Preparation method of high-stability paprika red pickering emulsion

Abstract

The application discloses a preparation method of high-stability paprika red pickering emulsion and belongs to the technical field of food emulsification. The preparation method comprises the following steps: S1, preparation of modified citrus fiber; S2, preparation of a paprika red oil phase; S3, preparation of a sodium caseinate-modified citrus fiber composite system; and S4, preparation of the paprika red pickering emulsion. The modified citrus fiber is mixed with sodium caseinate to form a composite polysaccharide-protein delivery system as an emulsifier, and natural pigment paprika red is emulsified, so that the high-stability paprika red pickering emulsion has good light stability and heat stability, the system is stable, the smell is light, the raw materials used are safe and harmless, the preparation method is green and environmentally friendly, and the high-stability paprika red pickering emulsion has a wide market prospect.

Description

TECHNICAL FIELD

[0001] The application relates to the field of food emulsification technology, in particular to a preparation method of high-stability capsicum red pickering emulsion. BACKGROUND

[0002] Capsicum red is a kind of natural carotenoid food additive prepared from capsicum (Capsicum L.) peels and products thereof through extraction, filtration, concentration and capsaicin removal processes, and the main components are capsicum red and capsicum rubrum, which is a deep red oily liquid. Capsicum red can be dissolved in edible oil at will, and the effective content of the pigment can be well controlled, so it is widely used in various red oil foods. However, the poor water solubility, poor stability to ultraviolet light and certain capsaicin odor limit the market and application of capsicum red natural pigment to some extent.

[0003] Unlike the traditional emulsion system using surfactants, the pickering emulsion dispersion system using solid particles as emulsifiers is widely used in the fields of chemical industry, cosmetics and food due to safety, greenness and stronger stability. By controlling the types of solid particles and their distribution in the emulsion and the dispersed phase and the continuous phase, various different requirements can be flexibly met. The commonly used solid particles of food pickering emulsion include proteins and polysaccharides, and a kind of solid particle can act alone in the emulsion, but the combination of two or more kinds of solid particles can produce a synergistic effect to further improve the stability of the emulsion system, and at the same time, protect the biological active substances in the emulsion which are sensitive to light, heat and pH. Such a combination of solid particles is called a multi-component delivery carrier.

[0004] Citrus fiber is a kind of natural dietary fiber with citrus flavor extracted from the peels of citrus fruits, which has a health care effect on the body and can reduce the risk of diabetes and hypertension. Its viscosity is high and its water holding capacity is strong, so it is often used as a thickening stabilizer in food. At the same time, the water-soluble dietary fiber in citrus fiber can be adsorbed on the surface of oil, and the insoluble part has a large internal surface area, excellent space network structure and water holding capacity, so it can also play an emulsifying role. Compared with Tween and Span emulsifiers, it is a food raw material, has no addition limit and is green and safe, but the emulsifying effect is weaker than the former two, and further research is needed to modify and enhance its emulsifying performance. SUMMARY

[0005] To solve the above problems in the prior art, the application provides a preparation method of high-stability capsicum red pickering emulsion, which uses modified citrus fiber and sodium caseinate as emulsifiers to form a protein-polysaccharide composite delivery system to encapsulate natural pigment capsicum red and prepare high-stability capsicum red pickering emulsion.

[0006] Compared with the prior art, the application has the beneficial effects that:

[0007] (1) The citrus fiber is modified to enhance its emulsification properties, and the modified citrus fiber is used as an emulsifier, which is green and safe as a food raw material, has no addition amount limit, and has various benefits to the human body. Meanwhile, it has a certain special aroma, which can mask the pungent odor of capsanthin to a certain extent and improve the sensory evaluation of the product. The application provides a solution for widening the application mode of citrus fiber in products.

[0008] (2) The capsanthin is encapsulated by a protein-polysaccharide composite delivery system composed of sodium caseinate and modified citrus fiber. In addition to the formation of a complex due to covalent and electrostatic interactions, the citrus fiber can make the casein micelles in sodium caseinate have better emulsification effect, and the synergistic effect is stronger. The prepared pickering emulsion can better improve the stability and water solubility of capsanthin than ordinary emulsion.

[0009] The technical scheme of the application is implemented as follows: a preparation method of high-stability capsanthin pickering emulsion, comprising the following steps:

[0010] S1. Preparation of modified citrus fiber: citrus fiber and deionized water are mixed to obtain a citrus fiber solution, food-grade anhydrous ethanol is added after high-speed shearing, and then the mixture is uniformly mixed and left to stand for a period of time. The bottom precipitate is separated by 5000 rpm centrifugation for 20 min, dried and crushed to obtain modified citrus fiber;

[0011] S2. Preparation of capsanthin oil phase: 150,000 cu of oil-soluble capsanthin pigment is dissolved in vegetable oil, vitamin E is added, and the mixture is stirred uniformly to obtain an oil phase solution;

[0012] S3. Preparation of sodium caseinate-modified citrus fiber composite system: sodium caseinate is dissolved in deionized water, and modified citrus fiber obtained in step S1 is added in proportion, and the mixture is uniformly stirred in a water bath to obtain an aqueous phase solution of the sodium caseinate-modified citrus fiber composite system;

[0013] S4. Preparation of capsanthin pickering emulsion: the oil phase solution is added to the aqueous phase solution, and the mixture is stirred and kept warm in a water bath for 15 min, and then high-speed shearing and high-pressure homogenization are performed to obtain high-stability capsanthin pickering emulsion.

[0014] Preferably, in the S1 step, the citrus fiber: deionized water = 1:15 (m:m), and the citrus fiber solution: food-grade anhydrous ethanol = 1:5 (v:v). The high-speed shearing rate is 10000-16000 rpm for 10 min.

[0015] Preferably, in the S2 step, the vegetable oil is one or a mixture of both of soybean oil and sunflower seed oil.

[0016] Preferably, in the S2 step, the oil-soluble capsanthin: vegetable oil = 1:5 (m:m), and the added amount of vitamin E is 1wt% of the final pickering emulsion.

[0017] Preferably, in the S3 step, the added amount of sodium caseinate is 0.5wt% of the final pickering emulsion, and the added amount of modified citrus fiber is 1-4 times of the sodium caseinate. The water bath temperature is 50℃.

[0018] Preferably, in the S4 step, the oil phase solution: water phase solution = 1:3-9 (m:m). The water bath temperature is 50℃, the high-speed shearing condition is 12000rpm for 10min, and the high-pressure homogenization pressure is 60Mpa. DETAILED DESCRIPTION

[0019] In order to better understand the technical content of the present application, the following specific examples are provided to further illustrate the present application.

[0020] The test methods used in the embodiments of the present application are all conventional methods unless otherwise specified.

[0021] The materials, reagents, etc. used in the embodiments of the present application can be obtained from commercial channels unless otherwise specified.

[0022] Test methods:

[0023] (1) Citrus fiber emulsification capacity test: 1wt% sample solution was prepared in purified water and stirred until completely dissolved. Soybean oil: sample solution = 1:4 (m:m) was mixed, and after high-speed shearing at 15000rpm for 10min, it was left to stand. The height of the emulsion layer and the total sample layer height were accurately measured after 48h, and the sample emulsification capacity (%) was obtained from the emulsion layer height / total sample layer height.

[0024] (2) Capsanthin pickering emulsion emulsion stability test: 30mL of prepared capsanthin pickering emulsion was added to a 50mL centrifuge tube, centrifuged at 5000rpm for 20min, and the supernatant was removed. The centrifugal precipitation rate (%) was obtained from the following formula:

[0025] Centrifugal precipitation rate (%) = (w2-w0) / (w1-w0)

[0026] In the formula: w0— centrifuge tube weight, g; w1— total weight of centrifuge tube and emulsion, g; w2— total weight of centrifuge tube and sediment, g. The larger the centrifugal precipitation rate, the worse the system stability; on the contrary, the better the stability.

[0027] (3) The heat stability test of the paprika red Pickering emulsion: add the prepared paprika red Pickering emulsion to purified water, configure a 0.2wt% paprika red aqueous solution and seal. Place in a 70°C constant temperature water bath for 6h, after cooling, measure the absorbance at 460nm with a spectrophotometer, and the heat stability of the paprika red Pickering emulsion is reflected by the pigment retention rate (%) = absorbance after water bath / absorbance before water bath.

[0028] (4) The light stability test of the paprika red Pickering emulsion: add the prepared paprika red Pickering emulsion to purified water, configure a 0.2wt% paprika red aqueous solution and seal. Place it under a 40W, 250nm ultraviolet light source, continuously irradiate for 3h, and measure the absorbance at 460nm with a spectrophotometer, and the light stability of the paprika red Pickering emulsion is reflected by the pigment retention rate (%) = absorbance after irradiation / absorbance before irradiation.

[0029] (5) Odor sensory evaluation: invite 10 sensory evaluation team members (5 males and 5 females) to conduct sensory evaluation of the prepared paprika red Pickering emulsion in terms of odor according to the scoring standard in Table 1.

[0030] Table 1 Sensory evaluation scoring standard

[0031] Level Odor score (10 points) 1 No noticeable hot or other offensive odor (7-10 points) 2 Slightly hot or other offensive odor (4-6 points) 3 Noticeably hot or other offensive odor (1-3 points)

[0032] Example 1

[0033] A method for preparing a high-stability paprika red Pickering emulsion, comprising the following steps:

[0034] S1 Preparation of modified citrus fiber: weigh the citrus fiber, mix it uniformly with deionized water at a ratio of 1:15 (m:m) to obtain a citrus fiber solution, treat it with high-speed shearing at 10000rpm for 10min, then mix it uniformly at a ratio of 1:5 (v:v) with food-grade anhydrous ethanol, centrifuge the bottom precipitate at 5000rpm for 20min after standing for a period of time, dry and crush to obtain modified citrus fiber;

[0035] S2 Preparation of paprika red oil phase: weigh oil-soluble paprika red pigment with a content of 150,000cu, dissolve it in soybean oil at a ratio of 1:5 (m:m), add 1wt% vitamin E to the final product, and stir uniformly to obtain an oil phase solution;

[0036] Preparation of sodium caseinate-modified citrus fiber composite system: Sodium caseinate accounting for 0.5wt% of the final product was dissolved in deionized water, and modified citrus fiber obtained in step S1 was added in a ratio of sodium caseinate: modified citrus fiber = 1:1 (m:m), and stirred uniformly in a 50°C water bath to obtain a water phase solution of sodium caseinate-modified citrus fiber composite system;

[0037] Preparation of paprika red pickering emulsion: The oil phase solution was added to the water phase solution in a ratio of oil phase solution: water phase solution = 1:9 (m:m), and after stirring and incubation at 50°C for 15 min, high-pressure homogenization was performed at 60 MPa after high-speed shearing at 12000 rpm for 10 min, to obtain a high-stability paprika red pickering emulsion.

[0038] Example 2

[0039] The high-speed shearing rate in step S1 of Example 1 was adjusted to 12000 rpm, and the other steps were consistent with Example 1, to obtain a high-stability paprika red pickering emulsion.

[0040] Example 3

[0041] The high-speed shearing rate in step S1 of Example 1 was adjusted to 14000 rpm, and the other steps were consistent with Example 1, to obtain a high-stability paprika red pickering emulsion.

[0042] Example 4

[0043] The high-speed shearing rate in step S1 of Example 1 was adjusted to 16000 rpm, and the other steps were consistent with Example 1, to obtain a high-stability paprika red pickering emulsion.

[0044] Example 5

[0045] The ratio of sodium caseinate and modified citrus fiber in step S3 of Example 3 was adjusted to sodium caseinate: modified citrus fiber = 1:2 (m:m), and the other conditions were consistent with Example 3, to obtain a high-stability paprika red pickering emulsion.

[0046] Example 6

[0047] The ratio of sodium caseinate and modified citrus fiber in step S3 of Example 3 was adjusted to sodium caseinate: modified citrus fiber = 1:3 (m:m), and the other conditions were consistent with Example 3, to obtain a high-stability paprika red pickering emulsion.

[0048] Example 7

[0049] Adjust the ratio of sodium caseinate and modified citrus fiber in step S3 of example 3 to sodium caseinate: modified citrus fiber = 1:4 (m:m), and other conditions are consistent with example 3, to obtain a high stability of paprika red pickering emulsion.

[0050] Example 8

[0051] Adjust the ratio of oil phase solution and water phase solution in step S4 of example 5 to oil phase solution: water phase solution = 1:7 (m:m), and other conditions are consistent with example 5, to obtain a high stability of paprika red pickering emulsion.

[0052] Example 9

[0053] Adjust the ratio of oil phase solution and water phase solution in step S4 of example 5 to oil phase solution: water phase solution = 1:5 (m:m), and other conditions are consistent with example 5, to obtain a high stability of paprika red pickering emulsion.

[0054] Example 10

[0055] Adjust the ratio of oil phase solution and water phase solution in step S4 of example 5 to oil phase solution: water phase solution = 1:3 (m:m), and other conditions are consistent with example 5, to obtain a high stability of paprika red pickering emulsion.

[0056] Comparative example 1

[0057] The difference between example 5 is that the citrus fiber is not modified, and the emulsion is prepared directly using citrus fiber, and other steps are consistent with example 5, to obtain a paprika red pickering emulsion.

[0058] Comparative example 2

[0059] The difference between example 5 is that the emulsion is not prepared with citrus fiber or modified citrus fiber, step S1 is cancelled, and step S3 is adjusted to: sodium caseinate accounting for 1.5wt% of the final product is dissolved in deionized water, and the solution is stirred uniformly in a water bath at 50℃ to obtain a sodium caseinate aqueous solution. Other conditions are consistent with example 5, to obtain a paprika red pickering emulsion.

[0060] Comparative example 3

[0061] The difference between example 5 is that the emulsion is not prepared with sodium caseinate, and step S3 is adjusted to: modified citrus fiber accounting for 1.5wt% of the final product is dissolved in deionized water, and the solution is stirred uniformly in a water bath at 50℃ to obtain a modified citrus fiber aqueous solution. Other conditions are consistent with example 5, to obtain a paprika red pickering emulsion.

[0062] Comparative example 4

[0063] The difference from Example 5 is that sodium caseinate and modified citrus fiber are not used, and Tween 80 is used instead to prepare the emulsion, step S1 is cancelled, and step S3 is adjusted as follows: 1.5wt% of Tween 80 in the final product is weighed and dissolved in deionized water, and stirred uniformly in a 50°C water bath to obtain an aqueous phase solution. Other conditions are consistent with Example 5, and a paprika red Pickering emulsion is obtained.

[0064] The modified citrus fiber prepared in step S1 of Examples 1, 2, 3, and 4 is tested for emulsifying capacity, with sodium caseinate as a control, and the results are as follows:

[0065] Table 2 Emulsifying capacity of modified citrus fiber

[0066] Sample Emulsifying power (%) Example 1 59.3 Example 2 63.6 Example 3 71.0 Example 4 66.1

[0067] As can be seen from Table 2, among the shear rates of 10000, 12000, 14000, and 16000 rpm, the modified citrus fiber prepared under the condition of 14000 rpm in Example 3 has the best emulsifying capacity. As the shear rate increases, the particle size of the citrus fiber gradually decreases, and the increase in internal area increases the water and oil holding capacity. However, if the shear rate is too high, the fiber structure of the citrus fiber will be disintegrated, and the emulsifying capacity will decrease.

[0068] The paprika red Pickering emulsions prepared in Examples 3, 5-10 and Comparative Examples 1-4 are tested for emulsion stability, thermal stability, and light stability, and the results are as follows:

[0069] Table 3 Thermal stability and light stability of paprika red Pickering emulsion

[0070]

[0071]

[0072] As can be seen from Table 3, Examples 3 and 5-7, as the amount of citrus fiber added increases, the stability of the paprika red Pickering emulsion increases first and then decreases, and the sample of Example 5 has the best stability, indicating that the ratio of sodium caseinate to modified citrus fiber = 1:2 (m:m) is the best. As can be seen from Examples 8-10 and Comparative Examples 1-4, as the ratio of paprika red oil phase in the emulsion increases, the stability of the paprika red Pickering emulsion composed of sodium caseinate and modified citrus fiber decreases, but is still better than the stability of the emulsion with a single solid particle or Tween 80 as an emulsifier, indicating that the composite delivery system can greatly enhance the stability of the paprika red Pickering emulsion and better protect the effective coloring ingredients of paprika red. At the same time, the modification of citrus fiber also effectively enhances its emulsifying performance.

[0073] The odor sensory evaluation of the paprika red pickering emulsions prepared in Examples 3, 5-10 and Comparative Examples 1-4 was carried out, and the results were as follows:

[0074] Table 4 Odor sensory evaluation of paprika red pickering emulsions

[0075] Odor score (10 points) Example 3 7.83 Example 5 7.97 Example 6 8.10 Example 7 8.43 Example 8 8.02 Example 9 7.64 Example 10 6.27 Comparative Example 1 7.66 Comparative Example 2 5.48 Comparative Example 3 7.39 Comparative Example 4 5.02

[0076] As can be seen from Table 4, as the amount of modified citrus fiber increases, the odor score gradually increases, and the score is significantly improved compared with the sample using only sodium caseinate or Tween 80, indicating that the modified citrus fiber has a taste masking effect and reduces the paprika odor of paprika red.

[0077] The above only describes the preferred embodiments of the present application, and it should be noted that for ordinary skilled in the art, without departing from the principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should be considered as the protection scope of the present application.

Claims

1. A method for preparing a highly stable paprika oleoresin picking emulsion, characterized in that, Includes the following steps: Preparation of S1 modified citrus fiber: Citrus fiber was weighed and mixed evenly with deionized water to obtain a citrus fiber solution. The mass ratio of citrus fiber to deionized water was 1:

15. After high-speed shearing, food-grade anhydrous ethanol was added and mixed evenly. The volume ratio of citrus fiber solution to food-grade anhydrous ethanol was 1:

5. After standing, the bottom precipitate was separated by centrifugation at 5000 rpm for 20 min. After drying and pulverizing, modified citrus fiber was obtained. Preparation of S2 Capsicum Red Oil Phase: Weigh out 150,000 cu of oil-soluble capsicum red pigment and dissolve it in vegetable oil. Add vitamin E. The mass ratio of oil-soluble capsicum red pigment to vegetable oil is 1:

5. The amount of vitamin E added is 1 wt% of the final picking emulsion. Stir evenly to obtain an oil phase solution. Preparation of S3 sodium caseinate-modified citrus fiber composite system: Sodium caseinate was weighed and dissolved in deionized water, and the amount of sodium caseinate added was 0.5 wt% of the final pickering emulsion; modified citrus fiber obtained in step S1 was added, and the amount of modified citrus fiber added was 1 to 4 times that of sodium caseinate. The mixture was stirred evenly in a water bath to obtain an aqueous solution of sodium caseinate-modified citrus fiber composite system. Preparation of S4 paprika oleoresin pickering emulsion: The oil phase solution was added to the aqueous phase solution, and the mass ratio of oil phase solution to aqueous phase solution was 1:(3~9). After stirring and keeping warm in a water bath for 15 min, the high-stability paprika oleoresin pickering emulsion was obtained by high-speed shearing and high-pressure homogenization. In step S1, the high-speed shearing rate is 10,000~16,000 rpm for 10 minutes; In step S4, the high-speed shearing conditions are 12000 rpm for 10 min, and the high-pressure homogenization pressure is 60 MPa. In steps S3 and S4, the water bath temperature is 50°C.

2. The method for preparing a highly stable paprika oleoresin picking emulsion as described in claim 1, characterized in that: In step S2, the vegetable oil is one or a mixture of soybean oil and sunflower seed oil.

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