A method for preparing and application of osa modified starch microcapsules co-encapsulating carotenoids and essential oils

Abstract

The application discloses a kind of preparation method and application of OSA modified starch microcapsule co-embedded carotene and essential oil, belong to food microcapsule field.The present application uses OSA starch as emulsifier, carotene, MCT and essential oil are used as core material, and the emulsion particle size D90 of finally obtained is less than 1 μm, TSI is less than 3, system stability is excellent, can be kept uniform and stable after application to beverage after 6 weeks of accelerated aging, there is no oil floating, oil ring separation or delamination flocculation phenomenon, solve the problem that carotene and essential oil are respectively embedded and compounded in prior art, process simple adaptation industrial production, the microcapsule obtained can be directly applied to beverage and other food systems.

Description

Technical Field

[0001] This invention relates to a method for preparing and applying OSA-modified starch microcapsules co-encapsulated with carotenoids and essential oils, belonging to the field of microcapsules. Background Technology

[0002] In the formulation system of functional beverages, β-carotene and emulsified flavoring are important nutritional / coloring and flavoring components, respectively. β-carotene, as a fat-soluble nutrient and natural pigment, imparts characteristic color and nutritional value to the beverage; emulsified flavoring provides the beverage's distinctive flavor. In actual production, they are often prepared separately as independent emulsion systems and then compounded to control their respective emulsification state and stability. Specifically, β-carotene emulsions often use polyglycerol fatty acid esters (PGEs) as emulsifiers for stabilization, while emulsified flavorings often use sodium octenyl succinate starch (OSA starch) for emulsification and encapsulation.

[0003] However, a long-standing problem plaguing the industry is that flavor emulsions stabilized by OSA starch and β-carotene emulsions stabilized by PGEs exhibit excellent emulsification stability when used alone, but when mixed, they rapidly separate, float oil, and increase in particle size. The root cause of this instability is: (1) Free PGEs molecules can migrate from the MCT interface to the OSA-orange oil interface, inserting into and replacing the hydrophobic octenyl sites of OSA molecules, leading to OSA desorption and defects in the interface film; (2) OSA macromolecules cannot form an ordered three-dimensional network structure at the PGEs-MCT interface, but instead undergo multi-layer disordered stacking through weak hydrophobic interactions and hydrogen bonds, forming a thick and loose high dissipation layer, which significantly reduces the mechanical strength of the interface film; (3) The mismatch between different film thicknesses and viscoelasticity (OSA film is thick and highly elastic, while PGEs film is thin and highly rigid) causes the interface film to rupture simultaneously when droplets collide, and the complete miscibility of orange oil and MCT further accelerates the fusion and separation of oil droplets. To overcome this problem, the industry typically employs high-pressure homogenization after compounding. However, this not only increases energy consumption and equipment investment, but the heat generated during homogenization may also accelerate the degradation of β-carotene and the loss of flavorings through volatilization. Some solutions attempt to address this by screening for "compatible emulsifier pairs," but so far, a universal technical solution has not been developed, and the risk of mixing instability cannot be fundamentally eliminated.

[0004] For a long time, the encapsulation systems for β-carotene and essential oils have been developed and prepared separately. Existing technologies have always focused on optimizing the stability of a single encapsulation system, without fundamentally changing the core contradiction of instability caused by interfacial interactions after the two systems are combined. Furthermore, they have failed to simplify the production process and reduce the loss of active ingredients and flavor substances during processing while ensuring stability. There are already relatively mature technical solutions for the encapsulation of β-carotene. For example, high-content β-carotene microcapsules can be prepared by spray drying using OSA starch and β-cyclodextrin as the main wall materials and sunflower seed oil as the dissolving carrier. A bilayer emulsion system based on OSA-modified starch-chitosan has also been used for β-carotene encapsulation, significantly improving the stability of the emulsion. Liang Rong et al. studied the construction of an oil-in-water nanoemulsion for β-carotene encapsulation using OSA-modified starch as an emulsifier. DSM's patent (CN104244735B) discloses a composition containing modified polysaccharides and fat-soluble active ingredients, but the flavoring agent involved is a water-soluble component, which can dissolve in the aqueous phase, fundamentally different from the encapsulation behavior of fat-soluble essential oils.

[0005] Extensive research has been conducted on the encapsulation of essential oils. OSA starch, possessing both hydrophilic and hydrophobic properties, demonstrates excellent suitability for essential oil encapsulation. Previous studies have used OSA starch as the wall material to prepare perilla essential oil microcapsule powder via spray drying; cocoa essential oil Pickering emulsions constructed using OSA starch as a solid particle stabilizer have also been shown to exhibit good antioxidant and antibacterial activities. Liang Rong et al., in addition to studying the encapsulation of β-carotene, also disclosed a method for encapsulating peppermint essential oil using OSA nanoemulsions. Wang Ke et al. further investigated the encapsulation and release characteristics of peppermint flavoring encapsulated with OSA starch, examining the effects of substitution degree and enzymatic hydrolysis on the encapsulation effect.

[0006] As can be seen from the above, OSA starch is a widely validated and excellent wall material suitable for encapsulating β-carotene and essential oils separately. However, the above studies all only focused on encapsulating a single type of core material—either encapsulating carotenoids alone or essential oils alone. There is still a possibility that when the two components are encapsulated separately and then compounded, interfacial migration and interactions between different emulsion systems may occur, leading to instability in the mixed system. This cannot meet the requirements of one-step addition and direct compounding in industrial production, and additional homogenization treatment is still needed to stabilize the system, failing to prevent the processing loss of active ingredients and flavor substances from the source. Summary of the Invention

[0007] [Technical Solution] To address the aforementioned technical problems, this invention provides a method for preparing OSA-modified starch microcapsules co-encapsulated with carotenoids, MCT, and essential oils. This invention uses carotenoids and essential oils as the core material and OSA-modified starch as the single wall material, obtaining a stable oil-in-water emulsion through a one-step emulsification process. This fundamentally avoids the instability problem caused by interfacial interactions when two independent emulsification systems are combined. Based on this, a microcapsule powder co-encapsulated with carotenoids and essential oils is also provided. The microcapsule product co-encapsulating the two active components can be directly obtained through drying. It can be directly used in the formulation of functional beverages and other products without additional homogenization, effectively simplifying the production process and reducing losses due to carotenoid degradation and essential oil volatilization during processing.

[0008] The first objective of this invention is to provide a method for preparing OSA-modified starch microcapsules co-encapsulated with carotenoids, medium-chain triglycerides (MCTs), and essential oils, comprising the following steps: S1. Aqueous phase dissolution: Mix OSA-modified starch with water until homogeneous, adjust pH to 3.0-4.0, stir and dissolve under heating conditions, and then cool the aqueous phase system to below 50°C. S2, Oil Phase 1 Dissolution: β-carotene, MCT, and antioxidants are dissolved under heating conditions with stirring to obtain oil phase 1; S3, Shear Emulsification: Add oil phase 1 from S2 to the aqueous phase obtained from S1 for the first shear mixing. After cooling, add essential oil and perform a second shear mixing to obtain a crude emulsion. S4. Homogenization: The crude emulsion obtained in S3 is subjected to static defoaming and homogenization to obtain an emulsion in which OSA-modified starch co-encapsulated carotenoids, MCT and essential oils.

[0009] In one embodiment of the present invention, the OSA modified starch microcapsules contain carotenoids, essential oils and MCT as core materials; the mass ratio of β-carotene:MCT:essential oil is (1-10):(20-30):(20-40).

[0010] In one embodiment of the present invention, the OSA-modified starch has an OSA content of 1.8% to 2.8% and a viscosity (15%, 30°C) of 60 to 80 cP, based on the mass fraction of the grafted OSA group to the total mass of starch.

[0011] In one embodiment of the present invention, the OSA-modified starch is used as a wall material; the mass concentration of OSA-modified starch in the aqueous phase is 10% to 25% (w / w) based on the total mass of the aqueous phase.

[0012] In one embodiment of the present invention, the mass ratio of the core material solution to the wall material solution is 1:2~8.

[0013] In one embodiment of the present invention, the emulsion obtained in S4 is dried to obtain microcapsule powder co-encapsulated with carotenoids, citrus essential oils and MCT.

[0014] In one embodiment of the present invention, the drying includes spray drying and freeze drying; preferably, spray drying.

[0015] In one embodiment of the present invention, the inlet air temperature of the spray dryer is 175-190°C and the outlet air temperature is 85-90°C.

[0016] In one embodiment of the present invention, the emulsified flavor stabilizer, preservative, and acidity regulator are optional additives, and the addition amounts are 3%~5%, 0.05%~0.3%, and 0.1%~1% of the total mass, respectively. Those skilled in the art can flexibly adjust the addition amount of each component according to the product storage requirements and pH adjustment requirements, without having a substantial impact on the core technical effect of the present invention.

[0017] In one embodiment of the present invention, the emulsified fragrance stabilizer includes one or more of sucrose isobutyrate ester (SAIB) and rosin glyceryl ester, preferably SAIB.

[0018] In one embodiment of the present invention, the preservative includes sodium benzoate and potassium sorbate.

[0019] In one embodiment of the present invention, the acidity regulator adjusts the pH and is selected from one or more of citric acid, formic acid, and lactic acid, preferably citric acid.

[0020] In one embodiment of the present invention, the antioxidant includes one or more of α-tocopherol and tocopherol acetate, preferably α-tocopherol.

[0021] In one embodiment of the present invention, in S1, the heating condition is 40-60°C, and the stirring is shear stirring at 3000-5000 rpm for 20-40 min.

[0022] In one embodiment of the present invention, in S2, the heating condition is 130-150°C, and the stirring and dissolving time is 8-15 min.

[0023] In one embodiment of the present invention, in S3, the conditions for the first shear mixing are shearing at 5000-8000 rpm for 1-5 min; and the conditions for the second shear mixing are shearing at 5000-8000 rpm for 5-15 min.

[0024] In one embodiment of the present invention, in S3, the cooling is cooling to below 50°C.

[0025] In one embodiment of the present invention, in S4, the homogenization pressure is 100-300 bar, the homogenization is performed 2-5 times, and the particle size D90 of the homogenized emulsion is <1 μm.

[0026] In one embodiment of the present invention, the ingredients, by weight, are: 400-600 parts water, 40-130 parts OSA starch, 0.5-3 parts citric acid, 0.5-10 parts α-tocopherol, 15-30 parts MCT, 1-10 parts β-carotene, 10-30 parts SAIB, and 20-40 parts essential oil.

[0027] In one embodiment of the present invention, the β-carotene is a crystalline powder or an oil suspension; preferably an oil suspension.

[0028] In one embodiment of the present invention, the crystalline powder has a β-carotene content of ≥98%, and the oil suspension has a β-carotene mass fraction of 30%.

[0029] In one embodiment of the present invention, in S3, the essential oil includes citrus essential oils; the citrus essential oils include orange oil and lemon oil.

[0030] The second objective of this invention is to provide a microcapsule containing co-encapsulated carotenoids, MCT, and essential oils prepared by the above method.

[0031] A third objective of this invention is to provide a beverage containing the microcapsules.

[0032] In one embodiment of the present invention, the beverage is selected from carbonated beverages, fruit and vegetable juice beverages, milk beverages, plant protein beverages, sports drinks, or alcoholic beverages.

[0033] In one embodiment of the present invention, the alcoholic beverage is selected from beer, fruit wine, fortified wine, cocktail, sparkling wine or premixed wine.

[0034] In one embodiment of the present invention, the amount of the microcapsules added to the beverage is 0.002% to 0.04% (w / w).

[0035] A fourth object of the present invention is to provide a seasoning that contains the microcapsules.

[0036] In one embodiment of the present invention, the seasoning is selected from soy sauce, vinegar, spice oil, compound seasoning or sauce.

[0037] In one embodiment of the present invention, the amount of the microcapsules added to the seasoning is 0.01% to 2% (w / w).

[0038] The application of the microcapsules in the preparation of beverages and seasonings allows them to be directly added to beverage bases or seasoning bases and mixed with other raw materials. The system can be kept stable without additional homogenization treatment, and can simultaneously retain the nutritional value and coloring effect of β-carotene, as well as the characteristic flavor of essential oils. It effectively reduces the degradation of β-carotene and the volatilization loss of essential oil flavor substances during processing.

[0039] In one embodiment of the present invention, the microcapsules are used to improve the stability of carotenoids and essential oils in beverages and condiments.

[0040] In one embodiment of the present invention, the stability is defined as the absence of instability problems such as stratification, oil floating, and particle size increase.

[0041] In one embodiment of the present invention, the microcapsules are applied to a beverage and remain stable after being aged at 37°C for 6 weeks without exhibiting oil rings, flocculation, or stratification.

[0042] [Beneficial Effects] This invention uses OSA starch as the wall material and carotenoids, MCT, and essential oils as the core material to prepare an emulsion that simultaneously encapsulates aroma ingredients (essential oils), MCT, and β-carotene. The emulsion exhibits excellent thermal stability, uniform nanoscale particle size, and the absence of independent oil phases stable by two different emulsifiers. This fundamentally avoids the migration and substitution of different emulsifiers at the oil-phase interface, eliminating instability problems caused by interfacial film structure damage and performance mismatch. Applied to various carbonated beverages, it provides aroma and color while maintaining color, and there is no floating oil during beverage storage, meeting the stringent application requirements of downstream end customers. Further drying the emulsion yields microcapsule powder, which can also be directly used in the formulation of functional beverages and other end products. Preparation is completed simply by mixing with other raw materials, eliminating the need for additional high-pressure homogenization. This simplifies the production process, reduces energy consumption and equipment investment, and minimizes the degradation loss of β-carotene and the volatilization loss of essential oil flavor substances during processing, better preserving the product's nutrition and flavor. Suitable for large-scale industrial production, it has promising application prospects. Attached Figure Description

[0043] Figure 1 This is a model diagram of the instability mechanism of the β-carotene emulsion after mixing according to the present invention. Detailed Implementation

[0044] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explanation of the present invention and are not intended to limit the present invention.

[0045] The test methods involved in the following embodiments: 1. Detection of particle size DV(90) After diluting the emulsion, an appropriate amount was dropped into the sample cell of the Mastersizer-3000 laser particle size analyzer and dispersed with deionized water. The refractive indices of the sample and the continuous phase were 1.563 and 1.330, respectively. Measurements were started when the occlusion level reached 5%, with a test time of 30 seconds. Each sample was measured three times, and the average value was taken. D4.3 represents the volume average particle size, and D10, D50, and D90 represent the particle size values ​​when the cumulative distribution percentage reaches 10%, 50%, and 90%, respectively.

[0046] 2. Detection of β-carotene content Weigh a certain amount of emulsion and place it in a 100 mL brown volumetric flask. Add 10 mL of water and sonicate for 5 min. Add 40 mL of anhydrous ethanol and 40 mL of chloroform, and sonicate for another 5 min. Remove and cool, then dilute to the mark with anhydrous ethanol and shake well. Pipette 2.0 mL into a 50 mL brown volumetric flask, blow the solvent in the flask dry with nitrogen gas, then dissolve and dilute to the mark with cyclohexane, shake well, and measure the absorbance at 455 nm.

[0047] In the formula, X1 represents the mass percentage of β-carotene in the sample, A represents the absorbance of the test solution at 455 nm, m represents the sample weight, 2500 (in the numerator) represents the volume dilution factor of the sample, and 2500 (in the denominator) represents the percentage absorbance coefficient (E) of β-carotene. 1CM 1%.

[0048] 3. Emulsion stability index (TSI value) The physical stability of the emulsion was determined using a Formulaction Turbiscan stability analyzer. The Turbiscan analyzer uses near-infrared light as the light source and has transmitted light and backscattered light detectors. The measuring probe measures every 20 μm from the bottom to the top of the sample cell; a complete measurement from bottom to top is called one scan. Transmitted light and backscattered light change over time, indicating changes in the sample's particle size and concentration. For emulsion systems, backscattered light intensity (BS) is the evaluation index. Using the initial sample as a control, BS at different times reflects changes in the system. TSI comprehensively reflects changes in the emulsion's properties. TSI = ∑i ( ∑_h |scan_i-scan_(i-1) (h)|) / H In the formula, scani(h) is the backscattered light intensity of the sample at position h in the i-th scan; scani-1(h) is the backscattered light intensity of the sample at position h in the (i-1)-th scan; and H is the sample height.

[0049] 20 mL of the emulsion was transferred into a sample vial, ensuring it did not adhere to the vial walls. Measurement parameters were: temperature 60℃, scanning frequency 15 min / scan, and analysis time 8 h. The stability coefficient (TSI) and corresponding curve were obtained. A lower TSI value indicates a more stable emulsion.

[0050] 4. Observation of the microstructure of the emulsion The microstructural changes of the emulsion were observed using an OLYMPUS CX33 optical microscope. The prepared slide was placed on the stage, and the aperture was adjusted to the appropriate brightness. First, the image was found by adjusting the coarse adjustment knob under the low-power objectives (4×, 10×), and then the sample was found and imaged clearly under the high-power objectives by adjusting the fine adjustment knob. If higher contrast was required, the histogram was clicked, and the left and right boundary lines were dragged to increase the contrast. After confirming the desired image, the capture button was clicked to obtain the desired microscope image.

[0051] The raw materials used in the following examples: Water: Drinking water; Sodium benzoate: food grade, CAS number 532-32-1, quality meets the requirements of GB 1902-2005; Potassium sorbate: food grade, CAS number 24634-61-5, quality meets the requirements of GB 1886.39-2015; OSA starch: food grade, OSA content 2%, product viscosity (15% at 30℃) is 60-80 cP, product pH (25% at 30℃) is 3.8-4.2, quality meets the requirements of GB 1886.370-2023; Citric acid: food grade, CAS number 77-92-9, quality meets the requirements of GB1886.235-2016; Lactic acid: food grade, CAS number 50-21-5, quality meets the requirements of GB 1886.173-2016; Formic acid: food grade, CAS number 64-18-6, quality meets the requirements of GB / T 15896-2024; DL-α-Tocopherol: Food grade, CAS No. 10191-41-0 / 59-02-9, quality meets the requirements of GB 29942-2013; MCT: Food grade, CAS number 73398-61-5, quality meets the requirements of GB 28303-2012; β-Carotene: Food grade, including crystalline pure product with a content of more than 98% or 30% β-carotene oil suspension. The 30% β-carotene oil suspension is used in the examples. SAIB: Food grade, CAS No. 126-13-6; 34482-63-8; 27216-37-1, quality meets GB 30616-2020 requirements; Orange oil: food grade, CAS number 8008-57-9, D-limonene content ≥90%, quality meets QB / T 4756-2014 requirements; Lemon oil: food grade, CAS number 8808-56-8, quality meets the requirements of GB 1886.22—2016.

[0052] Example 1: A method for preparing microcapsules co-encapsulated with carotenoids, MCT and essential oils This embodiment provides a method for preparing microcapsules co-encapsulated with carotenoids, MCT, and essential oils, the steps of which are as follows: 1. Formula The formulation includes: 557.06 g water, 1.12 g preservative (composed of 0.56 g sodium benzoate and 0.56 g potassium sorbate), 70.00 g OSA starch (PG2000), 2.52 g acidity regulator (composed of 1.4 g citric acid, 0.56 g lactic acid, and 0.56 g formic acid), 0.70 g antioxidant (α-tocopherol), 25.90 g MCT, 3.50 g β-carotene, 14.00 g emulsified flavor stabilizer (SAIB), and 25.2 g orange oil. The preservative and acidity regulator are optional components. This embodiment provides a preferred formulation for commercial production. The amount of each component can be adjusted within the scope defined in the claims according to actual production needs.

[0053] 2. Preparation process S1. Aqueous phase dissolution: Under 60℃ water bath conditions, according to the formula, the modified starch is mixed with water evenly, and sodium benzoate, citric acid, potassium sorbate, lactic acid and formic acid are added at the same time. The pH is controlled at 3.5, and shearing is performed at 4000 rpm / min for 30 min. Then the aqueous phase system is cooled to below 50℃. S2, Oil Phase 1 Dissolution: According to the formula, β-carotene, α-tocopherol, MCT and SAIB are dissolved by stirring at 146℃ for 10 min; S3, Shear Emulsification: Under 50℃ water bath conditions, oil phase 1 was first added to the aqueous phase in S1, sheared at 6000 rpm / min for 2 min, and then the temperature was cooled to 50℃. Orange oil was then added, and sheared at 6000 rpm / min for 10 min. The particle size of the crude emulsion, D90, was <1.5μm.

[0054] S4. Homogenization: After standing to defoam, homogenize at a pressure of 200 bar, repeating twice. Control the particle size of the finished emulsion to D90 < 1 μm and TSI < 3.

[0055] S5. Emulsion filling: Homogenized emulsion is filled and stored at low temperature.

[0056] The prepared emulsion was directly added to the base of a commercially available carbonated beverage at a dosage of 10% (w / w) and aged for 6 weeks in a constant temperature chamber at 37℃±1℃. After aging, the beverage system remained homogeneous and stable, with no oil floating, oil ring precipitation, or flocculation stratification. After being stored at room temperature for 5 months, the carotene retention rate was 92%.

[0057] Example 2: A method for preparing microcapsule powder co-encapsulated with carotenoids, MCT and essential oils This embodiment provides a method for preparing microcapsule powder co-encapsulated with carotenoids, MCT, and essential oils, the steps of which are as follows: 1. Formula The emulsion contains 198.1 g of water, 0.6 g of preservative (composed of 0.3 g of sodium benzoate and 0.3 g of potassium sorbate), 43.6 g of OSA starch (PG2000), 2.6 g of acidity regulator (composed of 2.0 g of citric acid, 0.3 g of lactic acid, and 0.3 g of formic acid), 1.0 g of antioxidant (α-tocopherol), 17.5 g of MCT, 7.50 g of β-carotene, and 25 g of orange oil. The solid content of the emulsion is approximately 33%. The preservative and acidity regulator are optional additives. This embodiment provides a preferred additive ratio for commercial production. The amount of each component can be adjusted within the scope defined in the claims according to actual production needs.

[0058] 2. Preparation process S1. Aqueous phase dissolution: Under 60℃ water bath conditions, OSA starch was mixed with water according to the formula, and sodium benzoate, citric acid, potassium sorbate, lactic acid and formic acid were added at the same time. The pH was controlled at 3.5, and sheared at 4000 rpm / min for 30 min. Then the aqueous phase system was cooled to below 50℃. S2, Oil Phase 1 Dissolution: According to the formula, β-carotene, α-tocopherol, and MCT are dissolved by stirring at 146℃ for 10 min; S3, Shear Emulsification: Under 50℃ water bath conditions, oil phase 1 was first added to the aqueous phase in S1, sheared at 6000 rpm / min for 2 min, and then the temperature was cooled to 50℃. Orange oil was then added, and sheared at 7000 rpm / min for 15 min. The particle size of the crude emulsion, D90, was <1.5μm.

[0059] S4. Homogenization: After standing to defoam, homogenize at a pressure of 225 bar, repeating 3 times. Control the particle size D90 of the finished emulsion to be <1 μm, and keep it at 30℃~35℃. S5. Spray drying: The finished emulsion is spray dried. The inlet air temperature is controlled at 175℃, the outlet air temperature is 85℃, the feed rate is 28 rpm, and the atomization pressure is 0.05 MPa. Finally, microcapsule powder co-encapsulated with carotenoids and essential oils is obtained.

[0060] The prepared microcapsule powder was directly added to the base material of commercially available carbonated beverages at a dosage of 0.5% (w / w) and aged for 6 weeks in a constant temperature chamber at 37℃±1℃. After aging, the beverage system remained homogeneous and stable, without any oil floating, oil ring precipitation, or flocculation stratification.

[0061] Example 3: A method for preparing microcapsules co-encapsulated with carotenoids, MCT, and essential oils Based on Example 1, the OSA starch was adjusted to PG2000, CO03, SSOS-A, and JY-HZ01, while the other steps remained the same. The stability of the microcapsules co-encapsulated with carotenoids and essential oils prepared with different OSA starches was tested.

[0062] The results are shown in Table 1. When PG2000 starch was used to co-encapsulate carotenoids and essential oils, the emulsion stability coefficient was the lowest, indicating the best emulsion stability. PG2000 starch was used for co-encapsulation in subsequent applications.

[0063] Table 1 Effect of OSA starch on microcapsule stability

[0064] Note: Viscosity 15%\30℃: 15%: refers to the mass fraction of the starch emulsion prepared during the test being 15%, that is, 15g of dry starch dissolved in 85g of pure water to form a uniform test sample; 30℃: refers to the ambient / sample temperature being controlled at a constant temperature of 30℃ during the test; Unit: The unit of the test result is usually cP (centipoise), which is a commonly used unit of liquid viscosity, 1cP=1mPa·s.

[0065] Example 4: A method for preparing microcapsules co-encapsulated with carotenoids, MCT and essential oils This embodiment provides a method for preparing microcapsules co-encapsulating carotenoids, MCT, and essential oils, with the following steps: 1. Formula The formula includes: 471.10 g water, 105.00 g OSA starch, 1.40 g citric acid, 7.00 g α-tocopherol, 45.50 g MCT, 7.00 g β-carotene, 24.50 g SAIB, and 38.50 g orange oil.

[0066] 2. Preparation process S1. Aqueous phase dissolution: Under 60℃ water bath conditions, the modified starch was mixed with water according to the formula, the pH was adjusted to 3.5 with citric acid, and sheared at 2000 rpm / min for 20 min; then the aqueous phase system was cooled to below 50℃. S2, Oil Phase 1 Dissolution: According to the formula, β-carotene, α-tocopherol, MCT and SAIB are dissolved by stirring at 144℃ for 20 min; S3, Shear Emulsification: Under 50℃ water bath conditions, oil phase 1 is first added to the aqueous phase in S1, sheared at 6000 rpm / min for 2 min, then the temperature is cooled to 50℃, orange oil is added, and sheared at 8000 rpm / min for 10 min; the crude emulsion particle size D90 < 1.5 μm.

[0067] S4. Homogenization: Homogenize under static conditions to remove foam, at a pressure of 200 bar, for 3 cycles. Control the finished emulsion particle size D90 < 1 μm and TSI < 3.

[0068] S5. Emulsion filling: Homogenized emulsion is filled and stored at low temperature.

[0069] The prepared emulsion was directly added to the commercially available carbonated beverage base at a dosage of 10% (w / w) and aged for 6 weeks in an incubator at 37℃±1℃. After aging, the beverage system remained homogeneous and stable, with no oil floating, oil ring precipitation, or flocculation stratification observed.

[0070] Comparative Example 1 Unlike Example 1, conventional techniques used in existing industrial production were employed to emulsify β-carotene and essential oils, respectively, to obtain two mature and stable pigment and fragrance products.

[0071] The two emulsions were added directly to commercially available carbonated beverage base at a rate of 10% (w / w) and aged for 6 weeks in a constant temperature and humidity chamber at 37℃±1℃ and 75% relative humidity.

[0072] The results showed that during the first week of accelerated storage at 37°C, a distinct red oil ring appeared on the top of the beverage, indicating a significant decrease in its stability.

[0073] Comparative Example 2 Based on Example 1, S2 is adjusted as follows: S1. Aqueous phase dissolution: Same as in Example 1; S2, Oil Phase 1 Dissolution: Dissolve β-carotene, α-tocopherol, MCT, and SAIB at 146℃ for 10 min according to the mass proportions set in the formula; S3, Shearing emulsification: The aqueous phase obtained in S1 is divided into two equal parts, and oil phase 1 and orange oil are added to each part under a 50°C water bath. The mixture is sheared at 6000 rpm / min for 10 min to obtain emulsion 1 containing oil phase 1 and emulsion 2 containing orange oil. S4. Mixing: Mix emulsion 1 and emulsion 2, and shear at 6000 rpm / min for 10 min; S5. Homogenization: After standing to defoam, homogenize at a pressure of 200 bar, and homogenize twice. S6. Emulsion filling: Homogenized emulsion is filled and stored at low temperature.

[0074] The prepared emulsion was directly added to commercially available carbonated beverage base at a dosage of 10% (w / w) and aged for 6 weeks in a constant temperature and humidity chamber at 37℃±1℃ and 75% relative humidity.

[0075] The results showed that when oil phase 1 and orange oil were separately prepared into OSA-encapsulated emulsions and applied to beverages, oil rings appeared as early as the third week of accelerated aging, and the stability was significantly weaker than that of the single-co-encapsulated emulsion system of this invention. This indicates that emulsifying the two oil phases separately with OSA is not ideal.

[0076] The above results also indicate that when the two components are separately encapsulated and then compounded, the interfacial migration and interaction between the emulsion systems may lead to instability of the mixed system.

[0077] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A method for preparing OSA-modified starch microcapsules co-encapsulated with carotenoids, MCT, and essential oils, characterized in that, Includes the following steps: S1. Aqueous phase dissolution: Mix OSA-modified starch with water until homogeneous, adjust the pH to 3.0-4.0, stir and dissolve under heating conditions, and then cool the aqueous phase system to below 50°C. S2, Dissolution of oil phase 1: β-carotene and MCT are dissolved by stirring under heating to obtain oil phase 1; S3, Shear Emulsification: Add oil phase 1 from S2 to the aqueous phase obtained from S1 for the first shear mixing. After cooling, add essential oil and perform a second shear mixing to obtain a crude emulsion. S4. Homogenization: The crude emulsion obtained in S3 is subjected to static defoaming and homogenization to obtain an emulsion in which OSA-modified starch co-encapsulated carotenoids, MCT and essential oils. The emulsion obtained in S4 was dried to obtain microcapsule powder co-encapsulated with carotenoids, citrus essential oils and MCT; The emulsion contains carotenoids, essential oils, and MCT as core materials; the mass ratio of β-carotene:MCT:essential oil is (1-10):(20-30):(20-40). The OSA-modified starch is used as a wall material; the mass concentration of OSA-modified starch in the aqueous phase is 10%–25% (w / w) based on the total mass of the aqueous phase; the OSA content of the OSA-modified starch is 1.8%–2.8% based on the mass fraction of grafted OSA groups to the total mass of starch, and the viscosity (15%, 30℃) is 60–80 cP.

2. The preparation method according to claim 1, characterized in that, In S1, the heating conditions are 40-60°C, and the stirring is 1500-5000 rpm for 20-40 min.

3. The preparation method according to claim 1, characterized in that, In S3, the first shear mixing condition is shearing at 5000-8000 rpm for 1-5 minutes; the second shear mixing condition is shearing at 5000-8000 rpm for 5-15 minutes; and the cooling is cooling to below 50°C.

4. The preparation method according to claim 1, characterized in that, In S4, the homogenization pressure is 100-300 bar, and the homogenization is performed 2-5 times. After homogenization, the particle size D90 of the emulsion is <1 μm.

5. A microcapsule co-encapsulating carotenoids, MCT and essential oils obtained by the preparation method according to any one of claims 1 to 4.

6. A beverage, characterized in that, The beverage contains the microcapsules as described in claim 5.

7. The beverage according to claim 6, characterized in that, The beverages are selected from carbonated drinks, fruit and vegetable juices, dairy drinks, plant protein drinks, sports drinks, or alcoholic beverages.

8. A condiment, characterized in that, The seasoning contains the microcapsules of claim 5.

9. The application of the microcapsules according to claim 5 in the preparation of beverages and condiments.

10. The application according to claim 9, characterized in that, The microcapsules of claim 5 are used to improve the stability of carotenoids and essential oils in beverages and condiments.

Images