Walnut peptide antioxidant oral liquid as well as preparation method and application thereof

Abstract

The invention relates to walnut peptide antioxidant oral liquid and a preparation method and application thereof, the oral liquid is composed of walnut peptide, black mulberry powder, sorbitol, sodium carboxymethyl cellulose and purified water, and the walnut peptide is prepared by enzymolysis of walnut meal through alkaline protease and freeze drying. Through optimization of a single factor experiment and an orthogonal experiment, it is determined that the walnut peptide, the black mulberries, the sorbitol and the sodium carboxymethyl cellulose are in the optimal proportion of 6%, 0.5%, 12% and 0.3%, and the sensory score reaches 87.67. The oral liquid is remarkable in antioxidant activity, the DPPH clearance rate is 58.54%, the hydroxyl radical clearance rate is 81.04%, the superoxide anion clearance rate is 34.29%, and the total reducing power absorbance is 0.32. According to the invention, walnut meal resources are utilized, enzymolysis and compounding technologies are combined, the problems of resource waste and single function in traditional processing are solved, and the product has both taste and antioxidant function, and can be applied to the fields of nutritional supplements and functional foods.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of food processing, and particularly relates to a walnut peptide antioxidant oral liquid and a preparation method and application thereof. BACKGROUND

[0002] Walnut is an important oil crop in China. Many nutrients such as protein and fat in the by-product walnut meal after oil extraction are not fully utilized in most cases. Many experiments have demonstrated that walnut protein and its enzymatic products have anticancer and antioxidant effects. In the process of enzymatic protein, many functional peptides can be obtained, which have the functions of delaying memory loss, improving the digestive system, relieving nervous tension, and improving human immunity. In the prior art, the deep processing of walnut meal mainly focuses on protein extraction (such as alkali dissolution and acid precipitation method) or the development of single functional components, and lacks systematic research on the compounding process and sensory quality of comprehensive products (such as oral liquid). In addition, the existing oral liquid products still have deficiencies in antioxidant activity, taste and stability.

[0003] For example, the existing patent CN106036309A discloses a walnut protein beverage, but it does not involve the enzymatic process of polypeptides, and the ratio is not optimized by orthogonal test. Although the literature "Optimization of Enzyme-assisted Alkaline Extraction Process of Pecan Cake Protein" (Guo Yi et al., 2023) studies the extraction process of pecan protein, it does not convert it into an oral liquid product with antioxidant function. Therefore, it is of great industrial value to develop a high-efficiency compounded oral liquid based on walnut meal polypeptides, which has excellent sensory quality and antioxidant activity. SUMMARY

[0004] The purpose of the present application is to provide a walnut peptide antioxidant oral liquid and a preparation method and application thereof, which fills the blank of high-efficiency compounded oral liquid based on walnut meal polypeptides, which cannot have excellent sensory quality and antioxidant activity.

[0005] The walnut peptide antioxidant oral liquid of the present application comprises the following components in mass percentage:

[0006] Walnut peptide: 4% to 8%;

[0007] Black mulberry powder: 0.3% to 0.7%;

[0008] Sorbitol: 8% to 12%;

[0009] Sodium carboxymethyl cellulose: 0.3% to 0.7%;

[0010] The balance is purified water.

[0011] The preparation method of the walnut peptide antioxidant oral liquid is as follows:

[0012] Mix walnut peptide powder, black mulberry powder, sorbitol and sodium carboxymethyl cellulose;

[0013] Add purified water to dissolve and homogenize;

[0014] After filtration and sterilization, store in cold storage to obtain the finished product of oral liquid

[0015] The walnut peptide is prepared by the following steps:

[0016] a) Crush the walnut meal and prepare a 5% solution;

[0017] b) Adjust the pH of the solution to 8.5~9.5, add 8000~12000 U / g of alkaline protease, and hydrolyze at 45~55 ℃ for 5~7h;

[0018] c) After enzyme inactivation, centrifuge to obtain the supernatant, and freeze-dry to obtain walnut peptide powder.

[0019] Further, the preferred ratio of the ingredients is:

[0020] Walnut peptide: 6%;

[0021] Black mulberry powder: 0.5%;

[0022] Sorbitol: 12%;

[0023] CMC-Na: 0.3%.

[0024] Further, the antioxidant activity meets the following indicators:

[0025] DPPH free radical scavenging rate ≥58.54%;

[0026] Hydroxyl radical scavenging rate ≥81.04%;

[0027] Superoxide anion radical scavenging rate ≥34.29%;

[0028] Total reducing power ≥0.32.

[0029] Further, the mixture needs to be left for 30 min before homogenization to fully dissolve.

[0030] Further, the sterilization adopts high-temperature instantaneous sterilization process.

[0031] The walnut peptide oral liquid of the present application is used in the preparation of antioxidant food or nutritional supplements.

[0032] The present application is based on the antioxidant mechanism to create a walnut polypeptide oral liquid, especially adding black mulberry rich in anthocyanins, resveratrol and other natural antioxidant ingredients, through gradient compounding process (i.e. the process of configuring walnut peptide, black mulberry powder, sorbitol, carboxymethyl cellulose sodium according to the component amount of the present application), realizing the synergistic effect of walnut polypeptide and black mulberry active ingredients, significantly enhancing the ability to scavenge free radicals, delaying the aging of the body, and at the same time, through fine adjustment, the oral liquid is amber clear liquid, with sweet and soft taste, no special odor, high human absorption and utilization rate, providing consumers with product choices with high efficient antioxidant effect and comfortable drinking experience. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 Sensory evaluation test of walnut polypeptide oral liquid with different walnut peptide addition amounts

[0034] Figure 2 Sensory evaluation test of walnut polypeptide oral liquid with different black mulberry addition amounts

[0035] Figure 3 Sensory evaluation test of walnut polypeptide oral liquid with different sorbitol addition amounts

[0036] Figure 4 Sensory evaluation test of walnut polypeptide oral liquid with different CMC-Na addition amounts

[0037] Figure 5 Antioxidant activity comparison column chart of the example and the control group (hydroxyl radical, superoxide anion clearance rate) DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the spirit of the disclosed content will be described in detail below, and any person skilled in the art can make changes and modifications to the technology taught by the present application content without departing from the spirit and scope of the present application content.

[0039] The schematic embodiments of the present application and their descriptions are used to explain the present application, but not as a limitation of the present application.

[0040] Example 1: basic preparation method of walnut polypeptide oral liquid

[0041] Walnut meal pretreatment

[0042] Grind the walnut meal, pass through an 80-mesh sieve to obtain walnut meal powder. Weigh 50 g of walnut meal powder, add distilled water to make up to 1000 mL to prepare a 5% concentration of walnut meal solution.

[0043] Walnut peptide extraction

[0044] The pH of the walnut meal solution was adjusted to 8.5 by adding 1 mol / L NaOH solution, 5000 U / g of alkaline protease was added, and the enzyme hydrolysis was carried out in a 55°C water bath for 2 hours, during which the pH was maintained stable by adding NaOH solution dropwise. After enzyme hydrolysis, the enzyme was inactivated in a 100°C boiling water bath for 20 minutes, cooled to room temperature with cold water, the pH was adjusted to neutral with 1 mol / L hydrochloric acid, centrifuged at 3000 r / min for 20 minutes, the supernatant was collected, and freeze-dried to obtain walnut peptide powder.

[0045] Preparation of oral solution

[0046] Walnut peptide powder (8%), black mulberry powder (0.5%), sorbitol (12%), CMC-Na (0.5%) were added and dissolved in purified water, stirred for 30 minutes, homogenized at 10 MPa, filtered, sterilized at 121°C for 15 minutes, and refrigerated to obtain the oral solution.

[0047] The sensory evaluation was carried out according to Table 1.

[0048] Table 1 Sensory evaluation of walnut peptide oral solution

[0049]

[0050] Evaluation method: independent scoring by testers of different ages and genders, and significant analysis was carried out by SPSS 25 (P<0.05).

[0051] Sensory evaluation: smooth taste, light walnut flavor, uniform color, clear organization state, score 76.39.

[0052] Example 2: Preparation of oral solution with different amounts of walnut peptide

[0053] Under the conditions of fixed black mulberry powder 0.5%, sorbitol 12%, CMC-Na 0.5%, the amount of walnut peptide powder was adjusted to 4%, 6%, 8%, 10%, and 12%, and the oral solution was prepared according to the steps of Example 1.

[0054] Walnut peptide addition amount 6%:

[0055] Smooth taste, rich walnut flavor, uniform color and luster, clear organization state, sensory score 84.94, which is the optimal group of walnut peptide addition amount in single factor experiment.

[0056] Example 3: Preparation of oral solution with different amounts of black mulberry

[0057] Under the conditions of fixed walnut peptide powder 8%, sorbitol 12%, CMC-Na 0.5%, the amount of black mulberry powder was adjusted to 0.1%, 0.3%, 0.5%, 0.7%, and 0.9%, and the oral solution was prepared according to the steps of Example 1.

[0058] Black mulberry addition amount 0.7%:

[0059] Smooth taste, with a faint mulberry fruit flavor, uniform color, no sediment, sensory score of 79.33, the optimal group of black mulberry addition amount in single factor experiment.

[0060] Example 4: Preparation of oral solution with different sorbitol addition amounts

[0061] Under the conditions of fixed walnut peptide powder 8%, black mulberry powder 0.5%, CMC-Na 0.5%, adjust the sorbitol addition amount to 4%, 8%, 12%, 16%, 20%, and prepare the oral solution according to the steps of Example 1.

[0062] Sorbitol addition amount 12%:

[0063] Moderate sweetness, smooth taste, no sticky feeling, sensory score of 72.94, the optimal group of sorbitol addition amount in single factor experiment.

[0064] Example 5: Preparation of oral solution with different CMC-Na addition amounts

[0065] Under the conditions of fixed walnut peptide powder 8%, black mulberry powder 0.5%, sorbitol 12%, adjust the CMC-Na addition amount to 0.1%, 0.3%, 0.5%, 0.7%, 0.9%, and prepare the oral solution according to the steps of Example 1.

[0066] CMC-Na addition amount 0.3%:

[0067] Liquid is clear, has good flowability, no stratification phenomenon, sensory score of 74.56, the optimal group of CMC-Na addition amount in single factor experiment.

[0068] Example 6: Preparation of oral solution with optimal ratio optimized by orthogonal experiment

[0069] Based on the results of single factor experiment, select walnut peptide powder (4%, 6%, 8%), black mulberry powder (0.3%, 0.5%, 0.7%), sorbitol (4%, 8%, 12%), CMC-Na (0.3%, 0.5%, 0.7%) for L9(34) orthogonal experiment, and determine the optimal ratio as follows: 4

[0070] Walnut peptide powder 6%, black mulberry powder 0.5%, sorbitol 12%, CMC-Na 0.3%.

[0071] Preparation steps:

[0072] Weigh the raw materials according to the above ratio, dissolve in purified water, and stir for 30 min; ​

[0073] After 10 MPa homogenization treatment, filtration, sterilization at 121 ℃ for 15 min, and refrigeration, an oral solution is obtained.

[0074] Sensory evaluation: smooth taste, rich walnut flavor with a light fruit aroma, uniform color and luster, clear organization state without precipitation, and a score of 87.67, which is the optimal group of the orthogonal test.

[0075] Control group 1: different from the orthogonal group (Example 6) in that no black mulberry powder is added, and the same as the orthogonal group (Example 6) in other aspects.

[0076] Control group 2: different from the orthogonal group (Example 6) in that no walnut peptide powder is added, and the same as the orthogonal group (Example 6) in other aspects.

[0077] Antioxidant activity of the present example and control groups 1 and 2:

[0078] Test conditions for antioxidant activity:

[0079] 1. Determination of total reducing power

[0080] 100 μL of the oral solution was added to three centrifuge tubes using a pipette, and then PBS buffer (pH = 6.6) and 1% potassium ferricyanide solution were added and mixed well and shaken, and then placed in 50 ℃ water for 20 min, and then reduced to room temperature, 100 μL of 10% trichloroacetic acid solution was added to the three centrifuge tubes, and then mixed well and centrifuged in a centrifuge (4000 r / min for 10 min). After centrifugation, 100 μL of supernatant was taken to a 96-well plate, and then an equal amount of distilled water and 0.1% ferric chloride solution 20 μL was added, and the absorbance (A) of the test solution was measured at 700 nm. The positive control was an equal amount of Vc, and the average value was taken for the three experiments.

[0081] 2. Determination of DPPH free radical scavenging ability

[0082] In a 96-well plate, 50 μL of the oral solution sample solution was taken using a pipette, and an equal amount of 0.1 mmol / L DPPH solution was added, mixed well, and then placed in the dark for half an hour, and then the absorbance A1 of the test solution at 517 nm was measured using a microplate reader. The DPPH solution was replaced with 50 μL of anhydrous ethanol and the test was repeated, and the absorbance was measured using a microplate reader to obtain A2. The oral solution was replaced with 50 μL of anhydrous ethanol and the test was repeated, and the absorbance was measured using a microplate reader to obtain A3. The clearance rate was calculated according to the formula, and the positive control was an equal amount of Vc, and the experiment was repeated three times and the average value was taken. The DPPH free radical clearance rate is shown in formula (2-1):

[0083] (2-1)

[0084] 3. Determination of hydroxyl radical scavenging capacity

[0085] In a 96-well plate, 50 μL of oral liquid sample solution was added with a pipette, followed by the addition of an equal amount of 9 mmol / L ferrous sulfate solution and 9 mmol / L salicylic acid-ethanol solution. The well plate was gently shaken to mix thoroughly, and finally 50 μL of 8.8 mmol / L H2O2 solution was added to the well plate to initiate the reaction, and the well plate was incubated at 37°C for half an hour. The absorbance A1 of the test solution at 510 nm was measured by a microplate reader. The test was repeated by replacing the H2O2 solution with 50 μL of distilled water, and the absorbance was measured by a microplate reader to obtain A2. The test was repeated by replacing the oral liquid with 50 μL of distilled water, and the absorbance was measured by a microplate reader to obtain A3. The scavenging rate was calculated according to the formula, and the positive control was an equal amount of Vc. The experiment was repeated three times, and the average value was taken. The hydroxyl radical scavenging rate is shown in formula (2-2):

[0086] (2-2)

[0087] 4. Determination of superoxide anion radical scavenging capacity

[0088] In a centrifuge tube, 400 μL of 50 mmol / L Tris-HCI buffer solution (pH=8.2) was added and placed in a 25°C water bath. After 20 min, 100 μL of oral liquid and 25 mmol / L of o-phenanthroline were added, and the mixture was thoroughly mixed and incubated at the above temperature for 5 min. The reaction was terminated by adding 10 μL of 8% hydrochloric acid. In a 96-well plate, 100 μL of the test solution was added, and the absorbance A1 of the test solution at 325 nm was measured by a microplate reader. The test was repeated by replacing the o-phenanthroline solution with 100 μL of distilled water, and the absorbance was measured by a microplate reader to obtain A2. The test was repeated by replacing the oral liquid with 100 μL of distilled water, and the absorbance was measured by a microplate reader to obtain A3. The scavenging rate was calculated according to the formula, and the positive control was an equal amount of Vc. The experiment was repeated three times, and the average value was taken. The superoxide anion scavenging rate is shown in formula (2-3):

[0089] (2-3)

[0090] The total reducing power of this example was 0.32, the DPPH radical scavenging rate was 58.54%, the hydroxyl radical scavenging rate was 81.04%, and the superoxide anion radical scavenging rate was 34.29%, showing good antioxidant activity. The superoxide anion scavenging rate of control group 1 was 21.74%, and the hydroxyl radical scavenging rate was 59.28%. The superoxide anion scavenging rate of control group 2 was 32.86%, and the hydroxyl radical scavenging rate was 46.86%.

[0091] The antioxidant activity of the embodiment is significantly improved compared with control group 1, and the superoxide anion removal rate is increased by 57.7%, and the hydroxyl radical removal rate is increased by 36.7%. Compared with control group 2, the superoxide anion removal rate of the embodiment is increased by 25.81% (see Figure 5 ).

[0092] Example 7: verification experiment comparison

[0093] The optimal ratio of orthogonal experiment (Example 6) is compared with the combination with higher sensory score in single factor experiment (6% walnut peptide, 0.5% black mulberry, 12% sorbitol, 0.5% CMC-Na):

[0094] Orthogonal group (Example 6): the sensory score is 87.67, and the tissue state is more stable;

[0095] Single factor group: the sensory score is 84.94, and the fluidity is slightly poor.

[0096] The results show that the ratio determined by the orthogonal experiment (6% walnut peptide, 0.5% black mulberry, 12% sorbitol, 0.3% CMC-Na) is the best scheme.

[0097] The above only describes the preferred embodiments of the present application, which is only illustrative but not limiting. The skilled person understands that many changes, modifications and even equivalents can be made to the present application within the spirit and scope defined by the claims of the present application, but all will fall within the protection scope of the present application.

Claims

1. A walnut peptide antioxidant oral liquid, characterized in that, The walnut peptide oral liquid is composed of the following ingredients by weight percentage: Walnut peptides: 4%–8%; Black mulberry powder: 0.3%–0.7%; Sorbitol: 8%–12%; Sodium carboxymethyl cellulose: 0.3%–0.7%; The remainder is purified water; The preparation method of the walnut peptide antioxidant oral liquid is as follows: Mix walnut peptide powder, black mulberry powder, sorbitol and sodium carboxymethyl cellulose; Dissolve in purified water and homogenize. After filtration, sterilization, and refrigeration, the oral liquid product is obtained. The walnut peptide is prepared by the following steps: a) Grind the walnut meal and prepare a 5% solution; b) Adjust the pH of the solution to 8.5-9.5, add 8000-12000 U / g alkaline protease, and enzymatically hydrolyze at 45-55 ℃ for 5-7 h; c) After enzyme inactivation, centrifuge to collect the supernatant, and freeze-dry to obtain walnut peptide powder.

2. The walnut peptide antioxidant oral liquid according to claim 1, characterized in that, The preferred ratio of the components is as follows: Walnut peptides: 6%; Black mulberry powder: 0.5%; Sorbitol: 12%; CMC-Na: 0.3%.

3. A walnut peptide antioxidant oral liquid according to claim 1 or 2, characterized in that, The antioxidant activity described meets the following criteria: DPPH free radical scavenging rate ≥58.54%; Hydroxyl radical scavenging rate ≥81.04%; Superoxide anion radical scavenging rate ≥34.29%; Total reducing power ≥ 0.

32.

4. The walnut peptide antioxidant oral liquid according to claim 1, characterized in that, Before homogenization, the mixture needs to be allowed to stand for 30 minutes to fully dissolve.

5. The walnut peptide antioxidant oral liquid according to claim 1, characterized in that, The sterilization process employs a high-temperature instantaneous sterilization process.

6. The use of the walnut peptide oral liquid as described in any one of claims 1-6 in the preparation of antioxidant foods or nutritional supplements.

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