Jaboticaba pomace extract with anti-oxidation function and preparation method of jaboticaba pomace extract

Abstract

The invention discloses a preparation method of a jaboticaba pomace extract with an anti-oxidation function, and the jaboticaba pomace extract is prepared by taking jaboticaba pomace as a raw material and adopting a compound extraction process of coupling pectin lyase enzymolysis with physical wall breaking homogenization. Meanwhile, the invention further discloses a jaboticaba pomace extract with an antioxidant function, the anthocyanin extraction rate of the jaboticaba pomace extract is 7.9-8.6 mg / g, and the polyphenol extraction rate of the jaboticaba pomace extract is 60-66 mg / g. According to the jaboticaba pomace extract with the anti-oxidation function and the preparation method of the jaboticaba pomace extract, the extraction efficiency and the yield of polyphenol and anthocyanin in pomace are greatly improved by aiming at a compound extraction process for synergistically and efficiently extracting polyphenol and anthocyanin from jaboticaba pomace through enzymolysis coupling with physical wall-breaking homogenization of pectate lyase; the antioxidant performance of the extract is obviously superior to that of a commercially available common antioxidant vitamin C, under the condition of the same concentration, the scavenging rates of the extract on DPPH and ABTSfree radicals are more than 5 times that of the vitamin C, and the extract has outstanding activity.

Description

Technical Field

[0001] This invention belongs to the field of jaboticaba processing technology, specifically, it relates to a jaboticaba pomace extract with antioxidant function and its preparation method. Background Technology

[0002] Jaboticaba (scientific name: *Plinia cauliflora* (Mart.) Kausel), commonly known as tree grape or precious fruit, belongs to the genus *Plinia* in the family Myrtaceae. The fruit is rich in polyphenols, anthocyanins, organic acids, and other natural active ingredients. The flesh is translucent, soft, juicy, and flavorful, possessing a unique aroma and fragrance. Studies have shown that the active ingredients in jaboticaba have significant antioxidant activity, exerting their antioxidant and anti-aging effects by scavenging excess free radicals in the body. Long-term consumption of jaboticaba also has potential applications in regulating immune function and preventing cardiovascular diseases, and is beneficial for maintaining healthy skin and enhancing vitality in women. Furthermore, it has been shown to have potential effects in assisting the regulation of blood pressure, blood sugar, and blood lipid levels, as well as reducing liver cell damage and protecting liver function. However, fresh jaboticaba has a significant limitation in storage and preservation; its shelf life at room temperature is only 2-3 days, a characteristic that severely restricts its market circulation and the development of a large-scale industry. Currently, the processing and utilization of jaboticaba in China mainly focuses on producing low-value products such as juice and wine. The pomace generated during processing is mostly discarded as waste, resulting in extremely low resource utilization. It is worth noting that the core active ingredients in jaboticaba, such as polyphenols and anthocyanins, are mainly concentrated in the peel and seeds, meaning that the pomace byproducts after juicing still contain a large amount of untapped natural active ingredients. Currently, research on specific extraction processes for anthocyanins and polyphenols from jaboticaba pomace is lacking. Among existing related technologies, only lactic acid bacteria fermentation technology for whole jaboticaba fruit (authorization announcement number: CN 116077384 B) exists, but the polyphenol content in its product is only 2 mg / g. This process is not only cumbersome but also results in a low yield of active ingredients, making it difficult to meet the needs of high-value industrial utilization. Furthermore, existing technologies for extracting active ingredients from other similar fruit pomace also suffer from limited extraction efficiency. For example, the method for preparing freeze-dried powder from blueberry pomace using lactic acid bacteria fermentation (patent application number: 202211616455.7) yields a total phenol content of only 3.37 mg / g. The method for extracting anthocyanins from blueberry pomace using ultrasound-assisted hemicellulase (patent application number: 202511708730.1) achieves an anthocyanin extraction rate of 6.64 mg / g, but this technology is developed for blueberry pomace and cannot be directly applied to jaboticaba pomace, and it does not achieve synergistic and efficient extraction of polyphenols and anthocyanins.

[0003] In summary, polyphenols and anthocyanins in jaboticaba pomace are the core active ingredients responsible for its antioxidant and other physiological effects. In recent years, the planting area of ​​jaboticaba in my country has been expanding annually, and the supply of raw materials has become increasingly abundant. However, existing technologies, apart from fermenting the whole jaboticaba fruit, generally discard the pomace as waste, resulting in the incomplete utilization of its active factors and a serious waste of these active ingredients. Furthermore, existing active substance extraction technologies mostly only evaluate single polyphenols or single anthocyanins, exhibiting common problems such as low extraction rates, low resource utilization rates, and significant waste. The industry as a whole remains at the low-value utilization stage, and the level of in-depth development and high-value utilization urgently needs to be improved, failing to meet the needs of the jaboticaba industry's high-value development. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a jaboticaba pomace extract with antioxidant function that is specifically designed for the synergistic and efficient extraction of polyphenols and anthocyanins from jaboticaba pomace, filling the gap in the existing technology for a special extraction process for this type of pomace, and achieving simultaneous and efficient enrichment of polyphenols and anthocyanins.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0006] A method for preparing a jaboticaba pomace extract with antioxidant properties includes the following steps:

[0007] Prepare the materials and collect the jaboticaba pulp after separating the juice for later use;

[0008] Freeze-drying process: Jaboticaba fruit pomace is placed in a freeze dryer to freeze-dry and remove moisture, then ground and pulverized to obtain freeze-dried powder;

[0009] Enzymatic hydrolysis: Mix freeze-dried powder with water at a material-to-liquid ratio of 1:10~50, then add 1~5% pectin lyase for enzymatic hydrolysis. After enzymatic hydrolysis, obtain the enzymatic hydrolysate.

[0010] Enzyme inactivation treatment: The enzyme hydrolysate is subjected to enzyme inactivation treatment. After enzyme inactivation is completed and cooled, an enzyme-inactivated solution is obtained.

[0011] Shearing: The enzyme-inactivating solution is transferred to a shearing machine for shearing to obtain a shearing solution;

[0012] Homogenize by placing the shear fluid in a homogenizer and homogenizing it 1-3 times to obtain a homogenized liquid;

[0013] Centrifugation: Place the homogenized liquid in a centrifuge and centrifuge. After centrifugation, take the supernatant, which is the Jaboticaba pomace extract.

[0014] Furthermore, the present invention also provides a Jaboticaba pomace extract with antioxidant function prepared by the above preparation method, wherein the anthocyanin extraction rate is 7.5~9 mg / g and the polyphenol extraction rate is 55~70 mg / g.

[0015] The present invention has the following beneficial effects:

[0016] (1) This invention provides a composite extraction process for the synergistic and efficient extraction of polyphenols and anthocyanins from Jaboticaba pomace, which is a combination of pectin lyase enzymatic hydrolysis coupled with physical cell wall disruption and homogenization. This process significantly improves the extraction efficiency and yield of polyphenols and anthocyanins from pomace, filling the gap in existing technologies for a specific extraction process for this type of pomace. Compared with existing similar pomace active ingredient extraction technologies, this composite process has a better extraction effect.

[0017] (2) The Jaboticaba pomace extract obtained by the present invention has excellent antioxidant activity. Its antioxidant performance is significantly better than that of vitamin C, a commonly used antioxidant in the market. Under the same concentration conditions, the extract has a scavenging rate of more than 5 times that of vitamin C for DPPH and ABTS⁺ free radicals, and has outstanding activity advantages.

[0018] (3) This invention realizes the high-value utilization of by-products from jaboticaba pomace processing, effectively solves the technical pain points of waste of pomace resources and low comprehensive utilization rate in the current jaboticaba processing industry, promotes the upgrading of the jaboticaba industry from low-value processing to high-value processing, and has significant industrial promotion value and economic and social benefits. Attached Figure Description

[0019] Figure 1 This is a comparison chart of the DPPH free radical scavenging rates of the Jaboticaba pomace extract prepared in this invention and vitamin C.

[0020] Figure 2 This is a comparison chart of the ABTS⁺ free radical scavenging rates of the Jaboticaba pomace extract and vitamin C prepared in this invention. Detailed Implementation

[0021] To better understand this invention, the operation of the anthocyanin content determination experiment, total phenol content determination experiment, ABTS+ scavenging experiment, and DPPH free radical scavenging experiment will be specifically explained below, and the invention will be further illustrated with specific embodiments. However, the embodiments of this invention are not limited thereto. Unless otherwise specified, the raw materials and reagents used in the embodiments are all commercially available.

[0022] Example 1:

[0023] The preparation method of a Jaboticaba pomace extract with antioxidant function according to Example 1 of the present invention includes the following steps:

[0024] Prepare the raw materials and collect the jaboticaba pulp after separating the juice. It is preferable to use a screw press separator to process the washed jaboticaba and separate the juice.

[0025] For freeze-drying, the jaboticaba pomace is placed in a freeze dryer and freeze-dried at -80 ℃ to remove moisture. Then it is transferred to a grinder for grinding and pulverizing. The pulverized powder is passed through a 60-mesh sieve to obtain freeze-dried powder.

[0026] Enzymatic hydrolysis was performed by mixing freeze-dried powder with water at a material-to-liquid ratio of 1:20, followed by the addition of 1% pectin lyase. The mixture was stirred at 130 r / min for 1 hour at 40 °C, yielding the hydrolysate. The addition of pectin lyase specifically breaks down pectin-like substances in the cell walls and intercellular layers of Jaboticaba pomace, disrupting the integrity of the cell wall structure and allowing for the better release of more polyphenols and anthocyanins from the cells.

[0027] Enzyme inactivation treatment: The enzyme hydrolysate was placed in an environment with an enzyme inactivation temperature of 85 ℃ for 15 min for enzyme inactivation treatment. After enzyme inactivation, it was cooled for 10 min to obtain the enzyme inactivated solution.

[0028] Shearing: The enzyme-inactivating solution was transferred to a shearing machine and sheared at a shearing speed of 2000 r / min for 5 min to obtain a sheared solution. Shearing treatment can further break up the aggregated fruit pomace particles, increase the contact area between the fruit pomace and the extraction medium, and promote the rapid penetration of polyphenols and anthocyanins into the extract.

[0029] Homogenization involves placing the shearing fluid into a homogenizer and homogenizing twice under a homogenization pressure of 10 MPa to obtain a homogenized solution. Homogenization utilizes high-pressure shearing to achieve deep cell disruption, thoroughly releasing residual cell wall fragments and intracellular active ingredients. Simultaneously, it makes the extraction system more uniform and stable, reducing the adsorption loss of polyphenols and anthocyanins.

[0030] Centrifuge the homogenized liquid into a centrifuge and centrifuge for 20 minutes at a centrifugal force of 8000 g. After centrifugation, take the supernatant, which is the Jaboticaba pomace extract, denoted as JB1.

[0031] Example 2:

[0032] The preparation method of a Jaboticaba pomace extract with antioxidant function according to Example 2 of the present invention includes the following steps:

[0033] Prepare the raw materials and collect the jaboticaba pulp after separating the juice. It is preferable to use a screw press separator to process the washed jaboticaba and separate the juice.

[0034] For freeze-drying, the jaboticaba pomace is placed in a freeze dryer and freeze-dried at -80 ℃ to remove moisture. Then it is transferred to a grinder for grinding and pulverizing. The pulverized powder is passed through a 60-mesh sieve to obtain freeze-dried powder.

[0035] Enzymatic hydrolysis was performed by mixing freeze-dried powder with water at a ratio of 1:30, followed by the addition of 1.5% pectin lyase. The mixture was then hydrolyzed at a stirring speed of 120 r / min, a temperature of 45 ℃, and a time of 1.5 hours. The hydrolysate was obtained after the hydrolysis was completed.

[0036] Enzyme inactivation treatment: The enzyme hydrolysate was placed in an environment with an enzyme inactivation temperature of 75 ℃ for 20 min for enzyme inactivation treatment. After enzyme inactivation, it was cooled for 15 min to obtain the enzyme inactivated solution.

[0037] Shearing: Transfer the enzyme-inactivating solution to a shearing machine and shear at a shearing speed of 3000 r / min for 3 min to obtain the shearing solution.

[0038] Homogenization: The shear fluid is placed in a homogenizer and homogenized three times at a homogenization pressure of 5 MPa to obtain a homogenized liquid.

[0039] Centrifuge the homogenized liquid into a centrifuge and centrifuge for 30 minutes at a centrifugal force of 5000 g. After centrifugation, take the supernatant, which is the Jaboticaba pomace extract, denoted as JB2.

[0040] Example 3:

[0041] A method for preparing a Jaboticaba pomace extract according to Example 3 of the present invention includes the following steps:

[0042] Prepare the raw materials and collect the jaboticaba pulp after separating the juice. It is preferable to use a screw press separator to process the washed jaboticaba and separate the juice.

[0043] For freeze-drying, the jaboticaba pomace is placed in a freeze dryer and freeze-dried at -80 ℃ to remove moisture. Then it is transferred to a grinder for grinding and pulverizing. The pulverized powder is passed through a 60-mesh sieve to obtain freeze-dried powder.

[0044] Enzymatic hydrolysis was performed by mixing freeze-dried powder with water at a ratio of 1:40, followed by the addition of 1.5% pectin lyase. The hydrolysis was carried out under stirring conditions at a speed of 150 r / min, a temperature of 45 ℃, and a time of 2 hours. The hydrolysate was obtained after the hydrolysis was completed.

[0045] Enzyme inactivation treatment: The enzyme hydrolysate was placed in an environment with an enzyme inactivation temperature of 90 °C for 10 min for enzyme inactivation treatment. After enzyme inactivation, it was cooled for 15 min to obtain the enzyme inactivated solution.

[0046] Shearing: Transfer the enzyme-inactivating solution to a shearing machine and shear at a shearing speed of 1000 r / min for 7 min to obtain the shearing solution.

[0047] Homogenization: The shear fluid is placed in a homogenizer and homogenized once at a homogenization pressure of 20 MPa to obtain a homogenized liquid.

[0048] Centrifuge the homogenized liquid into a centrifuge and centrifuge at 7000 g for 25 min. After centrifugation, take the supernatant, which is the Jaboticaba pomace extract, denoted as JB3.

[0049] Comparative Example 1:

[0050] A method for preparing a jaboticaba pomace extract with antioxidant properties includes the following steps:

[0051] Prepare the raw materials and collect the jaboticaba pulp after separating the juice. It is preferable to use a screw press separator to process the washed jaboticaba and separate the juice.

[0052] For freeze-drying, the jaboticaba pomace is placed in a freeze dryer and freeze-dried at -80 ℃ to remove moisture. Then it is transferred to a grinder for grinding and pulverizing. The pulverized powder is passed through a 60-mesh sieve to obtain freeze-dried powder.

[0053] Mixing: The freeze-dried powder and water were mixed at a ratio of 1:30. The mixture was stirred for 1.5 hours at a stirring speed of 130 r / min and a temperature of 45 ℃. After the mixture was completed, it was cooled for 10 minutes to obtain the mixture.

[0054] Shearing: The mixture is transferred to a shearing machine and sheared for 5 minutes at a shearing rate of 2000 r / min to obtain shear fluid.

[0055] Homogenization: The shear fluid is placed in a homogenizer and homogenized twice under a homogenization pressure of 10 MPa to obtain a homogenized liquid.

[0056] Centrifuge the homogenized liquid into a centrifuge and centrifuge at 7000 g for 20 min. After centrifugation, take the supernatant, which is the Jaboticaba pomace extract, denoted as JB4.

[0057] Comparative Example 2:

[0058] A method for preparing a jaboticaba pomace extract with antioxidant properties includes the following steps:

[0059] Prepare the raw materials and collect the jaboticaba pulp after separating the juice. It is preferable to use a screw press separator to process the washed jaboticaba and separate the juice.

[0060] For freeze-drying, the jaboticaba pomace is placed in a freeze dryer and freeze-dried at -80 ℃ to remove moisture. Then it is transferred to a grinder for grinding and pulverizing. The pulverized powder is passed through a 60-mesh sieve to obtain freeze-dried powder.

[0061] Enzymatic hydrolysis was performed by mixing freeze-dried powder with water at a ratio of 1:30, followed by the addition of 1.5% pectin lyase. The hydrolysis was carried out under stirring conditions at a speed of 130 r / min, a temperature of 40 ℃, and a time of 1 hour. The hydrolysate was obtained after the hydrolysis was completed.

[0062] Enzyme inactivation treatment: The enzyme hydrolysate was placed in an environment with an enzyme inactivation temperature of 80 ℃ for 25 min for enzyme inactivation treatment. After enzyme inactivation, it was cooled for 10 min to obtain the enzyme inactivated solution.

[0063] Centrifuge the enzyme-inactivating solution into a centrifuge and centrifuge at 8000 g for 35 min. After centrifugation, take the supernatant, which is the Jaboticaba pomace extract, denoted as JB5.

[0064] The Jaboticaba pomace extracts prepared in Examples 1-3 and Comparative Examples 1-2 were evaluated using the following method.

[0065] 1. Anthocyanin content determination

[0066] A 0.2 mg / mL cyanidin-3-O-glucoside stock solution was prepared. 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6 mL of this stock solution were taken and placed in test tubes, two groups in total. Each group was then diluted to 1 mL with methanol to obtain a series of cyanidin-3-O-glucoside standard solutions. 4 mL of potassium chloride-hydrochloric acid buffer (pH=1.0) and sodium acetate-hydrochloric acid buffer (pH=4.5) were added to each solution, and the solutions were allowed to stand in the dark for 15 min. The absorbance of the two gradient standard solutions was measured at 520 nm and 700 nm, respectively. A blank was also measured simultaneously. The absorbance (A) was calculated using the formula. A standard curve was plotted with absorbance (A) on the ordinate and cyanidin-3-O-glucoside concentration (mg / mL) on the abscissa. The anthocyanin concentration of the samples was calculated by substituting the absorbance values ​​obtained from the above method into the standard curve.

[0067] .

[0068] Calculate the anthocyanin content and extraction rate of the sample according to the formula:

[0069] .

[0070] C: Anthocyanin concentration (mg / mL); V1: Test solution volume (mL); V2: Total extract volume (mL); V3: Test solution volume (mL).

[0071] .

[0072] m1: Anthocyanin content (mg); m2: Jaboticaba pomace powder content (g).

[0073] 2. Determination of total phenol content

[0074] A gallic acid stock solution of 0.32 mg / mL was prepared. 0, 0.02, 0.04, 0.06, 0.08, and 0.10 mL of this stock solution were diluted to 1 mL with pure water to obtain a series of gallic acid standard solutions. 20 μL of the standard solution was taken, 100 μL of 10% Folin-Ciocalteu was added, the mixture was shaken well, and reacted in the dark for 5 min. Then, 80 μL of 7.5% Na₂CO₃ solution was added, the mixture was shaken well, and reacted in the dark for 1 h. The absorbance was measured at 765 nm. A total phenol standard curve was plotted with the gallic acid concentration (mg / mL) on the x-axis and the absorbance on the y-axis. The total phenol concentration of the extract solution could be calculated by substituting the absorbance values ​​obtained from the standard curve into the sample solution, following the same method.

[0075] Calculate the total phenol content and extraction rate of the sample according to the formula:

[0076] .

[0077] C: Total phenol concentration (mg / mL); V1: Test solution volume (mL); V2: Total extract volume (mL); V3: Test solution volume (mL).

[0078] .

[0079] m1: Total phenol content (mg); m2: Jaboticaba pomace powder content (g).

[0080] 3. ABTS + Determination of free radical scavenging ability

[0081] Based on the anthocyanin content of the enzymatic hydrolysis extract of Jaboticaba pomace, its mass concentration was adjusted to 4, 6, 8, 10, 12, 14, and 16 ug / mL, and its ABTS was determined. + Free radical scavenging rate, and compared with vitamin C at the same concentration.

[0082] Mix 10 mL of 7 mmol / L ABTS+ solution and 10 mL of 4.96 mmol / L potassium persulfate solution thoroughly and react at room temperature in the dark for 16 h. Dilute the mixture with 10 mmol / L pH 7.4 phosphate-buffered saline (PBS) until the absorbance at 734 nm is 0.7 ± 0.02. Take 1.0 mL of each diluted extract and 4.0 mL of ABTS solution and react in the dark for 6 min. The absorbance at 734 nm is measured as sample group A1. Using distilled aqueous solution as a blank control, and following the same procedures as the sample group, the absorbance is measured as blank group A0. Using PBS instead of ABTS solution, and following the same procedures as the sample group, the absorbance is measured as control group A2. Vitamin C of corresponding concentration is used as a control for the extract. The measurements are repeated three times. ABTS+ + Free radical scavenging rate is calculated using the formula:

[0083] .

[0084] 4. DPPH free radical scavenging capacity determination

[0085] Based on the anthocyanin content of the enzymatic hydrolysis extract of Jaboticaba pomace, its mass concentration was adjusted to 5, 10, 15, 20, 25, 30, 35, and 40 ug / mL. Its DPPH free radical scavenging rate was measured and compared with that of vitamin C at the same concentration.

[0086] Take 1.0 mL of the diluted extract at different concentrations and react it with 4.0 mL of 0.1 mmol / L DPPH ethanol solution for 30 min. Measure the absorbance (A1) at 517 nm. Replace the extract and DPPH ethanol solution with anhydrous ethanol and measure the absorbance (A0) and (A2) respectively using the same method. Use vitamin C of the corresponding concentration as a control for the extract. Repeat the measurement three times. The DPPH free radical scavenging rate is calculated using the formula:

[0087] .

[0088] The following results were obtained by measuring using the above method.

[0089] 1. Extraction rate of anthocyanins and total phenols

[0090] The table below shows the extraction rate and enhancement rate of anthocyanins and total phenols in Examples 1-3 and Comparative Examples 1-2.

[0091]

[0092] Besides the samples mentioned above, in the prior art listed in the background of this invention, the authorized patent for whole fruit lactic acid bacteria fermentation of Jaboticaba (CN116077384B) only lists its polyphenol extraction rate as 2.0 mg / g; the patent application for blueberry pomace freeze-dried powder fermented with lactic acid bacteria (202211616455.7) only lists its polyphenol extraction rate as 3.37 mg / g; and the patent application for blueberry pomace extract (202511708730.1) only lists its anthocyanin extraction rate as 6.64 mg / g. None of these patents involve the extraction of both anthocyanins and polyphenols simultaneously, indicating that their extraction methods are relatively simple.

[0093] As shown in the table above, there are significant differences in anthocyanin and total phenolic content between the extracts obtained by physical cell wall disruption without pectin lyase enzymatic hydrolysis (Comparative Example 1, JB4), the extracts obtained by enzymatic hydrolysis without physical cell wall disruption (Comparative Example 2, JB5), and the extracts obtained by a composite process of enzymatic hydrolysis coupled with physical cell wall disruption and homogenization using pectin lyase (Examples 1-3, JB1-3). Compared to Comparative Example 1, the anthocyanin extraction rate of the pomace extract prepared by this invention is increased by 4.11%-13.88%, and the polyphenol extraction rate is increased by 2.39%-17.41%, showing a significant improvement. The above results confirm that incorporating pectin lyase into the extraction process of this invention can significantly improve the extraction efficiency of active ingredients in pomace, fully demonstrating the necessity and key role of enzymatic hydrolysis in this invention. Furthermore, the addition of pectin lyase alone, without physical cell disruption, also affects the release of polyphenols and anthocyanins from Jaboticaba pomace. Compared to Comparative Example 2, the extracts JB1, JB2, and JB3, obtained through a combined process of pectin lyase enzymatic hydrolysis coupled with physical cell disruption and homogenization, showed an anthocyanin extraction rate increase of 9.04%-10.14% and a polyphenol extraction rate increase of 5.59%-13.85%. Compared with existing related technologies, in terms of polyphenol yield, JB2 (65.42 mg / g) significantly increased by 3171% compared to whole Jaboticaba lactic acid bacteria fermented extract (2 mg / g), and significantly increased by 1841% compared to lactic acid bacteria fermented blueberry pomace freeze-dried powder (3.37 mg / g); in terms of anthocyanin yield, JB5 (8.04 mg / g) significantly increased by 21% compared to blueberry pomace extract (6.64 mg / g).

[0094] The above experimental data further confirms that the samples prepared using the composite process of pectin lyase enzymatic hydrolysis coupled with physical cell wall disruption and homogenization of the present invention have significantly higher anthocyanin and polyphenol contents than samples prepared by physical cell wall disruption extraction without pectin lyase enzymatic hydrolysis and samples prepared by extraction without physical cell wall disruption coupling with pectin lyase enzymatic hydrolysis, and are also superior to existing related technologies. At the same time, this patented technology is specifically designed for the synergistic extraction of anthocyanins and polyphenols from Jaboticaba pomace, fully demonstrating the core technical advantages of the present invention in the optimization of enzymatic hydrolysis process.

[0095] 2. Evaluation of in vitro antioxidant capacity

[0096] 2.1 DPPH free radical scavenging ability

[0097] Vitamin C, as a recognized positive control for antioxidant activity evaluation in existing technologies, enhances immunity by activating immune cells, promoting antibody and cytokine synthesis, and scavenging free radicals to reduce immune damage. It also reduces pigmentation by inhibiting the activity of key enzymes in melanin synthesis, reducing melanin, and resisting UV-induced oxidative damage, making it widely used in the field of skin-whitening functional foods. DPPH, a stable free radical compound, is a commonly used model substance for evaluating the antioxidant activity of natural products. This experiment used vitamin C as a positive control to compare and verify the antioxidant activity of the jaboticaba pomace extract prepared in this invention. The results are as follows... Figure 1 As shown, the Jaboticaba pomace extract JB2 prepared in this invention exhibits a significant dose-dependent relationship with vitamin C, with its DPPH free radical scavenging rate gradually increasing with increasing concentration. At a concentration of 5 μg / mL, the DPPH free radical scavenging rate of vitamin C is 19.45%, while the DPPH free radical scavenging rate of the Jaboticaba pomace extract JB2 of this invention reaches as high as 93.07%, an increase of 378.51% compared to vitamin C. This means that at this concentration, the antioxidant activity of extract JB2 is 5 times that of vitamin C. When the concentration of vitamin C is increased to 40 μg / mL, its DPPH free radical scavenging rate becomes 93.38%, approaching the scavenging rate of extract JB2 at a concentration of 5 μg / mL. These experimental results confirm that the Jaboticaba pomace extract prepared in this invention possesses excellent DPPH free radical scavenging ability, and its antioxidant activity is significantly superior to that of the commonly used antioxidant vitamin C.

[0098] 2.2 ABTS + Free radical scavenging ability

[0099] Under specific oxidative conditions, ABTS first transforms into ABTS free radicals, which, after further oxidation, form stable blue-green ABTS⁺ free radicals. These ABTS⁺ radicals can react with antioxidants, reducing them to colorless neutral ABTS molecules. Based on this reaction characteristic, the antioxidant capacity of a sample can be assessed. In this experiment, vitamin C was used as a recognized positive control for evaluating antioxidant activity in existing technologies to compare and verify the antioxidant activity of the jaboticaba pomace extract prepared in this invention. The experimental results are as follows: Figure 2 As shown, the ABTS⁺ free radical scavenging rate of vitamin C gradually increases with increasing mass concentration; while the ABTS⁺ free radical scavenging rate of the jaboticaba pomace extract JB2 prepared in this invention shows a trend of first increasing and then stabilizing. When the mass concentration is 4 μg / mL, the ABTS⁺ free radical scavenging rate of vitamin C is only 8.25%, while the ABTS⁺ free radical scavenging rate of the jaboticaba pomace extract JB2 of this invention reaches 87.61%, which is 961.94% higher than that of vitamin C at the same concentration. That is, the antioxidant activity of extract JB2 at this concentration is 10 times that of vitamin C. When the mass concentration is increased to 16 μg / mL, the ABTS⁺ free radical scavenging rate of the jaboticaba pomace extract JB2 of this invention is as high as 99.06%, while the ABTS⁺ free radical scavenging rate of vitamin C at the same concentration is only 24.19%. The above experimental results fully demonstrate that the Jaboticaba pomace extract prepared by this invention has excellent ABTS⁺ free radical scavenging ability, and its antioxidant activity is significantly better than that of the commonly used antioxidant vitamin C, highlighting the technical advantages of the product of this invention.

[0100] In summary, the present invention provides a jaboticaba pomace extract with antioxidant function and its preparation method. Combined with experimental data from the embodiments and comparative examples of the present invention, it is evident that the extract prepared using jaboticaba pomace as raw material and a composite extraction process involving pectinase enzymatic hydrolysis coupled with physical cell wall disruption and homogenization yields significantly higher anthocyanin and polyphenol extraction rates than conventional extraction methods and existing related technologies that do not employ this composite process. Furthermore, this process is specifically designed for the synergistic extraction of anthocyanins and polyphenols from jaboticaba pomace, demonstrating strong targeting and significant technological innovation. Experiments have confirmed that the jaboticaba pomace extract prepared by the present invention exhibits significantly higher scavenging rates against DPPH and ABTS⁺ free radicals than the commonly used antioxidant vitamin C, highlighting its significant advantages in antioxidant activity. This invention not only provides a practical and feasible technical solution for the high-value development and utilization of jaboticaba pomace by-products, effectively solving the industry pain points of wasteful and low-utilization rates of pomace resources in existing jaboticaba processing, but also significantly improves the comprehensive utilization rate of resources and the added value of products in the jaboticaba industry. At the same time, it further broadens the application fields of active ingredients in jaboticaba, realizing the efficient extraction and high-value application of active substances such as anthocyanins and polyphenols in pomace, and has important industrial promotion value and significant economic significance.

[0101] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the inventive concept, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a jaboticaba pomace extract with antioxidant function, characterized in that, Includes the following steps: Prepare the materials and collect the jaboticaba pulp after separating the juice for later use; Freeze-drying process: Jaboticaba fruit pomace is placed in a freeze dryer to freeze-dry and remove moisture, then ground and pulverized to obtain freeze-dried powder; Enzymatic hydrolysis: Mix freeze-dried powder with water at a material-to-liquid ratio of 1:10~50, then add 1~5% pectin lyase for enzymatic hydrolysis. After enzymatic hydrolysis, obtain the enzymatic hydrolysate. Enzyme inactivation treatment: The enzyme hydrolysate is subjected to enzyme inactivation treatment. After enzyme inactivation is completed and cooled, an enzyme-inactivated solution is obtained. Shearing: The enzyme-inactivating solution is transferred to a shearing machine for shearing to obtain a shearing solution; Homogenize by placing the shear fluid in a homogenizer and homogenizing it 1-3 times to obtain a homogenized liquid; Centrifugation: Place the homogenized liquid in a centrifuge and centrifuge. After centrifugation, take the supernatant, which is the Jaboticaba pomace extract.

2. The method for preparing the Jaboticaba pomace extract with antioxidant function according to claim 1, characterized in that: In the enzymatic hydrolysis step, the enzymatic hydrolysis reaction is carried out under a stirring environment with a stirring speed of 100~170 r / min, an enzymatic hydrolysis temperature of 30~65 ℃, and an enzymatic hydrolysis time of 1~5 hours.

3. The method for preparing the Jaboticaba pomace extract with antioxidant function according to claim 1, characterized in that: In the enzyme inactivation step, the enzyme inactivation temperature is 70~95 ℃, the enzyme inactivation time is 10~30 min, and the enzyme is cooled for 5~20 min after inactivation.

4. The method for preparing the Jaboticaba pomace extract with antioxidant function according to claim 1, characterized in that: In the freeze-drying process, the jaboticaba pomace is placed in a freeze dryer and freeze-dried at a temperature of -80°C to remove moisture. Then, it is transferred to a pulverizer for grinding and pulverizing. The pulverized powder is then passed through a 50-80 mesh sieve to obtain freeze-dried powder.

5. The method for preparing the Jaboticaba pomace extract with antioxidant function according to claim 1, characterized in that: In the shearing step, the shearing speed is 1000~4000 r / min and the shearing time is 2~9 min.

6. The Jaboticaba pomace extract with antioxidant function and its preparation method according to claim 1, characterized in that: In the homogenization step, the homogenization pressure is 5~30 MPa.

7. The method for preparing the Jaboticaba pomace extract with antioxidant function according to claim 1, characterized in that: In the centrifugation step, the centrifugal force is 4000~9000 g, and the centrifugation time is 10~40 min.

8. The method for preparing the Jaboticaba pomace extract with antioxidant function according to any one of claims 1-7, characterized in that: The jaboticaba pomace is obtained by processing the washed jaboticaba fruit using a screw press separator to separate the juice.

9. A jaboticaba pomace extract with antioxidant properties, characterized in that: It is prepared by the method for preparing the jaboticaba pomace extract with antioxidant function as described in any one of claims 1-8.

10. The Jaboticaba pomace extract with antioxidant function according to claim 9, characterized in that: The anthocyanin extraction rate of the Jaboticaba pomace extract was 7.5~9 mg / g, and the polyphenol extraction rate was 55~70 mg / g.

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