Deodorized porphyra haitanensis juice and preparation method thereof as well as anti-fatigue beverage and preparation method thereof

Abstract

The invention relates to the technical field of porphyra haitanensis processing, and provides deodorized porphyra haitanensis juice and a preparation method thereof and an anti-fatigue beverage and a preparation method thereof.The preparation method of the deodorized porphyra haitanensis juice comprises the following steps that neutral protease is used for conducting enzymolysis on the porphyra haitanensis juice, and enzymatic hydrolysate is obtained; performing physical fishy smell removal on the enzymatic hydrolysate to obtain a physical fishy smell removal solution; and performing microbial fermentation on the physical fishy smell removal liquid to obtain the fishy smell removal porphyra haitanensis juice. The preparation method of the fishy-smell-removed porphyra haitanensis juice is green and free of pollution, the fishy-smell-removed porphyra haitanensis juice can be rich in various metabolites and special flavor substances beneficial to human bodies, the nutritional value and characteristics of porphyra haitanensis products are enhanced, and high-value utilization of porphyra haitanensis resources is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of laver processing, and particularly relates to a deodorized laver juice and a preparation method thereof, and an anti-fatigue beverage and a preparation method thereof. Background Art

[0002] Laver is one of the important economic seaweeds in the world. It is rich in nutritional value and is a red alga with high protein, high dietary fiber, low fat, and low calorie. It has physiological activities such as antioxidant, anti-fatigue, blood pressure lowering, and cholesterol lowering, and can be used to make nutritional health foods. With the continuous improvement of living standards, people pay more and more attention to diet nutrition and health. Due to the above-mentioned many effects and benefits, laver foods and health products have received more and more attention from consumers. At present, consumers are more inclined to choose health drinks made from natural food raw materials, and laver drinks, as an important product form of laver, fit this consumption trend. However, at present, laver is still mainly in the form of primary processed products. Therefore, realizing the high-value utilization of low-value laver is an urgent need for the development of the laver industry.

[0003] Seaweeds contain various volatile substances and have a special fishy smell. The fishy smell components of laver are diverse in types and complex in structure. Its volatile fishy smell components are mainly aldehydes, ketones, and hydrocarbons, such as (E,Z)-2,6-nonadienal, octanal, 8-heptadecene, etc., which affect its popularity among consumers and limit the development of the laver industry. How to efficiently remove the fishy smell of laver has become one of the key technical problems in the high-value development and utilization of laver resources. Currently, common deodorization methods include physical deodorization and chemical deodorization. Physical deodorization is to cover or embed the fishy smell substances, mainly including adsorption method, masking method, complexation method, microencapsulation method, steam deodorization method, etc. It has the advantages of simple operation and low cost, but it is difficult to completely remove the fishy smell. Chemical deodorization method mainly uses chemical substances to react with the fishy smell components, mainly including acid-base treatment method, oxidation method, Maillard reaction method, etc. It has the advantage of significant deodorization effect, but there are also problems of strict condition control and high cost. Therefore, there is an urgent need in this field for a method that can completely remove the fishy smell in laver and enhance the nutritional value and characteristics of laver drinks. Summary of the Invention

[0004] The purpose of the present invention is to provide a deodorized laver juice and a preparation method thereof, and an anti-fatigue beverage and a preparation method thereof, aiming to improve the problems mentioned in the background art, and to prepare an anti-fatigue beverage containing deodorized laver juice, which has uniform color, is purplish red, has harmonious aroma, mellow laver flavor, strong fruity aroma, is sweet, sour, and refreshing, has a soft taste, has uniform texture and good stability, has good antioxidant activity and anti-fatigue activity, and is a nutritious and delicious compound beverage.

[0005] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0006] The present invention provides a method for preparing deodorized laver juice, comprising the following steps:

[0007] (1) Enzymatically hydrolyzing laver juice with neutral protease to obtain a hydrolyzate;

[0008] (2) Physically deodorizing the hydrolyzate to obtain a physically deodorized liquid;

[0009] (3) Microbially fermenting the physically deodorized liquid to obtain deodorized laver juice.

[0010] Preferably, the method for preparing laver juice in step (1) is: crushing laver to obtain laver powder, and mixing the laver powder and water to obtain laver juice; the final concentration of laver powder in the laver juice is 30 - 40 g / L, the addition amount of the neutral protease is 1×10 6 ~1.2×10 6 U / L, the temperature of the enzymatic hydrolysis is 40 - 50 °C, the time of the enzymatic hydrolysis is 4 - 6 h, and the pH of the enzymatic hydrolysis is 7.2 - 8.0.

[0011] Preferably, the physical deodorization in step (2) adopts: activated carbon adsorption method, β-cyclodextrin embedding method or maltodextrin flavoring method.

[0012] Preferably, the steps of the activated carbon adsorption method are: adding activated carbon to the hydrolyzate and reacting at 23 - 27 °C for 1.5 - 2.5 h; the addition amount of the activated carbon is 1.0% - 3.0% of the mass of the hydrolyzate;

[0013] The steps of the β-cyclodextrin embedding method are: adding β-cyclodextrin to the hydrolyzate and reacting at 27 - 33 °C for 0.5 - 1.5 h; the addition amount of the β-cyclodextrin is 0.5% - 2.5% of the mass of the hydrolyzate;

[0014] The steps of the maltodextrin flavoring method are: adding maltodextrin to the hydrolyzate and reacting at 27 - 33 °C for 0.5 - 1.5 h; the addition amount of the maltodextrin is 0.5% - 2.5% of the mass of the hydrolyzate.

[0015] Preferably, the strains for microbial fermentation in step (3) include yeast, Saccharomyces cerevisiae, Lactobacillus plantarum, Lactobacillus casei or Lactobacillus bulgaricus;

[0016] When the strain is yeast, the fermentation method is: adding yeast to the physically deodorized liquid and fermenting in an environment of 28 °C - 36 °C for 25 min - 45 min; the addition amount of the yeast is 0.3% - 0.7% of the mass of the physically deodorized liquid;

[0017] When the strain is *Saccharomyces cerevisiae*, the fermentation method is as follows: adding *Saccharomyces cerevisiae* to the physical deodorization liquid and fermenting for 1 h to 3 h at 27°C to 31°C; the addition amount of *Saccharomyces cerevisiae* is 0.3% to 0.7% of the mass of the physical deodorization liquid.

[0018] When the strain is *Lactobacillus plantarum*, the fermentation method is as follows: adding *Lactobacillus plantarum* to the physical deodorization liquid and fermenting for 1 h to 3 h at 31°C to 39°C; the addition amount of *Lactobacillus plantarum* is 1% to 9% of the mass of the physical deodorization liquid.

[0019] When the strain is *Lactobacillus casei*, the fermentation method is as follows: adding *Lactobacillus casei* to the physical deodorization liquid and fermenting for 15 h to 19 h at 31°C to 39°C; the addition amount of *Lactobacillus casei* is 2% to 6% of the mass of the physical deodorization liquid.

[0020] When the strain is *Lactobacillus bulgaricus*, the fermentation method is as follows: adding *Lactobacillus bulgaricus* to the physical deodorization liquid and fermenting for 4 h to 8 h at 37°C to 45°C; the addition amount of *Lactobacillus bulgaricus* is 1% to 5% of the mass of the physical deodorization liquid.

[0021] Preferably, when the strain is *Lactobacillus plantarum*, ultrasonic treatment is carried out during fermentation, the power of the ultrasonic treatment is 180 to 220 W, and the frequency of the ultrasonic treatment is 30 to 50 kHz.

[0022] The present invention also provides deodorized laver juice prepared by the preparation method described above.

[0023] The present invention also provides an anti-fatigue beverage containing the deodorized laver juice. The anti-fatigue beverage comprises the following raw materials in parts by mass: 60 to 90 parts of deodorized laver juice, 10 to 40 parts of grape juice, 3 to 7 parts of xylitol, 0.01 to 0.20 part of citric acid, and 0.05 to 0.25 part of sodium carboxymethylcellulose.

[0024] The present invention also provides a preparation method of the anti-fatigue beverage, comprising the following steps: mixing deodorized laver juice, grape juice, xylitol, citric acid and sodium carboxymethylcellulose, homogenizing, filling and sealing, sterilizing, and cooling to obtain the anti-fatigue beverage.

[0025] Preferably, the temperature of the homogenization is 50 to 70°C, and the pressure of the homogenization is 20 to 30 MPa; the sterilization method is pasteurization, the sterilization temperature is 70 to 90°C, and the sterilization time is 10 to 30 min.

[0026] The beneficial effects of the present invention are as follows:

[0027] The technical method of the present invention is a green deodorization method, which mainly uses multiple technologies such as enzymatic hydrolysis, physical deodorization, and ultrasonic-assisted microbial fermentation to efficiently deodorize laver, so that the deodorized laver juice is rich in a variety of metabolites and special flavor substances beneficial to the human body, and can significantly enhance the nutritional value and characteristics of laver beverages.

[0028] The anti-fatigue beverage of the present invention contains deodorized laver juice, grape juice, various vitamins, and low-calorie sweeteners. Among them, laver is rich in main active substances such as laver polysaccharides and polypeptides. Among them, laver polysaccharides have various physiological activities such as antioxidant, anti-fatigue, and immune regulation. Laver polypeptides have significant effects in reducing blood sugar, antioxidant, and enhancing immunity. Grapes have bright colors, strong fruity aromas, and are also rich in various chemical components including vitamins, minerals, and flavonoids, and have good antioxidant functions. The combination of the two can further optimize the flavor of laver juice and enhance the efficacy of the beverage in improving physical activity. Further, the component ratios of the anti-fatigue beverage of the present invention are appropriate, making the beverage have the qualities of coordinated aroma, soft taste, and uniform and delicate texture. Moreover, the beverage is extremely nutritious, has significant antioxidant properties, can effectively relieve physical fatigue, and realizes the high-value utilization of laver resources. Description of the Drawings

[0029] Figure 1 For the sensory evaluation results of Experimental Example 1(1);

[0030] Figure 2 For the electronic nose PCA analysis chart of Experimental Example 1(2);

[0031] Figure 3 For the sensory evaluation results of Experimental Example 1(3);

[0032] Figure 4 For the sensory evaluation results of Experimental Example 1(4);

[0033] Figure 5 For the GC-IMS volatile compound fingerprint map of Experimental Example 1(5);

[0034] Figure 6 For the body weight of mice during the experiment of Experimental Example 3;

[0035] Figure 7 For the swimming exhaustion time of mice in Experimental Example 3;

[0036] Figure 8 For the serum lactic acid content of mice in Experimental Example 3;

[0037] Figure 9 For the serum urea nitrogen content of mice in Experimental Example 3;

[0038] Figure 10It is the muscle glycogen content of the mice in Experimental Example 3;

[0039] Figure 11 It is the liver glycogen content of the mice in Experimental Example 3. Specific implementation mode

[0040] The present invention provides a method for preparing deodorized laver juice, comprising the following steps:

[0041] (1) Using neutral protease to enzymatically hydrolyze laver juice to obtain an enzymatic hydrolysate;

[0042] (2) Physically deodorizing the enzymatic hydrolysate to obtain a physically deodorized liquid;

[0043] (3) Microbiologically fermenting the physically deodorized liquid to obtain deodorized laver juice.

[0044] In the present invention, the preferred method for preparing the laver juice in step (1) is: crushing laver to obtain laver powder, and mixing the laver powder and water to obtain laver juice; the final concentration of laver powder in the laver juice is preferably 30-40 g / L, more preferably 32-38 g / L, and even more preferably 35 g / L. The addition amount of the neutral protease is preferably 1×10 6 ~1.2×10 6 U / L, more preferably 1.092×10 6 U / L. The temperature of the enzymatic hydrolysis is preferably 40-50 °C, more preferably 43-47 °C, and even more preferably 45 °C. The time of the enzymatic hydrolysis is preferably 4-6 h, more preferably 5 h. The pH of the enzymatic hydrolysis is preferably 7.2-8.0, more preferably 7.6.

[0045] In the present invention, the physical deodorization in step (2) adopts: activated carbon adsorption method, β-cyclodextrin inclusion method or maltodextrin flavor correction method.

[0046] In the present invention, the steps of the activated carbon adsorption method are: adding activated carbon to the enzymatic hydrolysate, preferably reacting at 23-27 °C for 1.5-2.5 h, more preferably reacting at 25 °C for 2 h; the addition amount of the activated carbon is preferably 1.0%-3.0% of the mass of the enzymatic hydrolysate, more preferably 2.0% of the mass of the enzymatic hydrolysate;

[0047] The steps of the β-cyclodextrin inclusion method are: adding β-cyclodextrin to the enzymatic hydrolysate, preferably reacting at 27-33 °C for 0.5-1.5 h, more preferably reacting at 30 °C for 1 h; the addition amount of the β-cyclodextrin is preferably 0.5%-2.5% of the mass of the enzymatic hydrolysate, more preferably 1.0%-2.0% of the mass of the enzymatic hydrolysate, and even more preferably 1.5% of the mass of the enzymatic hydrolysate;

[0048] The steps of the maltodextrin flavor correction method are as follows: Add maltodextrin to the enzymolysis solution, preferably react at 27-33°C for 0.5-1.5 h, more preferably react at 30°C for 1 h; the addition amount of the maltodextrin is preferably 0.5%-2.5% of the mass of the enzymolysis solution, more preferably 1.0%-2.0% of the mass of the enzymolysis solution, and even more preferably 1.5% of the mass of the enzymolysis solution.

[0049] In the present invention, the strains for microbial fermentation in step (3) include yeast, Saccharomyces cerevisiae, Lactobacillus plantarum, Lactobacillus casei or Lactobacillus bulgaricus;

[0050] The fermentation method when the strain is yeast is as follows: Add yeast to the physical deodorization solution, preferably ferment at 28°C-36°C for 25 min-45 min, more preferably ferment at 32°C for 35 min; the addition amount of the yeast is preferably 0.3%-0.7% of the mass of the physical deodorization solution, more preferably 0.5% of the mass of the physical deodorization solution;

[0051] The fermentation method when the strain is Saccharomyces cerevisiae is as follows: Add Saccharomyces cerevisiae to the physical deodorization solution, preferably ferment at 27°C-31°C for 1 h-3 h, more preferably ferment at 29°C for 2 h; the addition amount of the Saccharomyces cerevisiae is preferably 0.3%-0.7% of the mass of the physical deodorization solution, more preferably 0.5% of the mass of the physical deodorization solution;

[0052] The fermentation method when the strain is Lactobacillus plantarum is as follows: Add Lactobacillus plantarum to the physical deodorization solution, preferably ferment at 31°C-39°C for 1 h-3 h, more preferably ferment at 35°C for 2 h; the addition amount of the Lactobacillus plantarum is preferably 1%-9% of the mass of the physical deodorization solution, more preferably 5% of the mass of the physical deodorization solution;

[0053] The fermentation method when the strain is Lactobacillus casei is as follows: Add Lactobacillus casei to the physical deodorization solution, preferably ferment at 31°C-39°C for 15 h-19 h, more preferably ferment at 35°C for 17 h; the addition amount of the Lactobacillus casei is preferably 2%-6% of the mass of the physical deodorization solution, more preferably 4% of the mass of the physical deodorization solution;

[0054] The fermentation method when the strain is Lactobacillus bulgaricus is as follows: Add Lactobacillus bulgaricus to the physical deodorization solution, preferably ferment at 37°C-45°C for 4 h-8 h, more preferably ferment at 41°C for 6 h; the addition amount of the Lactobacillus bulgaricus is preferably 1%-5% of the mass of the physical deodorization solution, more preferably 3% of the mass of the physical deodorization solution.

[0055] In the present invention, when the strain is Lactobacillus plantarum, ultrasound is applied during the fermentation process. The power of the ultrasound is preferably 180 - 220 W, more preferably 220 W, and the frequency of the ultrasound is preferably 30 - 50 kHz, more preferably 40 kHz.

[0056] The present invention also provides the deodorized laver juice prepared by the preparation method described above.

[0057] The present invention also provides an anti - fatigue beverage containing the deodorized laver juice. The anti - fatigue beverage comprises the following raw materials in parts by mass: 60 - 90 parts of deodorized laver juice, 10 - 40 parts of grape juice, 3 - 7 parts of xylitol, 0.01 - 0.20 parts of citric acid, and 0.05 - 0.25 parts of sodium carboxymethylcellulose.

[0058] In the present invention, the parts by mass of the deodorized laver juice are preferably 60 - 90 parts, more preferably 70 - 80 parts, and even more preferably 75 parts.

[0059] In the present invention, the type of the grape juice is NFC freshly squeezed grape juice. The parts by mass of the grape juice are preferably 10 - 40 parts, more preferably 20 - 30 parts, and even more preferably 25 parts.

[0060] In the present invention, the parts by mass of the xylitol are preferably 3 - 7 parts, more preferably 5 parts.

[0061] In the present invention, the parts by mass of the citric acid are preferably 0.01 - 0.20 parts, more preferably 0.10 parts.

[0062] In the present invention, the parts by mass of the sodium carboxymethylcellulose are preferably 0.05 - 0.25 parts, more preferably 0.18 parts.

[0063] The present invention also provides a preparation method of the anti - fatigue beverage, comprising the following steps: mixing the deodorized laver juice, grape juice, xylitol, citric acid and sodium carboxymethylcellulose, homogenizing, filling and sealing, sterilizing, and cooling to obtain the anti - fatigue beverage.

[0064] In the present invention, the temperature of the homogenization is preferably 50 - 70 °C, more preferably 60 °C, and the pressure of the homogenization is preferably 20 - 30 MPa, more preferably 25 MPa; the sterilization method is pasteurization. The temperature of the sterilization is preferably 70 - 90 °C, more preferably 80 °C, and the time of the sterilization is preferably 10 - 30 min, more preferably 20 min.

[0065] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0066] Example 1

[0067] The present invention provides a method for preparing deodorized laver juice, comprising the following steps:

[0068] S1. The laver is broken into laver powder, and the laver powder is mixed with water to obtain laver juice with a final concentration of 35 g / L of laver powder; the laver juice is enzymatically hydrolyzed using neutral protease to obtain a hydrolyzate.

[0069] S2. The hydrolyzate is physically deodorized to obtain a physically deodorized liquid.

[0070] S3. High-activity dry yeast (purchased from Angel Yeast Co., Ltd.) is selected to ferment the physically deodorized liquid at a specific addition amount, fermentation temperature, and fermentation time to obtain deodorized laver juice.

[0071] S4. Ultrasonic treatment is introduced in step S3 to assist fermentation to improve the fermentation process.

[0072] Among them, the addition amount of the neutral protease in step S1 is 1.092×10 6 U / L, the temperature of the enzymatic hydrolysis is 45 °C, the pH of the enzymatic hydrolysis is 7.6, and the time of the enzymatic hydrolysis is 5 h.

[0073] S2 is: using the maltodextrin flavoring method to physically deodorize the hydrolyzate, adding maltodextrin accounting for 2.0% of the mass of the hydrolyzate to the hydrolyzate, and reacting at 30 °C for 1 h.

[0074] S3 is: adding high-activity dry yeast accounting for 0.5% of the mass of the physically deodorized liquid to the physically deodorized liquid and fermenting at 30 °C for 30 min.

[0075] S4 is: the treatment conditions for ultrasonic-assisted fermentation are as follows: select a GT SONIC-D9 ultrasonic cleaner, set the ultrasonic power to 200 W, set the ultrasonic frequency to 40 kHz, and the ultrasonic time is 0 min.

[0076] The present invention provides an anti-fatigue beverage, comprising the following components in parts by mass: the deodorized laver juice and NFC freshly squeezed grape juice are mixed in a ratio of 7:3, xylitol with an addition amount of 6% of the total mass of the deodorized laver juice and NFC freshly squeezed grape juice, citric acid with an addition amount of 0.05% of the total mass of the deodorized laver juice and NFC freshly squeezed grape juice, and sodium carboxymethylcellulose with an addition amount of 0.1% of the total mass of the deodorized laver juice and NFC freshly squeezed grape juice.

[0077] The present invention also provides a method for preparing the anti-fatigue beverage, comprising the following steps:

[0078] The ultrasonic-assisted fermentation liquid of Porphyra haitanensis and NFC original grape juice are mixed in a ratio of 7:3, and 6% of the total mass of xylitol, 0.05% of the total mass of citric acid, and 0.1% of the total mass of sodium carboxymethyl cellulose are added. The mixture is mixed and homogenized (60°C, 25MPa), filled and sealed, pasteurized (80°C, 20min), and cooled to finally obtain an anti-fatigue beverage product.

[0079] Example 2

[0080] This embodiment is basically the same as the embodiment 1, except that: S3 is to add 0.6% of brewer's yeast by weight of the physical deodorization liquid to the physical deodorization liquid, the fermentation temperature is 29° C., and the fermentation time is 2.5 h.

[0081] Example 3

[0082] This embodiment is basically the same as the embodiment 1, except that: S3 is to add 5% of the mass of the physical deodorizing liquid to the physical deodorizing liquid by Lactobacillus plantarum, the fermentation temperature is 37° C., and the fermentation time is 2.5 h.

[0083] Example 4

[0084] This embodiment is substantially the same as the embodiment 1, except that: S3 is to add 4% of the mass of the physical deodorizing liquid to the physical deodorizing liquid by Lactobacillus casei, the fermentation temperature is 37° C., and the fermentation time is 17 h.

[0085] Example 5

[0086] This embodiment is basically the same as the embodiment 1, except that: S3 is to add 3% of the mass of the physical deodorization liquid of Lactobacillus bulgaricus to the physical deodorization liquid, the fermentation temperature is 41° C., and the fermentation time is 6 h.

[0087] Example 6

[0088] This embodiment is basically the same as embodiment 3, except that: S4 is the processing condition of ultrasound-assisted fermentation, using a GT SONIC-D9 ultrasonic cleaning machine, with an ultrasonic power of 200 W, an ultrasonic frequency of 40 kHz, ultrasound at the beginning of fermentation, and an ultrasound duration of 30 min.

[0089] Example 7

[0090] This embodiment is basically the same as embodiment 6, except that: S4 is the processing condition of ultrasound-assisted fermentation, using a GT SONIC-D9 ultrasonic cleaning machine, with an ultrasonic power of 200 W, an ultrasonic frequency of 40 kHz, and an ultrasonic time of 150 min.

[0091] Comparative Example 1

[0092] This comparative example is basically the same as Example 7, except that: step S3 does not occur, and step S4 occurs.

[0093] Experimental Example 1

[0094] (1) Sensory evaluation of fermentation broths of different strains

[0095] Sensory evaluation was carried out on the samples obtained in S1, S2, and S4 of Examples 1 to 5. The sample numbers were: Example 1-S1, Example 1-S2, Example 1-S4, Example 2-S4, Example 3-S4, Example 4-S4, Example 5-S4.

[0096] All sensory evaluations were carried out in a sensory evaluation room, and each experiment was repeated three times. Before the experiment, the purpose of the experiment was informed to the group members. The group members consisted of 10 student volunteers from the Teaching and Research Section of Food Human Sciences and Health, including 6 females and 4 males, aged between 22 and 28 years. The volunteers had no history of taste and smell disorders, and agreed to the standard sample evaluation process before participation, and scored different samples according to the scoring criteria in Table 1. The results are shown in Figure 1 .

[0097] Table 1

[0098]

[0099] (2) Electronic nose analysis of fermentation broths of strains

[0100] Electronic nose analysis was carried out on the samples obtained in S1 and S2 of Example 1 and S4 of Examples 3 to 5. The sample numbers were: Example 1-S1, Example 1-S2, Example 3-S4, Example 4-S4, Example 5-S4.

[0101] An electronic nose system (PEN3, AIRSENSE GmbH, Germany) was used to analyze the samples. The electronic nose contained 10 different metal oxide sensors, forming a sensor array. The sampling needle was directly inserted into the sealed beaker containing the sample, and the electronic nose was used for determination. The determination conditions were: sampling time was 1 s / group; sensor self-cleaning time was 80 s; sensor zeroing time was 5 s; sample preparation time was 5 s; injection flow rate was 400 mL / min; analysis sampling time was 80 s. The characteristic values of 10 sensors were extracted, and then principal component analysis (PCA) was used to analyze the samples. The results are shown in Figure 2 .

[0102] (3) Sensory evaluation of deodorized Porphyra yezoensis juice under different ultrasonic / fermentation conditions

[0103] The sensory evaluation was carried out on the samples obtained in S4 of Examples 3, 6, 7 and Comparative Example 1. The sample numbers were: Example 3-S4, Example 6-S4, Example 7-S4, Comparative Example 1-S4. According to the sensory evaluation method and standard of the fermentation broth of different strains as described above (1), the results are shown in Figure 3 .

[0104] (4) Sensory evaluation of deodorized Porphyra haitanensis juice and anti-fatigue beverage

[0105] The sensory evaluation was carried out on the deodorized Porphyra haitanensis juice obtained in S4 of Examples 3 and 6 and the anti-fatigue beverages of Examples 3 and 6, and different samples were scored according to the following scoring criteria in Table 2. The sample numbers were: Example 3-S4, Example 6-S4, Example 3-B, Example 6-B. The results are shown in Figure 4 .

[0106] Table 2

[0107]

[0108]

[0109] (5) GC-IMS volatile compound fingerprint of deodorized Porphyra haitanensis juice and anti-fatigue beverage

[0110] The volatile flavor substances of the samples obtained in S4 of Examples 3 and 6 and the anti-fatigue beverages of Examples 3 and 6 were analyzed. The sample numbers were: Example 3-S4, Example 6-S4, Example 3-B, Example 6-B. The volatile flavor substances of the samples were analyzed by gas chromatography-ion mobility spectrometry (GC-IMS) (instrument model: G.A.S FlavourSpec). 8 ml of the sample was placed into a 20 mL headspace vial and tightly sealed with a rubber cap and a metal cap. A polar MXT-WAX gas chromatography column (30 m × 0.53 mm × 0.1 μm, Duren, Germany) was used for separation. Nitrogen (purity: 99.99%) was used as the carrier gas, and the linear pressure program was: 2 mL / min for 2 min, 15 mL / min for 8 min, 50 mL / min for 5 min, then increased to 100 mL / min for 10 min, and finally increased to 150 mL / min. The total running time was 30 min. Nitrogen was used as the drift gas at 250 mL / min, and the injection depth of the headspace needle was 1 cm. The identification of aroma compounds was based on the comparison of the retention index (RI) and relative drift time (RIP) of the compounds detected in the database with the reference substances. The retention index relative to the C4-C9 reference ketone mixture was calculated using the LAV software in the GC-IMS system, and qualitative analysis was carried out by GC×IMS library search established based on the GC-IMS and NIST databases. The results are shown in Figure 5 .

[0111] (6) Experimental results

[0112] The metabolic action of microorganisms can absorb and utilize some chemical substances in seaweeds. By selecting appropriate microbial strains, the small-molecule fishy components in seaweeds can be transformed into odorless macromolecular substances. For example Figure 1 As shown, when comparing the enzymolysis solution, the physical deodorization solution of maltodextrin, and the fermentation broths under the optimal technological conditions of different strains, the sensory score of Lactobacillus plantarum is the best. The sensory scores of the lactic acid bacteria fermentation broths (Examples 3-S4, 4-S4, and 5-S4) are significantly higher than those of the yeast fermentation broths (Examples 1-S4 and 2-S4) (P < 0.05). The sensory scores of the fermentation groups with different strains are all significantly higher than those of the physical deodorization solution (Example 1-S2, 73.5 ± 1.3) (P < 0.05), and the physical deodorization solution is significantly higher than the enzymolysis solution (Example 1-S1, 56.2 ± 1.1) (P < 0.05). This shows that the physical deodorization method with maltodextrin and strain fermentation have a positive impact on the flavor of deodorized laver juice. When the addition amount of Lactobacillus plantarum is 5.0% of the mass of the enzymolysis solution, the fermentation temperature is 37°C, and the fermentation time is 2.5 h, the best sensory score of the laver fermentation broth is 85.2 ± 1.23. At this time, the enzymolysis solution has the aroma of laver and the unique flavor of lactic acid fermentation.

[0113] Preferably, the sensory scores of the fermentation broths under the optimal technological conditions of the three Lactobacillus plantarum strains are analyzed by electronic nose together with the enzymolysis solution before deodorization and the physical deodorization solution. The characteristic values of 10 sensors are extracted, and the principal component analysis method (PCA) is used as the main discriminant analysis method. As Figure 2 shown, in the PCA principal component analysis, the first principal component is 55.6%, and the second principal component is 30.0%. The sum of the contribution rates of the first and second principal components is close to 85.6%. From the distribution of the samples in Figure 2 it can be seen that the 5 samples can be well distinguished. Combining the results of the sensory evaluation, the Lactobacillus plantarum fermentation broth (Example 3-S4) not only retains the original aroma of laver but also has the pleasant flavor unique to lactic acid fermentation.

[0114] Ultrasonic waves can significantly change the flavor of liquid foods. Under appropriate parameters, the original aroma components of foods can be maximally retained. However, there are significant differences in the ultrasonic conditions (frequency, time, intensity, and mode) and research objects used by different researchers, and the obtained results also vary significantly. Ultrasonic treatment was introduced at the initial stage of fermentation (Lactobacillus plantarum fermentation + ultrasonic treatment for 30 min at the start of fermentation, i.e., Example 6-S4) and throughout the fermentation process (Lactobacillus plantarum fermentation + ultrasonic treatment for 150 min throughout the fermentation process, i.e., Example 7-S4). In Experimental Example 1(3), sensory evaluation was carried out on the samples. As Figure 3As shown, appropriate ultrasonic treatment-assisted fermentation significantly improved the sensory score of the sample (P < 0.05). Combining 30 min of ultrasonic treatment at the initial stage of fermentation gave the best sensory score of 86.9 ± 1.6, and at this time the fermentation broth had a pleasant flavor. A large number of experiments have shown that at appropriate ultrasonic intensities, too long ultrasonic treatment time may lead to a decrease in esters. An appropriate ultrasonic action time is very important for accelerating the formation and stability of ester substances. The optimal ultrasonic treatment time varies for different samples, and specific analysis needs to be carried out according to the characteristics of specific samples.

[0115] Next, sensory evaluation was carried out to compare the sensory scores of the original Lactobacillus plantarum fermentation broth (Example 3-S4), the 30-min ultrasonic-assisted fermentation broth (Example 6-S4), and the anti-fatigue beverages prepared therefrom (Example 3-B, Example 6-B). Figure 4 As shown, the anti-fatigue beverage prepared from the ultrasonic-assisted fermentation broth significantly improved the sensory score of the anti-fatigue beverage, and the best sensory score was 92.1 ± 1.12 at this time (P < 0.05). The cavitation effect, shear effect, thermal effect, perturbation effect, and mechanical effect brought about by ultrasonic treatment will cause chemical and physical changes in biological structures, and may thus improve the flavor of food.

[0116] GC-IMS can play a more intuitive role in visually distinguishing the changes in volatile compounds. The change of the square color from blue to red represents an increase in the compound concentration. For red algae represented by purple laver, its volatile components are mainly aldehydes, ketones, and hydrocarbons. Figure 5As shown in the figure, 47, 48, 53, and 55 volatile substances can be identified from Example 3-S4, Example 6-S4, Example 3-B, and Example 6-B respectively by using a gas chromatography-ion mobility spectrometer. Ultrasound-assisted fermentation improved the flavor of laver after fermentation, significantly reducing the content of some off-flavor components such as 1-octen-3-ol, dimethyl disulfide, furfuryl methyl sulfide, diallyl sulfide, dimethyl sulfide, and benzaldehyde propylene glycol acetal (Area A), and introducing some pleasant aromatic substances such as 2,3-dimethylpyrazine, 2-methylpentanal, and 2-ethylfuran (Area B). There are obvious differences in the content of volatile components between the enzymolysis solution of Porphyra haitanensis and the anti-fatigue beverage. The anti-fatigue beverage prepared by compounding with grape juice masked the original fishy substances (such as 2-hexenal, 2,2,4,6,6-pentamethylheptane, 2,5-dimethylthiophene, etc.) (Area C), and at the same time introduced new aromatic flavor substances (such as butyl salicylate, γ-heptalactone, nerol, (E)-2-heptenal, p-methoxyacetophenone, etc.) (Area D), making the final product have a strong fruity aroma and the flavors of laver juice and grape juice coordinated. Fermentation is the development direction of seaweed deodorization treatment. By using modern analytical methods such as GC-IMS and electronic nose analysis, the change process of the removal of different types of fishy components in seaweed can be clearly understood. Sensory evaluation combined with modern analytical techniques can better evaluate the effect of seaweed deodorization.

[0117] Experimental Example 2

[0118] The quality evaluation experiment of the anti-fatigue beverage was carried out.

[0119] (1) Physical indicators

[0120] Determination of color difference: Use a high-precision spectrophotometer to measure the color change of the anti-fatigue beverage, and record the L*, a*, and b* values. Each sample was detected 3 times, and the average value of the results was taken.

[0121] Determination of browning index: Take 3 mL of the sample and add an equal amount of acetone, shake it, centrifuge at 3000 r / min for 10 min, filter the supernatant through a filter paper, and measure the OD value at 420 nm.

[0122] Determination of centrifugal precipitation rate: After the prepared anti-fatigue beverage was placed for 24 h, accurately measure 10 mL and add it to a centrifuge tube, centrifuge at a centrifugal speed of 8000 r / min for 15 min, discard the supernatant, and accurately weigh the weight of the centrifugal precipitate.

[0123] (2) Chemical substance content

[0124] Soluble solids: Measured with a hand-held refractometer.

[0125] pH value: Measured with a pH meter.

[0126] Acidity determination: Pipette 5 mL of the sample, add 50 mL of distilled water that has been boiled and cooled to room temperature, add 2 - 3 drops of phenolphthalein indicator, and titrate with 0.1 mol NaOH standard solution until it turns faintly pink. Take the end point as no fading in 30 s. Record the milliliters of the consumed NaOH standard solution and calculate the acidity.

[0127] Reducing sugar: DNS colorimetric method.

[0128] Total sugar: DNS colorimetric method.

[0129] Determination of total phenol content: Folin-Ciocalteu colorimetric method (using gallic acid as the standard solution).

[0130] Determination of total flavonoid content: Sodium nitrite - aluminum nitrate colorimetric method (using rutin as the standard solution).

[0131] Iodine content determination: Refer to the oxidation fading spectrophotometry by Liu Huanyun et al.

[0132] (3) Antioxidant activity

[0133] Determination of DPPH radical scavenging ability

[0134] Experimental group: Mix 300 μL of the sample, 1200 μL of deionized water, and 1500 μL of DPPH solution evenly.

[0135] Control group: Mix 300 μL of the sample, 1200 μL of deionized water, and 1500 μL of methanol solution evenly.

[0136] Blank group: Mix 300 μL of deionized water, 1200 μL of deionized water, and 1500 μL of DPPH solution evenly.

[0137] Let the evenly mixed working solutions of the experimental group, control group, and blank group stand in the dark at room temperature for 45 min. Measure the absorbance at a wavelength of 517 nm respectively. Repeat the parallel experiment three times and take the average value.

[0138] Determination of ABTS radical scavenging ability

[0139] Experimental group: Mix 300 μL of the sample, 1200 μL of deionized water, and 1500 μL of ABTS+ working solution evenly.

[0140] Control group: Mix 300 μL of the sample, 1200 μL of deionized water, and 1500 μL of absolute ethanol evenly.

[0141] Blank group: Mix 300 μL of deionized water, 1200 μL of deionized water, and 1500 μL of ABTS+ working solution evenly.

[0142] The working solution, which is a mixture of the experimental group, the control group, and the blank group, is evenly mixed and left to stand in the dark at room temperature for 6 min to allow sufficient reaction. The absorbance is measured at a wavelength of 734 nm, and three parallel experiments are repeated, and the average value is taken.

[0143]

[0144] Where: A_test is the absorbance of the sample group, A_control is the absorbance of the control group, and A_blank is the absorbance of the blank group.

[0145] Determination of total reducing ability

[0146] Take a 20 mL stoppered test tube, and successively add 3 mL of the sample solution, 0.6 mL of 0.2 mol / L PBS buffer solution with pH 6.6, and 1.5 mL of potassium ferricyanide solution (1%). After mixing evenly, place it in a water bath at 50 °C for 20 min, take it out and quickly cool it with running water; add 3 mL of trichloroacetic acid solution (10%) to the cooled solution to stop the reaction, and then centrifuge at 4000 r / min for 10 min; take 4.5 mL of the supernatant, and successively add 0.6 mL of ferric chloride solution (1%) and 6 mL of distilled water to it; after mixing evenly, let it stand for 5 min, and measure its absorbance value at a wavelength of 700 nm. Repeat the parallel determination three times and take the average value. The larger the absorbance value, the stronger the total reducing ability of the sample.

[0147] (4) Microbiological indicators

[0148] The method for determining the total number of colonies refers to the method specified in GB 4789.2—2016 of the national standard.

[0149] The method for determining coliforms refers to the method specified in GB 4789.3—2016 of the national standard.

[0150] (5) Determination of product nutritional components

[0151] The method for determining energy refers to GB 28050-2011 of the national standard.

[0152] The method for determining protein refers to GB / T 5009.5-2016 of the national standard.

[0153] The method for determining fat refers to GB / T 5009.6-2016 of the national standard.

[0154] Carbohydrates: Refer to the method of Cheng Yuehong et al.

[0155] The method for determining sodium content refers to GB / T 5009.91-2017 of the national standard.

[0156] (6) The determination results are shown in Table 3.

[0157] Table 3

[0158]

[0159]

[0160] The color, physical and chemical properties, antioxidant activity, and microbial index results of the anti-fatigue beverage are shown in Table 3. It can be seen that the anti-fatigue beverage has a uniform purplish-red color, good stability, rich in nutrients such as soluble solids, titratable acid, total phenols, flavonoids, iodine, total sugar, and reducing sugar, and its DPPH free radical scavenging activity is 65.62% ± 0.05, ABTS+ free radical scavenging activity is 18.79% ± 0.01, and the total reducing power is as high as 3.7996 ± 0.0093. Thus, it can be seen that this anti-fatigue beverage has good antioxidant activity, and the microbial content meets the national hygienic standards.

[0161] Experimental Example 3

[0162] An experiment was conducted to determine the anti-fatigue efficacy of the anti-fatigue beverage.

[0163] (1) Preparation of the gavage samples

[0164] The anti-fatigue beverage prepared in Example 6 was diluted 2-fold (low-dose anti-fatigue beverage group) and concentrated 2-fold (high-dose anti-fatigue beverage group) respectively to prepare the gavage beverage samples. Red Bull was concentrated 5-fold as the positive control group.

[0165] (2) Experimental animals and grouping

[0166] Six-week-old male BALB / c mice with a body weight of 18 - 22 g were selected. After 1 week of adaptive feeding, the mice were randomly divided into 5 groups according to their body weight, namely the control (Con), low-dose anti-fatigue beverage group (LB), medium-dose anti-fatigue beverage group (MB), high-dose anti-fatigue beverage group (HB), and positive control group (P), with 10 mice in each group. The mice were gavaged according to the method in Table 4. During the experiment, the status of the mice was observed, and they were weighed every 3 days and the records were made. The experiment lasted for 30 days, and the results are shown in Figure 6 . The mice in each group were subjected to 30-minute exercise training using a mouse rotary fatigue tester at a speed of 25 r / min on the 7th, 14th, and 21st days.

[0167] Table 4

[0168] Group Feeding method Con Gavage with 0.01 ml / g·bw normal saline LB Gavage with 0.01 ml / g·bw low-dose anti-fatigue beverage MB Gavage with 0.01 ml / g·bw medium-dose anti-fatigue beverage HB Gavage with 0.01 ml / g·bw high-dose anti-fatigue beverage P Gavage with 0.01 ml / g·bw Red Bull

[0169] (3) The kits and manufacturers used for the determination of biochemical indexes are shown in Table 5.

[0170] Table 5

[0171]

[0172] (4) Swimming exhaustion experiment

[0173] On the 30th day, after 1 hour of intragastric administration to the mice, a swimming exhaustion experiment was conducted. The mice were placed in a swimming tank with a water depth of 25 cm and a water temperature of about 25 °C and timed. When the swimming movements of the mice were significantly disordered and the heads of the mice sank into the water for 10 s and could not surface, it was determined that the mice were exhausted from swimming at this time. The time from the start of swimming to exhaustion of the mice was recorded as the swimming exhaustion time, and the results are shown in Figure 7 . After the swimming was over, the mice were quickly fished out and their hair was dried.

[0174] (5) Experimental animal treatment and sample collection

[0175] On the 31st day, the mice in each group were subjected to 30 min of exercise training using a mouse rotary fatigue tester. 30 min after the exercise ended, the mice were sacrificed by cervical dislocation. The plasma of the mice was taken into a sterilized centrifuge tube and centrifuged at 7500 r / min for 10 min at 4 °C, and then the supernatant was taken. The liver and skeletal muscle were dissected and collected and stored in a -80 °C refrigerator for subsequent detection.

[0176] (6) Determination of serum metabolites

[0177] Serum lactate was determined according to the method of the lactate test kit, and the results are shown in Figure 8 , and urea nitrogen was determined according to the method of the urea nitrogen test kit, and the results are shown in Figure 9 .

[0178] (7) Determination of muscle glycogen and liver glycogen

[0179] According to the usage method of the muscle glycogen test kit, the content of glycogen in the muscle of the mice was detected, and the results are shown in Figure 10 ; according to the usage method of the liver glycogen test kit, the content of glycogen in the liver of the mice was detected, and the results are shown in Figure 11 .

[0180] (8) Data statistics and processing

[0181] The experimental data were expressed as (Mean±SEM). One-way analysis of variance was performed using SPSS 26.0 software for data significance analysis, and P<0.05 was considered to indicate a statistically significant difference.

[0182] (9) Experimental results

[0183] During the experiment, the mice in each group had normal food intake, water intake, and behavioral activities, with shiny fur and bright eyes. As Figure 6 shown, the body weights of the mice in each group increased steadily during the experiment, and there was no significant difference in body weight among the 5 groups, indicating that the anti-fatigue beverage had no adverse effect on the growth of the mice.

[0184] The fatigue level of the body can be intuitively reflected by exercise endurance. Load-bearing swimming is a sports model for evaluating anti-fatigue experiments. The length of the load-bearing swimming time of mice can reflect their fatigue level and is often used to measure the efficacy of compounds in alleviating exercise fatigue. The longer the exhaustive swimming time of mice, the more obvious the effect of alleviating exercise fatigue. As Figure 7 shown, compared with the Con group, the swimming exhaustion time of mice in each intervention group was significantly increased (P<0.05). Compared with the Con group (5.3±0.6 min), the swimming exhaustion times of mice in the LB, MB, and HB groups were increased to 8.1±1.2 min, 9.4±1.4 min, and 10.0±1.9 min, respectively, and there were significant differences (P<0.05). The intervention effect of the high-dose anti-fatigue beverage group was the best, indicating that the anti-fatigue beverage intervention could improve the fatigue tolerance of mice.

[0185] When the body performs strenuous exercise, the oxygen consumption increases, resulting in cells being in an anoxic environment. Carbohydrates in the body will provide energy through anaerobic glycolysis. The glycolysis reaction accelerates, generating more lactic acid, which may not only cause a decrease in muscle contraction ability but also disrupt the body's acid-base balance, causing the blood pH value to drop, thereby inhibiting the anaerobic glycolysis process of sugar, affecting the synthesis of ATP, affecting the normal circulatory system in the body, and triggering body fatigue. Therefore, blood lactic acid concentration is an important indicator for measuring exercise fatigue. As Figure 8 shown, compared with the Con group (7.40±0.72), the serum lactic acid (LD) content level of mice in the anti-fatigue beverage intervention group was significantly decreased after exercise (P<0.05), but there was no significant difference among the LB, MB, and HB groups. It indicates that the anti-fatigue beverage can remove the LD generated during exercise, thereby enhancing the anti-fatigue effect.

[0186] When strenuous exercise causes the body to be unable to meet the energy demand by catabolizing carbohydrates and fats, proteins and amino acids will be catabolized to obtain sufficient energy. The catabolic ability of proteins and amino acids in the body during exercise is enhanced, increasing the content of the metabolite serum urea nitrogen (BUN), which can reflect the protein metabolism in the body and has a negative correlation with exercise tolerance, that is, the greater the increase in serum BUN, the worse the exercise load capacity of the body. As Figure 9 shown, compared with the Con group, the serum BUN levels of the LB, MB, HB, and P groups were significantly decreased (P<0.05), and the HB group (6.6±0.7 mmol / L) was significantly lower than the MB group (7.8±0.3 mmol / L), and the MB group was significantly lower than the LB group (8.3±0.2 mmol / L). The above results indicate that the anti-fatigue beverage intervention can remove the accumulation of metabolites generated during exercise, thereby enhancing the anti-fatigue effect, and the effect of the high-dose anti-fatigue beverage is better.

[0187] Glycogen is an important energy source in the body and is mainly present in the liver and muscles. During exercise, when blood sugar levels drop, liver glycogen is converted into glucose, and the energy supply of muscle glycogen is achieved through the anaerobic glycolysis pathway of the body. Therefore, glycogen reserves directly affect the body's exercise ability, and there is a positive correlation between the body's glycogen reserve and its exercise tolerance. As Figure 10 , 11 shown, compared with the Con group, the liver glycogen and muscle glycogen contents of the mice in the anti-fatigue beverage group increased after exercise. For muscle glycogen, the anti-fatigue beverage group was significantly increased compared with the control group (P<0.05), but there was no significant difference between the LB and MB groups and between the MB and HB groups. For liver glycogen, the anti-fatigue beverage group was significantly increased compared with the control group (P<0.05), and the high-dose anti-fatigue beverage group (11.2±0.7mg / g) was higher than the positive control group (10.9±0.8mg / g), but there was no significant difference among the MB, HB, and P groups. The above results indicate that the anti-fatigue beverage can, to a certain extent, increase the reserve of liver glycogen or muscle glycogen in the body, or slow down the consumption of glycogen in the body, ensure the energy supply during exercise, and the high-dose group has a better effect than the medium-dose group and the low-dose group.

[0188] The anti-fatigue beverage can significantly prolong the weight-bearing swimming time of mice, reduce the accumulation of the exercise metabolite serum LD and BUN, and increase the muscle glycogen and liver glycogen contents of mice; the test results show that the anti-fatigue beverage can improve the exercise ability of animals, delay the occurrence of animal fatigue, and promote the recovery of the body after exercise.

[0189] In summary, the anti-fatigue beverage from Porphyra haitanensis and its preparation method provided by the present invention use Porphyra haitanensis as a raw material to enzymatically extract its nutrients, then use physical methods and ultrasonic-assisted fermentation methods to remove the fishy smell of the enzymatic hydrolysate, and then compound it with grape juice to develop a nutritious and delicious functional beverage. The final product has uniform color, is purplish-red, has a harmonious aroma, a strong Porphyra flavor, a rich fruity aroma, is sweet and sour and refreshing, has a soft taste, has uniform texture and good stability, has good antioxidant activity and anti-fatigue activity, and is a nutritious and delicious compound Porphyra haitanensis health beverage. The present invention helps to promote the rational utilization of Porphyra haitanensis resources, enrich the market of functional beverages, and has high practical popularization value.

[0190] As can be seen from the above examples, the present invention provides a deodorized Porphyra haitanensis juice and its preparation method and an anti-fatigue beverage and its preparation method. The preparation method of the deodorized Porphyra haitanensis juice includes the following steps: enzymatically hydrolyzing the Porphyra haitanensis juice with neutral protease to obtain an enzymatic hydrolysate; performing physical deodorization on the enzymatic hydrolysate to obtain a physically deodorized liquid; and performing microbial fermentation on the physically deodorized liquid, which is the deodorized Porphyra haitanensis juice. The preparation method of the deodorized Porphyra haitanensis juice in the present invention is green and pollution-free, can make the deodorized Porphyra haitanensis juice rich in various metabolites and special flavor substances beneficial to the human body, enhance the nutritional value and characteristics of Porphyra haitanensis products, and realize the high-value utilization of Porphyra haitanensis resources.

[0191] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing deodorized Porphyra haitanensis juice, characterized in that: The following steps are involved: (1) enzymolyzing the Porphyra haitanensis juice using a neutral protease to obtain an enzymolyzate; (2) physically removing the fishy smell from the enzymatic hydrolyzate to obtain a physically deodorized liquid; (3) subjecting the physically deodorized liquid to microbial fermentation to obtain deodorized Porphyra hainanensis juice.

2. The preparation method according to claim 1, characterized in that: The preparation method of the porphyra juice in step (1) is as follows: crushing the porphyra to obtain porphyra powder, mixing the porphyra powder with water to obtain the porphyra juice; the final concentration of the porphyra powder in the porphyra juice is 30-40 g / L, and the amount of the neutral protease added is 1×10 6 ~1.2×10 6 U / L, the enzymatic hydrolysis temperature is 40-50°C, the enzymatic hydrolysis time is 4-6h, and the enzymatic hydrolysis pH is 7.2-8.

0.

3. The preparation method according to claim 2, characterized in that: The physical deodorization in step (2) adopts: activated carbon adsorption method, β-cyclodextrin embedding method or maltodextrin flavoring method.

4. The preparation method according to claim 3, characterized in that: The activated carbon adsorption method comprises the following steps: adding activated carbon to the enzymatic hydrolysate and reacting for 1.5 to 2.5 hours at 23 to 27° C.; the amount of activated carbon added is 1.0% to 3.0% of the mass of the enzymatic hydrolysate; The steps of the β-cyclodextrin embedding method are as follows: adding β-cyclodextrin to the enzymatic hydrolysate, reacting at 27-33° C. for 0.5-1.5 h; the amount of β-cyclodextrin added is 0.5%-2.5% of the mass of the enzymatic hydrolysate; The maltodextrin flavoring method comprises the following steps: adding maltodextrin to the enzymolysis solution, reacting at 27-33° C. for 0.5-1.5 hours; and the amount of maltodextrin added is 0.5%-2.5% of the mass of the enzymolysis solution.

5. The preparation method according to claim 4, characterized in that: The strains of the microbial fermentation in step (3) include yeast, saccharomyces cerevisiae, Lactobacillus plantarum, Lactobacillus casei or Lactobacillus bulgaricus; When the strain is yeast, the fermentation method is as follows: adding yeast to the physical deodorization liquid, and fermenting for 25 minutes to 45 minutes at 28°C to 36°C; the amount of yeast added is 0.3% to 0.7% of the mass of the physical deodorization liquid; When the strain is brewer's yeast, the fermentation method is as follows: adding brewer's yeast to the physical deodorization liquid, and fermenting for 1 hour to 3 hours at 27° C. to 31° C.; the amount of brewer's yeast added is 0.3% to 0.7% of the mass of the physical deodorization liquid; When the strain is Lactobacillus plantarum, the fermentation method is as follows: adding Lactobacillus plantarum to the physical deodorization liquid, and fermenting for 1h to 3h at 31°C to 39°C; the amount of Lactobacillus plantarum added is 1% to 9% of the mass of the physical deodorization liquid; When the strain is Lactobacillus casei, the fermentation method is as follows: adding Lactobacillus casei to the physical deodorization liquid, and fermenting for 15h to 19h at 31°C to 39°C; the amount of Lactobacillus casei added is 2% to 6% of the mass of the physical deodorization liquid; When the strain is Lactobacillus bulgaricus, the fermentation method is as follows: adding Lactobacillus bulgaricus to the physical deodorization liquid, and fermenting for 4h to 8h at 37°C to 45°C; the addition amount of Lactobacillus bulgaricus is 1% to 5% of the mass of the physical deodorization liquid.

6. The preparation method according to claim 5, characterized in that: When the bacterial species is Lactobacillus plantarum, ultrasound is performed during the fermentation process, the power of the ultrasound is 180-220 W, and the frequency of the ultrasound is 30-50 kHz.

7. The deodorized Porphyra haitanensis juice prepared by the preparation method according to any one of claims 1 to 6.

8. An anti-fatigue beverage containing the deodorized Porphyra hainanensis juice according to claim 7, characterized in that: The anti-fatigue beverage comprises the following raw materials in parts by weight: 60-90 parts of deodorized laver juice, 10-40 parts of grape juice, 3-7 parts of xylitol, 0.01-0.20 parts of citric acid, and 0.05-0.25 parts of sodium carboxymethyl cellulose.

9. A method for preparing the anti-fatigue beverage according to claim 8, characterized in that: The preparation method comprises the following steps: mixing the deodorized laver juice, grape juice, xylitol, citric acid and sodium carboxymethyl cellulose, homogenizing, filling and sealing, sterilizing and cooling to obtain the anti-fatigue beverage.

10. The preparation method according to claim 9, characterized in that: The homogenization temperature is 50-70° C., and the homogenization pressure is 20-30 MPa; the sterilization method is pasteurization, the sterilization temperature is 70-90° C., and the sterilization time is 10-30 min.

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