Method for preparing macadimia nut oil body emulsion gel

Abstract

The invention discloses a method for preparing macadamia nut oil body emulsion gel, which comprises the following steps: (1) mixing a carrageenan solution and a konjac glucomannan solution, adding a resveratrol solution to obtain a mixed solution, carrying out ice bath on the mixed solution, and shearing and dispersing to obtain a compound polysaccharide particle dispersion liquid; and (2) mixing the compound polysaccharide particle dispersion liquid obtained in the step (1), macadamia nut oil and water to obtain a mixture, shearing and dispersing the mixture, and performing ice bath to obtain the macadamia nut oil emulsion gel. The macadamia nut oil body emulsion gel prepared by the method has better antioxidant stability, structural strength and shear resistance, and can meet the shelf life and use requirements of related products.

Description

Technical Field

[0001] The invention belongs to the technical field of emulsion gels, and particularly relates to a method for preparing macadamia nut oil body emulsion gel. Background Art

[0002] Macadamia is a tree nut native to southeastern Queensland, Australia. It is extremely rich in oil, mainly unsaturated fatty acids, especially monounsaturated fatty acids. Currently, the processing of macadamia nuts is mainly in the primary stage, and the development in the field of deep processing is relatively slow. The potential added value of nuts has not been fully explored and improved. Research and development of macadamia oil has become a new direction for future development.

[0003] Emulsion gel is a gel-like semisolid based on emulsion, supplemented by physical induction methods such as heating, acidification, and shearing. The continuous phase forms a spatial network structure, which is filled with the dispersed phase. It has the advantages of both emulsion and gel. The unique three-dimensional network structure can fix the emulsified oil droplets in the network structure, thereby inhibiting the flocculation and aggregation of oil droplets. Compared with a single emulsion or gel, emulsion gel has the advantages of stable structure, adjustable viscoelasticity, and the ability to embed hydrophilic or hydrophobic components. At the same time, the release rate can be controlled by designing different gel matrices to achieve targeted release.

[0004] Emulsion gel can be used in the development of creamy foods or cosmetics. In food development, as a typical amphiphilic and stable food system, it can not only meet people's needs in terms of chewing properties and flavor improvement, but also establish a good bioactive substance delivery system, which has a wide and important application in improving the nutritional quality of food systems; emulsion gel can also be used to replace the use of animal fats in food and reduce the intake of saturated fats and trans fatty acids. In the development of cosmetics, emulsion gel can be used in products such as creams, lotions, and masks, providing good spreadability and stability.

[0005] Through research, it was found that macadamia oil body can be easily made into emulsion gel, but the macadamia oil body emulsion gel prepared by the existing process has poor antioxidant stability, structural strength and shear resistance, and cannot meet the shelf life and usage requirements of related products. Summary of the invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a method for preparing a macadamia oil body emulsion gel. The macadamia oil body emulsion gel prepared by the method has good antioxidant stability, structural strength and shear resistance, and can meet the shelf life and use requirements of related products.

[0007] The above technical objectives of the present invention are achieved through the following technical solutions:

[0008] A method for preparing a macadamia oil body emulsion gel comprises the following steps: (1) mixing a carrageenan solution and a konjac gum solution, adding a resveratrol solution to obtain a mixed solution, ice-bathing the mixed solution, and then shearing and dispersing it to obtain a composite polysaccharide particle dispersion; (2) mixing the composite polysaccharide particle dispersion obtained in step (1), macadamia oil bodies and water to obtain a mixture, shearing and dispersing the mixture, and then ice-bathing it to obtain the macadamia oil body emulsion gel.

[0009] Preferably, in step (1), the carrageenan solution is obtained by mixing κ-carrageenan and water and then heating and dissolving them, and the konjac gum solution is obtained by mixing konjac gum and water and then heating and dissolving them, and the mass concentration of the carrageenan solution and the konjac gum solution is 1%-3%.

[0010] Preferably, in step (1), the carrageenan solution and the konjac gum solution are mixed in a mass ratio of (0.25-1):(0.25-1).

[0011] Preferably, the heating to dissolve refers to heating to dissolve in a water bath at 70-90° C. for 20-50 min.

[0012] Preferably, in step (1), the resveratrol solution is obtained by dissolving resveratrol powder in ethanol, and the mass concentration of the resveratrol solution is 0.2%-0.5%.

[0013] Preferably, in step (1), the mass concentration of resveratrol in the mixed solution is 0.03-0.08%.

[0014] Preferably, in step (1), the ice bath time is 8-15 min.

[0015] Preferably, in step (1), the shear dispersion refers to shearing at 5000-10000 rpm for 8-15 min.

[0016] Preferably, in step (2), the mass content of the composite polysaccharide particle dispersion in the mixture is 0.05%-0.6%.

[0017] Further preferably, in step (2), the mass content of the composite polysaccharide particle dispersion in the mixture is 0.1%-0.4%.

[0018] Preferably, in step (2), the mass content of macadamia oil bodies in the mixture is 40%-80%.

[0019] Further preferably, in step (2), the mass content of macadamia oil bodies in the mixture is 50%-75%.

[0020] Preferably, in step (2), the shear dispersion refers to shearing at 5000-10000 rpm for 8-15 min.

[0021] Preferably, in step (2), the ice bath time is 8-15 min.

[0022] Preferably, in step (2), the method for preparing macadamia oil bodies comprises the following steps:

[0023] (1) mixing macadamia nut kernels with water, grinding the mixture, and filtering to obtain a macadamia nut kernel crude emulsion;

[0024] (2) adding sucrose to the macadamia nut kernel crude emulsion in a mass ratio of 1:(0.1-0.3) to dissolve the crude emulsion to obtain a first emulsion, adjusting the pH of the first emulsion to 6-8, centrifuging the emulsion, and collecting the supernatant;

[0025] (3) dispersing the supernatant in water to obtain a dispersion, then adding sucrose to the dispersion in a mass ratio of dispersion to sucrose of 1:(0.1-0.3) to obtain a second emulsion, adjusting the pH of the second emulsion to 6-8 and centrifuging to collect the supernatant, wherein the supernatant is the macadamia kernel oil body.

[0026] The beneficial effect of the present invention is that the method for preparing the macadamia oil body emulsion gel of the present invention adds composite polysaccharide particles prepared by κ-carrageenan and konjac gum to the macadamia oil body emulsion, and combines them with the loaded antioxidant resveratrol to obtain the macadamia oil body emulsion gel with certain structural strength, strong shear resistance and storage stability, thereby ensuring product quality and extending the shelf life. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a curve diagram showing the storage modulus G' and loss modulus G" of the macadamia oil emulsion gel prepared in Examples 3-6 of the present invention and Comparative Example 1 as a function of stress;

[0028] Figure 2 It is a curve diagram showing the change of viscosity of the macadamia oil emulsion gel prepared in Examples 3-6 of the present invention and Comparative Example 1 as a function of shear rate;

[0029] Figure 3 It is a curve diagram showing the storage modulus G' and loss modulus G" of the macadamia oil body emulsion gel prepared in Examples 7, 4, 8 and Comparative Examples 2 and 3 of the present invention as a function of stress;

[0030] Figure 4 The graph is a graph showing the viscosity of the macadamia oil emulsion gel prepared in Examples 7, 4, 8 and Comparative Examples 2 and 3 of the present invention as a function of shear rate. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with specific embodiments.

[0032] Embodiment 1:

[0033] A method for preparing a macadamia oil body emulsion gel comprises the following steps:

[0034] (1) Preparation of macadamia oil bodies:

[0035] Take 120g of macadamia kernels, weigh 1200g of distilled water, and then divide the distilled water into four equal parts (300g / part), add the first part of distilled water and 120g of macadamia kernels into a blender, grind at 25000rpm for 2min, filter the ground slurry through four layers of gauze, mix the filter residue obtained after filtration with the second part of distilled water, stir again at the same speed in the blender for 2min and filter to obtain the filter residue, repeat the above operation for 2 more times, mix the four filter slurries obtained in total, and obtain the macadamia kernel crude emulsion;

[0036] 500 g of macadamia kernel crude emulsion was added with 100 g of sucrose, and the mixture was stirred until completely dissolved to obtain a first emulsion. The pH value of the first emulsion was adjusted to 6.8 with 0.1 mol / L HCl solution and 1 mol / L NaOH solution. The pH-adjusted first emulsion was transferred to a centrifuge tube, and centrifuged at 10,000 rpm for 30 min at 4°C to collect the floating milky substance.

[0037] The collected supernatant was dispersed in distilled water at a mass ratio of 1:6, and the dispersion was obtained by stirring. 20% sucrose by mass of the dispersion was added to the dispersion and the dispersion was fully stirred to break up the aggregates to obtain a second emulsion. The pH value of the second emulsion was adjusted to 6.8 with 0.1 mol / L HCl solution and 1 mol / L NaOH solution. The mixture was centrifuged at 10000 rpm for 30 min at 4°C. The floating milky substance finally obtained was the macadamia kernel oil body, which was set aside.

[0038] (2) Preparation of resveratrol solution:

[0039] The resveratrol powder was dissolved in ethanol to prepare a resveratrol solution with a mass concentration of 0.2%, which was set aside.

[0040] (3) Preparation of κ-carrageenan solution and konjac gum solution:

[0041] Dissolve κ-carrageenan and konjac gum powders in distilled water respectively, heat in a water bath at 70° C. for 50 min to dissolve, and prepare κ-carrageenan solutions with a mass concentration of 1% and konjac gum solutions with a mass concentration of 1%.

[0042] (4) mixing a κ-carrageenan solution and a konjac gum solution in a mass ratio of 1:0.25, adding a resveratrol solution to obtain a mixed solution, wherein the mass concentration of resveratrol in the mixed solution is 0.03%, and after an ice bath for 8 minutes, shearing in a disperser at 5000 rpm for 15 minutes to obtain a composite polysaccharide particle dispersion;

[0043] (5) The complex polysaccharide particle dispersion, macadamia oil body and water are mixed to obtain a mixture, wherein the mass content of the complex polysaccharide particle dispersion in the mixture is 0.05%, and the mass content of the macadamia oil body is 40%. The mixture is sheared at 5000 rpm in a disperser for 15 minutes and then ice-bathed for 8 minutes to obtain a macadamia oil body emulsion gel.

[0044] Embodiment 2:

[0045] A method for preparing a macadamia oil body emulsion gel comprises the following steps:

[0046] (1) Preparation of macadamia oil bodies:

[0047] Take 120g of macadamia kernels, weigh 1200g of distilled water, and then divide the distilled water into four equal parts (300g / part), add the first part of distilled water and 120g of macadamia kernels into a blender, grind at 25000rpm for 2min, filter the ground slurry through four layers of gauze, mix the filter residue obtained after filtration with the second part of distilled water, stir again at the same speed in the blender for 2min and filter to obtain the filter residue, repeat the above operation for 2 more times, mix the four filter slurries obtained in total, and obtain the macadamia kernel crude emulsion;

[0048] 500 g of macadamia kernel crude emulsion was added with 100 g of sucrose, and the mixture was stirred until completely dissolved to obtain a first emulsion. The pH value of the first emulsion was adjusted to 6.8 with 0.1 mol / L HCl solution and 1 mol / L NaOH solution. The pH-adjusted first emulsion was transferred to a centrifuge tube, and centrifuged at 10,000 rpm for 30 min at 4°C to collect the floating milky substance.

[0049] The collected supernatant was dispersed in distilled water at a mass ratio of 1:6, and the dispersion was obtained by stirring. 20% sucrose by mass of the dispersion was added to the dispersion and the dispersion was fully stirred to break up the aggregates to obtain a second emulsion. The pH value of the second emulsion was adjusted to 6.8 with 0.1 mol / L HCl solution and 1 mol / L NaOH solution. The mixture was centrifuged at 10000 rpm for 30 min at 4°C. The floating milky substance finally obtained was the macadamia kernel oil body, which was set aside.

[0050] (2) Preparation of resveratrol solution:

[0051] The resveratrol powder was dissolved in ethanol to prepare a resveratrol solution with a mass concentration of 0.5%, which was set aside.

[0052] (3) Preparation of κ-carrageenan solution and konjac gum solution:

[0053] Dissolve κ-carrageenan and konjac gum powders in distilled water respectively, heat and dissolve in a 90° C. water bath for 20 min to prepare κ-carrageenan solutions with a mass concentration of 3% and konjac gum solutions with a mass concentration of 3%.

[0054] (4) mixing a κ-carrageenan solution and a konjac gum solution in a mass ratio of 1:1, adding a resveratrol solution to obtain a mixed solution, wherein the mass concentration of resveratrol in the mixed solution is 0.08%, and after an ice bath for 15 minutes, shearing in a disperser at 10,000 rpm for 8 minutes to obtain a composite polysaccharide particle dispersion;

[0055] (5) The complex polysaccharide particle dispersion, macadamia oil body and water are mixed to obtain a mixture, wherein the mass content of the complex polysaccharide particle dispersion in the mixture is 0.6%, and the mass content of the macadamia oil body is 80%. The mixture is sheared at 10000 rpm in a disperser for 8 minutes and then ice-bathed for 15 minutes to obtain a macadamia oil body emulsion gel.

[0056] Embodiment 3:

[0057] A method for preparing a macadamia oil body emulsion gel comprises the following steps:

[0058] (1) Preparation of macadamia oil bodies:

[0059] Take 120g of macadamia kernels, weigh 1200g of distilled water, and then divide the distilled water into four equal parts (300g / part), add the first part of distilled water and 120g of macadamia kernels into a blender, grind at 25000rpm for 2min, filter the ground slurry through four layers of gauze, mix the filter residue obtained after filtration with the second part of distilled water, stir again at the same speed in the blender for 2min and filter to obtain the filter residue, repeat the above operation for 2 more times, mix the four filter slurries obtained in total, and obtain the macadamia kernel crude emulsion;

[0060] 500 g of macadamia kernel crude emulsion was added with 100 g of sucrose, and the mixture was stirred until completely dissolved to obtain a first emulsion. The pH value of the first emulsion was adjusted to 6.8 with 0.1 mol / L HCl solution and 1 mol / L NaOH solution. The pH-adjusted first emulsion was transferred to a centrifuge tube, and centrifuged at 10,000 rpm for 30 min at 4°C to collect the floating milky substance.

[0061] The collected supernatant was dispersed in distilled water at a mass ratio of 1:6, and the dispersion was obtained by stirring. 20% sucrose by mass of the dispersion was added to the dispersion and the dispersion was fully stirred to break up the aggregates to obtain a second emulsion. The pH value of the second emulsion was adjusted to 6.8 with 0.1 mol / L HCl solution and 1 mol / L NaOH solution. The mixture was centrifuged at 10000 rpm for 30 min at 4°C. The floating milky substance finally obtained was the macadamia kernel oil body, which was set aside.

[0062] (2) Preparation of resveratrol solution:

[0063] The resveratrol powder was dissolved in ethanol to prepare a resveratrol solution with a mass concentration of 0.4%, which was set aside.

[0064] (3) Preparation of κ-carrageenan solution and konjac gum solution:

[0065] Dissolve κ-carrageenan and konjac gum powders in distilled water respectively, heat in a water bath at 80° C. for 30 minutes to dissolve, and prepare κ-carrageenan solutions with a mass concentration of 2% and konjac gum solutions with a mass concentration of 2%.

[0066] (4) mixing a κ-carrageenan solution and a konjac gum solution in a mass ratio of 1:1, adding a resveratrol solution to obtain a mixed solution, wherein the mass concentration of resveratrol in the mixed solution is 0.05%, and after an ice bath for 10 minutes, shearing in a disperser at 8000 rpm for 10 minutes to obtain a composite polysaccharide particle dispersion;

[0067] (5) The composite polysaccharide particle dispersion, macadamia oil body and water are mixed to obtain a mixture, wherein the mass content of the composite polysaccharide particle dispersion is 0.1%, and the mass content of the macadamia oil body is 75%. The mixture is sheared at 8000 rpm in a disperser for 10 minutes and then ice-bathed for 10 minutes to obtain a macadamia oil body emulsion gel.

[0068] Embodiment 4:

[0069] A method for preparing a macadamia oil body emulsion gel, the only difference from Example 3 is that the mass content of the complex polysaccharide particle dispersion in the mixture in step (5) is 0.2%, and the other steps and parameters are exactly the same as Example 3.

[0070] Embodiment 5:

[0071] A method for preparing a macadamia oil body emulsion gel, the only difference from Example 3 is that the mass content of the complex polysaccharide particle dispersion in the mixture in step (5) is 0.3%, and the other steps and parameters are exactly the same as those in Example 3.

[0072] Embodiment 6:

[0073] A method for preparing a macadamia oil body emulsion gel, the difference from Example 3 is only that the mass content of the complex polysaccharide particle dispersion in the mixture in step (5) is 0.4%, and the other steps and parameters are exactly the same as Example 3.

[0074] Embodiment 7:

[0075] A method for preparing a macadamia oil body emulsion gel, which differs from Example 4 only in that in step (4), a κ-carrageenan solution and a konjac gum solution are mixed in a mass ratio of 1:0.5, and other steps and parameters are exactly the same as those in Example 4.

[0076] Embodiment 8:

[0077] A method for preparing a macadamia oil body emulsion gel, which is different from Example 4 only in that in step (4), a κ-carrageenan solution and a konjac gum solution are mixed in a mass ratio of 0.5:1, and other steps and parameters are exactly the same as those in Example 4.

[0078] Comparative Example 1:

[0079] A method for preparing a macadamia oil body emulsion gel, which differs from Example 3 only in that in step (5), no complex polysaccharide particle dispersion is added to the mixture, and the other steps and parameters are exactly the same as those in Example 3.

[0080] Comparative Example 2:

[0081] A method for preparing a macadamia oil body emulsion gel, which is different from Example 4 only in that no konjac gum solution is added in step (4), and only the κ-carrageenan solution and the resveratrol solution are mixed to obtain a mixed solution, and the other steps and parameters are exactly the same as those in Example 4.

[0082] Comparative Example 3:

[0083] A method for preparing a macadamia oil body emulsion gel, which is different from Example 4 only in that no κ-carrageenan solution is added in step (4), and only the konjac gum solution and the resveratrol solution are mixed to obtain a mixed solution, and the other steps and parameters are exactly the same as those in Example 4.

[0084] Comparative Example 4:

[0085] A method for preparing a macadamia oil body emulsion gel, which is different from Example 4 only in that no resveratrol solution is added in step (4), and the other steps and parameters are exactly the same as Example 4.

[0086] Test example:

[0087] 1. Test on the properties of macadamia oil lotion gel.

[0088] 1. Test on the gel properties of macadamia oil body emulsion with different addition amounts of complex polysaccharide particle dispersion.

[0089] The rheological properties of the macadamia oil emulsion gels prepared in Examples 3-6 of the present invention and Comparative Example 1 were tested under stress scanning and shear scanning, and the test results are as follows: Figure 1-2 As shown, the gel-sol transition stress τ of the macadamia oil emulsion gel prepared in Examples 3-6 of the present invention and Comparative Example 1 was tested. f and yield stress τ y , the results are shown in Table 1 below. .

[0090] Table 1: Test results

[0091] <![CDATA[τ f (Well)]]> <![CDATA[τ y (Well)]]> Comparative Example 1 8.1 3.3 Example 3 46.6 25.6 Example 4 58.6 36.3 Example 5 31.5 19.2 Example 6 31.5 18.3

[0092] Depend on Figure 1 It can be seen that at different addition amounts of composite polysaccharide particle dispersion, the prepared macadamia oil body emulsion gel has an obvious linear viscoelastic region, and the storage modulus G' within the linear viscoelastic range is higher than the loss modulus G", indicating that the macadamia oil body emulsion formed a solid gel at different composite polysaccharide particle concentrations.

[0093] Combination Figure 1 As shown in Table 1, the linear viscoelastic range of the oil body emulsion gel (Comparative Example 1) without adding the composite polysaccharide particle dispersion is the smallest, and its yield point stress τ y The modulus and modulus of the emulsion gel are significantly lower than those of the emulsion gel to which the composite polysaccharide particle dispersion is added, indicating that the strength of its internal structure is relatively weak. Therefore, the structural strength of the emulsion gel can be significantly improved by adding the specific composite polysaccharide particle dispersion of the present invention. When the mass content of the added composite polysaccharide particle dispersion is 0.1% (Example 3), the modulus of the oil body emulsion gel is significantly improved. When the mass content of the added composite polysaccharide particle dispersion reaches 0.2% (Example 4), the modulus, linear viscoelastic region, and yield point stress τ of the emulsion gel are significantly improved. y All of them reach the maximum, and are much higher than the corresponding values ​​of emulsion gels at other concentrations, indicating that the oil body emulsion gel has the greatest structural strength at this concentration; when the mass content of the added composite polysaccharide particle dispersion is 0.3% (Example 5) and 0.4% (Example 6), the modulus curves of the oil body emulsion gel at the two concentrations are almost overlapped, indicating that when the addition amount of the composite polysaccharide particle dispersion is higher than 0.3%, the influence of the particles on the structure tends to be stable.

[0094] Depend on Figure 2It can be seen that under different addition amounts of composite polysaccharide particle dispersions, all samples showed shear thinning phenomenon, but the static apparent viscosity and apparent viscosity under shear of the oil body gel with added composite polysaccharide particles were much higher than the apparent viscosity of the oil body emulsion gel without added composite polysaccharide particles, indicating that the addition of composite polysaccharide particles can greatly improve the shear resistance of the oil body emulsion gel. For the oil body emulsion gel without adding composite polysaccharide particles (Comparative Example 1), its static apparent viscosity is 17.6Pa·s, which quickly drops to below 10Pa·s after shearing. The oil body emulsion gel has a lower static viscosity under weak structural strength and becomes thinner under shearing. After adding the specific composite polysaccharide particles of the present invention, the static apparent viscosity of the oil body emulsion gel increases rapidly. When the mass content of the added composite polysaccharide particle dispersion is 0.2% (Example 4), the static apparent concentration of the oil body emulsion gel is the highest, which is 162Pa·s, which is more than 10 times the static viscosity of the emulsion gel without adding microgel particles (Comparative Example 1). This is related to the stronger structure constructed by the oil body molecules and the microgel particles. At higher shear rates, when the addition amount of the composite polysaccharide particle dispersion is 0.2% (Example 4) and 0.4% (Example 6), the emulsion gel shows a higher apparent viscosity, and has higher shear resistance at both concentrations.

[0095] 2. Test on the gel properties of macadamia oil body emulsion with different ratios of κ-carrageenan solution and konjac gum solution in complex polysaccharide particle dispersion.

[0096] The rheological properties of the macadamia oil emulsion gels prepared in Examples 7, 4, 8 and Comparative Examples 2 and 3 of the present invention were tested under stress scanning and shear scanning, and the test results are as follows: Figure 3-4 As shown, the gel-sol transition stress τ of the macadamia oil body emulsion gel prepared in Examples 7, 4, 8 and Comparative Examples 2 and 3 of the present invention was tested. f and yield stress τ y , the results are shown in Table 2 below.

[0097] Table 2: Test results

[0098] <![CDATA[τ f (Well)]]> <![CDATA[τ y (Well)]]> Comparative Example 2 17.2 9.2 Example 7 46.2 32.3 Example 4 58.6 36.3 Example 8 20.5 12.2 Comparative Example 3 39.2 24.5

[0099] Depend on Figure 3 It can be seen that under different composite ratios of κ-carrageenan solution and konjac gum solution, the prepared macadamia oil body emulsion gel has an obvious linear viscoelastic region, and the storage modulus G' within the linear viscoelastic range is higher than the loss modulus G", indicating that the macadamia oil body emulsion formed a solid gel under different composite ratios of κ-carrageenan solution and konjac gum solution.

[0100] Combination Figure 3As shown in Table 2, when the composite polysaccharide particle dispersion does not contain konjac gum (Comparative Example 2), the prepared emulsion gel modulus is the lowest, and the yield stress τ y The modulus of the emulsion gel was less than 10Pa, indicating that the microgel particles prepared by using κ-carrageenan alone could not construct an emulsion gel with high structural strength with the macadamia oil body molecules. As konjac gum was added to the composite polysaccharide particle dispersion and its proportion increased, the modulus of the oil body emulsion gel showed a rule of first rising and then falling. When the composite ratio was 1:0.5 (Example 7) and 1:1 (Example 4), the modulus of the emulsion gel was close and had similar yield stress τ y and linear viscoelastic region, indicating that the anti-external strength of the emulsion gel under the two composite ratios is close; when the composite ratio of κ-carrageenan solution and konjac gum solution is 0.5:1 (Example 8), the content of konjac gum in the microgel particles is higher than that of κ-carrageenan, and the modulus size, yield stress τ y , gel-sol transition point stress τ f There was a significant decline, that is, the ability of the emulsion gel to resist external forces weakened, which shows that when the microgel particles prepared by κ-carrageenan and konjac gum stabilize the macadamia oil body emulsion gel, κ-carrageenan plays a leading role; when the composite ratio of κ-carrageenan solution and konjac gum solution is 0:1 (Comparative Example 3), the modulus of the emulsion gel rebounds and the yield stress increases accordingly, indicating that the strength of the emulsion gel prepared by the microgel particles under the composite ratio has significantly rebounded. At this time, the microgel particles are composed of konjac gum alone. The microgel particles under the composite ratio may be composed of polysaccharide gel particles and polysaccharide chains. The spatial structure of the emulsion gel formed is relatively tight, which can provide a certain resistance to external pressure.

[0101] Depend on Figure 4 It can be seen that the macadamia oil body emulsion gel under different composite ratios of κ-carrageenan solution and konjac gum solution has the property of shear-thinning pseudoplastic fluid; when the composite ratio of κ-carrageenan solution and konjac gum solution is 1:0 (Comparative Example 2), the shear resistance of the emulsion gel is poor, and the viscosity of the gel quickly drops to below 10Pa·s at a low shear rate, indicating that the simple κ-carrageenan particles have a poor effect on maintaining the stability of the viscosity of the oil body emulsion gel; when the composite ratio of κ-carrageenan solution and konjac gum solution is 1:0.5~0:1, the viscosity of the emulsion gel in each ratio is higher than that in 1:0, and the viscosity is higher than that in 1:0 when the shear rate is higher than 15S -1 It shows that adding a certain amount of konjac gum to the microgel particles is beneficial to improve the viscosity of the emulsion gel, but at a higher shear rate, the composite ratio of the microgel particles has little effect on the shear resistance of the macadamia oil emulsion gel.

[0102] 2. Antioxidant stability test of macadamia oil emulsion gel.

[0103] The oxidative stability of the macadamia oil body emulsion gels prepared in Examples 3-8 of the present invention and Comparative Examples 1-4 after ultraviolet irradiation was tested respectively, specifically, irradiated for 15 h under an ultraviolet lamp with a power of 125 W and a wavelength of 365 nm, wherein the peroxide value was tested as follows: 0.5 g of the emulsion gel was vortexed in 1.5 mL of a mixture of isooctane and isopropanol (3:1, v / v) for 30 s, and then centrifuged at 10000 rpm for 2 min, 200 μL of the organic phase was added to 2.8 mL of a mixture of methanol and n-butanol (2:1, v / v) and mixed, 15 μL of a 3.94 M ammonium thiocyanate solution and 15 μL of a 0.132 M ferrous solution prepared in advance were added, and the absorbance was measured at a wavelength of 510 nm using an ultraviolet spectrophotometer after reacting in the dark for 20 min.

[0104] The test method for the malondialdehyde content is to take 0.1g of the emulsion, add 1.9mL of distilled water and 4mL of TBA reagent, boil in boiling water for 15 minutes, cool at room temperature, and then centrifuge at 10,000rpm for 15 minutes. The supernatant is taken and the absorbance is measured at a wavelength of 532nm using an ultraviolet spectrophotometer. The lipid peroxide content and malondialdehyde content in the macadamia oil body emulsion gel after ultraviolet irradiation are shown in Table 3 below.

[0105] Table 3. Antioxidant stability test results

[0106]

[0107] It can be seen from Table 3 that the macadamia oil body emulsion gel prepared by the present invention has a lipid peroxide content of no more than 2762.1 mmol / kg and a malondialdehyde content of no more than 11.5 mmol / kg after ultraviolet irradiation test, and has excellent antioxidant stability; By comparing Example 3 with Comparative Example 1, it can be seen that when the composite polysaccharide particle dispersion is not added during the preparation process, the antioxidant stability of the obtained macadamia oil body emulsion gel will be greatly reduced; By comparing Example 4 with Comparative Examples 2-3, it can be seen that when the composite polysaccharide particle dispersion in the preparation process lacks one of the konjac gum solution and the κ-carrageenan solution, the antioxidant stability of the obtained macadamia oil body emulsion gel will be greatly reduced; By comparing Example 4 with Comparative Example 4, it can be seen that when the resveratrol solution is not added during the preparation process, the antioxidant stability of the obtained macadamia oil body emulsion gel will be greatly reduced.

[0108] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for preparing macadamia oil body emulsion gel, Features: The following steps are involved: (1) mixing a carrageenan solution and a konjac gum solution, adding a resveratrol solution to obtain a mixed solution, ice-bathing the mixed solution, and then shearing and dispersing the mixed solution to obtain a composite polysaccharide particle dispersion; (2) The composite polysaccharide particle dispersion obtained in step (1), macadamia oil body and water are mixed to obtain a mixture, and the mixture is sheared and dispersed, and then ice-bathed to obtain the macadamia oil body emulsion gel.

2. A method for preparing macadamia oil emulsion gel according to claim 1, Features: In step (1), the carrageenan solution is obtained by mixing κ-carrageenan and water and then heating and dissolving them, and the konjac gum solution is obtained by mixing konjac gum and water and then heating and dissolving them, and the mass concentration of the carrageenan solution and the konjac gum solution is 1%-3%.

3. A method for preparing macadamia oil emulsion gel according to claim 1, Features: In step (1), the carrageenan solution and the konjac gum solution are mixed in a mass ratio of (0.25-1): (0.25-1).

4. A method for preparing macadamia oil emulsion gel according to claim 2, Features: The heating dissolution refers to heating and dissolving in a water bath at 70-90° C. for 20-50 min.

5. A method for preparing macadamia oil emulsion gel according to claim 1, Features: In step (1), the resveratrol solution is obtained by dissolving resveratrol powder in ethanol, and the mass concentration of the resveratrol solution is 0.2%-0.5%.

6. A method for preparing macadamia oil emulsion gel according to claim 1, Features: In step (1), the mass concentration of resveratrol in the mixed solution is 0.03-0.08%.

7. A method for preparing macadamia oil emulsion gel according to claim 1, Features: In step (1), the ice bath time is 8-15 min.

8. A method for preparing macadamia oil emulsion gel according to claim 1, Features: In step (1), the shear dispersion refers to shearing at 5000-10000 rpm for 8-15 min.

9. A method for preparing macadamia oil emulsion gel according to claim 1, Features: In step (2), the mass content of the composite polysaccharide particle dispersion in the mixture is 0.05%-0.6%.

10. A method for preparing macadamia oil emulsion gel according to claim 1, Features: In step (2), the mass content of macadamia oil bodies in the mixture is 40%-80%.

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