Food compound antioxidant and preparation method thereof

Abstract

The invention relates to the field of food additives, in particular to a food compound antioxidant and a preparation method thereof. The invention provides a food compound additive. The food compound additive comprises the following components in parts by weight: 50-80 parts of tara seeds; 45 to 55 parts of olive leaves; and 10 to 15 parts of methionine. According to the invention, the three components are mixed according to a certain proportion to prepare the compound antioxidant, and the antioxidant is resistant to high temperature and has stable oxidation resistance. And food can be protected in an omnibearing and multi-angle manner and is prevented from being oxidized. The invention also provides a preparation method of the food compound antioxidant. The preparation method comprises the following steps: S1, raw material treatment; s2, preparation of Tara polysaccharide; s3, preparing hydroxyl complex alcohol; and S4, preparing the food compound antioxidant. The preparation method is simple to operate and low in raw material cost.

Description

Technical Field

[0001] The present invention relates to the field of food additives, and in particular to a food compound antioxidant and a preparation method thereof. Background Art

[0002] Food antioxidants are a type of food additive that can prevent or delay food oxidation and deterioration, improve food stability and extend storage life. Their main function is to capture and neutralize free radicals, thereby eliminating the damage of free radicals to the human body and food. With the rapid development of the food industry and the increasing requirements of consumers for food safety, nutrition and quality, the market demand for food antioxidants continues to grow. As the attention to food safety issues increases, some synthetic antioxidants are restricted or banned due to possible health risks. This has prompted scientists to develop safer and more effective antioxidants and promoted the research on natural antioxidants. These natural antioxidants have gradually replaced some synthetic antioxidants because of their natural sources and good safety. The market demand for antioxidants from natural sources is gradually increasing, such as natural vitamin C, vitamin E, tea polyphenols, anthocyanins, etc.

[0003] Natural antioxidants have many defects. For example, natural antioxidants are prone to instability during processing, storage and use, resulting in weakened antioxidant effects; natural antioxidants have special smells and tastes, which may mask or change the original flavor of the food and affect consumer acceptance; natural antioxidants have poor water solubility; the extraction and purification process of natural antioxidants is more complicated and costly than that of artificial synthetic antioxidants.

[0004] Therefore, it is necessary to invent a food compound antioxidant with stable oxidative properties and simple preparation process. Summary of the invention

[0005] In view of the above-mentioned existing technical problems, the present invention provides a food compound antioxidant and a preparation method thereof. The food compound antioxidant prepared by this method has strong antioxidant performance, high thermal stability, good water solubility, and a simple preparation process, easy operation and low cost.

[0006] The present invention discloses a food compound antioxidant, comprising the following components in parts by weight:

[0007] 50-80 parts of tara seeds; 45-55 parts of olive leaves; 10-15 parts of methionine.

[0008] The present invention also discloses a method for preparing a food compound antioxidant, comprising the following steps:

[0009] S1 raw material processing: drying tara seeds and olive leaves, and then crushing them to obtain tara seed powder and olive leaf powder;

[0010] S2 Preparation of tara polysaccharide: Add the tara seed powder prepared in step S1 into a reaction bottle, then add pure water and ethanol into the reaction bottle, place the reaction bottle in an ultrasonic instrument, set the temperature of the ultrasonic instrument, the frequency of the ultrasonic wave and the ultrasonic time, after the ultrasonic wave is finished, take out the reaction bottle, filter the reaction liquid and collect the filtrate, the filtrate is the tara polysaccharide solution;

[0011] S3 Preparation of hydroxyl alcohol: Add the olive leaf powder prepared in step S1 into a beaker, then add methanol, heat and stir, filter and collect the filtrate after the stirring is completed, and the filtrate is the hydroxyl alcohol solution;

[0012] S4 Preparation of food compound antioxidant: Add the tara polysaccharide solution prepared in step S2 and the hydroxyl alcohol solution prepared in step S3 to the reactor, add methionine while stirring, and after the addition is completed, heat and stir for 0.5 to 1.5 hours. After the reaction is completed, cool the reaction solution, transfer it to a single-mouth bottle for reduced pressure concentration, and freeze-dry the concentrate to obtain a food compound antioxidant.

[0013] Preferably, in the S1 raw material processing step, the drying temperature is 45 to 55° C. and the drying time is 7 to 8 hours.

[0014] Preferably, in the S2 tara polysaccharide preparation step, the volume ratio of pure water to ethanol is 1:(0.3-0.6); the volume ratio of tara seed powder to pure water is 1:(8-10).

[0015] Preferably, in the S2 tara polysaccharide preparation step, the temperature of the sonicator is 30-35°C.

[0016] Preferably, in the S2 tara polyose preparation step, the frequency of the ultrasonic wave is 250-350W.

[0017] Preferably, in the S2 tara polysaccharide preparation step, the ultrasonication time is 5 to 10 minutes.

[0018] Preferably, in the S3 hydroxyl alcohol preparation step, the mass ratio of olive leaf powder to methanol is 1:(10-15).

[0019] Preferably, in the step of preparing the S3 hydroxy complex alcohol, the temperature of heating and stirring is 35 to 45°C.

[0020] Preferably, in the step S4 of preparing the food compound antioxidant, the temperature of heating and stirring is 60-70°C.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention provides a food compound antioxidant, comprising tara polysaccharide, hydroxytyrosol and methionine. The molecular structure of tara polysaccharide contains active groups, which can react with free radicals to neutralize their activity and reduce the occurrence of oxidative damage; there are multiple hydroxyl groups in the hydroxytyrosol molecule, which have high reactivity and can hydrogen bond with free radicals to form stable free radical intermediates. These intermediates will quickly decompose into harmless compounds, thereby avoiding the continuation of the free radical chain reaction; hydroxytyrosol can not only remove existing free radicals, but also inhibit the generation of free radicals through its antioxidant effect; methionine can chelate with metal ions, thereby inhibiting the oxidation reaction catalyzed by metal ions. The present invention mixes the three in a certain proportion to prepare a compound antioxidant, which is resistant to high temperatures and has stable antioxidant properties. Food can be protected from oxidation in all directions and angles.

[0023] The present invention also provides a preparation method of a food compound antioxidant, wherein tara polysaccharide is extracted by ultrasonic extraction, which is simple to operate and has a high extraction rate, wherein the ratio of tara polysaccharide powder to solvent needs to be controlled, because different ratios have a great influence on the dissolution rate of tara polysaccharide, and the solvent is a mixed solvent of pure water and ethanol, which is also to further improve the dissolution rate. This preparation method is simple to operate and has a low raw material cost. DETAILED DESCRIPTION

[0024] The following examples are provided for a better understanding of the present invention, but are not intended to limit the best mode of implementation, nor to limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

[0025] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be obtained commercially.

[0026] Example 1: A food compound antioxidant, composed of the following ingredients in parts by weight: 50 parts of tara seeds; 45 parts of olive leaves; and 10 parts of methionine.

[0027] A method for preparing a food compound antioxidant comprises the following steps:

[0028] S1 raw material processing: drying tara seeds and olive leaves, setting the drying temperature to 45°C and the drying time to 7 hours; after the drying is completed, taking out the dried tara seeds and dried olive leaves, and crushing them respectively to obtain tara seed powder and olive leaf powder;

[0029] S2 Preparation of tara polyose: Add the tara seed powder prepared in step S1 to a reaction bottle, then add pure water and ethanol to the reaction bottle, the mass ratio of the added tara seed powder to pure water is 1:8, and the volume ratio of pure water to ethanol is 1:0.3; after the solvents are added, place the reaction bottle containing the reaction liquid in an ultrasonic instrument, set the temperature of the ultrasonic instrument to 30°C, the frequency of the ultrasonic wave to 250W, and the ultrasonic time to 5 minutes. After the ultrasonic wave is finished, take out the reaction bottle, filter the reaction liquid and collect the filtrate, and the filtrate is the tara polyose solution;

[0030] S3 Preparation of hydroxyl alcohol: Add the olive leaf powder prepared in step S1 to a beaker, then add methanol, and heat and stir. The heating and stirring temperature is 35° C., the stirring rate is 70-100 rpm, and the heating and stirring is performed for 30-40 minutes. After the stirring is completed, filter and collect the filtrate, and the filtrate is the hydroxyl alcohol solution;

[0031] S4 Preparation of food compound antioxidant: Add the tara polysaccharide solution prepared in step S2 and the hydroxyl alcohol solution prepared in step S3 to the reactor, add methionine while stirring, and after the addition is completed, slowly heat up to 60°C and continue stirring for 0.5 to 1.5 hours. After the reaction is completed, cool the reaction solution to 25 to 28°C, transfer it to a single-mouth bottle for reduced pressure concentration, and put the concentrated solution into a freeze dryer for freeze drying. The temperature of the freeze dryer is -40 to -50°C. After freeze drying for 10 to 12 hours, the food compound antioxidant can be obtained.

[0032] Example 2: A food compound antioxidant, composed of the following ingredients in parts by weight: 55 parts of tara seeds; 47 parts of olive leaves; and 11 parts of methionine.

[0033] A method for preparing a food compound antioxidant comprises the following steps:

[0034] S1 raw material processing: drying tara seeds and olive leaves, setting the drying temperature to 47°C and the drying time to 7.2h; after the drying is completed, taking out the dried tara seeds and dried olive leaves, and crushing them respectively to obtain tara seed powder and olive leaf powder;

[0035] S2 Preparation of tara polysaccharide: Add the tara seed powder obtained in step S1 to a reaction bottle, and then add pure water and ethanol to the reaction bottle, the mass ratio of the added tara seed powder to pure water is 1:8.3, and the volume ratio of pure water to ethanol is 1:0.35; after the solvents are added, place the reaction bottle containing the reaction liquid in an ultrasonic instrument, set the temperature of the ultrasonic instrument to 31°C, the frequency of the ultrasonic wave to 270W, and the ultrasonic time to 6 minutes. After the ultrasonic wave is completed, take out the reaction bottle, filter the reaction liquid and collect the filtrate, and the filtrate is the tara polysaccharide solution;

[0036] S3 Preparation of hydroxyl alcohol: Add the olive leaf powder prepared in step S1 to a beaker, then add methanol, and heat and stir. The heating and stirring temperature is 35° C., the stirring rate is 70-100 rpm, and the heating and stirring is performed for 30-40 minutes. After the stirring is completed, the filtrate is collected, and the filtrate is the hydroxyl alcohol solution;

[0037] S4 Preparation of food compound antioxidant: Add the tara polysaccharide solution prepared in step S2 and the hydroxyl alcohol solution prepared in step S3 to the reactor, add methionine while stirring, and after the addition is completed, slowly heat up to 60°C and continue stirring for 0.5 to 1.5 hours. After the reaction is completed, cool the reaction solution to 25 to 28°C, transfer it to a single-mouth bottle for reduced pressure concentration, and put the concentrated solution into a freeze dryer for freeze drying. The temperature of the freeze dryer is -40 to -50°C. After freeze drying for 10 to 12 hours, the food compound antioxidant can be obtained.

[0038] Example 3: A food compound antioxidant, composed of the following ingredients in parts by weight: 60 parts of tara seeds; 49 parts of olive leaves; and 12 parts of methionine.

[0039] A method for preparing a food compound antioxidant comprises the following steps:

[0040] S1 raw material processing: drying tara seeds and olive leaves, setting the drying temperature to 49°C and the drying time to 7.4h; after the drying is completed, taking out the dried tara seeds and dried olive leaves, and crushing them respectively to obtain tara seed powder and olive leaf powder;

[0041] S2 Preparation of tara polysaccharide: Add the tara seed powder prepared in step S1 to a reaction bottle, and then add pure water and ethanol to the reaction bottle, the mass ratio of the added tara seed powder to pure water is 1:8.7, and the volume ratio of pure water to ethanol is 1:0.4; after the solvents are added, place the reaction bottle containing the reaction liquid in an ultrasonic instrument, set the temperature of the ultrasonic instrument to 32°C, the frequency of the ultrasonic wave to 290W, and the ultrasonic time to 7 minutes. After the ultrasonic wave is finished, take out the reaction bottle, filter the reaction liquid and collect the filtrate, and the filtrate is the tara polysaccharide solution;

[0042] S3 Preparation of hydroxyl alcohol: Add the olive leaf powder prepared in step S1 to a beaker, then add methanol, and heat and stir. The heating and stirring temperature is 40°C, the stirring rate is 70-100 rpm, and the heating and stirring is performed for 30-40 minutes. After the stirring is completed, filter and collect the filtrate, and the filtrate is the hydroxyl alcohol solution;

[0043] S4 Preparation of food compound antioxidant: Add the tara polysaccharide solution prepared in step S2 and the hydroxyl alcohol solution prepared in step S3 to the reactor, add methionine while stirring, and after the addition is completed, slowly heat up to 65°C and continue stirring for 0.5 to 1.5 hours. After the reaction is completed, cool the reaction solution to 25 to 28°C, transfer it to a single-mouth bottle for reduced pressure concentration, and put the concentrated solution into a freeze dryer for freeze drying. The temperature of the freeze dryer is -40 to -50°C. After freeze drying for 10 to 12 hours, the food compound antioxidant can be obtained.

[0044] Example 4: A food compound antioxidant, composed of the following ingredients in parts by weight: 65 parts of tara seeds; 51 parts of olive leaves; and 13 parts of methionine.

[0045] A method for preparing a food compound antioxidant comprises the following steps:

[0046] S1 raw material processing: drying tara seeds and olive leaves, setting the drying temperature to 51°C and the drying time to 7.6 hours; after the drying is completed, taking out the dried tara seeds and dried olive leaves, and crushing them respectively to obtain tara seed powder and olive leaf powder;

[0047] S2 Preparation of tara polyose: Add the tara seed powder prepared in step S1 to a reaction bottle, then add pure water and ethanol to the reaction bottle, the mass ratio of the added tara seed powder to pure water is 1:9, and the volume ratio of pure water to ethanol is 1:0.45; after the solvents are added, place the reaction bottle containing the reaction liquid in an ultrasonic instrument, set the temperature of the ultrasonic instrument to 33°C, the frequency of the ultrasonic wave to 310W, and the ultrasonic time to 8 minutes. After the ultrasonic wave is finished, take out the reaction bottle, filter the reaction liquid and collect the filtrate, and the filtrate is the tara polyose solution;

[0048] S3 Preparation of hydroxyl alcohol: Add the olive leaf powder prepared in step S1 to a beaker, then add methanol, and heat and stir. The heating and stirring temperature is 40°C, the stirring rate is 70-100 rpm, and the heating and stirring is performed for 30-40 minutes. After the stirring is completed, filter and collect the filtrate, and the filtrate is the hydroxyl alcohol solution;

[0049] S4 Preparation of food compound antioxidant: Add the tara polysaccharide solution prepared in step S2 and the hydroxyl alcohol solution prepared in step S3 to the reactor, add methionine while stirring, and after the addition is completed, slowly heat up to 65°C and continue stirring for 0.5 to 1.5 hours. After the reaction is completed, cool the reaction solution to 25 to 28°C, transfer it to a single-mouth bottle for reduced pressure concentration, and put the concentrated solution into a freeze dryer for freeze drying. The temperature of the freeze dryer is -40 to -50°C. After freeze drying for 10 to 12 hours, the food compound antioxidant can be obtained.

[0050] Example 5: A food compound antioxidant, composed of the following ingredients in parts by weight: 73 parts of tara seeds; 53 parts of olive leaves; and 14 parts of methionine.

[0051] A method for preparing a food compound antioxidant comprises the following steps:

[0052] S1 raw material processing: drying tara seeds and olive leaves, setting the drying temperature to 53°C and the drying time to 7.8h; after the drying is completed, taking out the dried tara seeds and dried olive leaves, and crushing them respectively to obtain tara seed powder and olive leaf powder;

[0053] S2 Preparation of tara polysaccharide: Add the tara seed powder prepared in step S1 to a reaction bottle, and then add pure water and ethanol to the reaction bottle, the mass ratio of the added tara seed powder to pure water is 1:9.5, and the volume ratio of pure water to ethanol is 1:0.53; after the solvents are added, place the reaction bottle containing the reaction liquid in an ultrasonic instrument, set the temperature of the ultrasonic instrument to 34°C, the frequency of the ultrasonic wave to 330W, and the ultrasonic time to 9 minutes. After the ultrasonic wave is completed, take out the reaction bottle, filter the reaction liquid and collect the filtrate, and the filtrate is the tara polysaccharide solution;

[0054] S3 Preparation of hydroxyl alcohol: Add the olive leaf powder prepared in step S1 to a beaker, then add methanol, and heat and stir. The heating and stirring temperature is 45° C., the stirring rate is 70-100 rpm, and the heating and stirring is performed for 30-40 minutes. After the stirring is completed, filter and collect the filtrate, and the filtrate is the hydroxyl alcohol solution;

[0055] S4 Preparation of food compound antioxidant: Add the tara polysaccharide solution prepared in step S2 and the hydroxyl alcohol solution prepared in step S3 to the reactor, add methionine while stirring, and after the addition is completed, slowly heat up to 70°C and continue stirring for 0.5 to 1.5 hours. After the reaction is completed, cool the reaction solution to 25 to 28°C, transfer it to a single-mouth bottle for reduced pressure concentration, and put the concentrated solution into a freeze dryer for freeze drying. The temperature of the freeze dryer is -40 to -50°C. After freeze drying for 10 to 12 hours, the food compound antioxidant can be obtained.

[0056] Example 6: A food compound antioxidant, composed of the following ingredients in parts by weight: 80 parts of tara seeds; 55 parts of olive leaves; and 15 parts of methionine.

[0057] A method for preparing a food compound antioxidant comprises the following steps:

[0058] S1 raw material processing: drying tara seeds and olive leaves, setting the drying temperature to 55°C and the drying time to 8 hours; after the drying is completed, taking out the dried tara seeds and dried olive leaves, and crushing them respectively to obtain tara seed powder and olive leaf powder;

[0059] S2 Preparation of tara polysaccharide: Add the tara seed powder prepared in step S1 to a reaction bottle, and then add pure water and ethanol to the reaction bottle, the mass ratio of the added tara seed powder to pure water is 1:10, and the volume ratio of pure water to ethanol is 1:0.6; after the solvents are added, place the reaction bottle containing the reaction liquid in an ultrasonic instrument, set the temperature of the ultrasonic instrument to 35°C, the frequency of the ultrasonic wave to 350W, and the ultrasonic time to 10 minutes. After the ultrasonic wave is completed, take out the reaction bottle, filter the reaction liquid and collect the filtrate, and the filtrate is the tara polysaccharide solution;

[0060] S3 Preparation of hydroxyl alcohol: Add the olive leaf powder prepared in step S1 to a beaker, then add methanol, and heat and stir. The heating and stirring temperature is 45° C., the stirring rate is 70-100 rpm, and the heating and stirring is performed for 30-40 minutes. After the stirring is completed, filter and collect the filtrate, and the filtrate is the hydroxyl alcohol solution;

[0061] S4 Preparation of food compound antioxidant: Add the tara polysaccharide solution prepared in step S2 and the hydroxyl alcohol solution prepared in step S3 to the reactor, add methionine while stirring, and after the addition is completed, slowly heat up to 70°C and continue stirring for 0.5 to 1.5 hours. After the reaction is completed, cool the reaction solution to 25 to 28°C, transfer it to a single-mouth bottle for reduced pressure concentration, and put the concentrated solution into a freeze dryer for freeze drying. The temperature of the freeze dryer is -40 to -50°C. After freeze drying for 10 to 12 hours, the food compound antioxidant can be obtained.

[0062] Comparative Example 1: A food compound antioxidant, composed of the following ingredients in parts by weight: 65 parts of tara seeds; 13 parts of methionine.

[0063] The preparation method and experimental conditions of the food compound antioxidant are the same as those in Example 4.

[0064] Comparative Example 2: A food compound antioxidant, composed of the following ingredients in parts by weight: 51 parts of olive leaves; 13 parts of methionine.

[0065] The preparation method and experimental conditions of the food compound antioxidant are the same as those in Example 4.

[0066] Comparative Example 3: A food compound antioxidant, composed of the following ingredients in parts by weight: 65 parts of tara seeds; 51 parts of olive leaves.

[0067] The preparation method and experimental conditions of the food compound antioxidant are the same as those in Example 4.

[0068] Comparative Example 4: A method for preparing a tara polysaccharide antioxidant, comprising the following steps:

[0069] S1 raw material processing: drying the tara seeds, setting the drying temperature to 51°C and the drying time to 7.6 hours; after the drying is completed, taking out the dried tara seeds and crushing them to obtain tara seed powder;

[0070] S2 Preparation of tara polysaccharide antioxidant: Add the tara seed powder obtained in step S1 to the reaction bottle, and then add pure water and ethanol to the reaction bottle, the mass ratio of the added tara seed powder to pure water is 1:9, and the volume ratio of pure water to ethanol is 1:0.45; after the solvents are added, place the reaction bottle containing the reaction liquid in an ultrasonic instrument, set the temperature of the ultrasonic instrument to 33°C, the frequency of the ultrasonic wave to 310W, and the ultrasonic time to 8 minutes. After the ultrasonic wave is over, take out the reaction bottle, filter the reaction liquid and collect the filtrate, concentrate the filtrate under reduced pressure, and put the concentrated solution into a freeze dryer for freeze drying. The temperature of the freeze dryer is -40 to -50°C. After freeze drying for 10 to 12 hours, the tara polysaccharide antioxidant can be obtained.

[0071] Comparative Example 5: A method for preparing a hydroxyl alcohol antioxidant, comprising the following steps:

[0072] S1 Raw material processing: drying the olive leaves, setting the drying temperature to 51°C and the drying time to 7.6h; after the drying is completed, taking out the dried olive leaves and crushing them to obtain olive leaf powder;

[0073] Preparation of S3 hydroxyl alcohol antioxidant: Add the olive leaf powder obtained in step S1 to a beaker, then add methanol, and heat and stir. The heating and stirring temperature is 40°C, the stirring rate is 70-100rpm, and the heating and stirring is 30-40min. After the stirring is completed, filter and collect the filtrate, concentrate the filtrate under reduced pressure, and put the concentrated solution into a freeze dryer for freeze drying. The temperature of the freeze dryer is -40 to -50°C. After freeze drying for 10 to 12h, the hydroxyl alcohol antioxidant can be obtained.

[0074] Comparative Example: 6: Commercially available food antioxidant.

[0075] The antioxidants prepared in Examples 1 to 6 and Comparative Examples 1 to 6 were tested at room temperature, and the test data are shown in the following table:

[0076]

[0077] As can be seen from the above table, when the content of tara polysaccharide, hydroxyl alcohol content and methionine content are different, the DPPH free radical scavenging rate of the prepared food compound antioxidant is different, which shows that the ratio of raw materials has a certain influence on the antioxidant performance of the antioxidant. When the content of tara polysaccharide is 50.4, the content of hydroxyl alcohol is 39.5, and the content of methionine is 10.1, the antioxidant performance is the best.

[0078] The antioxidants prepared in Examples 1 to 6 and Comparative Examples 1 to 6 were tested at different temperatures, and the test data are shown in the following table:

[0079]

[0080]

[0081] As can be seen from the above table, at different temperatures, the antioxidant properties of the antioxidants prepared in Examples 1 to 6 and Comparative Examples 1 to 6 are different; the differences between Examples 1 to 6 at different temperatures are not large compared to Comparative Examples 1 to 6, and the DPPH radical scavenging rates of the remaining examples except Example 1 can be maintained at more than 92%, indicating that the antioxidants prepared by the present invention are stable in nature and will not weaken in antioxidant properties as the temperature increases; Comparative Example 1 is an antioxidant prepared by compounding tara polysaccharide with methionine, and Comparative Example 3 is an antioxidant prepared by compounding tara polysaccharide with hydroxyl alcohol, and the DPPH radical scavenging rate is significantly lower than that of Example 4, but it can be seen in the temperature increase experiment that it still has good stability; Comparative Example 2 is an antioxidant prepared by compounding hydroxyl alcohol with methionine, and the DPPH radical scavenging rate is significantly lower than that of Example 4. In the temperature increase experiment, the stability of the antioxidant prepared by Comparative Example 2 decreases as the temperature increases. Comparative Example 4 is a tara polysaccharide antioxidant, Comparative Example 5 is a hydroxyl alcohol antioxidant, and Comparative Example 6 is a commercially available antioxidant. Compared with the antioxidant prepared in Example 4, the antioxidants of Comparative Examples 3 to 4 have much lower DPPH radical scavenging rates and poor stability.

[0082] In summary, the food compound antioxidant provided by the present invention has a high DPPH free radical scavenging rate, good antioxidant performance, good stability, and a wide applicable temperature range. Whether it is food that is ready to eat at room temperature or food that needs to be heated at high temperature before it can be eaten, this compound antioxidant can be used to ensure that the food is not oxidized, reduce the loss of food nutrients, thereby extending the shelf life of the food and maintaining its nutritional value. Among them, tara polysaccharide not only has an antioxidant effect, but also has good thickening, stabilization and emulsification properties, which can effectively improve the taste and texture of food, making the food more delicious.

[0083] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the scope of protection of the invention.

Claims

1. A food compound antioxidant, characterized in that: It is composed of the following components by weight: 50-80 parts of tara seeds; 45-55 parts of olive leaves; 10-15 parts of methionine.

2. A method for preparing a food compound antioxidant, characterized in that: The following steps are involved: S1 raw material processing: drying tara seeds and olive leaves, and then crushing them to obtain tara seed powder and olive leaf powder; S2 Preparation of tara polysaccharide: Add the tara seed powder prepared in step S1 into a reaction bottle, then add pure water and ethanol into the reaction bottle, place the reaction bottle in an ultrasonic instrument, set the temperature of the ultrasonic instrument, the frequency of the ultrasonic wave and the ultrasonic time, after the ultrasonic wave is finished, take out the reaction bottle, filter the reaction liquid and collect the filtrate, the filtrate is the tara polysaccharide solution; S3 Preparation of hydroxyl alcohol: Add the olive leaf powder prepared in step S1 into a beaker, then add methanol, heat and stir, filter and collect the filtrate after the stirring is completed, and the filtrate is the hydroxyl alcohol solution; S4 Preparation of food compound antioxidant: Add the tara polysaccharide solution prepared in step S2 and the hydroxyl alcohol solution prepared in step S3 to the reactor, add methionine while stirring, and after the addition is completed, heat and stir for 0.5 to 1.5 hours. After the reaction is completed, cool the reaction solution, transfer it to a single-mouth bottle for reduced pressure concentration, and freeze-dry the concentrate to obtain a food compound antioxidant.

3. The method for preparing a food compound antioxidant according to claim 2, characterized in that: In the S1 raw material processing step, the drying temperature is 45 to 55° C. and the drying time is 7 to 8 hours.

4. The method for preparing a food compound antioxidant according to claim 2, characterized in that: In the S2 tara polysaccharide preparation step, the volume ratio of pure water to ethanol is 1:(0.3-0.6); the volume ratio of tara seed powder to pure water is 1:(8-10).

5. The method for preparing a food compound antioxidant according to claim 2, characterized in that: In the S2 tara polysaccharide preparation step, the temperature of the sonicator is 30-35°C.

6. The method for preparing a food compound antioxidant according to claim 2, characterized in that: In the S2 tara polyol preparation step, the frequency of the ultrasonic wave is 250-350W.

7. The method for preparing a food compound antioxidant according to claim 2, characterized in that: In the S2 tara polysaccharide preparation step, the ultrasonication time is 5 to 10 minutes.

8. The method for preparing a food compound antioxidant according to claim 2, characterized in that: In the S3 hydroxyl alcohol preparation step, the mass ratio of olive leaf powder to methanol is 1:(10-15).

9. The method for preparing a food compound antioxidant according to claim 2, characterized in that: In the step of preparing S3 hydroxy complex alcohol, the temperature of heating and stirring is 35-45°C.

10. The method for preparing a food compound antioxidant according to claim 2, characterized in that: In the step S4 of preparing the food compound antioxidant, the temperature of heating and stirring is 60-70°C.

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