Method for removing cholesterol in fish oil and low-cholesterol fish oil

Abstract

The invention provides a method for removing cholesterol in fish oil and low-cholesterol fish oil, and relates to the technical field of health food processing. The method for removing cholesterol in fish oil comprises the following steps: mixing fish oil with an aqueous solution containing methyl-beta-cyclodextrin, stirring, standing, separating, and taking an upper oil layer to obtain low-cholesterol fish oil. The method for efficiently removing the cholesterol in the fish oil by using the methyl-beta-cyclodextrin (M-beta-CD) has the advantages of easiness in operation, high cholesterol removal rate, high fish oil recovery rate and the like, and can improve related quality indexes of the fish oil.

Description

Technical Field

[0001] The invention relates to the technical field of health food processing, in particular to a method for removing cholesterol from fish oil and low-cholesterol fish oil. Background Art

[0002] Fish oil is a health food made from fish by squeezing, boiling or organic solvent extraction. It is rich in ω-3 polyunsaturated fatty acids such as eicosapentaenoic acid and docosahexaenoic acid. It has the benefits of improving brain function, anti-tumor, regulating lipid and glucose metabolism, and improving athletic ability. It is widely used in the fields of medical treatment, food nutrition and health care, beauty and skin care, animal feed, sports nutrition, etc. However, fish oil contains a large amount of cholesterol. When the cholesterol content in the blood is too high, it may accumulate on the blood vessel wall to form plaques, leading to atherosclerosis, reducing blood flow to the heart and brain, and increasing the risk of heart disease and stroke. This does not meet the positioning of fish oil as a functional food and health food.

[0003] β-cyclodextrin is a cyclic oligosaccharide composed of seven glucose residues. Its hydrophobic inner cavity is similar in size to the cholesterol molecule, so it is often used to remove cholesterol from fish oil. However, β-cyclodextrin forms a paste during the cholesterol removal process, which makes it difficult to separate fish oil and results in low fish oil recovery.

[0004] Therefore, it is urgent to develop a cholesterol removal method with both high cholesterol removal rate and high fish oil recovery rate to reduce fish oil waste and improve production efficiency.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The purpose of the present invention is to provide a method for removing cholesterol from fish oil and low-cholesterol fish oil. The method of the present invention utilizes methyl-β-cyclodextrin (M-β-CD) to efficiently remove cholesterol from fish oil. The method has the advantages of easy operation, high cholesterol removal rate and high fish oil recovery rate, and can improve the quality-related indicators of fish oil.

[0007] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0008] In a first aspect, the present invention provides a method for removing cholesterol from fish oil, the method for removing cholesterol from fish oil comprising the following steps:

[0009] The fish oil and the aqueous solution containing methyl-β-cyclodextrin are mixed, stirred, allowed to stand for separation, and the upper oil layer is taken to obtain low-cholesterol fish oil.

[0010] Preferably, the added amount of the methyl-β-cyclodextrin is 5-40% of the mass of the fish oil, preferably 10-30%, and more preferably 30%.

[0011] Preferably, in the aqueous solution containing methyl-β-cyclodextrin, the solid content of methyl-β-cyclodextrin is 5 to 40%, preferably 10 to 30%, and more preferably 30%.

[0012] Preferably, the stirring treatment temperature is 30 to 70°C, preferably 50 to 60°C, and more preferably 50°C.

[0013] Preferably, the rotation speed of the stirring treatment is 100-300 rpm, preferably 150 rpm.

[0014] Preferably, the stirring treatment time is 5 to 25 min, preferably 15 to 25 min, and more preferably 15 min.

[0015] Preferably, the static separation time is 5 to 15 minutes, preferably 10 minutes.

[0016] Preferably, the cholesterol removal rate is greater than 26%, preferably greater than 45%.

[0017] Preferably, the recovery rate of the fish oil is above 80%.

[0018] In a second aspect, the present invention provides a low-cholesterol fish oil, which is prepared by the method described in the first aspect.

[0019] Preferably, the acid value of the low-cholesterol fish oil is 0.20-0.26 mg / g.

[0020] Preferably, the peroxide value of the low-cholesterol fish oil is 0.05-0.07 g / 100 g.

[0021] Preferably, the anisidine value of the low-cholesterol fish oil is 2.38-3.24.

[0022] Preferably, the iodine value of the low-cholesterol fish oil is 195.32-207.10 g / 100 g.

[0023] Preferably, the chromaticity of the low cholesterol fish oil includes: L * The value is 30.12~31.28, a * The value is -0.96~-0.70, b * The values ​​are 1.45~2.29, and the ΔE values ​​are 1.72~3.24.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention establishes a method for efficiently removing cholesterol from fish oil by using methyl-β-cyclodextrin (M-β-CD). The method has the advantages of easy operation, high cholesterol removal rate and high fish oil recovery rate, and can improve the quality-related indicators of fish oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 This is a comparison chart of the cholesterol removal rate and fish oil recovery rate of fish oil treated with different M-β-CD addition amounts.

[0028] Figure 2 The figure is a comparison of the cholesterol removal rate and fish oil recovery rate of fish oil treated with different removal time.

[0029] Figure 3 The figure is a comparison of the cholesterol removal rate and fish oil recovery rate of fish oil treated at different temperatures.

[0030] Figure 4 The figure is a comparison chart of the cholesterol removal rate and fish oil recovery rate of fish oil treated with β-CD and its derivatives provided in Comparative Examples 1 to 6. DETAILED DESCRIPTION

[0031] Unless otherwise defined herein, scientific and technical terms used in conjunction with the present invention shall have the meanings commonly understood by those of ordinary skill in the art. The meaning and scope of the terms should be clear, however, in the case of any potential ambiguity, the definitions provided herein take precedence over any dictionary or external definitions. In this application, unless otherwise stated, the use of "or" means "and / or". In addition, the use of the term "including" and other forms is non-limiting.

[0032] It should be noted that specific details are described in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in a variety of other ways different from those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0033] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] In a first aspect, the present invention provides a method for removing cholesterol from fish oil, the method for removing cholesterol from fish oil comprising the following steps:

[0035] The fish oil and the aqueous solution containing methyl-β-cyclodextrin are mixed, stirred, allowed to stand for separation, and the upper oil layer is taken to obtain low-cholesterol fish oil.

[0036] In the present invention, methyl-β-cyclodextrin (M-β-CD) is selected for removing cholesterol from fish oil, which can meet the purpose of simultaneously improving the cholesterol removal rate and the fish oil recovery rate for other cyclodextrin products. The method of the present invention has the advantages of easy operation, high cholesterol removal rate and high fish oil recovery rate, and can improve the quality-related indicators of fish oil to a certain extent.

[0037] As an optional embodiment of the present invention, the addition amount of the methyl-β-cyclodextrin is 5-40% of the mass of the fish oil, for example, it can be 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, etc., preferably 10-30%, and more preferably 30%.

[0038] As an optional embodiment of the present invention, in the aqueous solution containing methyl-β-cyclodextrin, the solid content of methyl-β-cyclodextrin is 5 to 40%, for example, it can be 5%, 6%, 7%, 8%, 9%, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, 40%, etc., preferably 10 to 30%, and more preferably 30%.

[0039] As an optional embodiment of the present invention, the temperature of the stirring treatment is 30-70°C, for example, it can be 30°C, 32°C, 35°C, 38°C, 40°C, 42°C, 45°C, 47°C, 50°C, 52°C, 55°C, 57°C, 60°C, 62°C, 65°C, 68°C, 70°C, etc., preferably 50-60°C, and more preferably 50°C.

[0040] As an optional embodiment of the present invention, the rotation speed of the stirring treatment is 100-300rpm, for example, it can be 100rpm, 110rpm, 120rpm, 130rpm, 140rpm, 150rpm, 160rpm, 170rpm, 180rpm, 190rpm, 200rpm, 220rpm, 230rpm, 240rpm, 250rpm, 260rpm, 280rpm, 300rpm, etc., preferably 150rpm.

[0041] As an optional embodiment of the present invention, the stirring treatment time is 5 to 25 minutes, for example, it can be 5 minutes, 6 minutes, 8 minutes, 10 minutes, 12 minutes, 14 minutes, 16 minutes, 18 minutes, 20 minutes, 22 minutes, 24 minutes, 25 minutes, etc., preferably 15 to 25 minutes, and more preferably 15 minutes.

[0042] As an optional embodiment of the present invention, the standing separation time is 5 to 15 minutes, for example, it can be 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, 15 minutes, etc., preferably 10 minutes.

[0043] As an optional embodiment of the present invention, the cholesterol removal rate is more than 26%, for example, it can be 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, etc., preferably more than 45%.

[0044] As an optional embodiment of the present invention, the recovery rate of the fish oil is above 80%, for example, it can be 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89% and the like.

[0045] In a second aspect, the present invention provides a low-cholesterol fish oil, which is prepared by the method described in the first aspect.

[0046] As an optional embodiment of the present invention, the acid value of the low cholesterol fish oil is 0.20-0.26 mg / g.

[0047] As an optional embodiment of the present invention, the peroxide value of the low-cholesterol fish oil is 0.05-0.07 g / 100 g.

[0048] As an optional embodiment of the present invention, the anisidine value of the low-cholesterol fish oil is 2.38-3.24.

[0049] As an optional embodiment of the present invention, the iodine value of the low-cholesterol fish oil is 195.32-207.10 g / 100 g.

[0050] As an optional embodiment of the present invention, the chromaticity of the low cholesterol fish oil includes: L * The value is 30.12~31.28, a * The value is -0.96~-0.70, b * The values ​​are 1.45~2.29, and the ΔE values ​​are 1.72~3.24.

[0051] The present invention is further described below by way of examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or directly purchased from the market.

[0052] The calculation formulas for the removal rate of cholesterol and the recovery rate of fish oil in the following embodiments and comparative examples are as follows:

[0053]

[0054] Example 1

[0055] This embodiment provides a method for removing cholesterol from fish oil, the method for removing cholesterol from fish oil comprising the following steps:

[0056] S1. Weighing fish oil: Weigh the fish oil from which cholesterol is to be removed.

[0057] S2. Add cholesterol-removing material: weigh methyl-β-cyclodextrin (M-β-CD) at a ratio of 30% of the mass of fish oil, weigh distilled water at a ratio of 70% of the mass of fish oil, mix M-β-CD and distilled water evenly, and add them to the fish oil to obtain a mixed solution.

[0058] S3. Cholesterol removal: The mixed solution was kept warm at 50°C and stirred at 150 rpm for 15 min to complete the removal of cholesterol.

[0059] S4. Standing separation: The mixed solution obtained after S3 treatment is allowed to stand for 10 minutes to separate the oil and water.

[0060] S5. Taking fish oil: taking the upper layer of fish oil to obtain the low-cholesterol fish oil.

[0061] It was calculated that the removal rate of cholesterol in Example 1 was 51.34%, and the recovery rate of fish oil was 84.84%.

[0062] Embodiments 2 to 13

[0063] Examples 2 to 13 provide methods for removing cholesterol from fish oil under different conditions. The only difference from Example 1 is that Examples 2 to 5 differ only in the amount of methyl-β-cyclodextrin added, Examples 6 to 9 differ only in the removal temperature of S3, and Examples 10 to 13 differ only in the removal time of S3, as shown in Table 1 below:

[0064] Table 1

[0065]

[0066] Calculate the cholesterol removal rate and fish oil recovery rate results:

[0067] Figure 1 The figure is a comparison of the cholesterol removal rate and fish oil recovery rate of fish oil treated with different M-β-CD addition amounts; Figure 1 As shown in the figure, when the amount of M-β-CD added increased from 10% to 25%, the cholesterol removal rate increased significantly from 16.05% to 49.25%. When the amount of M-β-CD added continued to increase to 30%, the cholesterol removal rate increased slightly to 51.29%, with no significant difference. The amount of M-β-CD added had no significant effect on the recovery rate of fish oil.

[0068] Figure 2 The figure is a comparison of the cholesterol removal rate and fish oil recovery rate of fish oil treated with different removal time; Figure 2 As shown in the figure, when the removal time increased from 5 min to 15 min, the cholesterol removal rate increased significantly from 15.13% to 25.12%. When the removal time was further extended to 25 min, the cholesterol removal rate increased slightly to 26.48%, with no significant improvement. The removal time had no significant effect on the fish oil recovery rate.

[0069] Figure 3 The figure is a comparison of the cholesterol removal rate and fish oil recovery rate of fish oil treated at different temperatures. When the temperature is increased from 30℃ to 50℃, the cholesterol removal rate slightly increases from 13.83% to 15.13%, with no significant difference. When the temperature is increased to 60℃, the cholesterol removal rate increases significantly from 15.13% to 20.86%. When the temperature continues to increase to 70℃, the cholesterol removal rate decreases significantly to 9.49%. There is no significant difference in the recovery rate of fish oil due to temperature.

[0070] Examples 14 to 22

[0071] Examples 14 to 22 provide methods for removing cholesterol from fish oil under different conditions, which differ from Example 1 only in that the amount of methyl-β-cyclodextrin added, the removal temperature, and the removal time are changed, as shown in Table 2 below:

[0072] Table 2

[0073]

[0074] The results of variance analysis were performed based on the test results of Examples 14 to 22 in Table 2 above, as shown in Table 3 below:

[0075] Table 3

[0076]

[0077]

[0078] From the results of Table 2 and Table 3, it can be seen that the range results show that the order of priority of the three factors is: M-β-CD addition amount > time > temperature. Variance analysis shows that the M-β-CD addition amount and time have a significant effect on the cholesterol removal rate (P<0.05); therefore, by comparing Examples 14 to 22 with Example 1, it can be seen that the conditions of Example 1 are optimal, that is, when the addition amount is 30%, the temperature is 50°C, and the time is 15 minutes, the cholesterol removal rate after treatment by the method is high and the fish oil recovery rate is high.

[0079] Comparative Examples 1 to 6

[0080] Comparative Examples 1 to 6 provide methods for removing cholesterol from fish oil using different removal materials, the methods comprising the following steps:

[0081] Dissolve 0.9 g of the removed material (according to Table 4 below) in 2.1 g of water, add 3.0 g of fish oil, shake at 50°C and 150 rpm for 90 min, centrifuge at 5000 rpm for 15 min, remove the upper layer of fish oil, weigh it and determine the cholesterol content.

[0082] Table 4

[0083]

[0084] Figure 4 The comparison chart of the cholesterol removal rate and fish oil recovery rate of fish oil treated with β-CD and its derivatives provided in Comparative Examples 1 to 6; Figure 4As shown, the cholesterol removal rates of β-cyclodextrin (β-CD) and methyl-β-cyclodextrin (M-β-CD) for fish oil were 28.65% and 26.39%, respectively, with no significant difference, but significantly higher than other derivatives. The cholesterol removal rates of hydroxyethyl-β-cyclodextrin (HE-β-CD), hydroxypropyl-β-cyclodextrin (HP-β-CD), carboxymethyl-β-cyclodextrin (CM-β-CD), and sulfobutyl-β-cyclodextrin (SBE-β-CD) were all lower than 10%. The fish oil recovery rates of the five cyclodextrin derivatives were all higher than 80%, with no significant difference. The recovery rate of β-CD was only 54.24%, significantly lower than the five derivatives. Therefore, according to the comparison between Example 1 and Comparative Examples 1 to 6, the present invention establishes a method for efficiently removing cholesterol from fish oil using methyl-β-cyclodextrin (M-β-CD), which has the advantages of easy operation, high cholesterol removal rate and high fish oil recovery rate, and can improve the quality-related indicators of fish oil to a certain extent.

[0085] Test Example 1

[0086] Test sample: low cholesterol fish oil obtained in Example 1;

[0087] Test method: The acid value is determined by the cold solvent automatic potentiometric titration method according to GB 5009.229-2016 "Determination of acid value in food". The peroxide value is determined by the potentiometric titration method according to GB 5009.227-2023 "Determination of peroxide value in food". The anisidine value is determined by referring to GB / T 24304-2009 "Determination of anisidine value of animal and vegetable fats and oils". The iodine value is determined by referring to GB / T 5532-2022 "Determination of iodine value of animal and vegetable fats and oils".

[0088] The test results are shown in Table 5 below:

[0089] Table 5

[0090]

[0091]

[0092] It can be seen from the test data in Table 5 that after cholesterol is removed by M-β-CD in Example 1, the acid value, peroxide value and anisidine value of the fish oil are significantly reduced, the color difference (ΔE) and iodine value have no significant changes, and the brightness (L*) of the fish oil is significantly improved, thereby improving the quality of the fish oil as a whole.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for removing cholesterol from fish oil, It is characterized in that The method for removing cholesterol from fish oil comprises the following steps: The fish oil and the aqueous solution containing methyl-β-cyclodextrin are mixed, stirred, allowed to stand for separation, and the upper oil layer is taken to obtain low-cholesterol fish oil.

2. The method for removing cholesterol from fish oil according to claim 1, It is characterized in that The addition amount of the methyl-β-cyclodextrin is 5-40% of the mass of the fish oil, preferably 10-30%, and more preferably 30%.

3. The method for removing cholesterol from fish oil according to claim 1, It is characterized in that In the aqueous solution containing methyl-β-cyclodextrin, the solid content of methyl-β-cyclodextrin is 5 to 40%, preferably 10 to 30%, and more preferably 30%.

4. The method for removing cholesterol from fish oil according to claim 1, It is characterized in that The stirring treatment is performed at a temperature of 30 to 70°C, preferably 50 to 60°C, and more preferably 50°C.

5. The method for removing cholesterol from fish oil according to claim 1, It is characterized in that The stirring process has a rotation speed of 100 to 300 rpm, preferably 150 rpm.

6. The method for removing cholesterol from fish oil according to claim 1, It is characterized in that The stirring treatment time is 5 to 25 minutes, preferably 15 to 25 minutes, and more preferably 15 minutes.

7. The method for removing cholesterol from fish oil according to claim 1, It is characterized in that The standing separation time is 5 to 15 minutes, preferably 10 minutes.

8. The method for removing cholesterol from fish oil according to claim 1, It is characterized in that The cholesterol removal rate is greater than 26%, preferably greater than 45%; And / or, the recovery rate of the fish oil is above 80%.

9. A low cholesterol fish oil, It is characterized in that The low-cholesterol fish oil is prepared by the method according to any one of claims 1 to 8.

10. The low-cholesterol fish oil according to claim 9, It is characterized in that The acid value of the low cholesterol fish oil is 0.20 to 0.26 mg / g; and / or, the peroxide value of the low cholesterol fish oil is 0.05-0.07 g / 100 g; and / or, the anisidine value of the low cholesterol fish oil is 2.38 to 3.24; and / or, the iodine value of the low cholesterol fish oil is 195.32-207.10 g / 100 g; And / or, the chromaticity of the low cholesterol fish oil includes: L * The value is 30.12~31.28, a * The value is -0.96~-0.70, b * The values ​​are 1.45~2.29, and the ΔE values ​​are 1.72~3.24.

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