water are miscible, as ethanol diffuses, the solubility of DHA algal oil and hydroxylated polycaprolactone at both ends decreases in the water and ethanol mixture, causing them to precipitate together. Furthermore, DHA algal oil is embedded in the hydroxylated polycaprolactone matrix to form nanoparticles encapsulating DHA algal oil. After drying, water and ethanol are removed to obtain DHA algal oil capsules. The DHA algal oil capsules obtained in step 2) have a size of 100nm-400nm; 3) Mix the DHA algal oil capsules with water to obtain mixture B; in step 3), the weight ratio of DHA algal oil capsules to water is 1:(1-20). 4) After mixing mixture B with raw milk and homogenizing, mixture C is obtained; in step 4), the weight ratio of mixture B to raw milk is 1:(4-99). 5) The mixture C was subjected to UHT ultra-high temperature instantaneous sterilization, and after cooling, a modified milk containing DHA algal oil capsules was obtained.

2. The preparation method according to claim 1, characterized in that, In step 2), the diameter of the microchannel is 0.1 mm-2 mm, and the volumetric flow rate when injecting the mixture is 50-2000 mL / min.

3. The preparation method according to claim 1, characterized in that, The wall thickness of the DHA algal oil capsules obtained in step 2) is 10nm-100nm.

4. The preparation method according to claim 1, characterized in that, In step 4), the homogenization pressure is 15-25 MPa, and the homogenization temperature is 50℃-75℃.

5. The preparation method according to claim 1, characterized in that, In step 5), the sterilization temperature of the UHT ultra-high temperature instantaneous sterilization is 135℃-150℃, and the sterilization time is 2-8s.

6. A modified milk containing DHA algal oil capsules prepared by the preparation method according to any one of claims 1-5.

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