Methods for increasing the content of native omega-3 fatty acids in animal products

Abstract

This invention provides a method for increasing the content of native Omega-3 fatty acids in animal products. The method utilizes microbial fermentation to produce a nutrient-rich microalgae powder formulation, which is then mixed into the diet of ruminants to obtain native milk containing Omega-3 fatty acids. The total Omega-3 fatty acid content of the animal product reaches 54-65 mg / 100 mL, including 31-35 mg / 100 mL of DHA, 10-12 mg / 100 mL of EPA, 4-6 mg / 100 mL of DPA, and 7-12 mg / 100 mL of ALA. This method significantly increases the content of Omega-3 fatty acids in native milk while addressing issues related to palatability, oxidative stability, and biosynthetic conversion rate.

Description

Technical Field

[0001] This invention relates to the field of biotechnology and provides a method for increasing the content of native Omega-3 fatty acids in animal products, specifically a method for increasing the content of native Omega-3 fatty acids in animal products using microalgae powder formulations. Background Technology

[0002] With the upgrading of global consumption levels and the popularization of national health awareness, per capita dairy product consumption is gradually increasing. According to relevant data, from 2018 to 2024, China's milk production showed an overall fluctuating upward trend, exceeding 9 million tons in 2024 compared to 2018. Currently, liquid milk and milk powder remain the main consumer categories in China's dairy product consumption structure, with liquid milk accounting for the largest market share at 44.0%. However, with the rise of plant-based alternatives and other beverages, competition from these new beverages has also impacted the dairy product market. Faced with a huge gap in the consumer market, consumers' pursuit of diversity in dairy product consumption structures has injected new momentum into its development. Healthy, premium, and functional dairy products may become the future development trend.

[0003] Numerous studies have shown that Omega-3 fatty acids possess physiological functions such as improving pregnancy survival rates, reducing pregnancy inflammation, promoting brain development, and preventing cardiovascular diseases. The Food and Agriculture Organization of the United Nations / World Health Organization (FAO / WHO) recommends that breastfeeding women consume 300 mg of DHA and EPA daily. Recent studies indicate that infants should consume 100 mg of DHA daily, and adolescents 250 mg of DHA daily to promote brain development and enhance intelligence. Milk, as a basic daily nutritional food, has a wide consumer base and is an ideal carrier for fortifying Omega-3 fatty acids. Among commercially available milk products, alpha-linolenic acid and arachidonic acid are common long-chain fatty acids found in milk, with added amounts reaching 10-20 mg / 100 mL, 2-30 mg / 100 mL, and 10-30 mg / 100 mL, respectively. Most methods involve directly adding certain nutrients to milk, which has significant drawbacks. For example, it affects the milk's flavor, making it difficult to avoid a fishy taste; the exogenous fats are unstable in their integration with the milk fat system, easily leading to rancidity and other oxidation phenomena; and the bioavailability of exogenous fats in the body is low. Therefore, finding a method to produce truly natural, flavorful, stable, and safe Omega-3 fatty acid milk—that is, utilizing the metabolic regulation of ruminants to convert ingested Omega-3 fatty acids into milk components—is the best way to overcome these shortcomings.

[0004] Ruminant feed formulations can be divided into silage, concentrates, and nutritional supplements. Aside from the small amount of oil in silage, flaxseed, fish oil, and algal oil are often the main sources of Omega-3 fatty acids. EPA, n-3DPA, and DHA fatty acids can only be obtained from fish oil or algal oil. However, the current threats and limitations to fish oil sources due to marine resource depletion, marine pollution, and nuclear contamination have forced a focus on microorganisms. Microorganisms are not affected by geographical or seasonal variations, have short cycles, and produce stable product content. Furthermore, they are rich in sterols, organic acids, proteins, astaxanthin, and other active substances, making them highly nutritious and serving as excellent protein, fat, and nutritional supplements for ruminants.

[0005] Therefore, developing a method to increase the content of native Omega-3 fatty acids in animal products has become a key technical challenge that urgently needs to be solved in this field. Summary of the Invention

[0006] To address the problems mentioned in the background section, this invention provides a method for increasing the content of native Omega-3 fatty acids in animal products. This invention utilizes microbial fermentation to produce a nutrient-rich microalgae powder formulation, which is then mixed into the diet of ruminants to obtain native milk containing Omega-3 fatty acids. The microalgae powder formulation used in this method significantly increases the content of Omega-3 fatty acids in native milk while addressing oxidative stability and biosynthetic conversion rate. Specifically, the DHA content can reach 31-35 mg / 100mL, the EPA content can reach 10-12 mg / 100mL, the DPA content can reach 4-6 mg / 100mL, the ALA content can reach 7-12 mg / 100mL, and the total Omega-3 fatty acid content can reach 54-65 mg / 100mL. This invention provides a feasible and green solution for providing high-quality functional milk (such as cow's milk) to the public.

[0007] In a first aspect, a method for increasing the content of native Omega-3 fatty acids in animal products is provided, including feeding animals with microalgae powder preparations to increase the content of native Omega-3 fatty acids in animal products;

[0008] The animal product contains 54-65 mg / 100 mL of total Omega-3 fatty acids, and the total Omega-3 fatty acids include at least one of the following components:

[0009] (1) The DHA content reaches 31-35 mg / 100mL;

[0010] (2) The EPA content reaches 10-12 mg / 100mL;

[0011] (3) The DPA content reaches 4-6 mg / 100mL;

[0012] (4) The ALA content reaches 7-12 mg / 100mL.

[0013] The microalgae powder preparation is prepared from a compound fermentation broth composed of compound raw materials and fermentation broth; the microalgae powder preparation includes essential fatty acids;

[0014] The essential fatty acids were obtained from the fermentation broth of Schizochytrium HS08; Schizochytrium HS08 is deposited at the China General Microbiological Culture Collection Center, with accession number CGMCC No. 40902;

[0015] The preparation process of the fermentation broth includes:

[0016] Step 1: Amplify and culture the microbial *Schizochytrium HS08* to obtain seed culture;

[0017] Step 2: Inoculate the seed culture with the fermentation liquid to prepare the fermentation broth; maintain the pH of the system at 2-10 during the fermentation process with a pH adjuster; during the fermentation process, supplement at least one of glucose and glycerol in a fed-batch manner to control the carbon source concentration; supplement the promoting factor in a fed-batch manner after 45-50 h of fermentation; or supplement the promoting factor in a fed-batch manner after 90-95 h of fermentation.

[0018] The promoting factor is at least one of amino acids, choline, sodium salts, and nutritional supplements.

[0019] In some embodiments, the animal product is animal milk. Preferably, it is ruminant animal milk. Preferably, it is cow or goat milk. In some embodiments, the animal may be a cow or a sheep. In some embodiments, the cow may be a dairy cow. In some embodiments, the dairy cow may be a Holstein cow.

[0020] In some embodiments, the essential fatty acid is selected from at least one of caprylic acid (C8:0), capric acid (C10:0), lauric acid (C12:0), myristic acid (C14:0), myristoleic acid (C14:1), pentadecanoic acid (C15:0), palmitic acid (C16:0), palmitoleic acid (C16:1), heptadecanoic acid (C17:0), stearic acid (C18:0), oleic acid (C18:1n9c), linoleic acid (C18:2n6c), α-linolenic acid (C18:3n3), arachidic acid (C20:0), erucic acid (C22:1n9), docosahexaenoic acid (C22:2), EPA (C20:5n3), nervonic acid (C24:1), and DHA (C22:6n3).

[0021] In some embodiments, the essential fatty acids are myristic acid (C14:0), palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1n9c), linoleic acid (C18:2n6c), arachidic acid (C20:0), erucic acid (C22:1n9), EPA (C20:5n3), and DHA (C22:6n3).

[0022] In some embodiments, the microalgae are oil-producing microorganisms, which can be eukaryotes. Preferably, the microalgae are one or more of *Phaeophyte* and *Schizochytrium*. More preferably, the microorganism provided by this invention is *Schizochytrium* HS08, deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 40902.

[0023] In some embodiments, the essential fatty acids in the fermentation broth, by mass percentage, include 0-0.7 wt% caprylic acid (C8:0), 0-0.5 wt% decanoic acid (C10:0), 0-0.02 wt% lauric acid (C12:0), 0.05-0.2 wt% myristic acid (C14:0), 0-0.08 wt% myristoleic acid (C14:1), 0-0.04 wt% pentadecanoic acid (C15:0), 4-7 wt% palmitic acid (C16:0), 0-0.08 wt% palmitoleic acid (C16:1), 0-0.05 wt% heptadecanoic acid (C17:0), and stearic acid (C18:0). 0.5-2.0wt%, oleic acid (C18:1n9c) 0.05-2.50wt%, linoleic acid (C18:2n6c) 0.03-5.90wt%, α-linolenic acid (C18:3n3) 0-1wt%, arachidic acid (C20:0) 0.01-0.15wt%, erucic acid (C22:1n9) 0.03-0.15wt%, docosahexaenoic acid (C22:2) 0-0.15wt%, EPA (C20:5n3) 0.03-1.20wt%, nervonic acid (C24:1) 0-0.05wt%, DHA (C22:6n3) 8-15wt%.

[0024] In some embodiments, the essential fatty acids in the fermentation broth, by mass percentage, include octanoic acid at a concentration of 0, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, and any two of the above values ​​forming a range.

[0025] In some embodiments, the essential fatty acids in the fermentation broth, by mass percentage, include decanoic acid at a concentration of 0, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, and any two of the above values ​​forming a range.

[0026] In some embodiments, the essential fatty acids in the fermentation broth, by mass percentage, include lauric acid at a concentration of 0, 0.01 wt%, 0.02 wt%, or any two of the above values.

[0027] In some embodiments, the essential fatty acids in the fermentation broth, by mass percentage, include myristic acid at a concentration of 0.05 wt%, 0.1 wt%, 0.15 wt%, 0.2 wt%, or any two of the above values ​​forming a range.

[0028] In some embodiments, the essential fatty acids in the fermentation broth, by mass percentage, include myristoleic acid at 0, 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, and any two of the above values ​​forming any one of the ranges.

[0029] In some embodiments, the essential fatty acids in the fermentation broth, by mass percentage, include pentadecanoic acid comprising any one of the ranges of 0, 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.04 wt%, and any two of the above values. In some embodiments, the essential fatty acids in the fermentation broth, by mass percentage, include palmitic acid comprising any one of the ranges of 4 wt%, 5 wt%, 6 wt%, 7 wt%, and any two of the above values.

[0030] In some embodiments, the essential fatty acids in the fermentation broth, by mass percentage, include palmitoleic acid at any of the following percentages: 0, 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, and any two of the above values ​​forming any one of the ranges.

[0031] In some embodiments, the essential fatty acids in the fermentation broth, by mass percentage, include heptadecanoic acid at a concentration of 0, 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt%, and any two of the above values ​​forming a range.

[0032] In some embodiments, the essential fatty acids in the fermentation broth, by mass percentage, include stearic acid at any of the following percentages: 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt%, 2wt%, and any two of the above values ​​forming any one of the ranges.

[0033] In some embodiments, the essential fatty acids in the fermentation broth, by mass percentage, include oleic acid at any of the following percentages: 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt%, 2wt%, 2.1wt%, 2.2wt%, 2.3wt%, 2.4wt%, 2.5wt%, and any two of the above values ​​forming any one of the ranges.

[0034] In some embodiments, the essential fatty acids in the fermentation broth, by mass percentage, include linoleic acid at the following proportions: 0.03 wt%, 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, 1.1 wt%, 1.2 wt%, 1.3 wt%, 1.4 wt%, 1.5 wt%, 1.6 wt%, 1.7 wt%, 1.8 wt%, 1.9 wt%, 2 wt%, 2.1 wt%, 2.2 wt%, 2.3 wt%, 2.4 wt%, 2.5 wt%. The range consists of any two values ​​from the following values: t%, 2.6wt%, 2.7wt%, 2.8wt%, 2.9wt%, 3wt%, 3.1wt%, 3.2wt%, 3.3wt%, 3.4wt%, 3.5wt%, 3.6wt%, 3.7wt%, 3.8wt%, 3.9wt%, 4wt%, 4.1wt%, 4.2wt%, 4.3wt%, 4.4wt%, 4.5wt%, 4.6wt%, 4.7wt%, 4.8wt%, 4.9wt%, 5wt%, 5.1wt%, 5.2wt%, 5.3wt%, 5.4wt%, 5.5wt%, 5.6wt%, 5.7wt%, 5.8wt%, 5.9wt%.

[0035] In some embodiments, the essential fatty acids in the fermentation broth, by mass percentage, include α-linolenic acid at any of the following ranges: 0%, 0.01wt%, 0.02wt%, 0.03wt%, 0.04wt%, 0.05wt%, 0.06wt%, 0.07wt%, 0.08wt%, 0.09wt%, 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, and any two of the above values.

[0036] In some embodiments, the essential fatty acids in the fermentation broth, by mass percentage, include arachidic acid at a concentration of 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%, 0.1 wt%, 0.15 wt%, and any two of the above values ​​forming any one of the ranges.

[0037] In some embodiments, the essential fatty acids in the fermentation broth, by mass percentage, include erucic acid at a concentration of 0.03wt%, 0.04wt%, 0.05wt%, 0.06wt%, 0.07wt%, 0.08wt%, 0.09wt%, 0.1wt%, 0.15wt%, and any two of the above values ​​forming any one of the ranges.

[0038] In some embodiments, the essential fatty acids in the fermentation broth, by mass percentage, include docosahexaenoic acid at any of the following percentages: 0, 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt%, 0.08 wt%, 0.09 wt%, 0.1 wt%, 0.15 wt%, and any two of the above values ​​forming any one of the ranges.

[0039] In some embodiments, the essential fatty acids in the fermentation broth, by mass percentage, include EPA at any of the following percentages: 0.03wt%, 0.04wt%, 0.05wt%, 0.06wt%, 0.07wt%, 0.08wt%, 0.09wt%, 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, 1.1wt%, 1.2wt%, and any two of the above values ​​forming any one of the ranges.

[0040] In some embodiments, the essential fatty acids in the fermentation broth, by mass percentage, include nervonic acid at a concentration of 0, 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt%, and any two of the above values ​​forming a range.

[0041] In some embodiments, the essential fatty acids in the fermentation broth, by mass percentage, include DHA at a concentration of 8 wt%, 9 wt%, 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, and any two of the above values ​​forming any one of the ranges.

[0042] In some embodiments, the essential fatty acids in the fermentation broth, by mass percentage, include myristic acid (C14:0) 0.05-0.2 wt%, palmitic acid (C16:0) 4-7 wt%, stearic acid (C18:0) 0.5-2.0 wt%, oleic acid (C18:1n9c) 0.05-2.50 wt%, linoleic acid (C18:2n6c) 0.03-5.90 wt%, arachidic acid (C20:0) 0.01-0.15 wt%, erucic acid (C22:1n9) 0.03-0.15 wt%, EPA (C20:5n3) 0.03-1.20 wt%, and DHA (C22:6n3) 8-15 wt%.

[0043] In some embodiments, the compound ingredients are selected from at least one of natural vitamin E, curcumin, citrus flavonoids, yeast selenium, choline chloride, sodium carbonate, folic acid, and grape seed extract.

[0044] In some embodiments, the microalgae powder preparation is prepared from a compound fermentation broth composed of compound raw materials and fermentation broth, comprising 2%-3% choline chloride, 1%-3% natural vitamin E, 1%-3% grape seed extract, and the remainder being fermentation broth, based on the total mass percentage of the compound fermentation broth.

[0045] In some embodiments, step 1, the amplification culture process, includes seed activation and seed expansion culture.

[0046] In some embodiments, the seed activation process is as follows: the microorganism *Schizochytrium HS08* is inoculated into the activation medium and cultured at 26-28℃ and 150-200 r / min for 24-48 h to obtain the activation solution.

[0047] In some embodiments, the activation culture medium consists of a solvent and a solute. The solvent is water, and the solute composition is: carbon source 40-60 g / L, nitrogen source 10-20 g / L, sodium chloride 20-30 g / L, sodium sulfate 5-6 g / L, potassium sulfate 1-3 g / L, ammonium sulfate 1-2 g / L, magnesium sulfate 0.1-0.5 g / L, potassium dihydrogen phosphate 1-4 g / L, dipotassium hydrogen phosphate 2.5 g / L, and trace elements 0.001-0.05 mg / L. The pH is natural. Among the trace elements, the mass ratio of ferric chloride, manganese sulfate, ammonium molybdate, cobalt sulfate, nickel sulfate, and copper sulfate is 1:1.5:2:1.5:1:1.

[0048] In some embodiments, the seed propagation process is as follows: the activation solution is continuously inoculated into the propagation culture medium for three stages to obtain seed liquid.

[0049] In some embodiments, the seed propagation process is as follows:

[0050] The activation solution was inoculated into a primary shake flask at an inoculation rate of 10-20%, and cultured in an expansion culture medium at 26-28℃ and 150-200 r / min for 24-48 h to obtain the primary seed culture.

[0051] Inoculate the primary seed culture at 10-20% into the secondary shake flask and culture it in the expansion medium at 26-28℃ and 150-200 r / min for 24-48 h to obtain the secondary seed culture.

[0052] The secondary seed culture was inoculated into a tertiary fermenter at a rate of 5-10% and cultured in an expansion medium at 26-28℃ and 150-200 r / min for 24-48 h to obtain the seed culture.

[0053] In some embodiments, the expansion culture medium consists of a solvent and a solute. The solvent is water, and the solute composition is: carbon source 25-45 g / L, nitrogen source 15-25 g / L, sodium chloride 20-30 g / L, sodium sulfate 5-6 g / L, potassium sulfate 1-3 g / L, ammonium sulfate 1-2 g / L, magnesium sulfate 0.1-0.5 g / L, potassium dihydrogen phosphate 1-4 g / L, dipotassium hydrogen phosphate 2.5 g / L, and trace elements 10-20 mg / L. The pH is natural. Among the trace elements, the mass ratio of ferric chloride, manganese sulfate, ammonium molybdate, cobalt sulfate, nickel sulfate, and copper sulfate is 1:1.5:2:1.5:1:1.

[0054] In some embodiments, during step 2, the inoculation amount of the seed liquid is 20-40%, the fermentation temperature is 20-35℃, the dissolved oxygen can be 0-100%, the rotation speed can be 50-200 r / min, and the fermentation time can be 110-150 h.

[0055] In some embodiments, during the fermentation process, the initial culture medium consists of a solvent and a solute, wherein the solvent is water, and the solute includes 10-30 g / L of nitrogen source, 5-20 g / L of carbon source, 4.0-5.0 g / L of ammonium sulfate, 10-20 g / L of anhydrous sodium sulfate, 4.0-5.0 g / L of magnesium sulfate, and 6.0-10 g / L of potassium dihydrogen phosphate.

[0056] In some embodiments, the initial culture medium consists of a solvent and a solute, wherein the solvent is water, and the solute includes 4.5 g / L soybean protein, 4 g / L whey protein, 5.0 g / L yeast extract, 5.0 g / L yeast extract, 1 g / L threonine, 3 g / L histidine, 5 g / L glutamic acid, 10 g / L glucose, 10 g / L glycerol, 5.0 g / L ammonium sulfate, 10 g / L anhydrous sodium sulfate, 4 g / L magnesium sulfate, and 6 g / L potassium dihydrogen phosphate.

[0057] In some embodiments, the initial culture medium consists of a solvent and a solute, wherein the solvent is water, and the solute includes 5.0 g / L soybean protein, 5.0 g / L peptone, 5.0 g / L yeast extract, 2 g / L branched-chain amino acids, 5 g / L glutamic acid, 20 g / L glucose, 2 g / L rhamnose, 1 g / L arabinose, 5.0 g / L ammonium sulfate, 10 g / L anhydrous sodium sulfate, 4 g / L magnesium sulfate, and 6 g / L potassium dihydrogen phosphate.

[0058] In some embodiments, the initial culture medium consists of a solvent and a solute, wherein the solvent is water, and the solute includes 5.0 g / L soybean protein, 5.0 g / L whey protein, 5.0 g / L corn steep liquor, 5.0 g / L peptone, 5.0 g / L yeast extract, 5 g / L glutamic acid, 20 g / L glucose, 5.0 g / L lactose, 5.0 g / L ammonium sulfate, 10 g / L anhydrous sodium sulfate, 4 g / L magnesium sulfate, and 6 g / L potassium dihydrogen phosphate.

[0059] In some embodiments, the nitrogen source may be one or more of the following: soybean protein, whey protein, corn steep liquor, peptone, yeast extract, yeast extract powder, and amino acids (e.g., branched-chain amino acids, cysteine, threonine, valine, glutamic acid, histidine). In some embodiments, the nitrogen source is added to the base material in a single step; in some embodiments, the nitrogen source may be added in a continuous stream during fermentation.

[0060] In some embodiments, the carbon source may be one or more of molasses, starch processing by-products, glycerol processing by-products, glacial glycol, glycerol, sucrose, white sugar, lactose, galactose, trehalose, rhamnose, and arabinose.

[0061] In some embodiments, the carbon concentration is maintained at 5-20 g / L throughout the fermentation process.

[0062] In some embodiments, the carbon source concentration is controlled as follows: during fermentation for 0-96 h, the carbon concentration is controlled at 40-70 g / L; during fermentation for 96-120 h, the carbon concentration is controlled at 5-20 g / L.

[0063] In some embodiments, the carbon source concentration is controlled as follows: during fermentation 0-48h, the carbon concentration is maintained at 60-80 g / L; during fermentation 48-96h, the carbon concentration is maintained at 40-60 g / L; during fermentation 96-120h, the carbon concentration is maintained at 5-15 g / L.

[0064] In some embodiments, the pH is controlled at 2-10, preferably 6-7, during fermentation using a pH adjuster.

[0065] In some embodiments, the pH adjuster may be an acidic regulator and an alkaline regulator, and the mass concentration may be 0-60%, preferably 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, or any two of the above values ​​forming a range.

[0066] In some embodiments, the pH adjuster may be one or more of sodium hydroxide, potassium hydroxide, sodium bicarbonate, ammonia, formic acid, acetic acid, guanidinoacetic acid, phosphoric acid, sulfuric acid, hydrochloric acid, citric acid, malic acid, succinic acid, ketoglutaric acid, tartaric acid, fumaric acid, dipotassium hydrogen phosphate, disodium hydrogen phosphate, potassium dihydrogen phosphate, and sodium dihydrogen phosphate.

[0067] In some embodiments, the pH adjuster is selected from at least one of sodium hydroxide with a mass concentration of 20%, acetic acid with a mass concentration of 20%, and malic acid with a mass concentration of 20%.

[0068] In some embodiments, the pH adjuster maintains the system pH at 2-10 during fermentation, synergistically promoting the addition of feed-in factors.

[0069] In some embodiments, the promoting factor is at least one selected from branched-chain amino acids, tartrate choline, histidine, and guanidinoacetic acid. In some embodiments, the components and amounts of the promoting factor are tartrate choline 0.04~0.06 g / L, histidine 3~3.2 g / L, and guanidinoacetic acid 0.5~0.6 g / L, respectively; or the components and amounts of the promoting factor are branched-chain amino acids 3~3.2 g / L and guanidinoacetic acid 0.5~0.6 g / L, respectively.

[0070] In some embodiments, the mixed fermentation broth is emulsified by stirring, homogenized, and spray-dried to obtain a microalgae powder formulation. In some embodiments, the spray drying conditions are as follows: spray liquid temperature is 70-80℃, inlet air temperature is 190-200℃, outlet air temperature is 80-85℃, and flow rate is controlled at 100-200 L / min.

[0071] In some embodiments, the mixed fermentation broth comprises 2%-3% choline chloride, 1%-3% natural vitamin E, and 1%-3% grape seed extract, with the remainder being fermentation broth, by weight percentage.

[0072] Secondly, a microalgae powder formulation is provided, including essential fatty acids.

[0073] In some embodiments, the essential fatty acid is selected from at least one of caprylic acid (C8:0), capric acid (C10:0), lauric acid (C12:0), myristic acid (C14:0), myristoleic acid (C14:1), pentadecanoic acid (C15:0), palmitic acid (C16:0), palmitoleic acid (C16:1), heptadecanoic acid (C17:0), stearic acid (C18:0), oleic acid (C18:1n9c), linoleic acid (C18:2n6c), α-linolenic acid (C18:3n3), arachidic acid (C20:0), erucic acid (C22:1n9), docosahexaenoic acid (C22:2), EPA (C20:5n3), nervonic acid (C24:1), and DHA (C22:6n3). In some embodiments, the essential fatty acids are myristic acid (C14:0), palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1n9c), linoleic acid (C18:2n6c), arachidic acid (C20:0), erucic acid (C22:1n9), EPA (C20:5n3), and DHA (C22:6n3).

[0074] In some embodiments, the essential fatty acids, by weight percentage of the total microalgae powder formulation, include 0-0.7 wt% caprylic acid (C8:0), 0-0.5 wt% decanoic acid (C10:0), 0-0.02 wt% lauric acid (C12:0), 0.05-0.2 wt% myristic acid (C14:0), 0-0.08 wt% myristoleic acid (C14:1), 0-0.04 wt% pentadecanoic acid (C15:0), 4-7 wt% palmitic acid (C16:0), 0-0.08 wt% palmitoleic acid (C16:1), 0-0.05 wt% heptadecanoic acid (C17:0), and stearic acid (C18:0). :0) 0.5-2.0wt%, oleic acid (C18:1n9c) 0.05-2.50wt%, linoleic acid (C18:2n6c) 0.03-5.90wt%, α-linolenic acid (C18:3n3) 0-1wt%, arachidic acid (C20:0) 0.01-0.15wt%, erucic acid (C22:1n9) 0.03-0.15wt%, docosahexaenoic acid (C22:2) 0-0.15wt%, EPA (C20:5n3) 0.03-1.20wt%, nervonic acid (C24:1) 0-0.05wt%, DHA (C22:6n3) 8-15wt%. In some embodiments, the essential fatty acids, by weight percentage of the total microalgae powder formulation, include myristic acid (C14:0) 0.05-0.2 wt%, palmitic acid (C16:0) 4-7 wt%, stearic acid (C18:0) 0.5-2.0 wt%, oleic acid (C18:1n9c) 0.05-2.50 wt%, linoleic acid (C18:2n6c) 0.03-5.90 wt%, arachidic acid (C20:0) 0.01-0.15 wt%, erucic acid (C22:1n9) 0.03-0.15 wt%, EPA (C20:5n3) 0.03-1.20 wt%, and DHA (C22:6n3) 8-15 wt%.

[0075] Thirdly, a method for preparing a microalgae powder formulation is provided, comprising:

[0076] Step 1: Amplify and culture the microorganisms to obtain seed culture;

[0077] Step 2: Inoculate the seed culture with the fermentation liquid to prepare the fermentation broth;

[0078] Step 3: Prepare microalgae powder formulation from fermentation broth.

[0079] Compared with the prior art, one of the above technical solutions has the following advantages or beneficial effects:

[0080] (1) The animal products produced by this invention are not only rich in DHA, but also have relatively high contents of EPA, DPA and ALA. The total content of Omega-3 fatty acids is also increased. The DHA content in Omega-3 fatty acid milk can reach 31-35 mg / 100mL, the EPA content can reach 10-12 mg / 100mL, the DPA content can reach 4-6 mg / 100mL, the ALA content can reach 7-12 mg / 100mL, and the total Omega-3 fatty acid content can reach 54-65 mg / 100mL, thus improving the product quality.

[0081] (2) The microalgae powder preparation prepared by the present invention is rich in nutrients. The microalgae powder preparation prepared by fermentation broth can reduce the purification cost in the production process and can be directly mixed into the daily animal feed. Through feeding experiments, it can be found that the microalgae powder preparation prepared by the method of the present invention has good oxidative stability, which is conducive to the production of native milk with high Omega-3 fatty acid content and has a good bio-co-conversion rate.

[0082] Terminology Explanation

[0083] Certain embodiments of the invention will now be described in detail, examples of which are illustrated by the accompanying structural and chemical formulas. The invention is intended to encompass all alternatives, modifications, and equivalents, all of which are included within its scope. Those skilled in the art will recognize that many similar or equivalent methods and materials can be used to practice the invention. The invention is by no means limited to the methods and materials described herein. In the event that one or more of the incorporated documents, patents, and similar materials differ from or contradict this application (including, but not limited to, defined terminology, application of terminology, described techniques, etc.), this application shall prevail.

[0084] It should be further appreciated that certain features of the invention, for clarity, have been described in multiple independent embodiments, but may also be provided in combination in a single embodiment. Conversely, various features of the invention, for brevity, have been described in a single embodiment, but may also be provided individually or in any suitable sub-combination.

[0085] Unless otherwise stated, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. All patents and publications related to this invention are incorporated herein by reference in their entirety.

[0086] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0087] In the following content, all numbers disclosed herein, whether or not they use words such as "approximately" or "about," are approximate values. The value of each number may vary by 1%, 2%, 5%, 7%, 8%, 10%, 15%, or 20%. Whenever a number with a value of N is disclosed, any numbers with values ​​of N+ / -1%, N+ / -2%, N+ / -3%, N+ / -5%, N+ / -7%, N+ / -8%, N+ / -10%, N+ / -15%, or N+ / -20% will be explicitly disclosed, where "+ / -" indicates addition or subtraction. Detailed Implementation

[0088] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. The specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention in any way. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concepts of this disclosure. Such structures and techniques have also been described in many publications.

[0089] All reagents used in this invention can be purchased commercially or prepared by the methods described in this invention.

[0090] The fatty acid detection in this invention is carried out in accordance with GB 5009.168 "National Food Safety Standard - Determination of Fatty Acids in Food".

[0091] Example 1 Seed culture expansion of *Schizochytrium*

[0092] The *Schizochytrium* used in this invention is deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 40902.

[0093] Activation culture medium: Solutes consist of 60 g / L glucose, 20 g / L glutamic acid, 20 g / L sodium chloride, 5 g / L sodium sulfate, 2 g / L potassium sulfate, 2 g / L ammonium sulfate, 0.5 g / L magnesium sulfate, 1 g / L potassium dihydrogen phosphate, 2.5 g / L dipotassium hydrogen phosphate, and 0.01 mg / L trace elements; the solvent is water. The solutes are dissolved in water for preparation, and the pH is natural. The mass ratio of ferric chloride, manganese sulfate, ammonium molybdate, cobalt sulfate, nickel sulfate, and copper sulfate in the trace element preparation is 1:1.5:2:1.5:1:1.

[0094] The culture medium consisted of the following solutes: glucose 45 g / L, glutamic acid 25 g / L, sodium chloride 20 g / L, sodium sulfate 5 g / L, potassium sulfate 2 g / L, ammonium sulfate 2 g / L, magnesium sulfate 0.5 g / L, potassium dihydrogen phosphate 1 g / L, dipotassium hydrogen phosphate 2.5 g / L, and trace elements 10 mg / L. The solvent was water. The solutes were dissolved in water for preparation, and the pH was natural. The mass ratio of the trace elements (ferric chloride, manganese sulfate, ammonium molybdate, cobalt sulfate, nickel sulfate, and copper sulfate) was 1:1.5:2:1.5:1:1.

[0095] The specific steps are as follows:

[0096] (1) A glycerol tube containing Schizochytrium HS08 was inoculated into the activation medium and cultured at 28℃ and 200 r / min for 36 h to obtain the activation solution.

[0097] (2) The activation solution was inoculated into a primary shake flask at an inoculation rate of 15%, and cultured in an expansion culture medium at 28℃ and 200 r / min for 48 h to obtain the primary seed solution;

[0098] The primary seed culture was inoculated into a secondary shake flask at 15% concentration and cultured in an expansion medium at 28℃ and 200 r / min for 48 h to obtain the secondary seed culture.

[0099] The secondary seed culture was inoculated into a tertiary fermenter at a rate of 10% and cultured in an expansion medium at 28°C and 200 r / min for 48 h to obtain the seed culture.

[0100] Example 2

[0101] (1) The *Schizochytrium* seed culture obtained in Example 1 was inoculated at 20% and transferred to an 8-ton fermenter containing the initial culture medium. Fermentation was carried out at 28°C and 200 r / min, with dissolved oxygen at 0-50% (dissolved oxygen levels during growth are dynamic). During fermentation, the pH was controlled at 6-7 using a pH adjuster (pH is dynamic during growth). The pH adjuster consisted of 20% sodium hydroxide, 20% acetic acid, and 20% malic acid. During fermentation, sterile glucose solution at a concentration of 50 g / L was added via a fed-batch method. The carbon concentration was controlled at 50-70 g / L from 0-96 h (a dynamic process) and at 10-20 g / L from 96-120 h (a dynamic process). After 120 h of cultivation, the fatty acid composition was analyzed and is shown in Table 1.

[0102] The initial culture medium consisted of the following solutes: soybean protein 5.0 g / L, whey protein 5.0 g / L, corn steep liquor 5.0 g / L, peptone 5.0 g / L, yeast extract 5.0 g / L, glutamic acid 5 g / L, glucose 20 g / L, lactose 5.0 g / L, ammonium sulfate 5.0 g / L, anhydrous sodium sulfate 10 g / L, magnesium sulfate 4 g / L, and potassium dihydrogen phosphate 6 g / L; and water as the solvent. The solutes were dissolved in water for preparation, and the pH was natural.

[0103] Table 1. Fatty acid composition of fermentation broth in Example 2

[0104]

[0105] (2) Add 3% choline chloride, 3% natural vitamin E and 1% grape seed extract to the fermentation broth, mix and emulsify to obtain a uniform and stable mixed fermentation broth, and then homogenize and spray dry to obtain microalgae powder. The spray liquid temperature is controlled at 75℃, the inlet air temperature is 200℃, the outlet air temperature is 83℃ and the flow rate is controlled at 150 L / min.

[0106] Example 3

[0107] (1) The *Schizochytrium* seed culture obtained in Example 1 was inoculated at 30% and transferred to an 8-ton fermenter containing the initial culture medium. Fermentation was carried out at 35°C, 150 r / min, and dissolved oxygen 0-70%. During fermentation, the pH was controlled to 6-7 using pH adjusters: 20% sodium hydroxide, 20% acetic acid, and 20% malic acid. During fermentation, a feedstock of sterile medium containing 60 g / L glucose and 30 g / L glycerol was added. The carbon concentration was controlled at 40-50 g / L from 0-96 h and at 5-15 g / L from 96-120 h. At 45 h of fermentation, a feedstock of sterile medium containing 3 g / L branched-chain amino acids and 0.5 g / L guanidinoacetic acid was added. After 120 h of culture, the fatty acid composition was analyzed as shown in Table 2.

[0108] The initial culture medium consisted of the following solutes: soybean protein 5.0 g / L, peptone 5.0 g / L, yeast extract 5.0 g / L, branched-chain amino acids 2 g / L, glutamic acid 5 g / L, glucose 20 g / L, rhamnose 2 g / L, arabinose 1 g / L, ammonium sulfate 5.0 g / L, anhydrous sodium sulfate 10 g / L, magnesium sulfate 4 g / L, and potassium dihydrogen phosphate 6 g / L; and water as the solvent. The solutes were dissolved in water for preparation, and the pH was natural.

[0109] Table 2 Fatty acid composition of fermentation broth in Example 3

[0110]

[0111] (2) Add 2% choline chloride, 1% natural vitamin E and 3% grape seed extract to the fermentation broth, mix and emulsify, then homogenize and spray dry to obtain microalgae powder. The spray liquid temperature is controlled at 80℃, the inlet air temperature is 190℃, the outlet air temperature is 85℃, and the flow rate is controlled at 200 L / min.

[0112] Example 4

[0113] (1) The seed culture of *Schizochytrium* obtained in Example 1 was transferred to an 8-ton fermenter containing the initial culture medium at a 40% inoculation rate and cultured at 25°C, 100 r / min, and dissolved oxygen 30%. During fermentation, the pH was controlled between 6.0 and 7.0 for 0-45 h, between 5.0 and 6.0 for 45-96 h, and between 4.0 and 5.0 for 96-120 h. During fermentation, sterile solution containing 100 g / L glucose and 50 g / L glycerol was added via a fed-batch method. The carbon concentration was maintained at 60-80 g / L for 0-48 h, 40-60 g / L for 48-96 h, and 5-15 g / L for 96-120 h. Sterile solution containing 0.04 g / L tartratecholine, 3 g / L histidine, and 0.5 g / L guanidinoacetic acid was added at 45 h and 96 h, respectively. After 120 h of culture, the fatty acid composition was analyzed, as shown in Table 3.

[0114] The initial culture medium consisted of the following solutes: soybean protein 4.5 g / L, whey protein 4 g / L, yeast extract 5.0 g / L, yeast extract 5.0 g / L, threonine 1 g / L, histidine 3 g / L, glutamic acid 5 g / L, glucose 10 g / L, glycerol 10 g / L, ammonium sulfate 5.0 g / L, anhydrous sodium sulfate 10 g / L, magnesium sulfate 4 g / L, and potassium dihydrogen phosphate 6 g / L. Water was used as the solvent. The solutes were dissolved in water for preparation, and the pH was natural.

[0115] Table 3 Fatty acid composition of fermentation broth in Example 4

[0116]

[0117] (2) Add 2.5% choline chloride, 1.5% natural vitamin E and 1.5% grape seed extract to the fermentation broth, mix and emulsify, then homogenize and spray dry to obtain microalgae powder. The spray liquid temperature is controlled at 70℃, the inlet air temperature is 195℃, the outlet air temperature is 85℃, and the flow rate is controlled at 100 L / min.

[0118] Comparative Example 1

[0119] The difference from Example 2 is that the carbon concentration was maintained at 20-40 g / L throughout the culture process, the initial culture medium was slightly different, and the rest of the process was the same as in Example 2.

[0120] Table 4 Fatty acid composition of fermentation broth in Comparative Example 1

[0121]

[0122] Comparative Example 2

[0123] The difference from Example 2 is that the pH adjustment agent used during the cultivation process is only 20% sodium hydroxide and 40% malic acid, while the rest of the process is the same as in Example 2.

[0124] Table 5. Fatty acid composition of fermentation broth in Comparative Example 2

[0125]

[0126] Comparative Example 3

[0127] The difference from Example 2 is that no compound raw materials (i.e., choline chloride, natural vitamin E, and grape seed extract) were added; the fermentation broth was directly spray-dried to obtain microalgae powder. The rest of the process was the same as in Example 2.

[0128] Application Example 1: Feeding Trial

[0129] (1) Experimental design

[0130] Healthy mid-lactation Holstein dairy cows were selected and randomly divided into groups of 6 cows each. Group 1 was the control group, fed a basal diet; Group 2 received the basal diet plus microalgae powder from Example 2; Group 3 received the basal diet plus microalgae powder from Example 3; Group 4 received the basal diet plus microalgae powder from Example 4; Group 5 received the basal diet plus microalgae powder from Comparative Example 1; Group 6 received the basal diet plus microalgae powder from Comparative Example 2; and Group 7 received the basal diet plus microalgae powder from Comparative Example 3. The microalgae powder was fed at a rate of 200g / day per cow, divided into two feedings per day. All cows had free access to feed and water. The experimental basal diet was formulated according to the dairy cow feeding standards (NY / T34—2004). The pre-feeding period was 7 days, and the trial period was 28 days.

[0131] (2) Sample collection

[0132] The feed intake of each cow in each group was recorded daily. On the last day of the experiment, milk samples were collected using a sampler. A total of 50 mL of milk samples were collected according to the ratio of morning:noon:evening = 4:3:3. After adding milk preservatives, the samples were sent to the testing center for milk component testing, as well as analysis of the content of DHA, EPA, DPA, and ALA in the milk components.

[0133] (3) Test results

[0134] Table 6. Effects of different microalgae powders on feed intake and milk yield in dairy cows

[0135]

[0136] Note: Different lowercase letters in the same column indicate significant differences. P <0.05), different capital letters indicate highly significant differences ( P <0.001), unmarked or identical letters indicate no significant difference (P >0.05).

[0137] As shown in Table 6, there was no significant difference in dry matter intake among the different groups of dairy cows ( P >0.05)

[0138] Table 7. Effects of different microalgae powders on dairy milk quality

[0139]

[0140] Note: Different lowercase letters in the same column indicate significant differences. P <0.05), different capital letters indicate highly significant differences ( P <0.001), unmarked or identical letters indicate no significant difference ( P >0.05).

[0141] As shown in Table 7, there were no significant differences in milk yield, milk fat percentage, milk protein percentage, and lactose percentage among the groups of dairy cows. P >0.05).

[0142] Table 8. Omega-3 fatty acid content in milk from different microalgae powder groups

[0143]

[0144] As shown in Table 8, after one month of feeding, the DHA content in dairy cow milk can reach 31-35 mg / 100 mL, the EPA content can reach 10-12 mg / 100 mL, the DPA content can reach 4-6 mg / 100 mL, the ALA content can reach 7-12 mg / 100 mL, and the total Omega-3 fatty acid content can reach 54-65 mg / 100 mL.

[0145] As can be seen from the experimental groups, in the fermentation process of Example 2, no feed-in promoting factor was added, and the microalgae powder preparation fed to animals resulted in relatively poor component content in the milk produced. In Comparative Examples 1-2, the fermentation processes used were different, and the microalgae powder preparations fed to animals produced the lowest component content in the milk produced. Comparative Example 3, which used a microalgae powder preparation without the use of compound raw materials, was metabolized in the gastrointestinal tract of cattle after feeding, resulting in a low DHA content that could be converted into milk.

[0146] In summary, by adding 200g / d of the microalgae powder described in Examples 2-4 to the diet of ruminants, significant enrichment of Omega-3 fatty acids in dairy cow milk can be achieved without adverse effects on milk composition-related indicators.

[0147] The method of this invention has been described through preferred embodiments. Those skilled in the art will readily be able to modify or appropriately alter and combine the methods and applications described herein within the scope, spirit, and context of this invention to implement and apply the technology of this invention. Those skilled in the art can refer to the content herein to appropriately improve process parameters. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included within the scope of this invention.

Claims

1. A method for increasing the content of native Omega-3 fatty acids in animal products, characterized in that, This includes feeding animals with microalgae powder formulations to increase the content of native Omega-3 fatty acids in animal products; The animal product contains 54-65 mg / 100 mL of total Omega-3 fatty acids, and the total Omega-3 fatty acids include at least one of the following components: (1) The DHA content reaches 31-35 mg / 100mL; (2) The EPA content reaches 10-12 mg / 100mL; (3) The DPA content reaches 4-6 mg / 100mL; (4) The ALA content reaches 7-12 mg / 100mL; The microalgae powder preparation is prepared from a compound fermentation broth composed of compound raw materials and fermentation broth; the microalgae powder preparation includes essential fatty acids; The essential fatty acids were obtained from the fermentation broth of Schizochytrium HS08; Schizochytrium HS08 is deposited at the China General Microbiological Culture Collection Center, with accession number CGMCC No. 40902; The preparation process of the fermentation broth includes: Step 1: Amplify and culture the microbial *Schizochytrium HS08* to obtain seed culture; Step 2: Inoculate the seed culture with the fermentation liquid to prepare the fermentation broth; during the fermentation process, supplement at least one of glucose and glycerol in a fed-batch manner to control the carbon source concentration; when fermentation is 45-50 h, supplement the promoting factor in a fed-batch manner; or when fermentation is 90-95 h, supplement the promoting factor in a fed-batch manner. The promoting factor is at least one of amino acids, choline, and sodium salts; The animal product is milk; The carbon source concentration is controlled in the following ways: ① During fermentation 0-96 h, the carbon concentration is controlled at 40-70 g / L; during fermentation 96-120 h, the carbon concentration is controlled at 5-20 g / L; or ② During fermentation 0-48 h, the carbon concentration is maintained at 60-80 g / L; during fermentation 48-96 h, the carbon concentration is maintained at 40-60 g / L; during fermentation 96-120 h, the carbon concentration is maintained at 5-15 g / L. During the fermentation process, the pH was controlled at 6-7 using a pH adjuster. The pH adjuster is sodium hydroxide with a mass concentration of 20%, acetic acid with a mass concentration of 20%, and malic acid with a mass concentration of 20%.

2. The method according to claim 1, characterized in that, The essential fatty acid is selected from at least one of the following: caprylic acid, capric acid, lauric acid, myristic acid, myristoleic acid, pentadecanoic acid, palmitic acid, palmitoleic acid, heptadecanoic acid, stearic acid, oleic acid, linoleic acid, alpha-linolenic acid, arachidic acid, erucic acid, docosahexaenoic acid, EPA, nervonic acid, and DHA.

3. The method according to claim 1, characterized in that, The essential fatty acids in the fermentation broth, by mass percentage, include 0-0.7 wt% octanoic acid, 0-0.5 wt% decanoic acid, 0-0.02 wt% lauric acid, 0.05-0.2 wt% myristic acid, 0-0.08 wt% myristoleic acid, 0-0.04 wt% pentadecanoic acid, 4-7 wt% palmitic acid, 0-0.08 wt% palmitoleic acid, 0-0.05 wt% heptadecanoic acid, 0.5-2.0 wt% stearic acid, 0.05-2.50 wt% oleic acid, 0.03-5.90 wt% linoleic acid, 0-1 wt% α-linolenic acid, 0.01-0.15 wt% arachidic acid, 0.03-0.15 wt% erucic acid, 0-0.15 wt% docosahexaenoic acid, 0.03-1.20 wt% EPA, 0-0.05 wt% nervonic acid, and 8-15 wt% DHA.

4. The method according to claim 1, characterized in that, The essential fatty acids in the fermentation broth, by mass percentage, include myristic acid 0.05-0.2 wt%, palmitic acid 4-7 wt%, stearic acid 0.5-2.0 wt%, oleic acid 0.05-2.50 wt%, linoleic acid 0.03-5.90 wt%, arachidic acid 0.01-0.15 wt%, erucic acid 0.03-0.15 wt%, EPA 0.03-1.20 wt%, and DHA 8-15 wt%.

5. The method according to claim 1, characterized in that, The compound ingredients are selected from at least one of the following: natural vitamin E, curcumin, citrus flavonoids, yeast selenium, choline chloride, sodium carbonate, folic acid, and grape seed extract.

6. The method according to claim 1, characterized in that, In the fermentation process described in step 2, the inoculation amount of seed liquid is 20-40%, the fermentation temperature is 20-35℃, the dissolved oxygen is 0-100%, the rotation speed is 50-200 r / min, and the fermentation culture time is 110-150 h.

7. The method according to claim 1, characterized in that, The promoting factor is at least one of branched-chain amino acids, tartrate choline, histidine, and guanidinoacetic acid.

8. The method according to claim 1, characterized in that, During the fermentation process, the initial culture medium consists of a solute and a solvent, wherein the solvent is water, and the solute includes 10-30 g / L of nitrogen source, 5-20 g / L of carbon source, 4.0-5.0 g / L of ammonium sulfate, 10-20 g / L of anhydrous sodium sulfate, 4.0-5.0 g / L of magnesium sulfate and 6.0-10 g / L of potassium dihydrogen phosphate.

9. The method according to claim 8, characterized in that, The solute and its concentration are each selected from one of the following combinations: (1) Soy protein 4.5 g / L, whey protein 4 g / L, yeast extract 5.0 g / L, yeast extract 5.0 g / L, threonine 1 g / L, histidine 3 g / L, glutamic acid 5 g / L, glucose 10 g / L, glycerol 10 g / L, ammonium sulfate 5.0 g / L, anhydrous sodium sulfate 10 g / L, magnesium sulfate 4 g / L and potassium dihydrogen phosphate 6 g / L; (2) Soy protein 5.0 g / L, peptone 5.0 g / L, yeast extract 5.0 g / L, branched-chain amino acids 2 g / L, glutamic acid 5 g / L, glucose 20 g / L, rhamnose 2 g / L, arabinose 1 g / L, ammonium sulfate 5.0 g / L, anhydrous sodium sulfate 10 g / L, magnesium sulfate 4 g / L and potassium dihydrogen phosphate 6 g / L; (3) Soy protein 5.0 g / L, whey protein 5.0 g / L, corn steep liquor 5.0 g / L, peptone 5.0 g / L, yeast extract 5.0 g / L, glutamic acid 5 g / L, glucose 20 g / L, lactose 5.0 g / L, ammonium sulfate 5.0 g / L, anhydrous sodium sulfate 10 g / L, magnesium sulfate 4 g / L and potassium dihydrogen phosphate 6 g / L.

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