Preparation technology and application of fruit powder product with high citrus flavonoid content

Abstract

This application belongs to the field of food processing technology, and particularly relates to a preparation technology and application of fruit powder products with high citrus flavonoid content. The preparation technology of fruit powder products with high citrus flavonoid content provided by this application first extracts blood orange peel through supercritical CO2 combined with ethanol extraction. The obtained blood orange peel flavonoid extract contains rich polymethoxylated flavonoid active ingredients, flavanones, flavonols, and flavonoid active ingredients. After being added to fruit powder, the types of flavonoids and the total flavonoid content are greatly increased, and the antioxidant and other biological activities are improved, thereby solving the problem of the lack of deep processing technology for whole blood oranges in the prior art.

Description

Technical Field

[0001] This application belongs to the field of food processing technology, and in particular relates to the preparation technology and application of fruit powder products with high citrus flavonoid content. Background Technology

[0002] Blood oranges are a special variety of sweet orange belonging to the genus Citrus in the family Rutaceae. At maturity, their flesh turns blood-red due to the presence of flavonoids such as anthocyanins and flavonols. These compounds give blood oranges their unique color and flavor, and are also beneficial to human health. Currently, the common way to utilize blood oranges is limited to eating the flesh fresh or making juice, with the peel often discarded. This method ignores the abundant active ingredients in the blood orange peel, thus missing the opportunity to further extract and utilize these beneficial components.

[0003] Traditional Chinese medicine considers every part of the citrus fruit to be medicinal, from the peel to the pulp and even the seeds, all possessing significant medicinal value. Among these, the peel is the most widely used and well-known. Aged citrus peel, known as "Chenpi" (aged peel), is warm in nature and bitter in taste, possessing the effects of strengthening the spleen, regulating qi, and resolving dampness and phlegm. Literature indicates that blood orange peel is rich in flavonoids, which exhibit important antioxidant, neuroprotective, antitumor, antibacterial, anti-inflammatory, and anti-obesity bioactivities, making them crucial active ingredients in blood orange peel. From traditional methods to modern high-tech approaches, numerous studies have mentioned and optimized different methods for extracting citrus flavonoids. Each method has its unique advantages and limitations in terms of yield, cost, properties, and efficiency. Therefore, choosing an appropriate extraction method is crucial for the utilization of citrus flavonoids. Although ethanol extraction is simple to operate, requires minimal equipment, and can extract the active flavonoid components from blood orange flavonoids, its extraction efficiency is not ideal. Supercritical CO2 extraction technology is renowned for its high efficiency and environmental friendliness, making it suitable for extracting flavonoid active ingredients. However, this technology exhibits some selectivity in its application to flavonoids. Flavonoids are not only numerous and diverse but also possess complex and varied structural types, resulting in diverse physiological activities. Different extraction methods yield different types and total amounts of flavonoid active ingredients, and single extraction techniques often have limitations. Sometimes, two single extraction techniques are combined to increase extraction efficiency. Further research into the separation and purification of flavonoid active ingredients in blood orange peel is beneficial for fully utilizing natural resources, making full use of blood orange peel, and combining it with blood orange juice to develop products for deep processing of the whole blood orange fruit.

[0004] Blood oranges can be divided into several varieties, including Tarocco blood orange, Moro blood orange, Ruby blood orange, and Rose blood orange. The types and contents of flavonoid active ingredients vary among different blood oranges. Tarocco blood orange is an important cultivated variety, and there is an urgent need to develop products for deep processing of Tarocco blood oranges. However, there is a lack of fruit powder products obtained from deep processing of blood oranges in China, especially fruit powder products obtained from deep processing of the whole blood orange peel. This has led to a lack of fruit powder products with high citrus flavonoid content. Summary of the Invention

[0005] In view of this, this application provides a technology and application for preparing fruit powder products with high citrus flavonoid content, in order to solve the problem of the lack of deep processing technology for whole blood oranges in the prior art.

[0006] The first aspect of this application provides a technology for preparing a fruit powder product with high citrus flavonoid content, the preparation technology including the following steps:

[0007] Step S1: Supercritical CO2 extraction is used to extract Tarocco blood orange peel powder to obtain supercritical CO2 extracted active ingredients and Tarocco blood orange peel powder extract residue.

[0008] Step S2: Extract the remaining material from Tarocco blood orange peel powder with ethanol to obtain the active ingredient extracted with ethanol.

[0009] Step S3: Mix the active ingredients extracted by supercritical CO2 and the active ingredients extracted by ethanol to obtain blood orange peel flavonoid extract;

[0010] Step S4: Mix the flavonoid extract from the blood orange peel with the juice from the Tarocco blood orange pulp to obtain a juice product with high citrus flavonoid content.

[0011] Step S5: Freeze-dry the juice product with high citrus flavonoid content to obtain a fruit powder product with high citrus flavonoid content.

[0012] Preferably, in step S1, the temperature of the extraction vessel used for the supercritical CO2 extraction is 50-70°C, and the entrainer is an 80%-90% aqueous ethanol solution.

[0013] Preferably, in step S1, the pressure of the extraction vessel used for supercritical CO2 extraction is 25-35 MPa, and the temperature of the extraction vessel is 50-70°C.

[0014] The pressure of the separation vessel used is 3-5 MPa, and the temperature of the separation vessel is 25-40℃;

[0015] The CO2 storage tank used outputs carbon dioxide at a flow rate of 20–30 L / h;

[0016] The supercritical extraction time is 80–160 min, and the entrainer is an 80%–90% aqueous ethanol solution.

[0017] Preferably, in step S2, the extraction temperature of the ethanol extraction is 60-80°C, and the solvent is a 30%-50% aqueous ethanol solution.

[0018] Preferably, in step S2, the extraction temperature of the ethanol extraction is 60-80°C, the extraction time is 10-20 min, and the solvent is a 30%-50% aqueous ethanol solution.

[0019] Preferably, in step S3, the blood orange peel flavonoid extract is a blood orange peel flavonoid extract after removing ethanol.

[0020] Preferably, in step S4, the method for preparing the juice of Tarocco blood orange pulp includes: juicing Tarocco blood orange pulp and drinking water in a 1:1 ratio, then adding 0.05% pectinase at 50°C for enzymatic hydrolysis, and filtering the enzymatically hydrolyzed juice to obtain the juice of Tarocco blood orange pulp.

[0021] Preferably, in step S5, the freeze-drying temperature is -60 to -40°C, and the time is 24 to 48 hours.

[0022] The second party of this application provides a fruit powder product with high citrus flavonoid content, which is prepared by the fruit powder product preparation technology with high citrus flavonoid content described in the first party.

[0023] This application provides a third-party application of a fruit powder product with high citrus flavonoid content in the preparation of food or health products.

[0024] In summary, this application provides a technology and application for preparing a fruit powder product with high citrus flavonoid content. The technology for preparing a fruit powder product with high citrus flavonoid content provided by this application includes: firstly, supercritical CO2 extraction of Tarocco blood orange peel powder and ethanol extraction of the residue from the Tarocco blood orange peel powder; then, mixing the active ingredients extracted by supercritical CO2 and the active ingredients extracted by ethanol to obtain a blood orange peel flavonoid extract; subsequently, freeze-drying the mixture of the blood orange peel flavonoid extract and the pulp juice to obtain a fruit powder product with high citrus flavonoid content; wherein, supercritical CO2 extraction has a good extraction effect on polymethoxylated flavonoid active ingredients in Tarocco blood orange peel powder, making supercritical CO2 extraction more effective. O2 extraction yields extracts rich in polymethoxylated flavonoids, while ethanol extraction of the residue shows good extraction effects on flavanones, flavonols, and flavonoids, as well as polymethoxylated flavonoids. This results in extracts rich in various functional active ingredients. Consequently, the blood orange peel flavonoid extract obtained through supercritical CO2 combined with ethanol extraction exhibits significantly increased flavonoid types and total flavonoid content. Further processing of the blood orange peel flavonoid extract and juice freeze-dried fruit powder product yields a fruit powder product with high citrus flavonoid content, thus solving the problem of the lack of deep processing technology for whole blood oranges in existing technologies. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 The figures are liquid chromatography results of supercritical CO2 extraction of active ingredients, ethanol extraction of active ingredients from raffinate, and conventional ethanol extraction of active ingredients in Test Example 1 of this application. Figure a shows the test results at a wavelength of 283 nm, and Figure b shows the test results at a wavelength of 330 nm.

[0027] Figure 2 The graph shows the total flavonoid content and flavonoid quantity of the active ingredients obtained by supercritical CO2 extraction, ethanol extraction of the raffinate, and conventional ethanol extraction in Test Example 1 of this application.

[0028] Figure 3 This diagram illustrates the types of flavonoids contained in the active ingredients obtained by supercritical CO2 extraction, ethanol extraction of the raffinate, and conventional ethanol extraction in Test Example 1 of this application.

[0029] Figure 4The figures show the results of in vitro antioxidant experiments of the active ingredients obtained by supercritical CO2 extraction, ethanol extraction of the raffinate, and conventional ethanol extraction in Test Example 1 of this application.

[0030] Figure 5 The figures show the antibacterial results of the active ingredients obtained by supercritical CO2 extraction, ethanol extraction of the raffinate, and conventional ethanol extraction in Test Example 1 of this application.

[0031] Figure 6 Figure 1 shows the results of high performance liquid chromatography (HPLC) analysis of the active ingredients in the conventional Tarocco blood orange fruit powder of Comparative Example 2 and the fruit powder with high citrus flavonoid content of Example 1 in Test Example 2 of this application. Figure 2a shows the test results at a wavelength of 283 nm, and Figure 2b shows the test results at a wavelength of 330 nm.

[0032] Figure 7 This is a schematic diagram showing the content of flavonoids in the supercritical CO2 extracted active ingredients obtained at different supercritical CO2 extraction vessel temperatures in Examples 1-5 of this application;

[0033] Figure 8 This is a schematic diagram showing the content of flavonoids in the supercritical CO2 extractant obtained under different supercritical CO2 extraction vessel pressures in Examples 1 and 6-9 of this application;

[0034] Figure 9 This is a schematic diagram showing the content of flavonoids in the supercritical CO2 extraction active ingredients obtained by different supercritical CO2 extraction entrainer concentrations in Examples 1, 10-13 of this application;

[0035] Figure 10 This is a response surface plot of Example 29 of this application, which uses response surface methodology to analyze the effects of temperature, pressure and entrainer concentration in the supercritical CO2 extraction vessel on the content of flavonoids in the active ingredient extracted by supercritical CO2.

[0036] Figure 11 This is a Pareto plot of the effect of temperature, pressure and entrainer concentration of supercritical CO2 extraction vessel on the content of flavonoids in the active ingredient of supercritical CO2 extraction, which was analyzed by response surface methodology in Example 29 of this application.

[0037] Figure 12 This is a schematic diagram showing the content of flavonoids in the ethanol-extracted active ingredients obtained at different ethanol extraction temperatures in Examples 1 and 14-18 of this application.

[0038] Figure 13 This is a schematic diagram showing the content of flavonoids in the ethanol-extracted active ingredients obtained at different ethanol extraction times in Examples 1, 19-23 of this application;

[0039] Figure 14This is a schematic diagram showing the content of flavonoids in the ethanol-extracted active ingredients obtained from different ethanol extraction solvent concentrations in Examples 1 and 24-28 of this application;

[0040] Figure 15 This is a response surface plot of Example 30 of this application, which uses response surface methodology to analyze the effects of ethanol extraction temperature, time, and solvent concentration on the content of flavonoids in the active ingredient extracted by ethanol extraction.

[0041] Figure 16 This is a Pareto plot of the effect of temperature, time and solvent concentration in the supercritical extraction vessel on the content of flavonoids in the active ingredient extracted by ethanol, as analyzed by response surface methodology in Example 30 of this application. Detailed Implementation

[0042] This application provides a technology and application for preparing fruit powder products with high citrus flavonoid content, which solves the problem of the lack of deep processing technology for whole blood oranges in the existing technology.

[0043] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0044] Given the current lack of deep processing technology and product development for whole blood oranges in China, this application provides a technology for preparing a fruit powder product with high citrus flavonoid content. The preparation technology provided in this application obtains a fruit powder product with high citrus flavonoid content through deep processing of the whole blood orange. The preparation technology first uses supercritical CO2 extraction of Tarocco blood orange peel, then uses ethanol extraction of the Tarocco blood orange peel powder residue, and then mixes the extracts to obtain a compound blood orange peel flavonoid extract. The supercritical CO2 combined with ethanol extraction significantly improves the utilization rate of Tarocco blood orange peel, and greatly increases the types and total flavonoids in the blood orange peel flavonoid extract. Subsequently, the blood orange peel flavonoid extract and the juice from the Tarocco blood orange pulp are mixed and freeze-dried to obtain the fruit powder product. This deep processing of the whole blood orange results in a fruit powder product with high citrus flavonoid content, thus filling the gap in the domestic market for deep processing technology of whole blood oranges.

[0045] The supercritical CO2 extraction method used here refers to the extraction of Tarocco blood orange peel using a fluid whose thermodynamic state is above the critical point (Pc, Tc) (i.e., supercritical CO2). The critical point is the state point where the interface between the gas and liquid just disappears. Supercritical fluids have very unique physicochemical properties; their density is close to that of liquids, their viscosity is close to that of gases, and they also have characteristics such as a large diffusion coefficient, low viscosity, and high dielectric constant. This allows supercritical CO2 to penetrate into the interior of the material more easily, improving the separation effect. Therefore, it is widely used as an excellent extraction medium. CO2 is not only non-toxic and harmless, but also inexpensive and readily available. Furthermore, it does not damage heat-sensitive compounds. By adjusting the extraction process, selective extraction of target substances can be achieved. Tarocco blood orange peel contains a wide variety of active ingredients, including flavonoids, etc. The active ingredients include polymethoxyflavonoids such as isohesperidin, sweet orange flavonoids, 5,7,8,4'-tetramethoxyflavonoids, nobiletin, 3,5,6,7,8,3',4'-heptamethoxyflavonoids, demethylnobiletin, and hesperidin, as well as glycosylated flavanones such as rutin and hesperidin. Polymethoxyflavonoids contain a high number of methoxy groups and are nonpolar substances; therefore, direct ethanol extraction is not effective for extracting polymethoxyflavonoids from Tarocco blood orange peel. Supercritical CO2 extraction, however, offers higher yields for low-polarity substances. Applying this method to extract polymethoxyflavonoids allows for the extraction of diverse and abundant polymethoxyflavonoids from Tarocco blood orange peel, resulting in an extract rich in polymethoxyflavonoids.

[0046] After supercritical CO2 extraction of Tarocco blood orange peel, in addition to obtaining supercritical CO2 extractable active ingredients rich in polymethoxylated flavonoids, the extract also includes Tarocco blood orange peel powder residue. During the supercritical CO2 extraction process, the cell walls of Tarocco blood orange peel are destroyed and the pores are enlarged. At the same time, polymethoxylated flavonoids are extracted, and the residue mainly contains active ingredients with polar groups. This makes it easier to leach the polar active ingredients in the Tarocco blood orange peel powder residue. Therefore, when the Tarocco blood orange peel powder residue is mixed with an ethanol aqueous solution and placed in an ultrasonic cleaner for ethanol extraction, flavanones, flavonols, and flavonoid active ingredients can be fully extracted, resulting in a diverse and rich extract of active ingredients.

[0047] The preparation process of Tarocco blood orange pulp juice is as follows: Tarocco blood orange pulp and drinking water are juiced in a 1:1 ratio, and then 0.05% pectinase is added at 50℃ for enzymatic hydrolysis. After enzymatic hydrolysis, the juice is filtered to obtain Tarocco blood orange pulp juice.

[0048] The preparation process of freeze-drying fruit powder products is as follows: blood orange peel flavonoid extract obtained by supercritical CO2 co-ethanol extraction and Tarocco blood orange pulp juice are mixed and 5% β-cyclodextrin is added and stirred evenly. The mixture is then freeze-dried at -58℃ for 48h to obtain fruit powder products with high citrus flavonoid content.

[0049] As a preferred option, considering that the extraction temperature and entrainer concentration used in supercritical CO2 extraction have a significant impact on the extraction rate of polymethoxyflavonoid active ingredients, this application provides a preferred technical solution, in which the extraction vessel temperature is controlled within the range of 50–70°C and the ethanol aqueous solution entrainer concentration is controlled within the range of 80%–90%.

[0050] As a preferred option, considering that the temperature and solvent concentration of ethanol extraction have a significant impact on the extraction rate of flavanone active ingredients, this application provides a preferred technical solution, in which the temperature range is controlled at 60-80℃ and the solvent concentration of the ethanol aqueous solution is controlled at 30%-50%.

[0051] Example 1

[0052] Example 1 of this application provides a technology for preparing fruit powder products with high citrus flavonoid content. The preparation technology includes the following steps: raw material preparation, supercritical CO2 extraction, ethanol extraction, compounding blood orange peel flavonoid extract, and fruit powder preparation.

[0053] The raw material preparation steps include: selecting several plump and mold-free Tarocco blood oranges, washing them with clean water, separating the peel from the pulp, cutting the peel into uniform small pieces, drying them in a 50℃ hot air drying oven, and then pulverizing them through a 60-mesh sieve to obtain Tarocco blood orange peel powder. The peel powder is then subjected to supercritical CO2 synergistic ethanol extraction. The pulp juicing process includes: juicing Tarocco blood orange pulp and drinking water in a 1:1 ratio, then adding 0.05% pectinase at 50℃ for enzymatic hydrolysis, filtering after enzymatic hydrolysis to obtain Tarocco blood orange pulp juice, which is used for subsequent preparation of fruit powder.

[0054] The steps of supercritical CO2 extraction include: adding 25g of Tarocco blood orange peel powder to the extraction vessel, sealing the vessel with the filling material, then placing the extraction vessel into a supercritical extraction apparatus. CO2 and ethanol, the entrainer, are mixed and pumped into the extraction vessel. The valves of the extraction vessel, separation vessel, and CO2 storage tank are opened, allowing CO2 to circulate within these three parts, i.e., a dynamic method for extracting polymethoxyflavonoids from the peel. The extraction conditions are: extraction pressure of 30MPa, extraction vessel temperature of 60℃, separation vessel pressure of 5MPa, temperatures of separation vessels 1 and 2 of 35℃ and 30℃ respectively, 85% ethanol aqueous solution as the entrainer, carbon dioxide flow rate of 25L / h, and supercritical extraction time of 180min. After supercritical CO2 extraction, the supercritical CO2 extracted active ingredients and residual Tarocco blood orange peel powder are obtained.

[0055] The pressure in the separation vessel of this supercritical CO2 extraction is controlled below 6 MPa, which destroys the supercritical CO2 state and turns it into a gaseous state, thereby effectively separating the supercritical CO2 extract active ingredients rich in polymethoxyflavonoids.

[0056] The ethanol extraction process includes: placing the remaining Tarocco blood orange peel powder and ethanol aqueous solution into a 40kHz ultrasonic cleaner at a material-to-liquid ratio of 1:20 to extract the active ingredient; the ethanol extraction temperature is 70℃, the time is 15min, and the concentration of the ethanol aqueous solution is 40%.

[0057] The steps for compounding blood orange peel flavonoid extract include: mixing the active ingredients extracted by supercritical CO2 and the active ingredients extracted by ethanol to obtain blood orange peel flavonoid extract; removing the ethanol from the blood orange peel flavonoid extract by rotary evaporation at 50°C to obtain a concentrated blood orange peel flavonoid extract solution.

[0058] The steps for preparing fruit powder include: adding concentrated flavonoid extract from blood orange peel to the juice of Tarocco blood orange pulp, adding 5% β-cyclodextrin and stirring evenly, then freeze-drying at -58℃ for 48 hours to obtain fruit powder with high citrus flavonoid content.

[0059] Comparative Example 1

[0060] Comparative Example 1 of this application provides a traditional method for extracting active ingredients from the peel of Tarocco blood orange using ethanol. The difference between this method and Example 1 is that it does not involve supercritical CO2 extraction.

[0061] The traditional method for extracting active ingredients from Tarocco blood orange peel with ethanol includes: directly mixing Tarocco blood orange peel powder with an ethanol aqueous solution at a material-to-liquid ratio of 1:20 in a 40kHz ultrasonic cleaner to extract the active ingredients using traditional ethanol extraction; the ethanol extraction temperature is 70℃, the time is 15min, and the concentration of the ethanol aqueous solution is 40%.

[0062] Comparative Example 2

[0063] Comparative Example 2 of this application provides a method for preparing traditional Tarocco blood orange fruit powder. The difference between this method and Example 1 is that the blood orange peel flavonoid extract described in Example 1 is not added.

[0064] The traditional method for preparing Tarocco blood orange powder includes: adding 5% β-cyclodextrin to the juice of Tarocco blood orange pulp, stirring evenly, and then freeze-drying at -58℃ for 48 hours to obtain traditional Tarocco blood orange powder.

[0065] Test Example 1: This test example performs qualitative and quantitative analysis, antioxidant performance testing, and antibacterial activity testing on the active ingredients obtained by supercritical CO2 extraction, ethanol extraction, and conventional ethanol extraction provided in Comparative Example 1. Qualitative and quantitative analyses were performed using an ultra-high resolution quadrupole combined electrostatic field track-trap liquid chromatography-mass spectrometry (LC-MS) system and a high performance liquid chromatography (HPLC) system. The LC-MS system was used to analyze all flavonoid species, while the HPLC system was used for qualitative and quantitative analysis of the 10 flavonoids with the highest content. In the HPLC analysis process, standard solutions of isohesperidin, sweet orange flavonoid, 5,7,8,4'-tetramethoxyflavonoid, nobiletin, 3,5,6,7,8,3',4'-heptamethoxyflavonoid, demethylnobiletin, hesperidin, rutin, and hesperidin were mixed to establish a standard curve. The parameters of the standard curve are shown in Table 1. Then, the HPLC system used to establish the standard curve was used to test the active ingredients obtained by supercritical CO2 extraction, ethanol extraction, and conventional ethanol extraction. The results are shown in Table 2 and [Table 3]. Figure 1-3 As shown, attached Figure 3 The corresponding flavonoid types are shown in Table 3-4;

[0066]

[0067] Table 1

[0068]

[0069] Table 2

[0070]

[0071] Table 3

[0072]

[0073] Table 4

[0074] From Table 2-4, Figure 1-3It can be seen that traditional ethanol extraction yields a relatively small number of flavonoid active ingredients, totaling 42, with a total flavonoid content of approximately 2699 mg / 100g. However, supercritical CO2 combined with ethanol extraction can extract a diverse range of polymethoxyflavonoid active ingredients in abundant quantities, reaching 51 different types, with a total flavonoid content of approximately 3016 mg / 100g. Specifically, supercritical CO2 extraction yields a higher content of polymethoxyflavonoid active ingredients. This indicates that the supercritical CO2 extraction method used in this application can effectively extract isohesperidin, sweet hesperidin, 5,7,8,4'-tetramethoxyflavonoids, and other active ingredients from the peel of Tarocco blood oranges. Hesperidin, 3,5,6,7,8,3',4'-heptamethoxyflavonoids, demethylhesperidin, and tangeretin are among the polymethoxyflavonoid active ingredients used to obtain an extract rich in polymethoxyflavonoid active ingredients. Supercritical CO2 extraction, after extracting polymethoxyflavonoid active ingredients containing a high proportion of methoxy groups, leaves behind mainly active ingredients containing polar groups such as hydroxyl groups in the raffinate. Therefore, ethanol extraction of the raffinate can fully extract flavanones, flavonols, and flavonoid active ingredients, resulting in an extract containing a rich variety and high content of active ingredients. This significantly increases the total flavonoid content by 11.8% compared to traditional ethanol extraction, and also introduces nine more types of flavonoids.

[0075] Antioxidant performance testing includes in vitro DPPH free radical scavenging capacity testing, ABTS free radical scavenging capacity testing, and FRAR total antioxidant capacity testing. The test results are as follows: Figure 4 As shown, from Figure 4 It can be seen that the antioxidant properties of the ethanol extract of the raffinate containing flavanones, flavonols, and flavonoid active ingredients are higher than those of the traditional ethanol extract.

[0076] The antibacterial activity test used Escherichia coli as the bacterial strain. The test results for inhibition by Escherichia coli are as follows: Figure 5 As shown, from Figure 5 It can be seen that supercritical CO2 extract can achieve significant antibacterial effect at a concentration of about 10 mg / mL. Escherichia coli is difficult to proliferate after about 6 hours, and the proliferation rate of E. coli is also slow after about 6 to 12 hours. In contrast, the antibacterial effect of traditional ethanol extract at a concentration of about 10 mg / mL is poor. E. coli proliferates rapidly after 2 hours. Therefore, the antibacterial activity of supercritical CO2 extract, which contains a variety of polymethoxyflavonoid active ingredients in rich amounts, is significantly higher than that of traditional ethanol extract.

[0077] Test Example 2

[0078] This test example uses high-performance liquid chromatography (HPLC) to qualitatively and quantitatively analyze the active ingredients of the traditional Tarocco blood orange fruit powder described in Comparative Example 2 and the fruit powder with high citrus flavonoid content described in Example 1. The test parameters used for HPLC analysis are the same as those in Test Example 1. The test results are shown in Table 5 and... Figure 6 As shown.

[0079]

[0080] Table 5

[0081] from Figure 6 It can be seen that the fruit powder with high citrus flavonoid content after adding the blood orange peel flavonoid extract described in Example 1 introduces polymethoxylated flavonoids unique to the peel into the active ingredients, which improves the total flavonoid content and nutritional value of the fruit powder and achieves high utilization of the whole blood orange.

[0082] As can be seen from Table 5, after adding the blood orange peel flavonoid extract described in Example 1, the contents of polymethoxyflavonoids, flavanones and total flavonoids were higher, with the total flavonoid content increasing by 157.57%.

[0083] Examples 2-5

[0084] This embodiment provides a method for supercritical CO2 synergistic ethanol extraction of blood orange peel. The difference between this method and Example 1 is that the temperature of the supercritical CO2 extraction vessel is adjusted. In Examples 2-5, the extraction vessel temperatures are 40℃, 50℃, 70℃ and 80℃, respectively.

[0085] Examples 6-10

[0086] This embodiment provides a method for supercritical CO2 synergistic ethanol extraction of blood orange peel. The difference between this method and Example 1 is that the pressure of the supercritical CO2 extraction vessel is adjusted. In Examples 6-10, the extraction pressures are 15 MPa, 20 MPa, 25 MPa and 35 MPa, respectively.

[0087] Examples 10-13

[0088] This embodiment provides a method for supercritical CO2 synergistic ethanol extraction of blood orange peel. The difference between this method and Example 1 is that the concentration of the entrainer in the supercritical CO2 extraction is adjusted. In Examples 10-13, the entrainers are 75%, 80%, 90%, and 95% aqueous ethanol solutions, respectively.

[0089] Examples 14-18

[0090] This embodiment provides a method for supercritical CO2 synergistic ethanol extraction of blood orange peel. The difference between this method and Example 1 is that the ethanol extraction temperature is adjusted. In Examples 14-18, the ethanol extraction temperatures are 40℃, 50℃, 60℃, 80℃ and 90℃, respectively.

[0091] Examples 19-23

[0092] This embodiment provides a method for supercritical CO2 synergistic ethanol extraction of blood orange peel. The difference between this method and Example 1 is that the ethanol extraction time is adjusted. In Examples 19-23, the ethanol extraction time is 5 min, 10 min, 20 min, 25 min, and 30 min.

[0093] Examples 24-28

[0094] This embodiment provides a method for supercritical CO2 synergistic ethanol extraction of blood orange peel. The difference between this method and Example 1 is that the concentration of the ethanol aqueous solution used for ethanol extraction is adjusted. In Examples 24-28, the concentration of the ethanol aqueous solution is 20%, 30%, 50%, 60%, and 70%.

[0095] Example 29

[0096] To determine the effects of temperature, pressure, and entrainer concentration on the flavonoid content in the supercritical CO2 extraction active ingredient, this embodiment employs response surface methodology.

[0097] The results of the response surface design for the supercritical CO2 extraction process and the variance analysis of the supercritical CO2 extraction process model are shown in Tables 6-7.

[0098]

[0099] Table 6

[0100]

[0101] Table 7

[0102] Using Design-Expert software, a quadratic regression was performed on the data in Table 6 to obtain the regression model of flavonoid yield on supercritical pressure (A), supercritical temperature (B), and entrainer concentration (C):

[0103] Y=19.1+0.2918A+1.73B-0.5778C-0.5069AB-0.3355AC-0.3343BC-2.23A2-2.9B2-0.5943C2

[0104] ANOVA was used to analyze the regression parameters of the response surface and to verify the regression model and the significance of each parameter. The results are shown in Table 7.

[0105] The model's p < 0.01 indicates the response surface model is highly significant. The simulation lack-of-fit term p = 0.2588 > 0.05 is not significant, indicating the selected model is suitable. The correlation coefficient R of this equation is... 2 =0.9862, indicating good model correlation. The coefficient of variation (CV) reflects the confidence level of the model; the lower the value, the higher the confidence level. In this experiment, the CV = 2.87, indicating that the model equation can reflect the true experimental values ​​well. The difference between Adjusted R2 and Predicted R2 is less than 0.2, and the signal-to-noise ratio Adeq Precision = 20.4032 > 4, indicating sufficient model signal. This model can be used to analyze and predict the yield of polymethoxyflavonoid active ingredients.

[0106] The significance test results of the coefficients of the above regression model show that the first-order terms of extraction temperature (B) and entrainer concentration (C) have significant effects; the quadratic terms A2 and B2 of the model also have significant effects. From the F-values, the order of the main effects of the influencing factors is: extraction temperature > entrainer concentration > extraction pressure.

[0107] The optimal extraction conditions for polymethoxyflavonoid active ingredients fitted by the model were: temperature 63.5℃; pressure 29.736 MPa; and entrainer concentration 81.2%. To verify the model's effectiveness, three replicate extractions were performed under these conditions. The measured values ​​(19.42 ± 0.007 mg / g) fell within the 95% mean confidence interval of the predicted values ​​(19.51 mg / g), confirming the model's predictability.

[0108] From the response surface diagram ( Figure 10 ) and Pareto chart ( Figure 11 The results show the degree of influence of each factor. Only supercritical temperature and entrainer concentration exceed the significance threshold, indicating that these two factors are key factors affecting the yield of polymethoxyflavonoid active ingredients extracted by supercritical CO2. Among them, the interaction effect of supercritical temperature and entrainer concentration is greater than that of the other two.

[0109] Example 30

[0110] To determine the effects of temperature, time, and solvent concentration during ethanol extraction on the content of flavonoids in the active ingredient extracted by ethanol, this embodiment employs response surface methodology.

[0111] The results of the response surface design for the ethanol extraction process and the variance analysis of the ethanol extraction process model are shown in the table below.

[0112] As shown in Table 8-9.

[0113]

[0114] Table 8

[0115]

[0116] Table 9

[0117] Using Design-Expert software, a quadratic regression was performed on the data in Table 8 to obtain the regression model of flavonoid yield on temperature (A), time (B), and solvent concentration (C):

[0118] Y=8.74+0.243A+0.1524B+0.1768C+0.2138AB+0.1AC-0.0585BC-0.6353A2-0.849B2-0.4476C2

[0119] ANOVA was used to analyze the regression parameters of the response surface and to verify the significance of the regression model and each parameter. The results are shown in Table 9.

[0120] The model's p < 0.001 indicates the response surface model is highly significant. The simulation lack-of-fit term p = 0.4973 > 0.05 is not significant, indicating the selected model is suitable. The correlation coefficient R of this equation is... 2 =0.984, indicating good model correlation. The coefficient of variation (CV) reflects the confidence level of the model; the lower the value, the higher the confidence level. In this experiment, the CV = 1.73, indicating that the model equation can reflect the true experimental values ​​well. The difference between Adjusted R2 and Predicted R2 is less than 0.2, and the signal-to-noise ratio Adeq Precision = 16.4319 > 4, indicating sufficient model signal. This model can be used to analyze and predict the yield of glycosylated flavanone active ingredients.

[0121] The significance test results for each term of the regression model coefficients show that the linear terms of all three factors have a significant impact; the interaction term AB has a significant impact; and the quadratic terms of the model all have a significant impact. From the F-values, the order of the main effects of the influencing factors is: temperature > solvent concentration > time.

[0122] The optimal extraction conditions for glycosylated flavanone active ingredients, fitted by the model, were: temperature 72.3℃; extraction time 15.55 min; and concentration 42.2%. To verify the model's effectiveness, three replicate extractions were performed under these conditions. The measured values ​​(8.79 ± 0.09 mg / g) fell within the 95% mean confidence interval of the predicted values ​​(8.80 mg / g), confirming the model's predictability.

[0123] From the response surface diagram ( Figure 15 ) and Pareto chart ( Figure 16 It can be seen that the influence of each factor is similar to that of the supercritical extraction process mentioned above. Temperature and ethanol concentration are the two most significant factors, indicating that these two factors are the key factors affecting the yield of glycosylated flavanone active ingredients.

[0124] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for preparing a fruit powder product with high citrus flavonoid content, characterized in that, Including the following steps: Step S1: Supercritical CO2 extraction is used to extract Tarocco blood orange peel powder to obtain supercritical CO2 extracted active ingredients and Tarocco blood orange peel powder extract residue. Step S2: Extract the remaining material from Tarocco blood orange peel powder with ethanol to obtain the active ingredient extracted with ethanol. Step S3: Mix the active ingredients extracted by supercritical CO2 and those extracted by ethanol to obtain blood orange peel flavonoid extract; Step S4: Mix the flavonoid extract from blood orange peel with the juice from Tarocco blood orange pulp to obtain a juice product with high citrus flavonoid content. Step S5: Freeze-dry the juice product with high citrus flavonoid content to obtain a fruit powder product with high citrus flavonoid content; In step S1, the temperature of the extraction vessel used for the supercritical CO2 extraction is 50~70℃, and the entrainer is an 80%~90% aqueous ethanol solution. The pressure of the extraction vessel used for the supercritical CO2 extraction is 25~35MPa; The pressure of the separation vessel used is 3~5MPa, and the temperature of the separation vessel is 25~40℃; The CO2 storage tank used outputs carbon dioxide at a flow rate of 20~30L / h; The supercritical extraction time is 80~160 min; In step S2, the extraction temperature of the ethanol extraction is 60~80℃, and the solvent is a 30%~50% aqueous ethanol solution; The extraction time for the ethanol extraction is 10-20 minutes.

2. The method for preparing a fruit powder product with high citrus flavonoid content according to claim 1, characterized in that, In step S3, the blood orange peel flavonoid extract is the blood orange peel flavonoid extract after removing ethanol.

3. The method for preparing a fruit powder product with high citrus flavonoid content according to claim 1, characterized in that, In step S4, the method for preparing the juice of Tarocco blood orange pulp includes: juicing Tarocco blood orange pulp and drinking water in a 1:1 ratio, then adding 0.05% pectinase at 50°C for enzymatic hydrolysis, and filtering the enzymatically hydrolyzed juice to obtain the juice of Tarocco blood orange pulp.

4. The method for preparing a fruit powder product with high citrus flavonoid content according to claim 1, characterized in that, In step S5, the freeze-drying temperature is -60~-40℃ and the time is 24~48h.

5. The application of a fruit powder product with high citrus flavonoid content in food preparation, characterized in that, The fruit powder product with high citrus flavonoid content is prepared by the method for preparing the fruit powder product with high citrus flavonoid content according to any one of claims 1-4.

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