A conjugated linoleic acid nanoemulsion and preparation method thereof

Abstract

The invention belongs to the field of functional additives in the field of food, and particularly relates to a conjugated linoleic acid nanoemulsion and a preparation method thereof. The conjugated linoleic acid nanoemulsion is prepared from the following raw materials in parts by weight: 5-10 parts of conjugated linoleic acid, 10-12 parts of nonionic surfactant, 0.005-0.01 parts of chelating agent, 0.005-0.02 parts of antioxidant, 0.005-0.01 parts of preservative and 100-105 parts of water. The preparation method comprises the following steps: SS1 weighing components, S2 adding antioxidant, S3 adding other components, S4 preparing colostrum, S5 volume fixing, so that the conjugated linoleic acid can be dispersed in water in the form of oil droplets, and the conjugated linoleic acid is protected from being easily oxidized; the conjugated linoleic acid can be dispersed and dissolved in water without turbidity, precipitation or stratification. The preparation method is simple to prepare, does not require a homogenizer and an emulsifier, and does not require heating. The conjugated linoleic acid nanoemulsion can be widely used in food processing, beverages, health products and animal feed.

Description

Technical Field

[0001] The invention belongs to the field of functional additives in the field of food, and in particular relates to a conjugated linoleic acid nanoemulsion and a preparation method thereof. Background Art

[0002] Conjugated linoleic acid (CLA) is a functional unsaturated fatty acid and a food supplement approved by the US FDA. In 2009, it was approved by the Ministry of Health of my country as a new resource food (new food raw material). Conjugated linoleic acid is made from natural safflower seed oil through conjugation reaction, molecular distillation and purification. It is the general name for a series of octadecadienoic acids containing conjugated double bonds and having multiple positional and geometric isomers. Its molecular formula is: C 18 H 32 O2.

[0003] Conjugated linoleic acid has a wide range of physiological functions, including scavenging free radicals, enhancing the body's antioxidant capacity and immune function, promoting growth and development, regulating blood cholesterol and triglyceride levels, preventing atherosclerosis, promoting fat oxidation and decomposition, and promoting human protein synthesis. The products are widely used in health care products, food, medicine, feed, cosmetics and other industries.

[0004] Since conjugated linoleic acid itself is chemically unstable, it is easily oxidized and damaged by light. Currently, the commercial forms of conjugated linoleic acid mainly include free conjugated linoleic acid, conjugated linoleic acid ethyl ester, conjugated linoleic acid triglyceride, conjugated linoleic acid microcapsule powder, conjugated linoleic acid emulsion, conjugated linoleic acid calcium salt, etc.

[0005] Patent CN201910642403.9, a conjugated linoleic acid nanoemulsion and a preparation method thereof, discloses that the preparation method includes the steps of mixing an aqueous phase and an oil phase for shear emulsification and homogenization, wherein the aqueous phase is an aqueous solution containing starch and a small molecule filler; the oil phase is a conjugated linoleic acid glyceride containing an oil phase antioxidant, and no emulsifier or stabilizer is added to the product. The particle size of the emulsion does not change substantially during illumination, heating, and the like, and the oil is not oxidized. However, the problems that the dough has low moisture retention and strong viscosity, and is very easy to agglomerate in an extruder, resulting in uneven extrusion of the extruder and easy blockage of the extruder, etc., are not solved. However, the steps of shear emulsification and homogenization are required, and the preparation is complicated, and simple preparation is not achieved. The present invention does not require a homogenizer and an emulsifier, and does not require heating.

[0006] Patent CN101502478A is based on nonionic amphiphilic surfactant transparent nanoemulsion and its application. Short-chain alcohol, ionic amphiphilic surfactant, thickener, etc. are mainly selected as the main system, mixed with various vegetable oils, turbine stirred and then homogenized by high pressure to finally obtain nanoemulsion. The preparation is complicated. The present invention does not need homogenizer and emulsifier, and does not need heating.

[0007] Patent CN202010047964.7, a purification preparation method and application of high-purity conjugated linoleic acid glycerides, discloses a purification preparation method and application of high-purity conjugated linoleic acid glycerides compounds, which adopts high-purity conjugated linoleic acid or conjugated linoleic acid esters and glycerol for synthesis and preparation to prepare conjugated linoleic acid glycerides compounds, and can also prepare standard or pure products of two different substitution positions of linoleic acid diglyceride. However, it does not solve the problems of low moisture retention and strong viscosity of the dough, and it is very easy to agglomerate in the extruder, resulting in uneven extrusion of the extruder and easy blockage of the extruder. At the same time, it does not solve the problem of infinite dispersion and dissolution of conjugated linoleic acid in water without turbidity, precipitation, stratification and oxidation. Summary of the invention

[0008] The conjugated linoleic acid nanoemulsion prepared by the invention is dispersed in water in the form of oil droplets, thereby protecting the conjugated linoleic acid from being easily oxidized; the conjugated linoleic acid can be dispersed and dissolved in water without turbidity, precipitation or stratification; the preparation method is simple, no homogenizer and emulsifier are required, and no heating is required; the conjugated linoleic acid nanoemulsion can be widely used in food processing, beverages, health products and animal feed.

[0009] To achieve the above purpose, the technical solution adopted by the present invention is:

[0010] A conjugated linoleic acid nanoemulsion comprises the following raw materials in parts by weight: 5-10 parts of conjugated linoleic acid, 10-12 parts of nonionic surfactant, 0.005-0.01 parts of chelating agent, 0.005-0.02 parts of antioxidant, 0.005-0.01 parts of preservative and the balance of water.

[0011] Furthermore, the following raw materials are included in parts by weight: 5 parts of conjugated linoleic acid, 10 parts of nonionic surfactant, 0.01 parts of chelating agent, 0.01 parts of antioxidant, 0.01 parts of preservative and the balance of water.

[0012] Furthermore, the conjugated linoleic acid nanoemulsion also includes a solubilizer, and the solubilizer includes at least one of polyoxyethylene castor oil, alkyl glucoside 0810, hydrogenated castor oil or coconut oil alcohol ether-7.

[0013] Furthermore, the nonionic surfactant includes polysorbate 60 or polysorbate 80.

[0014] Furthermore, the antioxidant is selected from one or more of ascorbyl palmitate, butylated hydroxyanisole, butylated hydroxytoluene, propyl gallate, butylated hydroxyanisole, tert-butylhydroquinone or tocopherol.

[0015] Furthermore, the preservative is selected from one or more of ethyl p-hydroxybenzoate, sodium benzoate or potassium sorbate.

[0016] Furthermore, the chelating agent includes disodium ethylenediaminetetraacetate.

[0017] The preparation method of the conjugated linoleic acid nanoemulsion comprises the following steps:

[0018] S1 weighing the components: weighing the conjugated linoleic acid, nonionic surfactant, chelating agent, antioxidant, preservative and water according to the above weights; S2 adding antioxidant: adding the antioxidant to the conjugated linoleic acid and stirring to dissolve it;

[0019] S3: Add other components: Add nonionic surfactant to the mixture of S2 and stir evenly;

[0020] S4: preparing colostrum: adding the chelating agent and preservative in the raw materials into a proper amount of water, stirring to dissolve, and then adding the mixture into S3, stirring fully to form colostrum;

[0021] S5: Add the remaining water to the mixed solution of S4 to make the volume to 100 parts, and stir well to obtain the conjugated linoleic acid nanoemulsion.

[0022] Furthermore, the solubilizing agent is added in step S4.

[0023] Furthermore, the temperature of the stirring treatment is controlled at 20-30°C.

[0024] Beneficial effects of the present invention:

[0025] 1. The present invention prepares a conjugated linoleic acid nanoemulsion, which is dispersed in water in the form of oil droplets to protect the conjugated linoleic acid from being easily oxidized; the present invention can prepare high-purity conjugated linoleic acid, wherein the mass concentration of conjugated linoleic acid glyceride is below 3%, and the conjugated linoleic acid is dispersed and dissolved in water without turbidity, precipitation, or stratification. The preparation method is simple, does not require a homogenizer and an emulsifier, and does not require heating, and can be widely used in food processing, beverages, health products, and animal feed.

[0026] 2. The nanoemulsion of the present invention can withstand a pH 3-11 environment and 3-500 times dilution. The particle size of the emulsion does not change substantially during illumination, heating, etc., and the oil is not oxidized. Meanwhile, the antibacterial property is better in an alkaline solution. The conjugated linoleic acid of the present invention is prone to structural changes during high temperature reactions. Stirring at normal temperature is beneficial to preventing oxidation and structural transformation of the conjugated linoleic acid, thereby ensuring a low content of conjugated linoleic acid glyceride. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is described in detail below. The description in this section is only exemplary and explanatory and should not have any limiting effect on the scope of protection of the present invention.

[0028] Implementation Example 1

[0029] Ingredients include:

[0030] Conjugated Linoleic Acid 5g Tertiary Butyl Hydroquinone 0.01g Polysorbate 60 10g Polyoxyethylene castor oil 40 10g Alkyl Glucoside 0810 2.5g Disodium EDTA 0.01g Sodium Benzoate 0.15g water Add to 100ml

[0031] The preparation method of the conjugated linoleic acid nanoemulsion comprises first weighing the above-mentioned weight component raw materials and then sequentially performing the following steps:

[0032] 1. Add tert-butylhydroquinone to conjugated linoleic acid and stir to dissolve.

[0033] 2. Add polysorbate 60, polyoxyethylene castor oil 40 and alkyl polyglycoside 0810 into 1 and stir well.

[0034] 3. Add disodium EDTA, thiourea and sodium benzoate into appropriate amount of water, stir to dissolve, then add into step 1 and stir thoroughly to form colostrum.

[0035] 4. Add water to 100 ml and stir thoroughly to obtain conjugated linoleic acid nanoemulsion.

[0036] Implementation Example 2

[0037] Ingredients include:

[0038] Conjugated Linoleic Acid 5g Butylated Hydroxyanisole 0.02g Polysorbate 80 10g Polyoxyethylene castor oil 20 10g Hydrogenated castor oil PEG40 1.5g Disodium EDTA 0.01g Sodium bisulfite 0.5g Sodium Benzoate 0.15g water Add to 100ml

[0039] The preparation method of the conjugated linoleic acid nanoemulsion comprises first weighing the above-mentioned weight component raw materials and then sequentially performing the following steps:

[0040] 1. Add butylated hydroxyanisole to conjugated linoleic acid and stir to dissolve.

[0041] 2. Add polysorbate 80, polyoxyethylene castor oil 20 and hydrogenated castor oil PEG40 into 1 and stir well.

[0042] 3. Add disodium EDTA, sodium bisulfite and sodium benzoate into appropriate amount of water, stir to dissolve, then add to 1 and stir thoroughly to form colostrum.

[0043] 4. Add water to 100 ml and stir thoroughly to obtain conjugated linoleic acid nanoemulsion.

[0044] Implementation Example 3

[0045] Ingredients include:

[0046] Conjugated Linoleic Acid 5g Propyl Gallate 0.01g Polysorbate 80 10g Hydrogenated castor oil PEG40 5g Coco-7 5g Disodium EDTA 0.01g Sodium bisulfite 0.5g Sodium Benzoate 0.15g water Add to 100ml

[0047] The preparation method of the conjugated linoleic acid nanoemulsion comprises the following steps: firstly weighing the above-mentioned weight component raw materials and then sequentially carrying out the following steps: 1. adding propyl gallate to conjugated linoleic acid and stirring to dissolve it.

[0048] 2. Add polysorbate 80, hydrogenated castor oil PEG40 and cocoether-7 into 1 and stir well.

[0049] 3. Add disodium EDTA, sodium bisulfite and sodium benzoate into appropriate amount of water, stir to dissolve, then add to 1 and stir thoroughly to form colostrum.

[0050] 4. Add water to 100 ml and stir thoroughly to obtain conjugated linoleic acid nanoemulsion.

[0051] Comparative Example 1

[0052] In this comparative example, after stirring in step 2, the following step is added: the mixture is rapidly heated to 65° C., sheared at 4500 rpm for 5 min, and then cooled to 30° C. at a rate of 1° C. / min. The rest is the same as in Example 3.

[0053] Comparative Example 2

[0054] In this comparative example, in step 3, after sufficient stirring, the following steps are added: rapidly heating to 85° C., shearing at 4000 rpm for 7 min, and then cooling to 40° C. at a rate of 3° C. / min. Other steps are the same as those in Example 3.

[0055] Parameters detection of conjugated linoleic acid nanoemulsion

[0056] The five conjugated linoleic acid nanoemulsions prepared in Examples 1-3 and Comparative Examples 1-3 were tested for acid and alkali resistance. Equal amounts of the three emulsions were placed in 100 ml sample tubes, and the pH was adjusted to pH = 3, pH = 7, and pH = 11 with citric acid and sodium carbonate, respectively. The sample tubes were placed in a 57°C oven for accelerated experiments to examine the changes in the emulsion particle size (D99, μm) and state. The results are shown in Table 1:

[0057] Table 1.

[0058]

[0059] It can be seen from the table data that the conjugated linoleic acid nanoemulsion obtained by this method has excellent stability under acidic, neutral and alkaline conditions, but in the comparative example, under accelerated heating conditions, the emulsion particle size remains stable, but the emulsion does not show stratification or oil floating.

[0060] Peroxide value and antioxidant performance evaluation

[0061] The three nanoemulsions prepared in Examples 1 to 3 were evaluated for their destructive antioxidant properties. The three nanoemulsions were packaged in PET bottles and placed in an accelerated oven at 57°C. The peroxide value (PV, meq / kg) and acid value (AV, mg KOH / g) of the products were regularly tested. The results are shown in Table 2.

[0062] Table 4.

[0063]

[0064] It can be seen from the destructive antioxidant experiment that the nanoemulsion of the present invention has good antioxidant performance, and the peroxide value and acid value have no significant change after 20 days of acceleration under severe destructive conditions. This shows that the nanoemulsion of the system has good antioxidant stability.

[0065] Routine testing

[0066] The conjugated linoleic acid nanoemulsion of Example 3 was subjected to routine testing as follows:

[0067] Quality Report

[0068]

[0069] It should be noted that, in this article, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0070] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. The above is only a preferred implementation of the present invention. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, ordinary technicians in this technical field can make several improvements, modifications or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a conjugated linoleic acid nanoemulsion, characterized in that: The preparation method comprises the following steps: S1 weighing components: weighing 5-10 parts of conjugated linoleic acid, 10-12 parts of non-ionic surfactant, 0.005-0.01 parts of chelating agent, 0.005-0.02 parts of antioxidant, 0.005-0.01 parts of preservative and water; the non-ionic surfactant includes polysorbate 60; the conjugated linoleic acid nanoemulsion also includes a solubilizer, and the solubilizer includes polyoxyethylene castor oil 40 and alkyl polyglycoside 0810; S2: Add antioxidant to conjugated linoleic acid and stir to dissolve. S3: Add other components: Add nonionic surfactant to the mixture of S2 and stir evenly; S4: preparing colostrum: adding the chelating agent and preservative in the raw materials into a proper amount of water, stirring to dissolve, and then adding the mixture into S3, stirring fully to form colostrum; S5: Add the remaining water to the mixed solution of S4 to make the volume to 100 parts, and stir thoroughly to obtain the conjugated linoleic acid nanoemulsion, wherein the conjugated linoleic acid nanoemulsion is dispersed in the water in the form of oil droplets, and the oil droplet particle size D99 is 0.48 μm to 0.51 μm; Wherein, the temperature of the stirring treatment is controlled at 20-30°C.

2. The method for preparing the conjugated linoleic acid nanoemulsion according to claim 1, characterized in that: The antioxidant is selected from one or more of ascorbyl palmitate, butylated hydroxyanisole, butylated hydroxytoluene, propyl gallate, butylated hydroxyanisole, tert-butylhydroquinone or tocopherol.

3. The method for preparing the conjugated linoleic acid nanoemulsion according to claim 1, characterized in that: The preservative is selected from one or more of ethyl p-hydroxybenzoate, sodium benzoate or potassium sorbate.

4. The method for preparing the conjugated linoleic acid nanoemulsion according to claim 1, characterized in that The chelating agents include disodium EDTA.

5. A conjugated linoleic acid nanoemulsion, characterized in that: The conjugated linoleic acid nanoemulsion is prepared by the preparation method according to any one of claims 1 to 4, comprising the following raw materials in parts by weight: 5-10 parts of conjugated linoleic acid, 10-12 parts of a nonionic surfactant, 0.005-0.01 parts of a chelating agent, 0.005-0.02 parts of an antioxidant, 0.005-0.01 parts of a preservative and the remainder of water, wherein the conjugated linoleic acid nanoemulsion also comprises a solubilizer, which comprises polyoxyethylene castor oil 40 and alkyl polyglycoside 0810; and the nonionic surfactant comprises polysorbate 60.

6. The conjugated linoleic acid nanoemulsion according to claim 5, characterized in that The invention comprises the following raw materials in parts by weight: 5 parts of conjugated linoleic acid, 10 parts of nonionic surfactant, 0.01 parts of chelating agent, 0.01 parts of antioxidant, 0.01 parts of preservative and the balance of water.

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