Low-fat double gel capable of synchronously encapsulating curcumin and EGCG (epigallocatechin gallate) as well as preparation method and application of low-fat double gel
By constructing a low-fat dual gel consisting of an oleogel and a hydrogel under low-fat conditions, the co-delivery and stability issues of curcumin and EGCG were resolved, enabling their application in healthy low-fat foods and differentiated protection of active ingredients.
Patent Information
- Application Number
- CN202511124007.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-12
- Publication Date
- 2025-11-07
AI Technical Summary
Existing technologies struggle to achieve efficient co-delivery of curcumin and EGCG under low-fat conditions, and their sensitivity to light and temperature results in poor chemical stability and low bioavailability.
A low-fat dual-gel system was adopted, in which curcumin and EGCG were encapsulated in oleogel and hydrogel respectively, and then mixed to form a low-fat dual-gel. The specific steps included dissolving curcumin and oleogel agent in vegetable oil, dissolving EGCG and hydrogel agent in water, and then mixing them to form a low-fat dual-gel.
A stable low-fat dual gel was constructed with a low oil-to-gel ratio, achieving simultaneous encapsulation of curcumin and EGCG, improving its rheological properties and colorability, making it suitable for healthy low-fat foods, and enhancing the stability and protective effect of the active ingredients.
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Figure CN120898965A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the field of food processing, and particularly relates to a low-fat double gel synchronously encapsulating curcumin and EGCG as well as a preparation method and application thereof. BACKGROUND
[0002] With the improvement of living standards, high-fat dietary patterns are becoming increasingly common. This shift in dietary patterns is closely related to the continued rise in the incidence of chronic non-communicable diseases. In this context, dietary intervention strategies based on bioactive ingredients show important application value. Curcumin and epigallocatechin-3-gallate (EGCG) are natural polyphenolic compounds derived from turmeric and green tea, respectively, and have attracted much attention due to their significant antioxidant, anti-inflammatory, and anticancer activities. Studies have shown that the combination of EGCG and curcumin can produce synergistic effects in disease prevention and health promotion. However, the distinct hydrophilic / lipophilic properties of the two make it difficult to achieve effective co-delivery in food systems. In addition, the sensitivity of EGCG and curcumin to light and temperature results in poor chemical stability and low bioavailability. To address these issues, there is an urgent need to develop a new carrier system to protect these two nutrients.
[0003] Double gels, as a new hybrid gel system, have attracted much attention in the field of functional foods due to their unique thermodynamic stability, excellent viscoelasticity, and controllable delivery properties. Compared with emulsions and emulsion gels, the semi-solid properties of double gels provide the system with higher physical stability. In addition, the presence of structured aqueous and oil phases allows it to simultaneously load hydrophilic and lipophilic active ingredients, and the structure and release properties can be controlled by adjusting the ratio of the two phases. Based on these unique advantages, double gel systems have become a frontier in the co-delivery of bioactive ingredients. Existing studies have shown that increasing the oil gel ratio in double gels can enhance the stability of the system and the protection effect of active ingredients, so research has focused on double continuous and water-in-oil double gel systems with high oil phase ratios. However, this contradicts the current trend of low-fat healthy diets. To address this challenge, the development of stable water-in-oil or double continuous double gel systems with low oil phase ratios not only conforms to the modern trend of healthy diets, but also provides an innovative solution for the stable protection of functional ingredients. SUMMARY
[0004] In order to overcome the shortcomings and deficiencies of the prior art, the primary purpose of the present application is to provide a preparation method of a low-fat double gel synchronously encapsulating curcumin and EGCG.
[0005] Another purpose of the present application is to provide a low-fat double gel synchronously encapsulating curcumin and EGCG prepared by the above method.
[0006] Another object of the present application is to provide the use of the low-fat double gel synchronously encapsulating curcumin and EGCG.
[0007] The object of the present application is achieved by the following solutions:
[0008] A preparation method of a low-fat double gel synchronously encapsulating curcumin and EGCG, comprising the following steps:
[0009] (1) adding curcumin and an oil gel agent into vegetable oil, stirring and dissolving to obtain curcumin-loaded oil gel;
[0010] (2) adding EGCG and a water gel agent into water, stirring and dissolving to obtain EGCG-loaded water gel;
[0011] (3) mixing the curcumin-loaded oil gel obtained in step (1) with the EGCG-loaded water gel obtained in step (2), and then stirring to obtain the low-fat double gel synchronously encapsulating curcumin and EGCG.
[0012] The oil gel agent in step (1) is at least one of lacquer wax, beeswax, glycerol monostearate, rice bran wax, candelilla wax, carnauba wax, sunflower wax, and corn wax, preferably a mixture of lacquer wax and other waxes, and more preferably a mixture of lacquer wax and beeswax, wherein the mass percentage of lacquer wax in the mixture of lacquer wax and beeswax is 60% to 80%.
[0013] The vegetable oil in step (1) is at least one of camellia oil, soybean oil, rapeseed oil, peanut oil, sunflower oil, rice bran oil, corn oil, flaxseed oil, olive oil, wheat germ oil, cottonseed oil, almond oil, sesame oil, coconut oil, and palm oil.
[0014] The amounts of curcumin, the oil gel agent, and the vegetable oil in step (1) satisfy the following conditions: the addition amount of the oil gel agent is 10% to 30% of the mass of the vegetable oil; and the addition amount of curcumin is 0.1% to 1.0% of the mass of the vegetable oil.
[0015] The stirring and dissolving in step (1) is preferably heating and stirring and dissolving at 90 to 120℃, and after complete dissolution, cooling to room temperature to form the curcumin-loaded oil gel.
[0016] The water gel agent in step (2) includes one of gelatin, pectin, whey protein isolate, κ-carrageenan, xanthan gum, gellan gum, sodium alginate, guar gum, and locust bean gum.
[0017] The amounts of EGCG, the water gel agent, and water in step (2) satisfy the following conditions: the addition amount of the water gel agent is 8% to 12% of the mass of the water; and the addition amount of EGCG is 0.1% to 2.0% of the mass of the water.
[0018] The stirring dissolution in step (2) is preferably heating stirring dissolution at 70-80℃, and after complete dissolution, cooling to room temperature to form the EGCG-loaded hydrogel.
[0019] The mass ratio of curcumin-loaded oil gel to EGCG-loaded hydrogel in step (3) is 2:8-4:6.
[0020] The stirring in step (3) refers to mixing by stirring at 70-80℃, and then cooling to solidification to obtain the low-fat double gel synchronously encapsulating curcumin and EGCG. The stirring speed is 200-1200rpm, and the time is 25-35min, and the cooling refers to cooling at 0-5℃, preferably cooling under ice water bath.
[0021] The obtained low-fat double gel synchronously encapsulating curcumin and EGCG can be one of O / H type or H / O type or BC (bi-continuous) type double gel.
[0022] A low-fat double gel synchronously encapsulating curcumin and EGCG prepared by the above method.
[0023] The application of the above low-fat double gel synchronously encapsulating curcumin and EGCG in preparing functional fat substitutes.
[0024] The present application has the following advantages and beneficial effects relative to the prior art:
[0025] The present application breaks through the technical limitation of traditional double gel system, successfully constructs three different types of double gel systems (O / H type, BC type and H / O type) under the condition of low oil phase ratio (20%-40%), and the preparation method is simple and controllable, and the raw materials are green and natural. Not only the synchronous encapsulation of two lipophilic / hydrophilic natural active ingredients (curcumin and EGCG) is realized, but also excellent rheological properties and coloring properties are possessed, which can be used as fat substitutes in foods such as yogurt, ice cream and cheese, to reduce calories and meet the requirements of healthy low-fat foods.
[0026] The double gel system of the present application can realize controllable adjustment of system performance by adjusting the ratio of oil gel and hydrogel. Specifically, by increasing the ratio of oil gel, the structure and stability of the gel can be enhanced; the bi-continuous double gel can effectively improve the thermal stability of curcumin, and the water-in-oil type has outstanding protective effect on EGCG. This flexible and adjustable strategy can realize differential protection of active ingredients, and can be used as a co-delivery carrier of active ingredients to meet the delivery and controlled release requirements of different functional foods. BRIEF DESCRIPTION OF DRAWINGS
[0027] Figure 1 The appearance and optical microscope images of the double gels prepared for Examples 1-3 and Comparative Examples 1-6.
[0028] Figure 2 Rheological properties of the double gels prepared for Examples 1-3 and Comparative Examples 5-6.
[0029] Figure 3 XRD patterns of the double gels prepared for Examples 1-3 and Comparative Examples 5-6 (a) and DSC patterns of the double gels prepared for Examples 1-3 (b).
[0030] Figure 4 Retention rates of curcumin and EGCG after heat and UV treatment of the double gels prepared for Examples 1-3 and Comparative Examples 5-6. DETAILED DESCRIPTION
[0031] The present application is further described in detail by reference to the following examples and drawings, but the embodiments of the present application are not limited to the examples. In the examples, unless specific conditions are noted, the procedures were carried out according to the conventional conditions or the conditions recommended by the manufacturers. In the examples, unless the manufacturers are noted, the reagents and instruments used were the conventional products that can be purchased in the market.
[0032] In the examples, unless otherwise noted, the reagents used were the conventional products that can be purchased in the market.
[0033] Example 1
[0034] The present example provides a low-fat double gel synchronously encapsulating curcumin and EGCG and a method for preparing the same, specifically:
[0035] (1) Preparation of the oil gel: 20 parts by mass of a mixture of lacquer wax and beeswax (the mass fraction of lacquer wax in the mixture of lacquer wax and beeswax is 60%) and 0.2 parts by mass of curcumin were added to 100 parts by mass of camellia oil, heated to 100°C, and magnetically stirred at a speed of 800 rpm until completely dissolved. After cooling to room temperature, an oil gel loaded with curcumin was formed.
[0036] (2) Preparation of the water gel: 10 parts by mass of gelatin powder and 0.2 parts by mass of EGCG were slowly added to 100 parts by mass of pure water, heated to 75°C, and magnetically stirred at a speed of 800 rpm until dissolved. After cooling to room temperature, a water gel loaded with EGCG was formed.
[0037] (3) Preparation of the double gel system: The prepared water gel and oil gel were mixed at a mass ratio of 8:2 at 75°C, and magnetically stirred at a speed of 1200 rpm for 30 min. Subsequently, the obtained emulsion gel was cooled to solidification in an ice water bath, and a double gel synchronously encapsulating curcumin and EGCG was obtained.
[0038] Example 2
[0039] The difference from Example 1 is only that in step (3), the mass ratio of the hydrogel and the oil gel is replaced by 7:3, and the other and Example 1 remain the same, to obtain a double gel synchronously encapsulating curcumin and EGCG.
[0040] Example 3
[0041] The difference from Example 1 is only that in step (3), the mass ratio of the hydrogel and the oil gel is replaced by 6:4, and the other and Example 1 remain the same, to obtain a double gel synchronously encapsulating curcumin and EGCG.
[0042] Comparative Example 1
[0043] The difference from Example 1 is that in step (1), the oil gel agent therein is directly replaced by 20 parts by mass of a mixture of lacquer wax and beeswax to 20 parts by mass of beeswax, and in step (3), the mass ratio of the hydrogel and the oil gel is replaced by 7:3, and the other and Example 1 remain the same, to obtain a double gel synchronously encapsulating curcumin and EGCG.
[0044] Comparative Example 2
[0045] The difference from Comparative Example 1 is only that the mass ratio of the hydrogel and the oil gel is replaced by 6:4, and the other and Comparative Example 1 remain the same, to obtain a double gel synchronously encapsulating curcumin and EGCG.
[0046] Comparative Example 3
[0047] The difference from Example 1 is that in step (1), the oil gel agent therein is directly replaced by 20 parts by mass of a mixture of lacquer wax and beeswax to 20 parts by mass of lacquer wax, and in step (3), the mass ratio of the hydrogel and the oil gel is replaced by 7:3, and the other and Example 1 remain the same, to obtain a double gel synchronously encapsulating curcumin and EGCG.
[0048] Comparative Example 4
[0049] The difference from Comparative Example 3 is only that the mass ratio of the hydrogel and the oil gel is replaced by 6:4, and the other and Comparative Example 3 remain the same, to obtain a double gel synchronously encapsulating curcumin and EGCG.
[0050] Comparative Example 5
[0051] Steps (1) and (3) of Example 1 are omitted, and the other and Example 1 remain the same, to obtain a pure hydrogel loaded with EGCG.
[0052] Comparative Example 6
[0053] Steps (2) and (3) of Example 1 are omitted, and the other and Example remain the same, to obtain a pure oil gel loaded with curcumin.
[0054] Effect Example
[0055] 1. The gels prepared in Examples 1-3 and Comparative Examples 1-6 were observed by optical microscope, and the results are as follows Figure 1 The regular spherical oil droplets can be clearly observed in Example 1, indicating the formation of an oil gel embedded in a water gel (O / H type) system. When the proportion of oil gel is increased to 40% (Example 3), the system undergoes a phase transition, forming a structure in which the water gel is dispersed in the continuous phase of the oil gel. This enables the physical separation and stable coexistence of the two active ingredients. In Example 2 (30% oil gel proportion), the oil droplets are observed to exhibit partial aggregation, and the water phase exhibits an incomplete continuous state. This phenomenon indicates that a bi-continuous gel network structure is formed between the oil gel phase and the water gel phase, which is a characteristic of a typical bi-continuous (BC type) double gel.
[0056] When pure beeswax is used as the oil gel agent (Comparative Examples 1-2), a bi-continuous phase or water-in-oil double gel cannot be formed when the proportion of oil gel is less than 40%. When pure lacquer wax is used as the oil gel agent (Comparative Examples 3-4), larger and irregularly shaped droplets are observed, and obvious stratification occurs at the bottom, indicating that a single wax-based double gel structure is difficult to maintain. In contrast, based on the synergistic effect of the composite wax, stable bi-continuous or water-in-oil double gel systems can be successfully constructed even at a lower oil gel proportion (30%-40%).
[0057] 2. The dynamic viscoelasticity and steady shear viscosity of the gels prepared in Examples 1-3 and Comparative Examples 5-6 were tested using a rheometer, and the results are as follows Figure 2 The viscoelastic properties of the gels can be evaluated by the storage modulus (G') and loss modulus (G") of the frequency sweep. The G' of all samples is greater than the G', and all samples exhibit the typical characteristics of a gel. The G' and G" values of the samples of Examples 1-3 are higher than those of the sample of Comparative Example 5, but lower than those of the sample of Comparative Example 6. An increase in the proportion of oil gel promotes the closer arrangement of the dispersed phase, thereby enhancing the internal structure of the obtained gel, and ultimately causing the double gel to exhibit an increased G', indicating that the double gel system has a certain anti-deformation ability. The d) of the variable temperature scan experiment Figure 2 further confirms that an increase in the proportion of oil gel can significantly improve the G' and G" of the double gel during heating. The amplitude sweep results show that when the strain exceeds the critical value (0.3%), the pure oil gel exhibits obvious structural collapse (G' is lower than G"). However, within the same strain range, the water gel and the double gel both maintain a higher G' value than G", highlighting the role of the water gel in enhancing the structural stability of the double gel. The above data confirm that the prepared double gel has a higher anti-deformation ability than the pure water gel and the pure oil gel, and that increasing the proportion of oil gel has better performance.
[0058] 3. The crystal properties of the gels prepared in Examples 1-3 and Comparative Examples 5-6 were tested using X-ray diffraction (XRD) technique, and the results are shown in Figure a of Figure 3 Except for Comparative Example 5, the rest of the gels showed relatively prominent diffraction peaks, and the peak intensity was higher as the oil gel ratio increased, which indicated that the hydrogel mainly had an amorphous structure, and the crystal transformation of the gel molecules occurred after the introduction of the lacquer wax and beeswax oil gel. In addition, the higher the oil gel ratio, the more stable the gel system formed, and the more ordered the crystallization arrangement of the double gel molecules.
[0059] 4. The thermodynamic properties of the double gels prepared in Examples 1-3 were tested by differential scanning calorimetry (DSC), and the results are shown in Figure b of Figure 3 It was found that the double gels all had a melting peak above 105°C, and the peak temperature did not show a significant difference, however, the melting peak in the sample of Example 2 was more sharp, and no melting peak at a lower temperature was observed, which was attributed to the unique double-continuous phase structure, indicating that the eutectic behavior of the substances in the system of Example 2 was possible.
[0060] 5. The retention rates of curcumin and EGCG after heat and ultraviolet treatment are shown in Figure Figure 4
[0061]
[0062] In the formula, W1 is the total mass of the active ingredients in the initial sample, and W2 is the total mass of the active ingredients in the sample after heating or ultraviolet treatment.
[0063] Under the condition of heat treatment at 85°C for 2h, the retention rate of EGCG in the pure hydrogel was 54.5% (Comparative Example 5), and the retention rate of curcumin in the pure oil gel was 50.5% (Comparative Example 6), while after the encapsulation of the double gel (Examples 1-3), the retention rates of EGCG and curcumin were increased to more than 70% and 75%, respectively, indicating that the double gel could effectively improve the thermal stability of EGCG and curcumin. It is worth noting that the protective effect of different double gel structures on the two active ingredients was selective: the H / O type (Example 3) had the best protective effect on EGCG (the retention rate was as high as 86.5%), while the BC double-continuous type (Example 2) was more conducive to the stability of curcumin (the retention rate was as high as 99.5%). In terms of ultraviolet stability (irradiation at 365nm for 2h), the H / O type (Example 3) showed the best protective effect on curcumin and EGCG. This result indicated that the H / O type double gel structure dominated by the oil phase could improve the stability of curcumin and EGCG under heat and ultraviolet conditions. In summary, the double gel system had significant advantages in protecting curcumin and EGCG.
[0064] The above embodiments are the preferred embodiments of the present application, but the embodiments of the present application are not limited to the above embodiments, and any changes, modifications, substitutions, combinations, simplifications, etc. made without departing from the spirit and principles of the present application should be equivalent replacement manners and should be included in the protection scope of the present application.
Claims
1. A method of preparing a low-fat double gel encapsulating curcumin and EGCG in sync, characterized by The method comprises the following steps: (1) adding curcumin and oil gel to vegetable oil, stirring to dissolve to obtain curcumin-loaded oil gel; (2) adding EGCG and water gel to water, stirring to dissolve to obtain EGCG-loaded water gel; (3) mixing the curcumin-loaded oil gel obtained in step (1) with the EGCG-loaded water gel obtained in step (2), and then stirring to obtain the low-fat double gel synchronously encapsulating curcumin and EGCG.
2. The method according to claim 1, wherein the oil gel in step (1) is at least one of lacquer wax, beeswax, glycerol monostearate, rice bran wax, candelilla wax, carnauba wax, sunflower wax, and corn wax; preferably at least two of them, and the mixture must contain lacquer wax.
3. The method according to claim 1, wherein the oil gel in step (1) is a mixture of lacquer wax and beeswax, and the mass percentage of lacquer wax in the mixture is 60-80%.
4. The method according to claim 1, wherein the vegetable oil in step (1) is at least one of camellia oil, soybean oil, rapeseed oil, peanut oil, sunflower oil, rice bran oil, corn oil, flaxseed oil, olive oil, wheat germ oil, cottonseed oil, almond oil, sesame oil, coconut oil, and palm oil; The amount of curcumin, oil gel and vegetable oil in step (1) satisfies: the addition amount of oil gel is 10-30% of the mass of vegetable oil; the addition amount of curcumin is 0.1-1.0% of the mass of vegetable oil.
5. The method according to claim 1, wherein the water gel in step (2) comprises one of gelatin, pectin, whey protein isolate, κ-carrageenan, xanthan gum, gellan gum, sodium alginate, guar gum, and locust bean gum; The amount of EGCG, water gel and water in step (2) satisfies: the addition amount of water gel is 8-12% of the mass of water; the addition amount of EGCG is 0.1-2.0% of the mass of water.
6. The method according to claim 1, wherein the mass ratio of curcumin-loaded oil gel to EGCG-loaded water gel in step (3) is 2:8-4:
6.
7. The method according to claim 1, wherein the stirring in step (3) is mixing by stirring at 70-80℃, and then cooling to solidification to obtain the low-fat double gel synchronously encapsulating curcumin and EGCG; wherein the stirring speed is 200-1200 rpm, the stirring time is 25-35 min, and the cooling is cooling at 0-5℃.
8. A low-fat double gel synchronously encapsulating curcumin and EGCG prepared by the method according to any one of claims 1-7. 9. The low-fat double gel encapsulating curcumin and EGCG in sync according to claim 8, characterized in that: The obtained low-fat double gel encapsulating curcumin and EGCG in sync is one of O / H type or H / O type or bi-continuous type double gel.
10. Use of the low-fat double gel encapsulating curcumin and EGCG in sync according to claim 8 or 9 for the preparation of functional fat replacers.