Liquid feed antioxidant and preparation method thereof

Abstract

The invention relates to the technical field of feed processing, in particular to a liquid feed antioxidant and a preparation method thereof. The invention relates to a liquid feed antioxidant, which is prepared from the following preparation raw materials in parts by mass: 8 to 10 parts of butylated hydroxytoluene, 5 to 7 parts of tert-butylhydroquinone, 5 to 6 parts of propyl gallate, 4 to 5 parts of butylated hydroxyanisole, 8 to 10 parts of plant extract, 10 to 12 parts of chelating synergist, 35 to 38 parts of ethanol and 60 to 65 parts of solvent, the chelating synergist is prepared by mixing an amphiphilic chelating agent and citric acid. The liquid feed antioxidant disclosed by the invention has remarkable oxidation resistance, a synergistic interaction effect, a good oxidation resistance maintaining effect and various beneficial biological activities, can effectively solve the problems that an existing feed antioxidant is poor in oxidation resistance effect and the oxidation resistance is easily and rapidly weakened, and is beneficial to promoting healthy growth of livestock and poultry.

Description

Technical Field

[0001] The present application relates to the field of feed processing technology, and in particular to a liquid feed antioxidant and a preparation method thereof. Background Art

[0002] During the storage process, the effective ingredients such as fats, vitamins, and carotenoids in the feed will undergo oxidation reactions, resulting in a decrease in the content of effective ingredients, among which the oxidation of fats is the most important. Fat oxidation will cause fat deterioration and produce odor. Fat oxidation and rancidity will lead to a variety of negative effects: the nutritional value of fats is reduced; fat oxidation produces unpleasant odors, resulting in poor palatability of feed and affecting animal feeding; the secondary products of fat oxidation react with proteins, reducing protein digestion and absorption; fat oxidation products have a destructive effect on vitamins, etc.

[0003] Currently, the composite antioxidant products on the market are mainly solid powders, which are adsorbed through mineral carriers. The ore contains iron ions, which oxidize in contact with most phenolic antioxidants to produce red quinone substances, which affect the content and sensory perception of the antioxidants during the storage period of the product, thereby affecting the protective effect of the antioxidants on the feed. Summary of the invention

[0004] The purpose of the present application is to provide a liquid feed antioxidant and a preparation method thereof in view of the deficiencies of the current technology. The liquid feed antioxidant of the present application has good antioxidant properties, and adding it to feed can solve the problem that the feed is easily oxidized and rancid. At the same time, it can also reduce contact with air and reduce the loss of its own content. The present application reasonably mixes plant extracts with a variety of antioxidants, and the product has strong antioxidant properties, which is suitable for the needs of antioxidant properties in various situations. The synergistic effect between plant extracts and a variety of antioxidants can be brought into play, and the antioxidant effect is significant, the antioxidant efficacy is strong, and the antioxidant capacity is well maintained. It can alleviate the body's oxidative stress response and promote the healthy growth of livestock and poultry, solving the problem that the existing feed antioxidants have poor antioxidant effects and the antioxidant capacity is easily and quickly weakened.

[0005] In the first aspect, the present application provides a liquid feed antioxidant, which adopts the following technical solution: A liquid feed antioxidant comprises the following raw materials, measured by weight: 8-10 parts of butylated hydroxytoluene, 5-7 parts of tert-butylhydroquinone, 5-6 parts of propyl gallate, 4-5 parts of butylated hydroxyanisole, 8-10 parts of plant extract, 10-12 parts of chelating enhancer, 35-38 parts of ethanol and 60-65 parts of solvent, wherein the chelating enhancer is prepared by mixing an amphiphilic chelating agent and citric acid.

[0006] By adopting the above technical solutions, butylated hydroxytoluene (BHT): As a commonly used antioxidant, BHT can effectively inhibit the generation of free radicals and chain reactions, thereby slowing down the oxidation process of feed. Tert-butylhydroquinone (TBHQ): TBHQ is also an effective antioxidant that can capture free radicals and terminate chain reactions to prevent oxidation of fats and oils in feed. Propyl gallate (PG): PG is a natural antioxidant with good thermal stability and antioxidant properties, which can protect the nutrients in feed from being destroyed by oxidation. Butylated hydroxyanisole (BHA): BHA is a synthetic antioxidant with strong antioxidant capacity, which can effectively extend the shelf life of feed. Plant extracts: Grape seed extract and marigold flower extract are rich in a variety of antioxidant substances, such as flavonoids, polyphenols, etc., which have strong antioxidant capacity, can remove free radicals in the body, and reduce oxidative stress. Chelating enhancer: It is made by mixing an amphiphilic chelating agent and citric acid. It can form a stable complex with metal ions to prevent the catalytic effect of metal ions on free radical reactions. At the same time, due to its own amphiphilicity, it can build a bridge between hydrophobic antioxidants and hydrophilic free radicals, so that there is actual physical contact between the antioxidants and the free radicals to play an antioxidant role. Solvent: It is used to dissolve various raw materials so that each component is evenly distributed in the feed. In summary, the liquid feed antioxidant of the present application achieves a synergistic antioxidant effect by reasonably proportioning a variety of antioxidants and plant extracts, combined with the effect of chelating enhancers, which can effectively solve the problem that the existing feed antioxidants have poor antioxidant effects and the antioxidant capacity is easily weakened quickly.

[0007] Preferably, the mass ratio of the amphiphilic chelating agent to citric acid is 3:1.

[0008] By adopting the above technical scheme, the mass ratio of amphiphilic chelating agent and citric acid is 3: 1, and this ratio can give full play to the synergistic effect of the two and improve the overall performance of feed antioxidants. First, amphiphilic chelating agent can form a stable complex with metal ions in feed, prevent the catalytic effect of metal ions on free radical reactions, thereby slowing down the oxidation process of feed. At the same time, due to its own amphiphilic properties, it can build a bridge between hydrophobic antioxidants and hydrophilic free radicals, so that there is actual physical contact between antioxidants and free radicals to play an antioxidant role. Secondly, citric acid, as a natural organic acid, has the effect of regulating pH value and enhancing stability. In this application, the addition of citric acid can adjust the pH value of feed, keep it within a suitable range, and is conducive to the stability of various components in feed and the performance of antioxidant properties. In addition, citric acid can also form a complex with amphiphilic chelating agent to further enhance its antioxidant properties. Therefore, the mass ratio of the amphiphilic chelating agent and citric acid is 3:1, which not only ensures the effective concentration of the amphiphilic chelating agent in the feed, but also exerts the regulatory effect of citric acid, so that the two can work together to improve the overall performance of the feed antioxidant.

[0009] Preferably, the preparation method of the amphiphilic chelating agent is to mix 2 kg of phytic acid with 5 kg of acetone, add 200 g of Tween 80, add 400 g of octadecenoic acid chloride while stirring, and then add 50 g of sodium carbonate, react at 30° C. for 10 hours, rotary evaporate the solvent, wash with water, and extract to obtain the amphiphilic chelating agent.

[0010] By adopting the above technical scheme, the effects and synergistic effects of the prepared amphiphilic chelating agent are as follows: Chelation: Amphiphilic chelating agents can form stable complexes with metal ions in feed, thereby preventing metal ions from catalyzing free radical reactions and reducing the occurrence of oxidation processes. Bridge effect: Due to its hydrophilic and hydrophobic properties, amphiphilic chelating agents can build bridges between hydrophobic antioxidants (such as butylated hydroxytoluene, tert-butylhydroquinone, etc.) and hydrophilic free radicals, promote physical contact between them, and enhance the antioxidant effect. Synergistic effect: The presence of amphiphilic chelating agents can improve the antioxidant properties of plant extracts and other antioxidants. Through synergistic effects, the antioxidant capacity of the entire liquid feed antioxidant is significantly improved. Protective effect: Amphiphilic chelating agents can also protect the active ingredients in plant extracts to prevent them from being oxidized and destroyed during storage and use, thereby extending the shelf life of the product and improving its stability. In summary, the amphiphilic chelating agent plays a key auxiliary role in the liquid feed antioxidant of the present application, which not only enhances the overall performance of the antioxidant, but also improves the stability and service life of the product.

[0011] Preferably, the plant extract is prepared by mixing marigold flower extract and grape seed extract in a mass ratio of 4:3.

[0012] By adopting the above technical scheme, the plant extract is prepared by mixing marigold flower extract and grape seed extract in a mass ratio of 4:3. This combination makes the antioxidant properties of the two plant extracts fully exerted, and there is a certain synergistic effect between the two. First, the quercetin in the marigold flower extract has important pharmacological effects such as antioxidant, anti-inflammatory, anti-allergic, and anti-tumor, which can effectively remove free radicals in the body, reduce oxidative stress, and protect cells from damage. Grape seed extract is rich in polyphenolic compounds, such as proanthocyanidins, etc. These compounds have strong antioxidant capacity and can combine with free radicals to prevent them from damaging cells. When the two plant extracts are mixed together, their antioxidant components can complement each other to form a more complete antioxidant system. For example, the quercetin in the marigold flower extract can reduce the generation of free radicals by inhibiting inflammatory reactions, while the polyphenolic compounds in the grape seed extract can directly remove the free radicals that have been generated. In this way, the combination of the two can more effectively resist oxidative stress and protect cell health. In addition, the addition of amphiphilic chelating agents can further enhance this synergistic effect. Since it can not only chelate with metal ions but also build a bridge between hydrophobic antioxidants and hydrophilic free radicals, it can make the antioxidant components in marigold flower extract and grape seed extract work better, thereby improving the antioxidant performance of the entire feed antioxidant.

[0013] Preferably, the method for preparing the marigold flower extract comprises the following steps: S51, adding 50 kg of marigold flower particles to 320 L of 97% acetone aqueous solution, and extracting at 50° C. for 12 h to obtain an extract; S52, the extract was pressurized and concentrated under the conditions of vacuum degree 0.06Mpa and temperature 52°C. When the solid content reached 93%, the concentration was stopped to obtain 16.2kg of concentrate; S53, adding 60 L of n-hexane to the concentrate, extracting at 30° C. for 3 h, and filtering to obtain a filter cake and a filtrate, wherein the filter cake is the marigold flower extract.

[0014] By adopting the above technical scheme, the quercetin in the marigold flower extract prepared has a strong antioxidant capacity, which can remove free radicals in the body, thereby slowing down the oxidation process of the feed. When used in combination with other antioxidants such as butylated hydroxytoluene, tert-butylhydroquinone, propyl gallate and butylated hydroxyanisole, a synergistic effect can be produced to further improve the antioxidant properties of the feed. The quercetin in the marigold flower extract has an anti-inflammatory effect, which can reduce the inflammatory response caused by the feed and protect the intestinal health of the animal. Working together with other antioxidants, it helps to alleviate the body's oxidative stress response and promote the healthy growth of livestock and poultry. The quercetin in the marigold flower extract has an anti-allergic effect, which can reduce the allergic reaction caused by the feed and improve the production performance of the animal. Working together with other antioxidants, it helps to improve the taste and nutritional value of the feed and increase the feed intake and growth rate of the animal. The quercetin in the marigold flower extract has a certain anti-tumor effect and can inhibit the growth and spread of tumor cells. Although the main purpose of using it in feed is anti-oxidation, this anti-tumor effect may also have a positive impact on the health of animals. In short, the role of marigold flower extract in this application is mainly reflected in its antioxidant, anti-inflammatory, anti-allergic and anti-tumor effects. Working together with other antioxidants, it can play a synergistic role between plant extracts and multiple antioxidants, significantly improve the antioxidant properties of feed, and solve the problem that the existing antioxidants for feed have poor antioxidant effects and their antioxidant capacity is easily weakened quickly.

[0015] Preferably, the solvent is soybean oil.

[0016] In a second aspect, the present application provides a method for preparing a liquid feed antioxidant, using the following technical solution: As a general technical concept, the present application also provides a method for preparing the above-mentioned liquid feed antioxidant, comprising the following steps: S71, adding propyl gallate to ethanol according to mass fractions and stirring to dissolve, to obtain solution A; S72. Add butylated hydroxytoluene, tert-butylhydroquinone, butylated hydroxyanisole, plant extract, chelating enhancer and solvent to solution A in order according to their mass proportions, stir evenly, and obtain a liquid feed antioxidant.

[0017] Preferably, in step S71, the stirring temperature is 50-60°C.

[0018] Preferably, in step S71, the stirring time is 40-50 minutes.

[0019] In summary, the beneficial technical effects of this application are: 1. Powerful antioxidant properties: Through the reasonable ratio of plant extracts and a variety of antioxidants, the product has a significant antioxidant effect and can effectively solve the problem of easy oxidation and rancidity of feed.

[0020] 2. Synergistic effect: The synergistic effect between plant extracts and various antioxidants makes the antioxidant effect more significant and improves the overall antioxidant capacity of the feed.

[0021] 3. Good effect of maintaining antioxidant capacity: Due to the effect of the chelating synergist, the liquid feed antioxidant of the present application can maintain its antioxidant performance for a long time and is not easy to weaken quickly.

[0022] 4. Relieve the body's oxidative stress response: The liquid feed antioxidant of the present application can effectively relieve the oxidative stress response in livestock and poultry and promote the healthy growth of livestock and poultry.

[0023] 5. Improve immunity: Plant extracts such as grape seed extract and marigold flower extract have the effect of enhancing immunity and help improve the resistance of livestock and poultry. DETAILED DESCRIPTION

[0024] The embodiments of the present application will be described in detail below in conjunction with the examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0025] In the following examples and preparation examples, 1 part means 1 kg.

[0026] Preparation Example 1 Preparation of amphiphilic chelating agent The preparation method of the amphiphilic chelating agent comprises the following steps: mixing 2 kg of phytic acid with 5 kg of acetone, adding 200 g of Tween 80, adding 400 g of octadecenoic acid chloride while stirring, and then adding 50 g of sodium carbonate, reacting at 30° C. for 10 h, rotary evaporating to remove the solvent, washing with water, and extracting to obtain the amphiphilic chelating agent.

[0027] Preparation Example 2 Preparation of marigold flower extract The preparation method of marigold flower extract comprises the following steps: S51, adding 50 kg of marigold flower particles to 320 L of 97% acetone aqueous solution, and extracting at 50° C. for 12 h to obtain an extract; S52, the extract was pressurized and concentrated under the conditions of vacuum degree 0.06Mpa and temperature 52°C. When the solid content reached 93%, the concentration was stopped to obtain 16.2kg of concentrate; S53, adding 60 L of n-hexane to the concentrate, extracting at 30° C. for 3 h, and filtering to obtain a filter cake and a filtrate, wherein the filter cake is the marigold flower extract.

[0028] Example 1 A liquid feed antioxidant comprises the following raw materials, measured by weight: 8 parts of butylated hydroxytoluene, 5 parts of tert-butylhydroquinone, 5 parts of propyl gallate, 4 parts of butylated hydroxyanisole, 8 parts of plant extract, 1 part of chelating enhancer, 35 parts of ethanol, and 60 parts of soybean oil, wherein the chelating enhancer is prepared by mixing an amphiphilic chelating agent and citric acid in a weight ratio of 3:1, and the plant extract is prepared by mixing a marigold flower extract and a grape seed extract in a weight ratio of 4:3.

[0029] The preparation method of the above-mentioned liquid feed antioxidant comprises the following steps: S71. Add propyl gallate to ethanol according to the mass fraction, raise the temperature to 50° C. and stir for 50 min to obtain solution A; S72. Add butylated hydroxytoluene, tert-butylhydroquinone, butylated hydroxyanisole, plant extract, chelating enhancer and soybean oil to solution A in order according to their mass proportions, stir evenly, and obtain a liquid feed antioxidant.

[0030] Example 2 A liquid feed antioxidant comprises the following raw materials, measured by weight: 10 parts of butylated hydroxytoluene, 7 parts of tert-butylhydroquinone, 6 parts of propyl gallate, 5 parts of butylated hydroxyanisole, 10 parts of plant extract, 12 parts of chelating enhancer, 38 parts of ethanol, and 65 parts of soybean oil, wherein the chelating enhancer is prepared by mixing an amphiphilic chelating agent and citric acid in a weight ratio of 3:1, and the plant extract is prepared by mixing a marigold flower extract and a grape seed extract in a weight ratio of 4:3.

[0031] The preparation method of the above-mentioned liquid feed antioxidant comprises the following steps: S71. Add propyl gallate to ethanol according to the mass fraction, raise the temperature to 60° C. and stir for 40 min to obtain solution A; S72. Add butylated hydroxytoluene, tert-butylhydroquinone, butylated hydroxyanisole, plant extract, chelating enhancer and soybean oil to solution A in order according to their mass proportions, stir evenly, and obtain a liquid feed antioxidant.

[0032] Example 3 A liquid feed antioxidant comprises the following raw materials, measured by weight: 9 parts of butylated hydroxytoluene, 6 parts of tert-butylhydroquinone, 5.5 parts of propyl gallate, 4.5 parts of butylated hydroxyanisole, 9 parts of plant extract, 11 parts of chelating enhancer, 36 parts of ethanol, and 63 parts of soybean oil, wherein the chelating enhancer is prepared by mixing an amphiphilic chelating agent and citric acid in a weight ratio of 3:1, and the plant extract is prepared by mixing a marigold flower extract and a grape seed extract in a weight ratio of 4:3.

[0033] The preparation method of the above-mentioned liquid feed antioxidant comprises the following steps: S71. Add propyl gallate to ethanol according to the mass fraction, raise the temperature to 55° C. and stir for 45 min to obtain solution A; S72. Add butylated hydroxytoluene, tert-butylhydroquinone, butylated hydroxyanisole, plant extract, chelating enhancer and soybean oil to solution A in order according to their mass proportions, stir evenly, and obtain a liquid feed antioxidant.

[0034] Comparative Example 1 The same as Example 3, except that an equal amount of propyl gallate is used instead of the plant extract.

[0035] Comparative Example 2 The same as Example 3, except that the plant extract is marigold flower extract.

[0036] Comparative Example 3 The same as Example 3, except that the plant extract is grape seed extract.

[0037] Comparative Example 4 The same as Example 3, except that the chelating enhancer is an amphiphilic chelating agent.

[0038] Comparative Example 5 The same as Example 3, except that the chelating enhancer is citric acid.

[0039] Performance Testing The liquid feed antioxidants prepared in Example 1, Example 3 and Comparative Examples 1 to Comparative Examples 5 were sampled and subjected to the following antioxidant effect evaluation test. The test results are shown in Table 1.

[0040] Weigh 8 groups of feed (homemade), 1 kg of feed per group, and 3 g of liquid feed antioxidant prepared by Example 1-Example 3 and Comparative Example 1-Comparative Example 5 were added to 8 experimental groups, mixed and bagged, placed in a test box, and kept at a temperature of 40 ° C. To ensure that the sample is fully in contact with oxygen in the air, the sample is mixed twice a day. Sampling was performed on 40 days for the determination of peroxide value. The specific detection method is as follows: 50 g of feed containing feed antioxidant was weighed into a 500 mL round-bottom flask and 150 mL of n-hexane was added. Reflux and leaching for 0.5 h under 30 ° C magnetic stirring. After the reaction was completed, centrifuged at 4500 r / min for 5 min, then rotary evaporated, and after rotary evaporation and desolventization, the peroxide value was detected and determined according to the method of "Determination of Peroxide Value in Food in GB5009.227-2016 National Food Safety Standard for Food". The lower the peroxide value, the better the antioxidant performance of the feed antioxidant.

[0041] Table 1 Performance test project Peroxide value (mmol / kg) Example 1 1.26 Example 2 1.23 Example 3 1.12 Comparative Example 1 7.35 Comparative Example 2 3.18 Comparative Example 3 4.86 Comparative Example 4 1.72 Comparative Example 5 2.31 Analyzing the data in Table 1, we can see that: 1) The liquid feed antioxidants prepared in Examples 1 to 3 have good antioxidant properties and can be added to feed to solve the problem of easy oxidation and rancidity of feed. At the same time, they can also reduce contact with air and reduce the loss of their own content.

[0042] 2) The comparative analysis of the performance of the liquid feed antioxidants prepared in Example 3 and Comparative Example 1 shows that the present application has a strong antioxidant property by reasonably mixing plant extracts with a variety of antioxidants, and is suitable for the needs of antioxidant performance in various situations. The synergistic effect between plant extracts and a variety of antioxidants can be brought into play, and the antioxidant effect is significant, the antioxidant efficacy is strong, and the antioxidant capacity is well maintained. It can alleviate the body's oxidative stress response and promote the healthy growth of livestock and poultry, solving the problem that the existing feed antioxidants have poor antioxidant effects and the antioxidant capacity is easily and quickly weakened.

[0043] 3) The performance comparison analysis of the liquid feed antioxidant prepared in combination with Example 3 and Comparative Examples 2-3 shows that the plant extract is prepared by mixing marigold flower extract and grape seed extract in a mass ratio of 4:3. This combination makes the antioxidant properties of the two plant extracts fully exerted, and there is a certain synergistic effect between the two. First, the quercetin in the marigold flower extract has important pharmacological effects such as antioxidant, anti-inflammatory, anti-allergic, and anti-tumor, which can effectively remove free radicals in the body, reduce oxidative stress, and protect cells from damage. Grape seed extract is rich in polyphenolic compounds, such as proanthocyanidins, etc. These compounds have strong antioxidant capacity and can combine with free radicals to prevent them from damaging cells. When these two plant extracts are mixed together, their antioxidant components can complement each other to form a more complete antioxidant system. For example, the quercetin in the marigold flower extract can reduce the generation of free radicals by inhibiting inflammatory reactions, while the polyphenolic compounds in the grape seed extract can directly remove the free radicals that have been generated. In this way, the combination of the two can more effectively resist oxidative stress and protect cell health, thereby improving the antioxidant properties of the entire feed antioxidant.

[0044] 4) The performance comparison analysis of the liquid feed antioxidant prepared in combination with Example 3 and Comparative Examples 4-5 shows that the mass ratio of amphiphilic chelating agent and citric acid is 3: 1. This ratio can give full play to the synergistic effect of the two and improve the overall performance of the feed antioxidant. First, the amphiphilic chelating agent can form a stable complex with the metal ions in the feed, preventing the catalytic effect of the metal ions on the free radical reaction, thereby slowing down the oxidation process of the feed. At the same time, due to its own amphiphilic properties, it can build a bridge between the hydrophobic antioxidant and the hydrophilic free radical, so that there is actual physical contact between the antioxidant and the free radical to play an antioxidant role. Secondly, citric acid, as a natural organic acid, has the effect of adjusting pH value and enhancing stability. The addition of citric acid can adjust the pH value of the feed, keep it within a suitable range, and is conducive to the stability of various components in the feed and the performance of antioxidant properties. In addition, citric acid can also form a complex with an amphiphilic chelating agent to further enhance its antioxidant properties. Therefore, the mass ratio of the amphiphilic chelating agent and citric acid is 3:1, which not only ensures the effective concentration of the amphiphilic chelating agent in the feed, but also exerts the regulatory effect of citric acid, so that the two can work together to improve the overall performance of the feed antioxidant.

[0045] The above embodiments are only used to explain the technical solutions of the present application rather than to limit them. Although the above embodiments provide a specific description of the present application, relevant technical personnel should understand that the specific implementation modes of the present invention can still be modified or replaced by equivalents, and any modifications and equivalent replacements that do not depart from the spirit and scope of the present application should be included in the scope of protection of the present application.

Claims

1. A liquid feed antioxidant, characterized in that: The preparation raw materials include the following by weight: 8-10 parts of butylated hydroxytoluene, 5-7 parts of tert-butylhydroquinone, 5-6 parts of propyl gallate, 4-5 parts of butylated hydroxyanisole, 8-10 parts of plant extract, 10-12 parts of chelating enhancer, 35-38 parts of ethanol and 60-65 parts of solvent, wherein the chelating enhancer is prepared by mixing an amphiphilic chelating agent and citric acid.

2. The liquid feed antioxidant according to claim 1, characterized in that: The mass ratio of the amphiphilic chelating agent to citric acid is 3:

1.

3. The liquid feed antioxidant according to claim 1, characterized in that: The preparation method of the amphiphilic chelating agent comprises the following steps: mixing 2 kg of phytic acid with 5 kg of acetone, adding 200 g of Tween 80, adding 400 g of octadecenoic acid chloride while stirring, and then adding 50 g of sodium carbonate, reacting at 30° C. for 10 h, rotary evaporating to remove the solvent, washing with water, and extracting to obtain the amphiphilic chelating agent.

4. The liquid feed antioxidant according to claim 1, characterized in that: The plant extract is prepared by mixing marigold flower extract and grape seed extract in a mass ratio of 4:

3.

5. The liquid feed antioxidant according to claim 1, characterized in that: The preparation method of the marigold flower extract comprises the following steps: S51, adding 50 kg of marigold flower particles to 320 L of 97% acetone aqueous solution, and extracting at 50° C. for 12 h to obtain an extract; S52, the extract was pressurized and concentrated under the conditions of vacuum degree 0.06Mpa and temperature 52°C. When the solid content reached 93%, the concentration was stopped to obtain 16.2kg of concentrate; S53, adding 60 L of n-hexane to the concentrate, extracting at 30° C. for 3 h, and filtering to obtain a filter cake and a filtrate, wherein the filter cake is the marigold flower extract.

6. The liquid feed antioxidant according to claim 1, characterized in that: The solvent is soybean oil.

7. A method for preparing a liquid feed antioxidant according to any one of claims 1 to 6, characterized in that: The following steps are involved: S71. Add propyl gallate to ethanol according to parts by mass and stir to dissolve to obtain solution A; S72. Add butylated hydroxytoluene, tert-butylhydroquinone, butylated hydroxyanisole, plant extract, chelating enhancer and solvent to solution A in order according to their mass proportions, stir evenly, and obtain a liquid feed antioxidant.

8. The method for preparing a liquid feed antioxidant according to claim 7, characterized in that: In step S71, the stirring temperature is 50-60°C.

9. The method for preparing a liquid feed antioxidant according to claim 7, characterized in that: In step S71, the stirring time is 40-50 minutes.