Low-fishy-smell DHA algae oil and preparation method thereof

Abstract

The invention discloses a preparation method of DHA algal oil with low fishy smell, which comprises the following steps: S1, in a protective atmosphere, sequentially carrying out degumming, deacidification, decoloration and winterization treatment on crude algal oil, and then deodorizing the winterized algal oil to obtain refined algal oil; s2, adding a composite antioxidant into the refined algae oil, and uniformly mixing to obtain the DHA algae oil with low fishy smell, wherein the acid value of the crude algae oil is controlled to be less than or equal to 0.5 through the deacidification treatment. The invention also discloses the DHA algae oil with low fishy smell prepared by the method. According to the preparation method of the DHA algal oil with low fishy smell disclosed by the invention, the content of the DHA algal oil produced by the method can reach 40-65%, the proportion of SN-2DHA in the total DHA can reach 40-55%, the peroxide value is lower than 1meq / kg, the anisidine value is lower than 2.5, and the DHA algal oil almost does not contain the peculiar fishy smell of DHA, and is odorless or only has light grass flavor.

Description

Technical Field

[0001] The invention relates to the technical field of DHA algae oil preparation technology, and in particular to DHA algae oil with low fishy smell and a preparation method thereof. Background Art

[0002] Docosahexaenoic acid is also known as DHA, and its molecular formula is C 22 H 32 O2, with a molecular weight of 328.49, is a straight-chain fatty acid containing 22 carbon atoms and 6 double bonds, belonging to the ω-3 series of unsaturated fatty acids. DHA is mainly distributed in the gray matter of the brain, nervous system, retinal system, myocardium, eosinophils and breast milk in the human body, and has important physiological functions. Since the human body cannot synthesize DHA on its own, it must take in enough DHA from the outside to maintain health. At present, DHA is mainly derived from fish oil, algae oil and fungi. Although DHA fish oil is cheap, due to objective factors such as pollution, the safety of fish oil has attracted the attention of scientists and bioengineering management agencies in various countries.

[0003] Algae oil is a pure plant DHA. DHA algae oil is extracted from microalgae without being passed through the food chain. Its eicosapentaenoic acid (EPA) content is very low and relatively safer. At present, DHA algae oil is mainly used in infant formula, health food, animal nutrition, food and beverage and other fields. Studies have found that the intake of DHA algae oil is crucial to the formation and development of infant brain cells and visual organs. It also has functional characteristics such as preventing postpartum depression, enhancing human resistance, preventing and reducing atherosclerosis and coronary heart disease. With the improvement of people's living standards, people's demand for DHA is increasing and the quality requirements are getting higher and higher. Therefore, DHA algae oil is more in line with public demand.

[0004] Since DHA molecules contain 6 unsaturated double bonds, they are easily oxidized to generate ketones, aldehydes and other substances harmful to the human body under light and high temperature conditions, accompanied by fishy smell, which seriously restricts the application of algae oil in the field of food processing. Therefore, it is necessary to provide a method for preparing algae oil DHA with low fishy smell.

[0005] At present, the mainstream manufacturers' patents and products are mainly concentrated in fermentation methods, extraction methods, and the application end of the products, with the focus on content, yield, structure, etc. There are not many related patents for the sensory indicators of the products, especially the taste and smell. The few patents are also biased towards extraction methods or the use of odor masking agents. There are few methods that directly control the fermentation and refinement process optimization, and use patented refining equipment to integrate and apply, to produce truly natural, additive-free, low-smell DHA algae oil. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a method for preparing DHA algae oil with low fishy smell. The DHA algae oil produced by the method can have a content of 40-65%, a proportion of SN-2DHA in the total DHA can reach 40-55%, a peroxide value lower than 1 meq / kg, an anisidine value lower than 2.5, and almost no fishy smell peculiar to DHA, and its taste and smell are odorless or only light grassy.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0008] The first aspect of the present invention provides a method for preparing DHA algae oil with low fishy smell, comprising the following steps:

[0009] S1. Under a protective atmosphere, the crude algae oil is sequentially degummed, deacidified, decolorized and winterized, and then the winterized algae oil is deodorized to obtain refined algae oil;

[0010] S2. Adding a composite antioxidant to the refined algae oil and mixing them evenly to obtain the DHA algae oil with low fishy smell;

[0011] The acid value of the crude algae oil is controlled to be ≤0.5 through deacidification treatment.

[0012] In view of the technical problem that DHA algae oil is easily oxidized and accompanied by a fishy smell, which seriously restricts the application of algae oil in the field of food processing, the present invention successfully solves the problem of the strong fishy smell of DHA algae oil by improving the algae oil refining process. Specifically, the present invention first adds a deacidification step between the degumming and decolorization treatments of the crude algae oil. Since oils and fats with high acid values ​​contain a high content of free fatty amines, it is easy to spoil and produce unpleasant odors. Through the deacidification treatment, the free fatty acids in the algae oil can be removed, and the acid value of the algae oil can be reduced, which is conducive to reducing the peculiar smell of the DHA algae oil. Furthermore, the inventors found that controlling the acid value of the algae oil to ≤0.5 can make the DHA algae oil finished product have a lower fishy smell.

[0013] Secondly, the present invention performs winterization treatment before deodorizing DHA algae oil. Winterization can further remove impurities in grease, making the grease purer, thereby reducing the risk factors of producing bad odors, and can further reduce the peculiar smell of DHA algae oil. Compared with the process of winterization after deodorization, the present invention performs winterization treatment before deodorizing DHA algae oil, which not only makes the comprehensive yield of grease higher (increase 10-15%), but also can make some pollutant indicators controlled lower, such as peroxide value, anisidine value, heavy metals, 3-mcpd, unsaponifiable matter, odor, etc.

[0014] Furthermore, in step S1 of the present invention, the method for preparing the crude algae oil is:

[0015] The Schizochytrium TKD-1 with a seed age of 24 hours is used and activated to obtain the Schizochytrium seed liquid; the Schizochytrium seed liquid is expanded and cultured in a primary seed tank and a secondary seed tank, and then subjected to a tertiary fermentation to obtain the Schizochytrium fermentation liquid; the Schizochytrium fermentation liquid is collected, the bacteria are collected by centrifugation, and the crude algae oil is obtained after drying, crushing and extraction.

[0016] Furthermore, the activation method is: inoculating the Schizochytrium TKD-1 into an activation medium at an inoculation rate of 5 to 10%, and culturing at 15 to 28° C. for 2 to 4 days;

[0017] The components of the activation medium include: glucose 120-150 g / L, yeast extract 2-4 g / L, corn steep liquor powder 3-5 g / L, K + 5-15mM, trace elements 0.3-1g / L, phosphate buffer with a pH of 5-7.

[0018] Furthermore, the concentration of the first-level seed tank bacteria of Schizochytrium expanded and cultured in the first-level seed tank is 30±8 g / L, and the concentration of the second-level seed tank bacteria of Schizochytrium expanded and cultured in the second-level seed tank is 60±10 g / L.

[0019] Furthermore, in step S1, the protective atmosphere is a nitrogen atmosphere with a concentration of ≥98%.

[0020] Further, in step S1, the deacidification method is:

[0021] a. Determine the acid value of the algae oil, then add 5 to 10% (w / w) sodium hydroxide to the algae oil according to the acid value and stir for 30 to 60 minutes;

[0022] b. Add 10-15% (v / v) hot water to the algae oil and continue stirring for 10-30 min; after standing for 2-4 h, take a sample to test the acid value; the temperature of the hot water is 90-100 ° C;

[0023] c. If the acid value is greater than 0.5, repeat steps a to b until the acid value is ≤ 0.5;

[0024] d. If the acid value is ≤0.5, wash the algae oil with water, stir for 10-30 minutes, and then let it stand for 2-4 hours; take the upper deacidified oil and proceed to the next decolorization treatment.

[0025] Furthermore, in step S1, the winterization method is:

[0026] e. The winterization tank is evacuated to -0.1MPa, and the feed valve is opened to feed the algae oil; after the feeding is completed, the feed liquid temperature is raised to 70-90°C and dehydrated for 1-2h;

[0027] f. Under constant stirring, the dehydrated algae oil is cooled to allow crystals to precipitate, the cooling time is 24 to 120 hours, and the temperature is lowered to 0 to 5°C;

[0028] g. Use plate and frame to filter the cooled algae oil to obtain winterized filtered oil.

[0029] Furthermore, in step S1, the deodorization device is a deodorization tank disclosed in the Chinese patent with publication number CN208599571U. The deodorization effect of this deodorization equipment is better than that of a conventional deodorization tower, which is a necessary condition for preparing low-smell oils. Furthermore, the deodorization is preferably carried out under a vacuum degree of 1500 to 1800 Pa. Under a high vacuum degree, steam can take away odorous substances and volatile impurities, which is beneficial to reduce the odor of DHA algae oil.

[0030] Furthermore, during the entire preparation process, pipelines and equipment should be strictly isolated from air, moisture and residues when cleaning or product replacement.

[0031] Furthermore, in step S2, the added amount of the composite antioxidant is 1 to 8 wt% of the refined algae oil, for example, the added amount may be 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt% and the like.

[0032] Furthermore, the composite antioxidant includes one or more of diglycerides, camphor flavonoids extract, quinoa soap, α-tocopherol, rosemary extract, VC palmitate, tea polyphenols, and phospholipids.

[0033] The second aspect of the present invention provides DHA algae oil with low fishy smell prepared by the preparation method.

[0034] Furthermore, in the low-fishy-smell DHA algae oil, the DHA algae oil content is 40-65%, the proportion of SN-2DHA in the total DHA is 40-55%, the peroxide value is lower than 1 meq / kg, and the anisidine value is lower than 2.5; it has no fishy smell, and its taste and smell are tasteless or lightly grassy.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The method for preparing low-smell DHA algae oil provided by the present invention can produce DHA algae oil with a content of 40-65%, a ratio of SN-2DHA to total DHA of 40-55%, a peroxide value of less than 1 meq / kg, an anisidine value of less than 2.5, and almost no fishy smell peculiar to DHA, and a taste and smell of no smell or only a light grassy smell. DETAILED DESCRIPTION

[0037] The present invention is further described below in conjunction with specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0039] Unless otherwise specified, the experimental methods used in the following examples and comparative examples are all conventional methods, and the materials, reagents, etc. used are all commercially available unless otherwise specified.

[0040] Example 1

[0041] This embodiment provides a method for preparing low-smell DHA algae oil, comprising the following steps:

[0042] Step 1: Inoculate the Schizochytrium sp. TKD-1 strain with a seed age of 24 hours into the activation medium at an inoculum rate of 10%, transfer to a constant temperature shaker with an oscillation speed of 110 r / min, and culture at 18° C. for 3 days to obtain Schizochytrium seed liquid; wherein the components of the activation medium include: glucose 150 g / L, yeast extract 5 g / L, corn steep liquor powder 5 g / L, K + 10mM, trace elements 1g / L, phosphate buffer with a pH of 6.8.

[0043] Step 2: Determine that the concentration of the first-level seed tank bacteria of Schizochytrium is 30±8g / L, and the concentration of the second-level seed tank bacteria of Schizochytrium is 60±10g / L; subject the Schizochytrium seed liquid to tertiary fermentation after expansion culture in the first-level seed tank and the second-level seed tank to obtain Schizochytrium fermentation liquid.

[0044] Step 3: Collect the fermentation broth of Schizochytrium, centrifuge it at 5000r / min for 10min, wash the Schizochytrium cells with distilled water for 3 times, and vacuum dry it at 65°C; use a nitrogen-filled and oxygen-exhausted workbench with a nitrogen concentration of 99% to mix chloroform and methanol in a 1:1 ratio to obtain a chloroform-methanol mixed solution, then crush the Schizochytrium cells and mix them with the chloroform-methanol mixed solution in a ratio of 1g:2mL, extract at 50°C and 200W microwave-assisted conditions for 60min, centrifuge it at 5000r / min for 8min, collect the chloroform-methanol mixed liquid layer and dry it under nitrogen protection to obtain crude algae oil.

[0045] Step 4: Put the crude algae oil into a hydration tank and heat it to 65±5°C, add a 10wt% phosphoric acid aqueous solution of the crude algae oil while stirring, and add it within 10 minutes. The mass fraction of the phosphoric acid aqueous solution is 1% and the temperature is also 65±5°C. After adding, stir at 30r / min for 15 minutes, and then stand for 3 hours to remove the bottom colloid and water to complete the degumming process;

[0046] Take a sample to determine the acid value, calculate the amount of sodium hydroxide (10% concentration) to be added according to the acid value, stir for 60 minutes after adding, then add 10% hot water, stir for 20 minutes, then let it stand for 2 hours, take a sample and measure the acid value again; if the acid value is ≤0.5, it means that it meets the process requirements, and the upper layer oil is deacidified oil and enters the next process; if the acid value is higher than 0.5, it is necessary to repeat alkali refining and water washing until the acid value is less than 0.5;

[0047] The crude algae oil after degumming and deacidification is heated to 80±5°C, 1.5wt% of silica is added to the crude algae oil, stirred for 30 minutes, cooled to below 60°C and filtered to obtain decolorized algae oil; the decolorized oil is continuously winterized in a decolorization tank at 0°C for 72 hours;

[0048] Then, the separated clear oil after winterization is put into a deodorization tower, and deodorized at a vacuum degree of 1500-1800 Pa to obtain refined algae oil, wherein the deodorization tower is a deodorization tank disclosed in patent ZL201820851239.3;

[0049] The device used in the refining process is equipped with a nitrogen charging port and an exhaust gas discharge port to ensure that the nitrogen concentration inside the device is 99%, thereby achieving the purpose of isolating oxygen. The cleaning and product switching before, during and after the entire refining process are strictly isolated from air and moisture.

[0050] Step 5: Add 8 wt% of the composite antioxidant (glycolide: cinnamon flavonoids extract: quinoa saponin = 1:1:1) to the refined winterized algae oil, and mix well to obtain low-smell DHA algae oil.

[0051] Example 2

[0052] This embodiment provides a method for preparing low-smell DHA algae oil, comprising the following steps:

[0053] Step 1: Inoculate the Schizochytrium sp. TKD-1 strain with a seed age of 24 hours into the activation culture medium at an inoculum size of 10%, transfer to a constant temperature shaker with a shaking speed of 110 r / min, culture at 28°C for 1 day, and then culture at 25°C for 2 days to obtain Schizochytrium seed solution; wherein the components of the activation culture medium include: 145 g / L glucose, 2.6 g / L yeast extract, 5.2 g / L corn steep liquor powder, 0.8 g / L trace elements, and phosphate buffer with a pH value of 6.8.

[0054] Step 2: Determine that the concentration of the first-level seed tank bacteria of Schizochytrium is 30±6g / L, and the concentration of the second-level seed tank bacteria of Schizochytrium is 60±8g / L; subject the Schizochytrium seed liquid to tertiary fermentation after expansion culture in the first-level seed tank and the second-level seed tank to obtain Schizochytrium fermentation liquid.

[0055] Step 3: Collect the fermentation broth of Schizochytrium, centrifuge it at 4500r / min for 10min, wash the Schizochytrium cells with distilled water for 3 times, and vacuum dry it at 55°C; use a nitrogen-filled and oxygen-exhausted workbench with a nitrogen concentration of 99% to mix chloroform and methanol in a ratio of 2mL:1mL to obtain a chloroform-methanol mixed solution, then crush the Schizochytrium cells and mix them with the chloroform-methanol mixed solution in a ratio of 1g:3mL, extract at 50°C and 200W microwave-assisted conditions for 60min, centrifuge it at 4000r / min for 10min, collect the chloroform-methanol mixed liquid layer and dry it under nitrogen protection to obtain crude algae oil.

[0056] Step 4: Put the crude algae oil into a hydration tank and heat it to 65±5°C, add a 10wt% phosphoric acid aqueous solution of the crude algae oil while stirring, and add it within 10 minutes. The mass fraction of the phosphoric acid aqueous solution is 1% and the temperature is also 65±5°C. After adding, stir at 30r / min for 15 minutes, and then stand for 3 hours to remove the bottom colloid and water to complete the degumming process;

[0057] Take a sample to determine the acid value, calculate the amount of sodium hydroxide (5% concentration) to be added according to the acid value, stir for 60 minutes after adding, then add 15% hot water, stir for 20 minutes, then let it stand for 4 hours, take a sample and measure the acid value again; if the acid value is ≤0.5, it means that it meets the process requirements, and the upper layer oil is deacidified oil and enters the next process; if the acid value is higher than 0.5, it is necessary to repeat alkali refining and water washing until the acid value is less than 0.5;

[0058] The crude algae oil after degumming and deacidification treatment is heated to 80±5°C, 1.5wt% silica of the crude algae oil is added, stirred for 30 minutes, cooled to below 60°C and filtered to obtain decolorized algae oil; after decolorization, the oil is continuously winterized in a decolorization tank at 0°C for 72 hours, and then the separated clear oil after winterization is put into a deodorization tower, and deodorized at a vacuum degree of 1500-1800Pa to obtain refined algae oil; wherein the deodorization tower is the deodorization tank disclosed in patent ZL201820851239.3;

[0059] The device used in the refining process is equipped with a nitrogen charging port and an exhaust gas discharge port to ensure that the nitrogen concentration inside the device is 99%, thereby achieving the purpose of isolating oxygen. The cleaning and product switching before, during and after the entire refining process are strictly isolated from air and moisture.

[0060] Step 5: Add 3 wt% of the refined algae oil to the composite antioxidant (α-tocopherol: phospholipid: VC palmitate = 5:4:2) and mix well to obtain low-smell DHA algae oil.

[0061] Comparative Example 1: Based on Example 5, the nitrogen concentration in step 3 and step 4 was controlled to be 99%, and DHA algae oil was prepared without adding composite antioxidant.

[0062] Comparative Example 1

[0063] DHA algae oil is produced according to the method of Example 2 in patent CN202310220412.

[0064] Comparative Example 2

[0065] The difference between Comparative Example 2 and Example 1 is that no composite antioxidant is added in step five.

[0066] Comparative Example 3

[0067] The difference between Comparative Example 3 and Example 1 is that no winterization treatment is performed in step 4.

[0068] Comparative Example 4

[0069] The difference between Comparative Example 4 and Example 1 is that the winterization process in step 4 is carried out after the deodorization process (most companies currently use this method).

[0070] Comparative Example 5

[0071] The difference between Comparative Example 5 and Example 1 is that the cleaning and product switching process in step 4 does not adopt a process of isolating air and moisture.

[0072] Comparative Example 6

[0073] The difference between Comparative Example 6 and Example 1 is that no deacidification treatment is performed in step 4.

[0074] Comparative Example 7

[0075] The difference between Comparative Example 7 and Example 1 is that in step 4, the deodorizing tank disclosed in ZL201820851239.3 is not used, but a tray-type deodorizing tank is used.

[0076] The DHA algae oil prepared in Example 1 and Comparative Examples 1 to 7 was tested, and the test indicators included: DHA content, peroxide value of DHA algae oil, anisidine value, SN-2 DHA content in total DHA content, etc. The results are shown in Table 1.

[0077] Rating criteria for flavor and smell: The basic score for flavor and smell is 10 points. No smell (10 points); slight smell (7-9 points); fishy smell (4-6 points); strong smell (0-3 points). Eight people participated in the flavor and smell evaluation and the average value was taken.

[0078] Table 1

[0079]

[0080] Note: ND = Not Detected

[0081] As shown in Table 1, the DHA algae oil produced in Example 1 has a DHA content of ≥55%, a proportion of SN-2 DHA in the total DHA of ≥45%, an anisidine value of ≤2.5, an unsaponifiable matter content of less than 1%, a flavor score of more than 18, and no peroxide value and 3-chloropropanol ester were detected. Example 1 is significantly better than the DHA algae oil prepared in Comparative Examples 1 to 7 in these indicators, and is also better than the current national standard (GB26400-2011 Food Additive Docosahexaenoic Acid Oil (Fermentation Method)).

[0082] In summary, the method for preparing low-fishy-smell DHA algae oil provided by the present invention successfully prepares low-fishy-smell DHA algae oil by adopting the deodorizing tank disclosed in ZL201820851239.3, adding deacidification and winterization treatment and other process optimizations. The low-fishy-smell DHA algae oil contains almost no fishy smell specific to DHA, and has a taste and smell that is tasteless or has only a faint grassy taste.

[0083] The above-described embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. A method for preparing DHA algae oil with low fishy smell, characterized in that: The following steps are involved: S1. Under a protective atmosphere, the crude algae oil is sequentially degummed, deacidified, decolorized and winterized, and then the winterized algae oil is deodorized to obtain refined algae oil; S2. Adding a composite antioxidant to the refined algae oil and mixing them evenly to obtain the DHA algae oil with low fishy smell; The acid value of the crude algae oil is controlled to be ≤0.5 through deacidification treatment.

2. The method for preparing a DHA algae oil with low fishy smell according to claim 1, characterized in that: In step S1, the preparation method of the crude algae oil is: The Schizochytrium TKD-1 with a seed age of 24 hours is used and activated to obtain a Schizochytrium seed liquid; the Schizochytrium seed liquid is subjected to a first-stage seed tank expansion culture and a second-stage seed tank expansion culture, and then subjected to a third-stage fermentation to obtain a Schizochytrium fermentation liquid; The fermentation liquid of Schizochytrium is collected, the bacteria are collected by centrifugation, and the crude algae oil is obtained after drying, crushing and extraction.

3. The method for preparing a DHA algae oil with low fishy smell according to claim 2, characterized in that: The activation method comprises: inoculating the Schizochytrium TKD-1 in an activation medium at an inoculum amount of 5 to 10%, and culturing at 15 to 28° C. for 2 to 4 days; wherein the components of the activation medium include: 120 to 150 g / L glucose, 2 to 4 g / L yeast extract, 3 to 5 g / L corn steep liquor powder, and K + 5-15mM, trace elements 0.3-1g / L, phosphate buffer with a pH of 5-7; The concentration of the first-stage seed tank bacteria of Schizochytrium expanded and cultured in the first-stage seed tank is 30±8 g / L, and the concentration of the second-stage seed tank bacteria of Schizochytrium expanded and cultured in the second-stage seed tank is 60±10 g / L.

4. The method for preparing a DHA algae oil with low fishy smell according to claim 1, characterized in that: In step S1, the protective atmosphere is a nitrogen atmosphere with a concentration of ≥98%.

5. The method for preparing a DHA algae oil with low fishy smell according to claim 1, characterized in that: In step S1, the deacidification method is: a. Determine the acid value of the algae oil, then add 5 to 10% sodium hydroxide to the algae oil according to the acid value and stir for 30 to 60 minutes; b. Add 10-15% hot water to the algae oil and continue stirring for 10-30 minutes; after standing for 2-4 hours, take a sample to test the acid value; c. If the acid value is greater than 0.5, repeat steps a to b until the acid value is ≤ 0.5; d. If the acid value is ≤0.5, wash the algae oil with water, stir for 10-30 minutes, and then let it stand for 2-4 hours; take the upper deacidified oil and proceed to the next decolorization treatment.

6. The method for preparing a DHA algae oil with low fishy smell according to claim 1, characterized in that: In step S1, the winterization method is: e. The winterization tank is evacuated to -0.1MPa, and the feed valve is opened to feed the algae oil; after the feeding is completed, the feed liquid temperature is raised to 70-90°C and dehydrated for 1-2h; f. Under constant stirring, the dehydrated algae oil is cooled to allow crystals to precipitate, the cooling time is 24 to 120 hours, and the temperature is lowered to 0 to 5°C; g. Use plate and frame to filter the cooled algae oil to obtain winterized filtered oil.

7. The method for preparing a DHA algae oil with low fishy smell according to claim 1, characterized in that: In step S1, the deodorization device is a deodorization tank disclosed in the Chinese patent publication number CN208599571U, and the deodorization is carried out under a vacuum degree of 1500-1800Pa.

8. The method for preparing a DHA algae oil with low fishy smell according to claim 1, characterized in that: In step S2, the added amount of the composite antioxidant is 1 to 8 wt % of the refined algae oil; The composite antioxidant comprises one or more of diglycerides, camphor flavonoids extract, quinoa soap, alpha-tocopherol, rosemary extract, VC palmitate, tea polyphenols and phospholipids.

9. DHA algae oil with low fishy smell prepared according to the preparation method according to any one of claims 1 to 8.

10. The DHA algae oil with low fishy smell according to claim 9, characterized in that The low-smell DHA algae oil has a DHA algae oil content of 40-65%, a SN-2DHA ratio of 40-55% of the total DHA, a peroxide value of less than 1 meq / kg, and an anisidine value of less than 2.5; it has no fishy smell, and its taste and odor are tasteless or lightly grassy.

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