Preparation method and application of a nano composite micelle for inhibiting high-temperature oxidation of grease

Abstract

The present invention discloses a preparation method and application of nano - composite micelles for inhibiting high - temperature oxidation of oils and fats, belonging to the field of food technology. The present invention uses components such as acetyl cellulose, soy lecithin, polyglycerol polyricinoleate, gum arabic solution, etc. By optimizing the encapsulation formula and applying the W / O / W multiple emulsion system, efficient co - encapsulation of incompatible composite antioxidants is achieved, with the effects of multiple antioxidants. The micelles of the obtained antioxidant system are uniform, have small particle sizes, high encapsulation rates, and good stability. The prepared composite powder can release antioxidants at different stages during the high - temperature oxidation process of oils and fats, achieving a long - term antioxidant effect during the oxidation process, significantly improving the thermal stability and dispersibility of antioxidants in high - temperature application scenarios, reducing the total polar substance content of thermally oxidized oils, and extending the use time of frying oils.

Description

Technical Field

[0001] The present invention relates to W / O / W nano-composite micelles, in particular to a preparation method and application of nano-composite micelles for inhibiting high-temperature oxidation of oils and fats, belonging to the field of food technology. Background Art

[0002] Fried foods are crispy and delicious, favored by consumers, and are an important part of the diet structure. Natural antioxidants have been widely used to extend the shelf life of fried products due to their healthy and efficient antioxidant properties. However, due to the poor thermal stability of natural antioxidants, they will degrade rapidly in high-temperature oils, severely limiting their antioxidant effect in frying oils. Therefore, encapsulating antioxidants through different technologies is a new trend to alleviate their decomposition during frying.

[0003] Currently, there are some encapsulation technologies for single antioxidants. The solvent method refers to making use of the strong solubility of antioxidants in specific edible solvents, first dissolving them in the solvent to form a concentrated antioxidant, and then adding it to the oil; the emulsification method refers to making it into a W / O emulsifier and adding it to food; the microcapsule method refers to embedding antioxidants in wall materials to alleviate the rapid oxidative degradation of active ingredients. However, existing encapsulation technologies generally choose polysaccharides such as gum arabic and maltodextrin as wall materials, and the prepared encapsulated products have problems such as low thermal stability and low loading rate, and it is difficult to apply them to the high-temperature frying process. Antioxidants with large polarity differences often have greater synergistic effects, but it is difficult to achieve this synergistic effect during oil processing.

[0004] Generally speaking, there is currently a lack of a method that can efficiently co-encapsulate antioxidants with different polarities for high-temperature antioxidant processes of oils and fats, such as enhancing the stability of frying oils during frying, reducing the oxidation of oils and fats and the formation of health hazards during frying, so as to improve the quality of fried products and ensure the safety of fried foods. Summary of the Invention

[0005] In order to solve the above problems, the present invention uses homogeneous particles of acetyl cellulose and soy lecithin with different thermal stabilities to achieve the co-encapsulation of a composite antioxidant composed of tea polyphenols and tocopherols in a water-in-oil-in-water (W / O / W) micelle system, and improves the application defects of tea polyphenols and tocopherols in high-temperature oils by releasing the composite antioxidant at different thermal oxidation stages. Further, the present invention optimizes the wall material combination, the compounding ratio of antioxidants, etc., and uses the combined technology of nano-composite micelle preparation and spray drying to make the prepared nano-composite micelles have high thermal stability and a wide application range.

[0006] The present invention provides a preparation method of nano-composite micelles for inhibiting high-temperature oxidation of oils and fats, comprising the following steps:

[0007] Step 1): Preparation of wall materials and core materials; the wall materials include acetyl cellulose and soy lecithin; the core materials include water-soluble tea polyphenols and fat-soluble tocopherols.

[0008] Step 2): Preparation of nano composite micelles: Using acetyl cellulose as the wall material, prepare the first W / O type nano micelles co-encapsulating tea polyphenols and tocopherols. Using soy lecithin as the wall material, prepare the second W / O type nano micelles co-encapsulating tea polyphenols and tocopherols. Using the two W / O type nano micelles, prepare the corresponding two W / O / W nano composite micelles.

[0009] Step 3): Spray-dry the two W / O / W nano composite micelles prepared in Step 2) with a 1:1 (w / w) compounding ratio to obtain a composite antioxidant powder encapsulating tea polyphenols and tocopherols.

[0010] In one embodiment of the present invention, the preparation steps of the nano composite micelles in Step 2) are as follows:

[0011] Step i):

[0012] Dissolve tea polyphenols in water to obtain the inner aqueous phase.

[0013] Disperse acetyl cellulose, polyglycerol polyricinoleate and α-tocopherol in sunflower seed oil to obtain the oil phase. Premix and stir the oil phase and the inner aqueous phase at a mass ratio of (1.2 - 3):1, and then successively carry out high-speed shearing, high-pressure homogenization, extrusion, and indirect ice bath ultrasound to prepare the first W / O type nano micelles. Referring to the preparation method of the first W / O type nano micelles, use soy lecithin as the wall material to prepare the second W / O type nano micelles.

[0014] Polyglycerol polyricinoleate is used as an emulsifier to prepare stable W / O type micelles; sunflower seed oil is used as the oil phase dispersion medium to carry the encapsulated water-soluble antioxidant (tea polyphenols). Sunflower seed oil, as a representative oil for frying oil, has a relatively high degree of unsaturation and a relatively faster oxidation rate. When using sunflower seed oil as the frying system, sunflower seed oil is selected as the oil phase dispersion medium during the preparation of nano micelles. If the frying system is other oils, the corresponding oils should be selected as the dispersion medium.

[0015] Step ii):

[0016] Dissolve acetyl cellulose, arabic gum, and pectin in water to obtain the outer aqueous phase.

[0017] Under stirring conditions, premix and stir the first W / O nano micelles prepared in Step i) and the outer aqueous phase at a mass ratio of (1.1 - 1.9):1, and then successively carry out high-speed shearing, high-pressure homogenization, extrusion, and indirect ice bath ultrasound to prepare the first W / O / W nano composite micelles co-encapsulating tea polyphenols and tocopherols.

[0018] In the external aqueous phase, relative to water, the concentration of gum arabic is 1-2% (w / w), and the concentration of pectin is 0.5-1.5% (w / w). Both act as emulsifiers to make the W / O / W type nano-composite micelles more stable.

[0019] Referring to the preparation method of the first type of W / O / W nano-composite micelles, soybean lecithin is used instead of acetyl cellulose as the wall material to prepare the second type of W / O / W nano-composite micelles.

[0020] In one embodiment of the present invention, in the oil phase, relative to sunflower oil, the concentration of tocopherol is 1.25-4.5% (w / w), the concentration of acetyl cellulose (or soybean lecithin) is 5-7% (w / w), and the concentration of polyglycerol polyricinoleate is 2-8% (w / w); in the internal aqueous phase, relative to water, the concentration of tea polyphenols is 1.25-4.5% (w / w); in the external aqueous phase, relative to water, the concentration of acetyl cellulose (or soybean lecithin) is 6-8% (w / w); relative to water, the concentration of gum arabic is 1-2% (w / w), and the concentration of pectin is 0.5-1.5% (w / w).

[0021] In one embodiment of the present invention, the pH value of the internal aqueous phase is 6.8-8.0.

[0022] In one embodiment of the present invention, in steps i) and ii), the speed of premixing and stirring is 500-1300 rpm, and the time is 3-10 min; the shear speed is 8000-20000 rpm, and the time is 1-2 min; the pressure of high-pressure homogenization is 15-30 MPa; extrusion is carried out using a high-pressure extrusion device equipped with a porous polycarbonate filter membrane, the working pressure is 1 MPa, the diameter of the membrane is 47 mm, the average pore diameter is 0.22-15 μm, and the number of extrusion times is 1-3 times; the temperature of indirect ice bath ultrasound is 0 °C, the frequency is 45-50 Hz, the power is 240 W, and the time is 15-25 min.

[0023] In one embodiment of the present invention, the materials in steps i) and ii) are placed in an ice-water bath during the intermittent process of preparing the nano-composite micelles.

[0024] In one embodiment of the present invention, the spray drying conditions in step 3) are that the inlet air pressure is 20-23 kPa, the inlet air temperature is 150-180 °C, and the feeding speed is 3-6 mL / min.

[0025] The present invention also provides antioxidant oils, which are oils added with composite antioxidant powders. The oils can be sunflower oil, palm oil, or peanut oil; the total concentration of the composite antioxidant in sunflower oil is 200-230 ppm.

[0026] Beneficial effects:

[0027] (1) The present invention uses components such as cellulose acetate, soy lecithin, polyglycerol polyricinoleate, gum arabic solution, etc. By optimizing the encapsulation formula and innovatively applying the W / O / W multiple emulsion system, efficient co-encapsulation of incompatible composite antioxidants into nano-composite micelles is achieved.

[0028] (2) The composite antioxidant powder of the present invention is obtained by compounding and drying two W / O / W nano-composite micelles. These two W / O / W nano-composite micelles use soy lecithin and cellulose acetate as wall materials respectively. Soy lecithin and cellulose acetate have different thermal degradation temperatures. The thermal degradation temperature of soy lecithin is 150-170°C, and the thermal degradation temperature of cellulose acetate is 220-230°C. They can release the encapsulated antioxidants at different stages of the high-temperature oxidation process of oils. When the antioxidants released by soy lecithin become weaker in antioxidant power due to thermal degradation or reaction consumption, the high-temperature-resistant cellulose acetate begins to release new antioxidants, achieving a long-term antioxidant effect during the oxidation process.

[0029] (3) The W / O / W nano-composite micelles of the present invention can achieve co-encapsulation of antioxidants with different solubilities such as tea polyphenols and tocopherols. The obtained antioxidant system has uniform and consistent micelles, small particle size, high encapsulation rate, good stability, and combines the multiple effects of tea polyphenols, tocopherols, cellulose acetate, and soy lecithin, and can be applied to the development of functional foods.

[0030] (4) The present invention compounded the dual antioxidants with synergistic effects - tocopherols and tea polyphenols in the optimal ratio through W / O / W nano-composite micelles, and then spray-dried two W / O / W nano-composite micelles using soy lecithin and cellulose acetate as wall materials respectively to obtain the composite antioxidant powder. When applied to the 180°C oxidation system, it significantly improves the thermal stability and dispersibility of the antioxidants in high-temperature application scenarios such as frying systems, reduces the total polar material content of thermally oxidized oils, and extends the use time of frying oils.

[0031] (5) The preparation method of the present invention has a simple process, is easy to operate, and has a low cost. Specific Embodiments

[0032] The present invention will be further illustrated below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. After reading the present invention, various equivalent modifications made by those skilled in the art fall within the scope defined by the appended claims of this application.

[0033] 1. Detection method for particle size and potential:

[0034] The particle size and zeta - potential of the secondary nano - composite micelles were measured at 25 °C using a dynamic light scattering and particle size analyzer. 1 mL of the sample was diluted with 10 mL of distilled water to avoid multiple scattering.

[0035] 2. Detection method of encapsulation efficiency:

[0036] Encapsulation efficiency (EE) of tea polyphenols:

[0037] 0.2 mL of the secondary nano - composite micelles was filtered through an ultracel - 10 membrane and centrifuged at 5000 rpm for 10 min at 4 °C to obtain the free active ingredient. The formula for calculating the encapsulation efficiency is as follows:

[0038] Encapsulation efficiency of tea polyphenols (%) = (1 - mass of free active ingredient / mass of total active ingredient in nano - reverse micelle suspension) × 100%.

[0039] Encapsulation efficiency (EE) of tocopherol:

[0040] Weigh 0.4 g of the secondary nano - composite micelles, add 8 mL of methanol solution, ultrasonicate for 5 min, vortex for 5 min, centrifuge at 4000 g for 5 min, then take 6 mL of the supernatant and transfer it to a 10 mL centrifuge tube, and dry it under nitrogen. After redissolving with 1 mL of methanol, filter it through a 0.22 μm organic filter membrane and inject the sample. Tocopherol was used as the standard for qualitative analysis, and the external standard method was used for the quantitative analysis of tocopherol. Liquid chromatography conditions: The liquid chromatography column is a Waters Atlants C18 reversed - phase chromatography column (150 mm × 4.6 mm × 3 μm), the injection volume is 20 μL. Mobile phase: 100% methanol, isocratic elution, flow rate 1 mL / min, column temperature 35 °C, detection wavelength 292 nm.

[0041] Encapsulation efficiency of tocopherol (%) = content of tocopherol / initial added amount of tocopherol × 100%.

[0042] 3. Detection method of free radical scavenging ability:

[0043] The antioxidant ability of the secondary nano - composite micelles was determined by the DPPH free radical scavenging ability. Add 50 μL of the secondary nano - composite micelles and 50 μL of DPPH (0.8 mM) reagent to a 96 - well plate, mix well, and place it in the dark at room temperature for 30 min. Measure the absorbance value of the mixture at 517 nm, using ethanol instead of the sample as a blank control, and take the average value of three parallel samples for each sample. The result is expressed as the scavenging rate of DPPH free radicals:

[0044]

[0045] In the formula, A blank: absorbance value of the blank group; A sample: absorbance value of the sample group.

[0046] 4. Detection method for antioxidant effect:

[0047] Under the condition of 180 °C oil bath, sunflower oil was heated for 12 h, and samples were taken every 2 h. The total polar compound content (TPC) of the samples was measured by testo. For the binary antioxidant system with different compounding ratios, the TPC content of the oil sample without any antioxidant was taken as 100%, which was used as the control group; the TPC inhibition rate of the oil samples in different groups during the heating process was expressed as the percentage of the difference from the control group.

[0048]

[0049] Example 1: Preparation of W / O / W nano-composite micelles and composite antioxidant powder for inhibiting high-temperature oxidation of oil

[0050] (1) 3 g of tea polyphenols was dissolved in 100 g of deionized water to obtain the inner aqueous phase.

[0051] 3 g of α-tocopherol, 6 g of acetyl cellulose with a viscosity of 200 cp, and 4.5 g of polyglyceryl polyricinoleate were dissolved in 117 g of sunflower oil and mixed to obtain the oil phase.

[0052] 4.5 g of acetyl cellulose with a viscosity of 200 cp, 1.5 g of gum arabic, and 0.5 g of pectin were dissolved in 139 g of deionized water to obtain the outer aqueous phase.

[0053] (2) Inner aqueous phase: oil phase: outer aqueous phase (w / w) = 1:1.27:1.4.

[0054] The inner aqueous phase and the oil phase were mixed in proportion, and the first-level micelles, that is, the first type of W / O nano-micelles, were prepared through pre-mixing and stirring, high-speed shearing, high-pressure homogenization, extrusion, and indirect ice-bath ultrasound in sequence.

[0055] The first-level micelles and the outer aqueous phase were passed through pre-mixing and stirring, high-speed shearing, high-pressure homogenization, extrusion, and indirect ice-bath ultrasound in sequence to prepare the second-level nano-composite micelles, that is, the first type of W / O / W nano-composite micelles; among them, the pre-mixing and stirring speed was 500 - 1300 rpm, and the time was 3 - 10 min; the shearing speed was 8000 - 20000 rpm, and the time was 1 - 2 min; the homogenization pressure was 15 - 30 MPa; the extrusion method was a high-pressure extrusion device equipped with a porous polycarbonate filter membrane; the working pressure was 1 MPa, the diameter of the membrane was 47 mm, the average pore diameter was 0.22 - 15 μm, and the extrusion times were 1 - 3 times; the temperature of the ice-bath ultrasound was 0 °C, the frequency was 45 - 50 Hz, the power was 240 W, and the time was 15 - 25 min.

[0056] Referring to the preparation methods of the first W / O type nano micelles and the first W / O / W nano composite micelles, taking the same mass of soy lecithin to replace acetyl cellulose in the oil phase and the external aqueous phase as the wall material, the second W / O type nano micelles and the second W / O / W nano composite micelles are prepared.

[0057] (3) The two W / O / W nano composite micelles prepared in step (2) are compounded according to a mass ratio of 1:1 and then spray-dried to obtain a composite antioxidant powder encapsulating tea polyphenols and tocopherols. Among them, the spray-drying conditions are that the inlet air pressure is 20 - 23 kPa, the inlet air temperature is 150 - 180 °C, and the feeding rate is 3 - 6 mL / min.

[0058] After testing, the average diameter of the prepared secondary nano composite micelle particles is 113 nm, the average potential is -31.68 mV, and it shows acceptable and reproducible uniformity. The average encapsulation rate of the secondary nano composite micelle particles with the two wall materials for tocopherol is 89.21%, the average encapsulation rate for tea polyphenols is 65.88%, and the average DPPH free radical scavenging rate is 92.30%.

[0059] The composite antioxidant powder is added to sunflower oil at 180 °C at a concentration of 0.01% and heated until its TPC reaches 27%. The TPC inhibition rates at each time point are shown in the table.

[0060] Table 1 TPC inhibition rates of the composite antioxidant powder during the heating of sunflower oil at 180 °C

[0061]

[0062]

[0063] Example 2: Preparation of W / O / W nano composite micelles and composite antioxidant powder for inhibiting high-temperature oxidation of oils

[0064] (1) Dissolve 3 g of tea polyphenols in 100 g of deionized water to obtain the internal aqueous phase.

[0065] (2) Weigh 3 g, 4.5 g, 6 g, 7.5 g, and 9 g of acetyl cellulose with a viscosity of 200 cp respectively, and dissolve them in 120 g, 118.5 g, 117 g, 115.5 g, and 114 g of sunflower oil respectively, 3 g of tocopherol, and 4.5 g of polyglyceryl polyricinoleate to obtain the oil phase.

[0066] Dissolve 4.5 g of acetyl cellulose with a viscosity of 200 cp, 1.5 g of arabic gum, and 0.5 g of pectin in 139 g of deionized water to obtain the external aqueous phase.

[0067] (2) The same as step (2) of Example 1.

[0068] (3)Same as step (3) of Example 1.

[0069] After detection, the average diameter, average potential, encapsulation efficiency, and average DPPH radical scavenging rate of the prepared secondary nano-composite micelle particles are shown in Table 2.

[0070] The composite antioxidant powder co-encapsulating tea polyphenols and tocopherols obtained by spray drying was added to sunflower oil at 180 °C at a concentration of 0.01% and heated until its TPC reached 27%. The TPC inhibition rates at each heating time point are shown in Table 3.

[0071] Table 2 Characterization of secondary nano-composite micelle particles prepared with different amounts of acetyl cellulose

[0072]

[0073] As can be seen from Table 2, the addition amount of acetyl cellulose has a certain influence on the average diameter, average potential, encapsulation efficiency, and DPPH radical scavenging rate of the secondary nano-composite micelles. With the increase in the addition amount of acetyl cellulose, the particle size of the prepared secondary nano-composite micelles increases. When the addition amount of acetyl cellulose in the oil phase is 6 g, that is, the addition amount is 4.5% (w / w), the encapsulation efficiencies of the composite micelles for tea polyphenols and tocopherols are the highest, 65.88% and 89.21% respectively. And the DPPH radical scavenging rate of the micelles is the highest at this addition amount, 92.30%.

[0074] Table 3 TPC inhibition rates of composite antioxidant powders prepared with different amounts of acetyl cellulose during heating of sunflower oil at 180 °C

[0075]

[0076] As can be seen from Table 3, during the whole simulated frying process, when the addition amount of acetyl cellulose in the oil phase is 6 g, that is, the addition amount is 4.5% (w / w), the ability of the prepared composite antioxidant powder to inhibit the TPC of thermally oxidized oil is the strongest, which is consistent with the free radical scavenging effect and antioxidant encapsulation efficiency.

[0077] Example 3: Preparation of W / O / W nano-composite micelles and composite antioxidant powders for inhibiting high-temperature oxidation of oils

[0078] (1) Dissolve 3 g of tea polyphenols in 100 g of deionized water to obtain the inner aqueous phase.

[0079] Dissolve 3 g of α-tocopherol, 6 g of acetyl cellulose with viscosities of 9 cp, 70 cp, 120 cp, 200 cp, and 300 cp, and 4.5 g of polyglycerol polyricinoleate in 117 g of sunflower oil and mix to obtain the oil phase.

[0080] Dissolve 4.5 g of acetyl cellulose with a viscosity of 200 cp, 1.5 g of gum arabic, and 0.5 g of pectin in 139 g of deionized water to obtain the outer aqueous phase;

[0081] (2) The same as step (2) of Example 1.

[0082] (3) The same as step (3) of Example 1.

[0083] After testing, the average diameter, average potential, encapsulation rate, and average DPPH radical scavenging rate of the prepared secondary nano-composite micelle particles are shown in Table 4.

[0084] Put the co-encapsulated tea polyphenols and tocopherol composite antioxidant powder obtained by spray drying into sunflower oil at 180 °C at a concentration of 0.01% and heat it until its TPC reaches 27%. The TPC inhibition rates at each heating time point are shown in Table 5.

[0085] Table 4 Characterization of secondary nano-composite micelle particles prepared from acetyl cellulose with different viscosities

[0086]

[0087] As can be seen from Table 4, the viscosity of acetyl cellulose has a certain effect on the average diameter, average potential, encapsulation rate, and DPPH radical scavenging rate of the secondary nano-composite micelles. As the viscosity of ethyl cellulose increases, the electrostatic repulsion between the loaded particles increases. Acetyl cellulose with a viscosity above 200 cp avoids the aggregation of the loaded particles and forms a stable nanoparticle system, so it has a smaller particle size and a larger absolute value of the potential. When the viscosity of acetyl cellulose is 200 cp, the encapsulation rates of the secondary nano-composite micelles for tea polyphenols and tocopherol are the highest, 62.46% and 80.05% respectively. And the DPPH radical scavenging rate of the micelles is the highest at this addition amount, 92.30%.

[0088] Table 5 TPC inhibition rate of secondary nano-composite micelle powder prepared from acetyl cellulose with different viscosities during heating in sunflower oil at 180 °C

[0089]

[0090] As can be seen from Table 5, during the whole simulated frying process, when the viscosity of acetyl cellulose in the oil phase is 200 cp, the prepared composite antioxidant powder has the strongest ability to inhibit the TPC of thermally oxidized oil, which is consistent with the free radical scavenging effect and antioxidant encapsulation efficiency.

[0091] Example 4: Preparation of W / O / W nano-composite micelles and composite antioxidant powder for inhibiting high-temperature oxidation of oils (1)

[0093] Weigh 4.5 g, 4 g, 3 g, 2 g, and 1.5 g of tea polyphenols respectively, and dissolve them in 98.5 g, 99 g, 100 g, 101 g, and 101.5 g of deionized water respectively to obtain an inner aqueous phase with a mass of 103 g;

[0094] Weigh respectively: 1.5 g of tocopherol is dissolved in 118.5 g of sunflower oil, 2 g of tocopherol is dissolved in 118 g of sunflower oil, 3 g of tocopherol is dissolved in 117 g of sunflower oil, 4 g of tocopherol is dissolved in 116 g of sunflower oil, 4.5 g of tocopherol is dissolved in 115.5 g of sunflower oil; Additionally, add 6 g of acetyl cellulose with a viscosity of 200 cp and 4.5 g of polyglyceryl polyricinoleate to obtain an oil phase;

[0095] Dissolve 4.5 g of acetyl cellulose with a viscosity of 200 cp, 1.5 g of arabic gum, and 0.5 g of pectin in 139 g of deionized water to obtain an outer aqueous phase;

[0096] (2) Follow the steps of (2) in Example 1.

[0097] (3) Follow the steps of (3) in Example 1.

[0098] After testing, the average diameter, average potential, encapsulation rate, and average DPPH free radical scavenging rate of the secondary nano - composite micelle particles prepared in these five groups are shown in Table 6.

[0099] Put the co - encapsulated composite antioxidant powder of tea polyphenols and tocopherol obtained by spray - drying into sunflower oil at 180 °C at a concentration of 0.01% and heat it until its TPC reaches 27%. The TPC inhibition rates at each heating time point are shown in Table 7.

[0100] Table 6 Characterization of secondary nano - composite micelle particles prepared with different antioxidant compounding ratios

[0101]

[0102] As can be seen from Table 6, the compounding ratio of tea polyphenols in the inner aqueous phase and tocopherol in the oil phase has no significant effect on the average diameter, average potential, and encapsulation rate of the secondary nano - composite micelles, while the DPPH free radical scavenging rate shows a trend of first increasing and then decreasing with the increase of the ratio of the two. Among them, when the addition ratio of tocopherol to tea polyphenols is 1:1, the DPPH free radical scavenging rate of the secondary nano - composite micelles is the highest, that is, the two antioxidants have the strongest antioxidant ability at a ratio of about 1:1. However, continuing to increase or decrease the ratio of tocopherol to tea polyphenols will lead to a decrease in their free radical scavenging rate.

[0103] Table 7 TPC inhibition rates of composite antioxidant powders prepared with different antioxidant compounding ratios during the heating process of sunflower oil at 180 °C

[0104]

[0105]

[0106] As can be seen from Table 7, consistent with the results of the free radical scavenging rate, during the high-temperature oxidation of sunflower oil, when the addition ratio of tocopherol to tea polyphenol is 1:1, the ability of the composite antioxidant powder to inhibit the TPC of thermally oxidized oil is the strongest.

[0107] Comparative Example 1: Preparation and application of nano-composite micelles with wall material containing only acetyl cellulose

[0108] (1) Dissolve 3 g of tea polyphenols in 100 g of deionized water to obtain the inner aqueous phase.

[0109] Dissolve 3 g of α-tocopherol, 6 g of acetyl cellulose with a viscosity of 200 cp, and 4.5 g of polyglycerol polyricinoleate in 117 g of sunflower oil and mix to obtain the oil phase.

[0110] Dissolve 4.5 g of acetyl cellulose with a viscosity of 200 cp, 1.5 g of gum arabic, and 0.5 g of pectin in 139 g of deionized water to obtain the outer aqueous phase.

[0111] (2) Different from step (2) of Example 1, the second W / O nano-micelles and the second W / O / W nano-composite micelles are not prepared.

[0112] (3) Different from step (3) of Example 1, the antioxidant powder is prepared only with one kind of W / O / W nano-composite micelles.

[0113] After detection, the average diameter of the prepared secondary nano-composite micelle particles is 213 nm, the average potential is -29.46 mV, and acceptable and reproducible uniformity is shown. The entrapment rate of tocopherol is 67.34%, the entrapment rate of tea polyphenols is 50.97%, and its DPPH free radical scavenging rate is 89.42%.

[0114] Put the antioxidant powder co-encapsulating tea polyphenols and tocopherol obtained by spray drying into sunflower oil at 180 °C at a concentration of 0.01% and heat it until its TPC reaches 27%. The TPC inhibition rates at each time point are shown in Table 8.

[0115] Table 8 TPC inhibition rate of secondary nano-composite micelle powder with wall material containing only acetyl cellulose during the heating of sunflower oil at 180 °C

[0116]

[0117] Comparative Example 2: Preparation and application of nano-composite micelles with wall material containing only soy lecithin

[0118] (1) Dissolve 3 g of tea polyphenols in 100 g of deionized water to obtain the inner aqueous phase.

[0119] Dissolve 6 g of soy lecithin with a viscosity of 200 cp, 3 g of tocopherol, and 4.5 g of polyglyceryl polyricinoleate in 117 g of sunflower oil to obtain an oil phase.

[0120] Dissolve 4.5 g of soy lecithin with a viscosity of 200 cp, 1.5 g of gum arabic, and 0.5 g of pectin in 139 g of deionized water to obtain an outer aqueous phase.

[0121] (2) The steps for preparing W / O nano-micelles and W / O / W nano-composite micelles refer to the preparation methods of the first type of W / O nano-micelles and the first type of W / O / W nano-composite micelles in step (2) of Example 1.

[0122] (3) Refer to step (3) of Example 1 to prepare antioxidant powder using only one type of W / O / W nano-composite micelle.

[0123] After testing, the average diameter of the prepared secondary nano-composite micelle particles is 385 nm, the average potential is -27.09 mV, and it shows acceptable and reproducible uniformity. The entrapment efficiency of tocopherol is 54.78%, the entrapment efficiency of tea polyphenols is 50.20%, and its DPPH radical scavenging rate is 86.01%.

[0124] Put the antioxidant powder co-encapsulating tea polyphenols and tocopherol obtained by spray drying into sunflower oil at 180 °C at a concentration of 0.01% and heat it until its TPC reaches 27%. The TPC inhibition rates at each time point are shown in Table 9.

[0125] Table 9 TPC inhibition rate of secondary nano-composite micelle powder with wall material containing only soy lecithin during heating in sunflower oil at 180 °C

[0126]

Claims

1. A preparation method of a nano composite micelle, the nano composite micelle being used for inhibiting high-temperature oxidation of grease, characterized in that, Dissolve tea polyphenols in water to prepare an inner aqueous phase, disperse acetyl cellulose, polyglycerol polyricinoleate and α-tocopherol in oil to prepare an oil phase, dissolve a mixture of acetyl cellulose, arabic gum and pectin in water to prepare an outer aqueous phase, mix the inner aqueous phase and the oil phase to obtain a first W / O type nano micelle, and mix the first W / O type nano micelle with the outer aqueous phase to obtain a first W / O / W nano composite micelle; The viscosity of the acetyl cellulose is 200 cp; in the oil phase, relative to the oil, the concentration of α-tocopherol is 1.25 - 4.5%, the concentration of acetyl cellulose is 5 - 7%, and the concentration of polyglycerol polyricinoleate is 2 - 8%; in the inner aqueous phase, relative to the water, the concentration of tea polyphenols is 1.25 - 4.5%; in the outer aqueous phase, relative to the water, the concentration of arabic gum is 1 - 2%, the concentration of pectin is 0.5 - 1.5%, and the concentration of acetyl cellulose is 6 - 8%; Dissolve tea polyphenols in water to prepare an inner aqueous phase, disperse soy lecithin, polyglycerol polyricinoleate and α-tocopherol in oil to prepare an oil phase, dissolve a mixture of soy lecithin, arabic gum and pectin in water to prepare an outer aqueous phase, mix the inner aqueous phase and the oil phase to obtain a second W / O type nano micelle, and mix the second W / O type nano micelle with the outer aqueous phase to obtain a second W / O / W nano composite micelle; In the oil phase, relative to the oil, the concentration of α-tocopherol is 1.25 - 4.5%, the concentration of soy lecithin is 5 - 7%, and the concentration of polyglycerol polyricinoleate is 2 - 8%; in the inner aqueous phase, relative to the water, the concentration of tea polyphenols is 1.25 - 4.5%; in the outer aqueous phase, relative to the water, the concentration of arabic gum is 1 - 2%, the concentration of pectin is 0.5 - 1.5%, and the concentration of soy lecithin is 6 - 8%; Mix the first W / O / W nano composite micelle and the second W / O / W nano composite micelle to obtain a nano composite micelle.

2. The method according to claim 1, wherein In the preparation of the first W / O type nano micelle and the second W / O type nano micelle, premix and stir the oil phase and the inner aqueous phase at a mass ratio of 1.2 - 3:1, and sequentially carry out high-speed shearing, high-pressure homogenization, extrusion, and indirect ice bath ultrasound to prepare the first W / O type nano micelle and the second W / O type nano micelle.

3. The method according to claim 1, wherein Premix and stir the first W / O nano micelle and the outer aqueous phase at a mass ratio of 1.1 - 1.9:1, and sequentially carry out high-speed shearing, high-pressure homogenization, extrusion, and indirect ice bath ultrasound to prepare the first W / O / W nano composite micelle with co-encapsulated tea polyphenols and tocopherols.

4. The method according to any one of claims 1 to 3, characterized in that, The oil includes but is not limited to sunflower oil, palm oil, and peanut oil.

5. A method for preparing a composite antioxidant powder, characterized in that, Dissolve tea polyphenols in water to prepare an inner aqueous phase, disperse acetyl cellulose, polyglycerol polyricinoleate and α-tocopherol in oil to prepare an oil phase, dissolve a mixture of acetyl cellulose, arabic gum and pectin in water to prepare an outer aqueous phase, mix the inner aqueous phase and the oil phase to obtain a first W / O type nano micelle, and mix the first W / O type nano micelle with the outer aqueous phase to obtain a first W / O / W nano composite micelle; The viscosity of the acetylcellulose is 200 cp; in the oil phase, relative to the oil, the concentration of α-tocopherol is 1.25-4.5%, the concentration of acetylcellulose is 5-7%, and the concentration of polyglyceryl polyricinoleate is 2-8%; in the inner aqueous phase, relative to water, the concentration of tea polyphenols is 1.25-4.5%; in the outer aqueous phase, relative to water, the concentration of arabic gum is 1-2%, the concentration of pectin is 0.5-1.5%, and the concentration of acetylcellulose is 6-8%. Dissolve tea polyphenols in water to prepare the inner aqueous phase, disperse soy lecithin, polyglyceryl polyricinoleate and α-tocopherol in oil to prepare the oil phase, dissolve the mixture of soy lecithin, arabic gum and pectin in water to prepare the outer aqueous phase, mix the inner aqueous phase and the oil phase to obtain the second W / O type nano micelles, and mix the second W / O type nano micelles with the outer aqueous phase to obtain the second W / O / W nano composite micelles; In the oil phase, relative to the oil, the concentration of α-tocopherol is 1.25-4.5%, the concentration of soy lecithin is 5-7%, and the concentration of polyglyceryl polyricinoleate is 2-8%; in the inner aqueous phase, relative to water, the concentration of tea polyphenols is 1.25-4.5%; in the outer aqueous phase, relative to water, the concentration of arabic gum is 1-2%, the concentration of pectin is 0.5-1.5%, and the concentration of soy lecithin is 6-8%. Compound the first W / O / W nano composite micelles and the second W / O / W nano composite micelles to obtain nano composite micelles, and then obtain the composite antioxidant powder by spray drying.

6. The nano composite micelles obtained by the method according to any one of claims 1-4 or the composite antioxidant powder obtained by the method according to claim 5.

7. Use of the nano composite micelles or composite antioxidant powder according to claim 6 in the preparation of antioxidant oils.

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