Preparation method of krill oil microcapsule powder with high oil loading capacity

Abstract

The invention discloses a preparation method of krill oil microcapsule powder with high oil loading capacity, which comprises the following steps: S1, dissolving zein and an antioxidant into an ethanol solution to prepare a zein ethanol solution; s2, dispersing the solution in the step S1 into a sodium caseinate-anionic polysaccharide solution to prepare a zein / sodium caseinate-anionic polysaccharide particle dispersion liquid for loading the krill oil; s3, carrying out rotary evaporation on the particle dispersion liquid prepared in S2 to remove ethanol, adding purified water to supplement the volume lost by ethanol evaporation, adding krill oil, and homogenizing to prepare krill oil Pickering emulsion; and S4, mixing the krill oil Pickering emulsion prepared in S3 with a maltodextrin solution or a maltodextrin and gelatin solution, and performing spray drying to obtain micro-capsule powder. The micro-capsule powder is obtained by preparing the krill oil Pickering emulsion with excellent freeze-thaw stability and thermal stability and then performing spray drying on the krill oil Pickering emulsion and the auxiliary materials, and the prepared micro-capsule powder is good in stability.

Description

Technical Field

[0001] The present invention relates to the field of food processing, and in particular to a method for preparing krill oil microcapsule powder with high oil loading. Background Art

[0002] Antarctic krill oil (KO) is rich in ω-3 polyunsaturated fatty acid phospholipids and other bioactive substances, such as astaxanthin, DHA, and EPA. Krill oil exhibits diverse biological activities. my country has approved krill oil as a new resource food ingredient. However, issues such as the low stability of krill oil's polyunsaturated fatty acids, a distinctive odor, and the susceptibility of astaxanthin to degradation significantly impact its nutritional and commercial value.

[0003] Krill oil, currently used as a dietary supplement, is typically encapsulated. However, after swallowing, the capsules release the oil rapidly, leaving an unpleasant odor in the stomach. Preparing krill oil into an emulsion, adding a wall material, and spray-drying it into a microcapsule powder is a method for improving krill oil stability, reducing odor, and increasing water dispersibility and absorption. Currently, krill oil is commonly emulsified and encapsulated into microcapsules to protect the krill oil and improve its water dispersibility. However, krill oil contains a high phospholipid content, resulting in high viscosity, making it difficult to prepare a stable krill oil emulsion. This affects the formability of the microcapsules and can result in a high oil yield of over 30% in the microcapsule powder. This results in poor encapsulation and poor microcapsule stability. Summary of the Invention

[0004] In summary, the present invention provides a method for preparing krill oil microcapsule powder with a high oil loading, wherein the prepared microcapsule powder has a high krill oil content and good stability.

[0005] The technical solution of the present invention is:

[0006] A method for preparing krill oil microcapsule powder with high oil loading, comprising the following steps:

[0007] S1: dissolving zein and an antioxidant in an ethanol solution to prepare a zein ethanol solution;

[0008] S2: dispersing the zein ethanol solution prepared in S1 into the sodium caseinate-anionic polysaccharide solution while stirring to prepare a zein / sodium caseinate-anionic polysaccharide particle dispersion for loading krill oil;

[0009] S3: The particle dispersion prepared in S2 is subjected to rotary evaporation to remove ethanol, purified water is added to make up for the volume lost by evaporation of ethanol, krill oil is added and dispersed and homogenized at high speed to prepare a krill oil Pickering emulsion;

[0010] S4: The krill oil Pickering emulsion prepared in S3 is mixed with a maltodextrin solution or a maltodextrin + gelatin solution, and the mixture is spray-dried to obtain a microcapsule powder.

[0011] The mass fraction of zein in the prepared zein ethanol solution is 5%-10%, and the added amount of the antioxidant accounts for 0.05-0.1% of the mass fraction of the zein ethanol solution.

[0012] Wherein, the mass fraction of the ethanol solution in S1 is 60%-90%.

[0013] The antioxidant is one or more of resveratrol, curcumin, quercetin, vitamin C, vitamin E, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and tert-butylhydroquinone (TBHQ).

[0014] The sodium caseinate-anionic polysaccharide solution is prepared by dissolving sodium caseinate and anionic polysaccharide in water, the weight ratio of sodium caseinate to anionic polysaccharide is (5-20):1, and sodium caseinate and anionic polysaccharide account for 1%-8% of the total mass fraction of the sodium caseinate-anionic polysaccharide solution.

[0015] The anionic polysaccharide is selected from one or more of xanthan gum, pectin, sodium alginate, carrageenan, carboxymethyl cellulose, gellan gum, gum arabic, propylene glycol alginate, and octenyl succinate starch.

[0016] Wherein, in said S2, the volume ratio of the zein ethanol solution to the sodium caseinate-anionic polysaccharide solution is 1:(1-5).

[0017] Wherein, in said S3, the volume ratio of krill oil to particle dispersion is (1-6):10.

[0018] Wherein, in said S4, the mass fraction of the maltodextrin solution is 5%-30%, preferably 10%.

[0019] Wherein, the mass fraction of maltodextrin in the maltodextrin+gelatin solution is 5%-20%, preferably 10%, and the mass fraction of gelatin is 5%-15%, preferably 10%.

[0020] Preferably, the volume ratio of the krill oil Pickering emulsion to the maltodextrin solution or the maltodextrin + gelatin solution is 1:1.

[0021] Compared with the prior art, the present invention provides a method for preparing a krill oil microcapsule powder with a high oil loading, comprising the following steps: S1: dissolving zein and an antioxidant in an ethanol solution to prepare a zein ethanol solution; S2: dispersing the solution in S1 into a sodium caseinate-anionic polysaccharide solution, stirring and dispersing, to prepare a zein / sodium caseinate-anionic polysaccharide particle dispersion for loading krill oil; S3: rotary evaporating the particle dispersion prepared in S2 to remove ethanol, adding purified water to replenish the volume lost due to ethanol evaporation, adding krill oil, and dispersing and homogenizing by high-speed shearing to prepare a krill oil Pickering emulsion; and S4: mixing the krill oil Pickering emulsion prepared in S3 with a maltodextrin solution or a maltodextrin+gelatin solution in a volume ratio of 1:1, and spray drying to prepare the microcapsule powder. The present invention prepares a krill oil Pickering emulsion with good stability and then spray-dries it with auxiliary materials to obtain krill oil microcapsule powder. Since the emulsion has excellent freeze-thaw stability and thermal stability, after adding wall materials, krill oil microcapsule powder with good fluidity can be obtained. The krill oil has a high oil content, good stability, high utilization rate, and good stability of the microcapsule powder.

[0022] The krill oil emulsion prepared by the present invention exhibits excellent thermal stability, centrifugal stability, freeze-thaw stability, and chemical stability, significantly slowing the oxidation of krill oil polyunsaturated fatty acids and the loss of astaxanthin. The prepared pickerelin emulsion, after addition to a wall material and spray drying, can produce a microcapsule powder high in krill oil, achieving high stability and efficient loading. Because the microcapsule wall material is a water-soluble component, the krill oil microcapsule powder exhibits excellent water dispersibility, and the natural antioxidants loaded into the particles effectively protect the krill oil polyunsaturated fatty acids and astaxanthin from oxidative decomposition. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is an appearance diagram of a krill oil Pickering emulsion according to an embodiment of the present invention;

[0024] Figure 2 This is the appearance diagram of the determination of centrifugal stability of krill oil Pickering emulsion;

[0025] Figure 3A This is the appearance of the freeze-thaw test of the krill oil Pickering emulsion in Example 2; Figure 3B This is the appearance picture of the freeze-thaw test of krill oil Pickering emulsion in comparative example 2; Figure 3C This is the appearance of the freeze-thaw test of krill oil Pickering emulsions of Comparative Examples 1 and 4;

[0026] Figure 4 This is a microscopic structure diagram of the krill oil microcapsule powder of the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with some specific embodiments. The specific embodiments are provided to further illustrate the present invention in detail, but are not intended to limit the scope of protection of the present invention.

[0028] Sources of materials and instrument descriptions used in the examples and comparative examples:

[0029] Ingredients Manufacturer Specification Performance parameters Zein Wuhan Jiangxin Biotechnology Co., Ltd. Food grade Nitrogen content 13.1%-17.0% Resveratrol Hebei Vidakang Biotechnology Co., Ltd. Food grade 97％ Curcumin Jiangxi Xuesong Natural Medicinal Oil Co., Ltd. Food grade 97％ Quercetin Xi'an Zebang Biotechnology Co., Ltd. Food grade 98％ Sodium caseinate Anhui Datang Bioengineering Co., Ltd. Food grade 90％ Xanthan gum Zhejiang Shangfang Biotechnology Co., Ltd. Food grade 90％ Sodium alginate Qingdao Mingyue Seaweed Group Co., Ltd. Food grade Medium viscosity pectin Wuhan Shengze Food Ingredients Co., Ltd. Food grade 70% esterification degree Krill Oil Shandong Kangjing Marine Bioengineering Co., Ltd. Food grade Phospholipids 50% ethanol Henan Liuhe Pharmaceutical Group Co., Ltd. Food grade Absolute ethanol or 95% ethanol water Commercially available Deionized water maltodextrin Shandong Xiwang Sugar Co., Ltd. Food grade Moisture content <6% gelatin Jiangxi Fumeitai Biotechnology Co., Ltd. Food grade Protein 90%

[0030] instrument:

[0031] Scanning electron microscope: Hitachi high-resolution scanning electron microscope model S-4800

[0032] Microscope: Olympus BX43

[0033] Example 1

[0034] Preparation steps of krill oil microcapsule powder:

[0035] S1: dissolving zein in a 65 wt % ethanol solution, and then adding an antioxidant (resveratrol) to obtain an antioxidant-containing zein ethanol solution, wherein the amount of the antioxidant added is 0.1% by mass of the solution, and the final concentration of the zein is 10 wt %;

[0036] S2: Sodium caseinate and anionic polysaccharide (xanthan gum) are dissolved in water to prepare a sodium caseinate-anionic polysaccharide solution, wherein the weight ratio of sodium caseinate to anionic polysaccharide is 20:1, and the total mass fraction of sodium caseinate and anionic polysaccharide in the sodium caseinate-anionic polysaccharide solution is 1 wt %. The zein ethanol solution prepared in S1 is mixed with the sodium caseinate-anionic polysaccharide solution in a volume ratio of 1:1 to obtain a particle dispersion;

[0037] S3: Ethanol is evaporated from the particle dispersion prepared in S2, purified water is added to make up for the volume loss due to ethanol evaporation, krill oil is added and dispersed and homogenized at high speed shearing, with the volume ratio of krill oil to particle dispersion being 6:10, to prepare a krill oil Pickering emulsion;

[0038] S4: The krill oil Pickering emulsion prepared in S3 and a maltodextrin solution (prepared by dissolving 20 parts by weight of maltodextrin in 80 parts by weight of water) were mixed in a volume ratio of 1:1, and spray-dried to obtain a microcapsule powder.

[0039] Example 2

[0040] Preparation steps of krill oil microcapsule powder:

[0041] S1: dissolving zein in a 90 wt % ethanol solution, and then adding an antioxidant (curcumin) to obtain an antioxidant-containing zein ethanol solution, wherein the amount of the antioxidant added is 0.05% by mass of the solution, and the final concentration of the zein is 5 wt %;

[0042] S2: Sodium caseinate and anionic polysaccharide (sodium alginate) are dissolved in water to prepare a sodium caseinate-anionic polysaccharide solution, wherein the weight ratio of sodium caseinate to anionic polysaccharide is 5:1, and the total mass fraction of sodium caseinate and anionic polysaccharide in the sodium caseinate-anionic polysaccharide solution is 8 wt %. The zein ethanol solution prepared in S1 is mixed with the sodium caseinate-anionic polysaccharide solution in a volume ratio of 1:5 to obtain a particle dispersion;

[0043] S3: Ethanol is evaporated from the particle dispersion prepared in S2, purified water is added to make up for the volume loss due to ethanol evaporation, krill oil is added and dispersed and homogenized at high speed shearing, with the volume ratio of krill oil to particle dispersion being 6:10, to prepare a krill oil Pickering emulsion;

[0044] S4: The krill oil Pickering emulsion prepared in S3 and a maltodextrin + gelatin solution (prepared by dissolving 10 parts by weight of maltodextrin and 10 parts by weight of gelatin in 80 parts by weight of water) were mixed in a volume ratio of 1:1, and spray-dried to obtain a microcapsule powder.

[0045] Example 3

[0046] Preparation steps of krill oil microcapsule powder:

[0047] S1: dissolving zein in a 75 wt % ethanol solution, and then adding an antioxidant (quercetin) to obtain an antioxidant-containing zein ethanol solution, wherein the amount of the antioxidant added is 0.1% by mass of the solution, and the final concentration of the zein is 5 wt %;

[0048] S2: Sodium caseinate and anionic polysaccharide (pectin) are dissolved in water to prepare a sodium caseinate-anionic polysaccharide solution, wherein the weight ratio of sodium caseinate to anionic polysaccharide is 10:1, and the total mass fraction of sodium caseinate and anionic polysaccharide in the sodium caseinate-anionic polysaccharide solution is 4 wt %. The zein ethanol solution prepared in S1 is mixed with the sodium caseinate-anionic polysaccharide solution in a volume ratio of 1:3 to obtain a particle dispersion;

[0049] S3: Ethanol is evaporated from the particle dispersion prepared in S2, purified water is added to make up for the volume loss due to ethanol evaporation, krill oil is added and dispersed and homogenized at high speed shearing, with the volume ratio of krill oil to particle dispersion being 3:10, to prepare a krill oil Pickering emulsion;

[0050] S4: The krill oil Pickering emulsion prepared in S3 and a maltodextrin solution (prepared by dissolving 20 parts by weight of maltodextrin in 80 parts by weight of water) were mixed in a volume ratio of 1:1, and spray-dried to obtain a microcapsule powder.

[0051] Comparative Example 1

[0052] S1: dissolving zein in a 90 wt % ethanol solution, and then adding an antioxidant (curcumin) to obtain an antioxidant-containing zein ethanol solution, wherein the amount of the antioxidant added is 0.05% by mass of the solution, and the final concentration of the zein is 5 wt %;

[0053] S2: dissolving anionic polysaccharide (sodium alginate) in water to prepare anionic polysaccharide solution, wherein the total mass fraction of anionic polysaccharide in the anionic polysaccharide solution is 8 wt %. The zein ethanol solution prepared in S1 and the anionic polysaccharide solution are mixed at a volume ratio of 1:5 to obtain a particle dispersion.

[0054] S3: Ethanol is evaporated from the particle dispersion prepared in S2, purified water is added to make up for the volume loss due to ethanol evaporation, krill oil is added and dispersed and homogenized at high speed shearing, with the volume ratio of krill oil to particle dispersion being 6:10, to prepare a krill oil Pickering emulsion;

[0055] S4: The krill oil Pickering emulsion prepared in S3 and a maltodextrin + gelatin solution (prepared by dissolving 10 parts by weight of maltodextrin and 10 parts by weight of gelatin in 80 parts by weight of water) were mixed in a volume ratio of 1:1, and spray-dried to obtain a microcapsule powder.

[0056] Comparative Example 2

[0057] Preparation steps of krill oil microcapsule powder:

[0058] S1: dissolving zein in a 90 wt % ethanol solution, and then adding an antioxidant (curcumin) to obtain an antioxidant-containing zein ethanol solution, wherein the amount of the antioxidant added is 0.05% by mass of the solution, and the final concentration of the zein is 5 wt %;

[0059] S2: Sodium caseinate and anionic polysaccharide (sodium alginate) are dissolved in water to prepare a sodium caseinate-anionic polysaccharide solution, wherein the weight ratio of sodium caseinate to anionic polysaccharide is 40:1, and the total mass fraction of sodium caseinate and anionic polysaccharide in the sodium caseinate-anionic polysaccharide solution is 8 wt %. The zein ethanol solution prepared in S1 is mixed with the sodium caseinate-anionic polysaccharide solution in a volume ratio of 1:5 to obtain a particle dispersion;

[0060] S3: Ethanol is evaporated from the particle dispersion prepared in S2, purified water is added to make up for the volume loss due to ethanol evaporation, krill oil is added and dispersed and homogenized at high speed shearing, with the volume ratio of krill oil to particle dispersion being 6:10, to prepare a krill oil Pickering emulsion;

[0061] S4: The krill oil Pickering emulsion prepared in S3 and a maltodextrin + gelatin solution (prepared by dissolving 10 parts by weight of maltodextrin and 10 parts by weight of gelatin in 80 parts by weight of water) were mixed in a volume ratio of 1:1, and spray-dried to obtain a microcapsule powder.

[0062] Comparative Example 3

[0063] Preparation steps of krill oil microcapsule powder:

[0064] S1: dissolving zein in a 90 wt % ethanol solution, and then adding an antioxidant (curcumin) to obtain an antioxidant-containing zein ethanol solution, wherein the amount of the antioxidant added is 0.05% by mass of the solution, and the final concentration of the zein is 5 wt %;

[0065] S2: Sodium caseinate and anionic polysaccharide (sodium alginate) are dissolved in water to prepare a sodium caseinate-anionic polysaccharide solution, wherein the weight ratio of sodium caseinate to anionic polysaccharide is 5:1, and the total mass fraction of sodium caseinate and anionic polysaccharide in the sodium caseinate-anionic polysaccharide solution is 3 wt %. The zein ethanol solution prepared in S1 is mixed with the sodium caseinate-anionic polysaccharide solution in a volume ratio of 1:5 to obtain a particle dispersion;

[0066] S3: Ethanol is evaporated from the particle dispersion prepared in S2, purified water is added to make up for the volume loss due to ethanol evaporation, krill oil is added and dispersed and homogenized at high speed shearing, with the volume ratio of krill oil to particle dispersion being 6:10, to prepare a krill oil Pickering emulsion;

[0067] S4: The krill oil Pickering emulsion prepared in S3 and a maltodextrin + gelatin solution (prepared by dissolving 10 parts by weight of maltodextrin and 10 parts by weight of gelatin in 80 parts by weight of water) were mixed in a volume ratio of 1:1, and spray-dried to obtain a microcapsule powder.

[0068] Comparative Example 4

[0069] Preparation steps of krill oil microcapsule powder:

[0070] S1: dissolving zein in a 90 wt % ethanol solution, and then adding an antioxidant (curcumin) to obtain an antioxidant-containing zein ethanol solution, wherein the amount of the antioxidant added is 0.05% by mass of the solution, and the final concentration of the zein is 5 wt %;

[0071] S2: Sodium caseinate and anionic polysaccharide (sodium alginate) are dissolved in water to prepare a sodium caseinate-anionic polysaccharide solution, wherein the weight ratio of sodium caseinate to anionic polysaccharide is 5:1, and the total mass fraction of sodium caseinate and anionic polysaccharide in the sodium caseinate-anionic polysaccharide solution is 0.5 wt %. The zein ethanol solution prepared in S1 is mixed with the sodium caseinate-anionic polysaccharide solution in a volume ratio of 1:5 to obtain a particle dispersion;

[0072] S3: Ethanol is evaporated from the particle dispersion prepared in S2, purified water is added to make up for the volume loss due to ethanol evaporation, krill oil is added and dispersed and homogenized at high speed shearing, with the volume ratio of krill oil to particle dispersion being 6:10, to prepare a krill oil Pickering emulsion;

[0073] S4: The krill oil Pickering emulsion prepared in S3 and a maltodextrin + gelatin solution (prepared by dissolving 10 parts by weight of maltodextrin and 10 parts by weight of gelatin in 80 parts by weight of water) were mixed in a volume ratio of 1:1, and spray-dried to obtain a microcapsule powder.

[0074] Comparative Example 5

[0075] Preparation steps of krill oil microcapsule powder:

[0076] S1: dissolving zein in a 90 wt % ethanol solution, and then adding an antioxidant (curcumin) to obtain an antioxidant-containing zein ethanol solution, wherein the amount of the antioxidant added is 0.05% by mass of the solution, and the final concentration of the zein is 5 wt %;

[0077] S2: Sodium caseinate and anionic polysaccharide (sodium alginate) are dissolved in water to prepare a sodium caseinate-anionic polysaccharide solution, wherein the weight ratio of sodium caseinate to anionic polysaccharide is 5:1, and the total mass fraction of sodium caseinate and anionic polysaccharide in the sodium caseinate-anionic polysaccharide solution is 10 wt %. The zein ethanol solution prepared in S1 is mixed with the sodium caseinate-anionic polysaccharide solution in a volume ratio of 1:5 to obtain a particle dispersion;

[0078] S3: Ethanol is evaporated from the particle dispersion prepared in S2, purified water is added to make up for the volume loss due to ethanol evaporation, krill oil is added and dispersed and homogenized at high speed shearing, with the volume ratio of krill oil to particle dispersion being 7:10, to prepare a krill oil Pickering emulsion;

[0079] S4: The krill oil Pickering emulsion prepared in S3 and a maltodextrin + gelatin solution (prepared by dissolving 10 parts by weight of maltodextrin and 10 parts by weight of gelatin in 80 parts by weight of water) were mixed in a volume ratio of 1:1, and spray-dried to obtain a microcapsule powder.

[0080] The microcapsule powders prepared in the Examples and Comparative Examples or the krill oil Pickering emulsion prepared in S3 were subjected to the following performance tests.

[0081] It should be noted that the krill oil Pickering emulsions of Comparative Examples 1 and 4 were separated and no homogeneous emulsions were obtained (e.g. Figure 1 As shown, Comparative Example 1 is Figure 1 As shown in the left figure, Comparative Example 4 is as follows Figure 1 As shown in the figure on the right), the stability of krill oil Pickering emulsion affects whether krill oil microcapsules can be embedded and formed. Therefore, the stability of krill oil Pickering emulsion was tested below.

[0082] 1. Determination of centrifugal stability of krill oil Pickering emulsions

[0083] The krill oil Pickering emulsions of Examples 1-3 and Comparative Examples 4 and 5 were transferred to a centrifuge tube and then centrifuged at 8000 rpm for 20 minutes. The appearance of the emulsion after centrifugation was recorded with a digital camera, as shown in FIG. Figure 2 As shown in the figure (from left to right are krill oil Pickering emulsions of Example 1, Example 2, Example 3 and Comparative Example 5), it can be seen that the krill oil Pickering emulsion is a very stable emulsion system. Comparative Example 4 has poor centrifugal stability and oil separation occurs (such as Figure 1 first image on the right).

[0084] 2. Heat and Freeze-Thaw Stability Assays

[0085] Heating: The krill oil Pickering emulsions of Example 2 and Comparative Example 2 were heated at 90°C for 120 minutes and then cooled to room temperature in an ice bath.

[0086] Freeze-thaw cycles: Freshly prepared emulsions were frozen at -20 °C for 24 h and then thawed at room temperature for three cycles.

[0087] The emulsion after heating and freeze-thaw cycles was observed under a microscope. The appearance of the krill oil Pickering emulsion of Example 2 after heating was as follows: Figure 3A As shown, the appearance of the krill oil Pickering emulsion of Comparative Example 2 after freeze-thawing is as follows Figure 3B As shown. It can be seen that the krill oil Pickering emulsion of Example 2 has relatively good thermal stability and freeze-thaw stability. The thermal stability of Comparative Examples 1 and 4 is not good, as shown in FIG. Figure 3C As shown in the left and right photos, the emulsion has oil precipitation.

[0088] 3. Determination of Oxidative Stability of Krill Oil Pickering Emulsions

[0089] Freshly prepared Pickering emulsion samples were placed in sealed glass bottles and maintained at 60°C. The peroxide value (POV) of the emulsions was measured every two days. A lower POV value indicates better oxidative stability of the emulsion. Due to poor appearance stability of Examples 1, 3, 4, and 5, their POV values ​​were not tested in this experiment.

[0090] POV determination method: 0.6 mL of emulsion was vortex mixed with 4.5 mL of isooctane:isopropanol (3:1, v / v) and centrifuged at 4000g for 6 minutes. 0.4 mL of supernatant was mixed with 5.6 mL of methanol:butanol (2:1, v / v), and 30 μL of 3.94 M ammonium ferrous tungstate cyanate and 30 μL of 0.072 M ferrous chloride solution were added in sequence. The reaction was carried out in the dark for 20 minutes, and the absorbance of the mixture solution was measured at 510 nm using a UV spectrophotometer. The standard curve established for POV cumene hydroperoxide was calculated as (R 2 =0.9957).

[0091] Table 1 Comparison of the stability of krill oil Pickering emulsions of Example and Comparative Example (peroxide value (POV), unit: mg / g oil)

[0092]

[0093]

[0094] 4. Determination of powder oil content

[0095] Approximately 1g of powdered capsules was added to 10mL of 2mol / L HCl solution and stirred with a magnetic stirrer for 30 minutes to rupture the capsule wall. 40mL of chloroform and 10mL of methanol were added, and the mixture was stirred for 30 minutes to extract the oil. The suspension was centrifuged at 10,000rpm for 10 minutes. The organic phase was collected and placed in a 60°C oven until the solvent completely evaporated. The remaining oil was weighed, and the oil loading was calculated according to the formula: Powder oil loading (%) = Oil weight in organic phase / Total powder weight * 100.

[0096] The oil content of the powders of Example 2, Comparative Example 2 and Comparative Example 4 was tested according to the above test method, and the results are as follows:

[0097] Example 2 Comparative Example 2 Comparative Example 4 Oil content / % 6.7％ 8.2％ 30.1％

[0098] The microstructure of the microcapsule powder obtained in Example 2 is as follows: Figure 4 shown.

[0099] The above are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for preparing krill oil microcapsule powder with high oil loading, characterized in that The following steps are involved: S1: dissolving zein and an antioxidant in an ethanol solution to prepare a zein ethanol solution; S2: dispersing the zein ethanol solution prepared in S1 into the sodium caseinate-anionic polysaccharide solution while stirring to prepare a zein / sodium caseinate-anionic polysaccharide particle dispersion for loading krill oil; S3: The particle dispersion prepared in S2 is subjected to rotary evaporation to remove ethanol, purified water is added to make up for the volume lost by evaporation of ethanol, krill oil is added and dispersed and homogenized at high speed to prepare a krill oil Pickering emulsion; S4: The krill oil Pickering emulsion prepared in S3 is mixed with a maltodextrin solution or a maltodextrin + gelatin solution, and the mixture is spray-dried to obtain a microcapsule powder.

2. The method for preparing the high oil-loading krill oil microcapsule powder according to claim 1, characterized in that: The mass fraction of zein in the prepared zein ethanol solution is 5%-10%, and the added amount of the antioxidant accounts for 0.05-0.1% of the mass fraction of the zein ethanol solution.

3. The method for preparing the krill oil microcapsule powder with high oil loading according to claim 1, characterized in that: The mass fraction of the ethanol solution in S1 is 65%-90%.

4. The method for preparing the high oil-loading krill oil microcapsule powder according to claim 1, wherein: The antioxidant is one or more of resveratrol, curcumin, quercetin, vitamin C, vitamin E, butylated hydroxyanisole, butylated hydroxytoluene, and tert-butylhydroquinone.

5. The method for preparing the high oil-loading krill oil microcapsule powder according to claim 1, wherein: The sodium caseinate-anionic polysaccharide solution is prepared by dissolving sodium caseinate and anionic polysaccharide in water, the weight ratio of sodium caseinate to anionic polysaccharide is (5-20):1, and sodium caseinate and anionic polysaccharide account for 1%-8% of the total mass fraction of the sodium caseinate-anionic polysaccharide solution.

6. The method for preparing the high oil-loading krill oil microcapsule powder according to claim 1, wherein: The anionic polysaccharide is selected from one or more of xanthan gum, pectin, sodium alginate, carrageenan, carboxymethyl cellulose, gellan gum, gum arabic, propylene glycol alginate, and octenyl succinate starch.

7. The method for preparing the high oil-loading krill oil microcapsule powder according to claim 1, wherein: In the S2, the volume ratio of the zein ethanol solution to the sodium caseinate-anionic polysaccharide solution is 1:(1-5).

8. The method for preparing the high oil-loading krill oil microcapsule powder according to claim 1, wherein: In S3, the volume ratio of krill oil to particle dispersion is (3-6):

10.

9. The method for preparing the krill oil microcapsule powder with high oil loading according to claim 1, characterized in that: In the S4, the mass fraction of the maltodextrin solution is 5%-30%; the mass fraction of maltodextrin in the maltodextrin+gelatin solution is 5%-20%, and the mass fraction of gelatin is 5%-15%.

10. The method for preparing the krill oil microcapsule powder with high oil loading according to claim 1, wherein: The volume ratio of krill oil Pickering emulsion and maltodextrin solution or maltodextrin + gelatin solution is 1:1.

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