Preparation method of pericarpium citri reticulatae extract emulsion

Abstract

The invention provides a preparation method of a pericarpium citri reticulatae extract emulsion. The preparation method comprises the following steps: placing dried orange peel in an alkaline solution with the pH value of 11.6-12.4, extracting at 40-70 DEG C for 0.5-1.5 h, separating, clarifying by using a ZTC1 + 1 clarifying agent, adding a stabilizer, uniformly mixing to obtain a water phase, uniformly mixing the water phase with vegetable oil, and sequentially shearing and homogenizing to obtain the dried orange peel extract emulsion. Through specific selection of extraction, clarification and stabilization treatment modes, compared with a traditional extraction, clarification and stabilization treatment mode, the extraction rate of polysaccharide and flavone in the pericarpium citri reticulatae is remarkably increased at the same time, the extraction rate of hesperidin which is a special active ingredient is remarkably increased, impurities in the pericarpium citri reticulatae extract emulsion can be more effectively removed, and the extraction efficiency of the pericarpium citri reticulatae extract emulsion is improved. Higher stability and flavone bioavailability are realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of plant extraction, and more specifically relates to a method for preparing a tangerine peel extract emulsion. Background Art

[0002] Tangerine peel, an outstanding example of both medicinal and edible properties, is prepared from the dried, mature peel of the Rutaceae plant Citrus and its cultivated varieties. It has the effects of strengthening the spleen and regulating qi, and drying dampness and resolving phlegm. Tangerine peel contains a variety of active ingredients, such as polysaccharides and flavonoids, which provide tangerine peel extracts with significant antioxidant, immune-enhancing, glucose tolerance-improving, and liver-protecting effects. Furthermore, it is worth mentioning that tangerine peel flavonoids also contain a relatively special active ingredient, hesperidin, which not only has powerful antioxidant, digestive, and anti-inflammatory effects, but also promotes cholesterol metabolism and lowers low-density lipoprotein cholesterol levels in the blood, thereby reducing the risk of cardiovascular disease. Therefore, finding methods to increase the content of polysaccharides and flavonoids, especially hesperidin, in tangerine peel extracts is crucial for the further development and promotion of tangerine peel products.

[0003] At present, the methods for extracting polysaccharides from tangerine peel are mostly water extraction, and the methods for extracting flavonoids are mostly enzymatic extraction, surfactant extraction, etc. However, the extraction rates of these methods are low, and they do not achieve the simultaneous extraction of polysaccharides and flavonoids, nor do they increase the extraction rate of hesperidin, a special active ingredient. Summary of the Invention

[0004] The present invention aims to overcome the deficiencies of the prior art and aims to provide a method for preparing a tangerine peel extract emulsion. By specifically selecting extraction, clarification and stabilization treatment methods, compared with traditional extraction, clarification and stabilization treatment methods, the present invention not only significantly improves the extraction rates of polysaccharides and flavonoids in tangerine peel, but also significantly improves the extraction rate of hesperidin, a special active ingredient, and can more effectively remove impurities in the tangerine peel extract emulsion, thereby achieving higher stability and flavonoid bioavailability.

[0005] The first object of the present invention is to provide a method for preparing a tangerine peel extract emulsion.

[0006] The second object of the present invention is to provide a tangerine peel extract emulsion obtained by the above method.

[0007] The third object of the present invention is to provide the use of the above-mentioned tangerine peel extract emulsion as and / or in the preparation of tangerine peel products.

[0008] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0009] The present invention provides a method for preparing a tangerine peel extract emulsion, comprising the following steps:

[0010] S1. Place the tangerine peel in an alkaline solution with a pH of 11.6 to 12.4, extract at 40 to 70°C for 0.5 to 1.5 hours, and separate;

[0011] S2. Clarify the S1 product with ZTC1+1 clarifier;

[0012] S3. Add a stabilizer to the S2 product, mix to obtain an aqueous phase, then mix the aqueous phase with the vegetable oil, and sequentially shear and homogenize to obtain;

[0013] Among them, the stabilizer in S3 is xanthan gum, carrageenan and sodium carboxymethyl cellulose in a mass ratio of 2-4:2-4:1-2, the volume ratio of the aqueous phase to the vegetable oil is 90-95:5-10, and the shearing is shearing at 10000-13000 rpm for 2-4 minutes.

[0014] Preferably, the tangerine peel described in S1 is one or more of green peel, two red peel, and big red peel, and the most preferred is big red peel that has been stored for more than 3 years.

[0015] Preferably, the particle size of the tangerine peel described in S1 is 40 to 60 mesh, most preferably 60 mesh.

[0016] Preferably, the usage ratio of the tangerine peel to the alkaline solution in S1 is 1 g:15-35 mL, most preferably 1 g:20 mL.

[0017] Preferably, the alkaline solution in S1 is a sodium carbonate solution with a concentration of 0.1 to 0.15M, such as 0.1M or 0.15M.

[0018] Preferably, the extraction in S1 is performed at 60° C. for 1 h.

[0019] Preferably, the separation in S1 is performed by centrifugation at 20-30°C and 4000-10000 g for 5-20 min, most preferably by centrifugation at 25°C and 8000 g for 10 min.

[0020] Preferably, the clarification treatment in S2 is as follows: adding component B of the ZTC1+1 clarifier to the tangerine peel extract emulsion, mixing, water bathing at 40-60° C. for 1.5-2.5 hours, then adding component A of the ZTC1+1 clarifier, mixing, standing to separate the layers, and then separating.

[0021] Further preferably, the clarification treatment in S2 is: adding component B of the ZTC1+1 clarifier to the tangerine peel extract emulsion, mixing, and then water bathing at 40-60° C. for 1.5-2.5 hours, and then adding component A of the ZTC1+1 clarifier, mixing, and then standing for 263.4-277.6 minutes, and then separating.

[0022] Further preferably, the final concentration of the B component in the tangerine peel extract emulsion is 0.04% (w / v) to 0.06% (w / v); the final concentration of the A component in the tangerine peel extract emulsion is 0.02% (w / v) to 0.03% (w / v).

[0023] More preferably, the water bath is at 50° C. for 2 h.

[0024] More preferably, the mixture is stirred for 0.4 to 0.6 minutes during the standing process, such as first standing for 28 to 32 minutes, then stirring at a speed of 45 to 55 rpm for 0.4 to 0.6 minutes, and then standing again for 235 to 245 minutes. Most preferably, the mixture is first standing for 30 minutes, then stirring at a speed of 50 rpm for 0.5 minutes, and then standing again for 240 minutes.

[0025] Further preferably, the separation is performed in sequence by filtration, centrifugation, dialysis, and concentration, such as: first filtering with 5 to 7 layers of gauze with a mesh size of 200 to 400 (preferably 6 layers of gauze with a mesh size of 300), then centrifuging at 20 to 30°C and 4000 to 10000g for 5 to 20 minutes (most preferably at 25°C and 8000g for 10 minutes), then taking the supernatant obtained by centrifugation, dialyzing to remove components with a molecular weight of less than 100 Da, and finally concentrating by rotary evaporation at 45 to 50°C (most preferably at 50°C).

[0026] Preferably, the final concentration of the xanthan gum in the tangerine peel extract emulsion is 0.15% (w / v) to 0.25% (w / v), and most preferably 0.2% (w / v).

[0027] Preferably, the mass ratio of xanthan gum, carrageenan and sodium carboxymethyl cellulose is 2:2:1.

[0028] Preferably, the vegetable oil in S3 is one or more of corn oil, soybean oil, and sunflower oil, and corn oil is most preferred.

[0029] Preferably, the volume ratio of the aqueous phase to the vegetable oil is 95:5.

[0030] Preferably, the shearing is performed at 12000 rpm for 3 min.

[0031] Preferably, the homogenization in S3 is carried out at 10-60 MPa for 1-3 min, and most preferably at 10 MPa for 1 min.

[0032] Preferably, the homogenization is repeated 2 to 3 times.

[0033] The tangerine peel extract emulsion obtained by the above method has fewer impurities, higher stability and flavonoid bioavailability, higher polysaccharide and flavonoid contents, and a higher hesperidin content among the flavonoids, which can better exert the efficacy of the tangerine peel extract emulsion. Therefore, the tangerine peel extract emulsion obtained by the above method and the use of the tangerine peel extract emulsion as and / or in preparing tangerine peel products should be within the scope of protection of the present invention.

[0034] The present invention has the following beneficial effects:

[0035] 1. By specifically selecting the extraction, clarification and stabilization treatment methods, the present invention not only significantly improves the extraction rates of polysaccharides and flavonoids in tangerine peel, but also significantly improves the extraction rate of hesperidin, a special active ingredient, compared with traditional extraction, clarification and stabilization treatment methods. It can also more effectively remove impurities in the tangerine peel extract emulsion, thereby achieving higher stability and flavonoid bioavailability.

[0036] 2. The process of the present invention is simple, the conditions are easy to control, and it is conducive to industrial-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a photo of tangerine peel extract.

[0038] Figure 2 The results are for the stability test of tangerine peel extract emulsion stored directly at 30°C for 5 days.

[0039] Figure 3 These are the stability test results of tangerine peel extract emulsion after sterilization and then storage at 30℃ for 5 days.

[0040] Figure 4 These are the particle size stability test results of tangerine peel extract emulsion. DETAILED DESCRIPTION

[0041] The present invention will be further described below with reference to the accompanying drawings and specific examples, but the examples do not limit the present invention in any way. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0042] Unless otherwise specified, the reagents and materials used in the following examples were commercially available.

[0043] 1. Determination of polysaccharide content (phenol-sulfuric acid method) and calculation of its extraction rate

[0044] First, glucose solutions of different concentrations (0, 20, 40, 60, 80, 100, 120, 140 μg / mL) were prepared, and their absorbances were measured at 490 nm using a spectrophotometer to draw a standard curve of the polysaccharide.

[0045] After the volume of testing sample was diluted 500 times with distilled water, 0.5 mL of 6% (w / v) phenol solution (prepared before use, stored in dark) was added in 1 mL of diluent, followed by 2.5 mL of 98.3 wt% concentrated sulfuric acid. After standing for 10 min, the sample was vortexed at 600 rpm for 0.5 min and placed for 20 min. The absorbance was then measured at 490 nm using a spectrophotometer. The polysaccharide content in the testing sample was determined according to a standard curve, and the extraction yield of the polysaccharide was calculated according to "the quality of polysaccharide in the polysaccharide extraction yield (%)=testing sample / the quality of original dried tangerine peel × 100%".

[0046] 2. Determination of flavonoid content (spectrophotometry) and calculation of extraction rate

[0047] First, rutin solutions of different concentrations (0, 20, 40, 60, 80, 100, 200 μg / mL) were prepared, and their absorbances were measured at 510 nm using a spectrophotometer to draw a standard curve of flavonoids.

[0048] After the volume of the test sample was diluted 10-fold with distilled water, 0.3 mL of 5% (w / v) sodium nitrite solution was added to 5 mL of the diluent, and the mixture was allowed to stand and incubated at 30° C. for 5 min. Then, 0.3 mL of 10% (w / v) AlCl solution was added, and the mixture was incubated at 30° C. for 6 min. Then, 2 mL of 1 M NaOH solution was added, and the volume was made up to 10 mL with deionized water. The mixture was allowed to stand for 15 min, and the absorbance was measured at 510 nm using a spectrophotometer. The flavonoid content in the test sample was determined according to the standard curve, and the flavonoid extraction yield was calculated according to “flavonoid extraction yield (%)=mass of flavonoids in the test sample / mass of original dried tangerine peel×100%”.

[0049] 3. Determination of Hesperidin Content (UPLC Method) and Calculation of Extraction Yield

[0050] The hesperidin content in the sample was determined by UPLC using the following conditions: a 0.1% (v / v) aqueous formic acid solution (phase A) and pure acetonitrile (phase B) as the mobile phases, a flow rate of 1 mL / min, an Agilent Eclipse XDB-C18 column, a column temperature of 35°C, an injection volume of 10 μL, and an elution program of: 0 → 5 min: 25% (v / v) mobile phase B; 5 → 15 min: 25% (v / v) → 80% (v / v) mobile phase B; 15 → 20 min: 80% (v / v) mobile phase B; 20 → 25 min: 25% (v / v) mobile phase B. The hesperidin extraction yield was calculated as follows: "Hesperidin extraction yield (%) = mass of hesperidin in the sample / mass of the original dried tangerine peel × 100%."

[0051] Example 1

[0052] 1. Alkali extraction

[0053] Take 30g of dried tangerine peel powder (large red peel stored for 3 years, particle size 60 mesh), divide it into 3 equal parts, add it to 200mL of water, 200mL of 0.1M sodium carbonate solution (pH is 11.6), and 200mL of 0.15M sodium carbonate solution (pH is 12.4), respectively, extract at 60℃ for 1h, and centrifuge at 25℃ and 8000g for 10min. The supernatant obtained by centrifugation is the tangerine peel extract.

[0054] The contents of polysaccharides, flavonoids and hesperidin in the tangerine peel extract were detected, and the extraction rates were calculated. The results are shown in Table 1.

[0055] Table 1

[0056] pH Polysaccharide extraction rate (%) Flavonoid extraction rate (%) Hesperidin extraction rate (%) 0M 7.0 31.94±3.22b 0.96±0.01b 0.18±0.00b 0.1M 11.6 33.32±0.12a 1.19±0.05a 0.53±0.03a 0.15M 12.4 33.64±0.20a 1.22±0.02a 0.51±0.01a

[0057] 2. Surfactant Extraction

[0058] Take 40g of dried tangerine peel powder (large red peel stored for 3 years, particle size 60 mesh), divide it into 4 parts, add them into 200mL of 0% (v / v), 0.05% (v / v), 0.1% (v / v), and 1% (v / v) Tween 80 aqueous solution, respectively, extract at 60℃ for 1h, and centrifuge at 25℃ and 8000g for 10min. The supernatant obtained by centrifugation is the tangerine peel extract.

[0059] The contents of polysaccharides, flavonoids and hesperidin in the tangerine peel extract were detected, and the extraction rates were calculated. The results are shown in Table 2.

[0060] Table 2

[0061] Polysaccharide extraction rate (%) Flavonoid extraction rate (%) Hesperidin extraction rate (%) 0% (v / v) 31.94±3.22a 0.96±0.01c 0.18±0.00a 0.05% (v / v) 28.88±0.90a 1.07±0.04b 0.09±0.00b 0.1% (v / v) 29.12±1.64a 1.10±0.01ab 0.08±0.00c 1% (v / v) 28.20±0.02a 1.14±0.04a 0.12±0.01d

[0062] 3. Enzymatic Extraction

[0063] Take 30g of dried tangerine peel powder (big red peel stored for 3 years, particle size 60 mesh), divide it into 3 parts, add them into 200mL of 0% (w / v), 0.01% (w / v), and 0.05% (w / v) cellulase aqueous solutions, respectively, extract at 50℃ (in order to provide the most suitable enzymolysis temperature for cellulase, the extraction temperature is adjusted here) after 1h, and then centrifuge at 25℃, 8000g for 10min. The supernatant obtained by centrifugation is the tangerine peel extract.

[0064] The contents of polysaccharides, flavonoids and hesperidin in the tangerine peel extract were detected, and the extraction rates were calculated. The results are shown in Table 3.

[0065] Table 3

[0066] Polysaccharide extraction rate (%) Flavonoid extraction rate (%) Hesperidin extraction rate (%) 0% (w / v) 31.94±3.22a 0.96±0.01ab 0.18±0.00a 0.01% (w / v) 32.36±0.50a 0.95±0.02b 0.16±0.00b 0.05% (w / v) 32.94±0.20a 0.97±0.01a 0.17±0.01ab

[0067] In summary, compared with water extraction, there was no significant difference in the polysaccharide extraction rate for surfactant extraction and enzymatic extraction, while the polysaccharide extraction rate for alkaline solution extraction was significantly improved, and the hesperidin extraction rate obtained by alkaline solution extraction was more than three times that of the other two extraction methods (surfactant extraction and enzymatic extraction). This shows that the alkaline extraction method of the present invention not only significantly improves the extraction rate of polysaccharides and flavonoids in dried tangerine peel, but also significantly improves the extraction rate of hesperidin, a special active ingredient, compared with traditional extraction methods (water extraction, enzymatic extraction, surfactant extraction, etc.).

[0068] Example 2

[0069] It was observed that the tangerine peel extract obtained by alkali extraction in Example 1 was still turbid. This was because the tangerine peel extract at this time still contained impurities such as tannins, proteins and small particles. Therefore, in order to obtain a clearer tangerine peel extract, a clarifier was added to remove impurities and clarify the extract in this example.

[0070] 1. Experimental Methods

[0071] (1) Clarification using ZTC1+1 Clarifier B 0.04% + A 0.02%

[0072] First, component A and component B in ZTC1+1 clarifier (purchased from Tianjin Zhentiancheng Technology Co., Ltd.) were dissolved in deionized water to prepare 1% (w / v) component A solution and 1% (w / v) component B solution, which were set aside.

[0073] 1% (w / v) of component B solution was added to 100 mL of the tangerine peel extract obtained by extraction with the 0.1 M sodium carbonate solution of Example 1 (so that the concentration of the 1% (w / v) component B solution in the tangerine peel extract was 4% (w / v), i.e., the final concentration of component B was 0.04% (w / v)), mixed, and incubated in a water bath at 50° C. for 2 h (stirring once every 30 min during this period, and flocculent precipitates were visible at the end of the water bath); 1% (w / v) of component A solution was then added (so that the concentration of the 1% (w / v) component A solution in the tangerine peel extract was 2% (w / v), i.e., the final concentration of component A was 0.04% (w / v)). The mixture was stirred at 50 rpm for 0.5 min after standing for 30 min, and then allowed to stand for 4 h. The large flocs were removed by coarse filtration through 300-mesh 6-layer gauze. The mixture was then centrifuged at 25°C and 8000 g for 10 min. The supernatant was dialyzed in flowing deionized water for 24 h using a semipermeable membrane with a cutoff of 100 Da to remove salt ions and other small molecular components (i.e., components with a molecular weight of more than 100 Da were collected). The mixture was finally concentrated by rotary evaporation at 50°C to the original volume of the tangerine peel extract to obtain the clarified and impurity-removed tangerine peel extract.

[0074] (2) Clarification using ZTC1+1 Clarifier B 0.06% + A 0.03%

[0075] The same method as that using ZTC1+1 clarifier B 4%+A 2% for clarification is used, except that the final concentration of component B is 0.06% (w / v) and the final concentration of component A is 0.03% (w / v).

[0076] (3) Clarification with 95% (v / v) ethanol solution

[0077] To 100 mL of the tangerine peel extract obtained by extraction with the 0.1 M sodium carbonate solution of Example 1, 95% (v / v) ethanol solution was added (to a final ethanol concentration of 20% (v / v)). After dispersion with stirring, the mixture was placed in a 4°C refrigerator for precipitation for 24 h, and then centrifuged at 25°C, 8000 g for 10 min. The supernatant obtained by centrifugation was dialyzed in flowing deionized water for 24 h using a semipermeable membrane with a cutoff of 100 Da to remove salt ions and other small molecular components (i.e., components with a molecular weight of more than 100 Da were collected). Finally, the mixture was concentrated by rotary evaporation at 50°C to the original volume of the tangerine peel extract to obtain the clarified and impurity-removed tangerine peel extract.

[0078] 2. Experimental Results

[0079] Take the 0.1M sodium carbonate solution extracted with the tangerine peel extract obtained in Example 1 and the three clarified and impurity-removed tangerine peel extracts, and take pictures to observe their clarity. The results are as follows: Figure 1 As shown. The "original extract" represents the tangerine peel extract obtained by extraction with 0.1M sodium carbonate solution in Example 1; "ZTC1+1B4%+A2%" represents the tangerine peel extract clarified using ZTC1+1 Clarifier B 0.04%+A 0.02%; "ZTC1+1B6%+A3%" represents the tangerine peel extract clarified using ZTC1+1 Clarifier B 0.06%+A 0.03%; and "Ethanol 20%" represents the tangerine peel extract clarified using 95% (v / v) ethanol solution. It can be seen that after treatment with 95% (v / v) ethanol solution, the tangerine peel extract still has significant turbidity; however, the tangerine peel extract clarified by the specific method of the present invention has significantly fewer impurities, indicating that the clarification method of the present invention can more effectively remove impurities from the tangerine peel extract.

[0080] In addition, the polysaccharide and flavonoid contents in the tangerine peel extract obtained by extraction with 0.1 M sodium carbonate solution in Example 1 and the tangerine peel extract clarified by the above-mentioned (1) and (2) were also tested, and the results are shown in Table 4. It can be seen that the clarification method of the present invention does not significantly affect the polysaccharide and flavonoid contents in the tangerine peel extract.

[0081] Table 4

[0082] Polysaccharide content (mg / mL) Flavonoid content (μg / mL) The tangerine peel extract obtained by alkali extraction in Example 1 15.97±1.61a 104.39±6.07a (1)ZTC1+1B4%+A2% 15.90±2.74a 104.11±11.99a (2)ZTC1+1B6%+A3% 17.80±1.58a 107.73±0.09a

[0083] Example 3

[0084] In order to further improve the stability of the tangerine peel extract, a stabilizer was added to the tangerine peel extract obtained by clarifying the tangerine peel extract using ZTC1+1 clarifier B 0.06%+A 0.03% in Example 2 for stabilization.

[0085] 1. Experimental Methods

[0086] (1) Stabilization treatment with stabilizer A

[0087] To 100 mL of the tangerine peel extract obtained by clarifying with ZTC1+1 clarifier B 0.06% + A 0.03% in Example 2, xanthan gum, carrageenan, and sodium carboxymethyl cellulose were added (so that the final concentrations in the tangerine peel extract were 0.2% (w / v), 0.2% (w / v), and 0.1% (w / v), respectively). After mixing to obtain an aqueous phase, the aqueous phase was mixed with corn oil in a volume ratio of 95:5, and then high-speed shearing was carried out at 12,000 rpm for 3 min. Subsequently, homogenization was carried out using a high-pressure homogenizer at 10 MPa for 1 min (repeated 3 times) to obtain a stabilized tangerine peel extract emulsion.

[0088] (2) Stabilization treatment with stabilizer B

[0089] The method of stabilization using stabilizer A is the same as that using sodium carboxymethyl cellulose with pectin, and the amount of pectin is adjusted to 0.5% (w / v). That is, the stabilizers are xanthan gum, carrageenan, and pectin, and their final concentrations in the tangerine peel extract are 0.2% (w / v), 0.2% (w / v), and 0.5% (w / v), respectively.

[0090] (3) Stabilization treatment with stabilizer C

[0091] The method of stabilization using stabilizer A is the same as that using sodium carboxymethyl cellulose with pectin, that is, the stabilizers are xanthan gum, carrageenan and pectin, and their final concentrations in the tangerine peel extract are 0.2% (w / v), 0.2% (w / v) and 0.1% (w / v), respectively.

[0092] (4) Stabilization treatment with stabilizer D

[0093] The method of stabilization using stabilizer A is the same as that using stabilizer A, except that carrageenan is replaced by pectin, and the amount of sodium carboxymethyl cellulose is adjusted to 0.2% (w / v), that is, the stabilizers are xanthan gum, pectin and sodium carboxymethyl cellulose, and their final concentrations in the tangerine peel extract are 0.2% (w / v), 0.2% (w / v) and 0.2% (w / v), respectively.

[0094] 2. Experimental Results

[0095] (1) Appearance stability

[0096] Take two 10 mL portions of the tangerine peel extract emulsion stabilized with stabilizers A to D. Store one portion directly at 30°C for 5 days, and sterilize the other portion at 121°C for 15 minutes before storing at 30°C for another 5 days. Take photos and observe the appearance and stability of the tangerine peel extract emulsion at 0, 1, 3, and 5 days.

[0097] The results of storing directly at 30℃ for 5 days are as follows Figure 2 As shown, the tangerine peel extract emulsion stabilized with stabilizer C showed stratification on the 3rd day, and its stability was significantly worse than that of the tangerine peel extract emulsions treated with the other three stabilizers.

[0098] After sterilization, the results of storage at 30℃ for 5 days are as follows: Figure 3 As shown, it can be seen that the tangerine peel extract emulsion stabilized by stabilizers B to C showed stratification on the first day, and the tangerine peel extract emulsion stabilized by stabilizer D also showed obvious stratification on the fifth day, indicating that the stability of the tangerine peel extract emulsion stabilized by stabilizers B to D is significantly worse than that of the tangerine peel extract emulsion stabilized by stabilizer A.

[0099] (2) Particle size stability

[0100] 10 mL of the tangerine peel extract emulsion stabilized with stabilizers A to D was taken, its particle size was measured, and then sterilized at 121° C. for 15 min. The particle size was then measured again. The emulsion was then stored at 30° C. for 5 days, and the particle size was measured on the third and fifth days of storage. The particle size was measured by dynamic light scattering analysis using a Zetasizer Nano (Malvern Paralytical, Malvern) at 25° C. using an argon laser (λ=658 nm) and a refractive index of 1.330 to determine the particle size distribution.

[0101] The results are as follows Figure 4 As shown, it can be seen that the particle size of the tangerine peel extract emulsion stabilized with stabilizer A is less than 1 μm before and after sterilization and within 5 days of storage, and the particle size does not change significantly throughout the entire process, indicating that its particle size stability is significantly better than that of the tangerine peel extract emulsion stabilized with stabilizers B to D.

[0102] (3) Bioavailability

[0103] The tangerine peel extract emulsion stabilized with stabilizer A and the tangerine peel extract obtained by extraction with 0.1 M sodium carbonate solution in Example 1 were taken as test samples, and the bioavailability of the flavonoids was determined after in vitro digestion.

[0104] The in vitro digestion process is as follows:

[0105] ① Oral digestion stage: 10 mL of the sample to be tested was mixed with 10 mL of oral digestion solution (0.1594 g sodium chloride, 0.0328 g ammonium nitrate, 0.0636 g potassium dihydrogen phosphate, 0.0202 g potassium chloride, 0.0308 g potassium citrate, 0.0021 g sodium urate, 0.0198 g urea, and 0.0146 g sodium bicarbonate dissolved in 100 mL of deionized water). The pH was adjusted to 6.8 with 1 M NaOH solution. 0.3 g of mucin was added and stirred until completely dissolved. The mixture was then placed in a temperature-controlled shaker at 37°C and 100 rpm for 1 min to simulate oral digestion.

[0106] ② Gastric digestion stage: The above oral digestion products were mixed with gastric digestive fluid (0.2 g sodium chloride and 0.7 mL hydrochloric acid were dissolved in 100 mL deionized water, and the pH was adjusted to 2.0 with 1.0 M hydrochloric acid) at a volume ratio of 1:1, and the pH was adjusted to 2.5 with 0.2 M NaOH solution. 0.32 g pepsin was added and stirred until completely dissolved. The mixture was then placed in a temperature-controlled shaker at 37°C and 100 rpm for 4 h to simulate gastric digestion.

[0107] ③ Small intestinal digestion stage: Take 40 mL of gastric digestion product, adjust the pH to 7.0 with 0.2 M NaOH solution, then add 4 mL of bile salt solution (5 mg / mL) and 2.5 mL of pancreatic lipase (4.8 mg / mL), and place it in a temperature-controlled shaker at 37°C and 100 rpm for 2 h to simulate small intestinal digestion.

[0108] The bioavailability was determined by centrifuging the small intestinal digestion product at 7500 g and 4°C for 50 min, collecting the mixed micellar phase in the intermediate layer, and removing the large droplets through a filter with a pore size of 0.45 μm. The flavonoid content at this point was then determined, and the bioavailability of the flavonoid was calculated according to the formula "flavonoid bioavailability (%) = flavonoid mass / flavonoid mass in the test sample × 100%".

[0109] The results showed that the bioavailability of flavonoids in the tangerine peel extract emulsion stabilized with stabilizer A was 49.3%, and the bioavailability of flavonoids in the tangerine peel extract obtained by extraction with 0.1 M sodium carbonate solution in Example 1 was 17.8%, indicating that the tangerine peel extract emulsion prepared by the method of the present invention has high stability and flavonoid bioavailability.

[0110] 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 considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A method for preparing a tangerine peel extract emulsion, characterized in that: The steps include: S1. Place the tangerine peel in an alkaline solution with a pH of 11.6 to 12.4, extract at 40 to 70°C for 0.5 to 1.5 hours, and separate; S2. Clarify the S1 product with ZTC1+1 clarifier; S3. Add a stabilizer to the S2 product, mix to obtain an aqueous phase, then mix the aqueous phase with the vegetable oil, and sequentially shear and homogenize to obtain; Among them, the stabilizer in S3 is xanthan gum, carrageenan and sodium carboxymethyl cellulose in a mass ratio of 2-4:2-4:1-2, the volume ratio of the aqueous phase to the vegetable oil is 90-95:5-10, and the shearing is shearing at 10000-13000 rpm for 2-4 minutes.

2. The method according to claim 1, characterized in that The usage ratio of the dried tangerine peel described in S1 to the alkaline solution is 1g:15-35mL.

3. The method according to claim 1, characterized in that The alkaline solution in S1 is a sodium carbonate solution with a concentration of 0.1 to 0.15 M.

4. The method according to claim 1, characterized in that The separation in S1 is performed by centrifugation at 20-30°C and 4000-10000g for 5-20 minutes.

5. The method according to claim 1, characterized in that: The clarification treatment in S2 is as follows: adding component B of the ZTC1+1 clarifier to the tangerine peel extract emulsion, mixing, and water bathing at 40-60° C. for 1.5-2.5 hours, then adding component A of the ZTC1+1 clarifier, mixing, standing and separating.

6. The method according to claim 5, characterized in that The final concentration of the B component in the tangerine peel extract emulsion is 0.04% (w / v) to 0.06% (w / v); the final concentration of the A component in the tangerine peel extract emulsion is 0.02% (w / v) to 0.03% (w / v).

7. The method according to claim 1, characterized in that The final concentration of the xanthan gum in the tangerine peel extract emulsion is 0.15% (w / v) to 0.25% (w / v).

8. The method according to claim 1, characterized in that: The homogenization in S3 is carried out at 10 to 60 MPa for 1 to 3 minutes.

9. The tangerine peel extract emulsion obtained by the method according to any one of claims 1 to 8.

10. Use of the tangerine peel extract emulsion according to claim 9 as and / or in the preparation of tangerine peel products.

Images