A method for preparing sea grape extract with antioxidant function

Abstract

The present invention provides a method for preparing a sea grape extract with antioxidant function, comprising the following steps: (1) washing and crushing the sea grapes; (2) adding an ethanol solution to the crushed sea grapes, heating, and obtaining a sea grape solution; (3) adding a composite enzyme to the sea grape solution in step (2) for enzymolysis; and then performing microwave extraction, with a microwave power of 260 to 320 W, to obtain a sea grape microwave liquid; the composite enzyme is prepared from pectinase, neutral protease, and cellulase; (4) filtering the sea grape microwave liquid in step (3), heating it, cooling it, and centrifuging it, collecting the supernatant, and obtaining a sea grape extract. The method for preparing the sea grape extract of the present invention not only fully extracts effective ingredients such as green algae polysaccharides, but also helps to reduce impurities, improve purity, and improve the activity of substances with antioxidant functions, is environmentally friendly and pollution-free, and reduces extraction costs.

Description

Technical Field

[0001] The invention relates to the field of sea grapes, and in particular to a method for preparing a sea grape extract with antioxidant function. Background Art

[0002] Sea grapes, scientifically known as Caulerpa lentillifera, belong to the Chlorophyta, Baumanales, Caulerpa family, Caulerpa genus. Sea grapes are widely distributed in Malaysia, Vietnam, the Philippines and other places. At present, they have been cultivated in Qingdao, Fujian, Guangdong, Guangxi, Hainan and other places in coastal areas of my country. Sea grapes are rich in amino acids, polysaccharides, unsaturated fatty acids and other trace elements. They can be eaten and used as medicine. They have high economic and nutritional value and are known as "green caviar". Existing sea grape extraction methods often use organic solvents. The large amount of solvents used is not environmentally friendly and the organic residues may cause the antioxidant function of the active substances in sea grapes to decrease. The extraction efficiency of active substances is not high and the extraction cost is high. Summary of the invention

[0003] In view of this, the present invention proposes a method for preparing a sea grape extract with antioxidant function.

[0004] The technical solution of the present invention is achieved in this way:

[0005] A method for preparing a sea grape extract with antioxidant function comprises the following steps:

[0006] (1) Wash and crush the sea grapes;

[0007] (2) adding an ethanol solution to the crushed sea grapes and heating the mixture to obtain a sea grape solution;

[0008] (3) adding a composite enzyme to the sea grape solution of step (2) for enzymolysis; and then performing microwave extraction at a microwave power of 260 to 320 W to obtain a sea grape microwave liquid; the composite enzyme is prepared from pectinase, neutral protease, and cellulase;

[0009] (4) filtering the sea grape microwave liquid in step (3), heating it, cooling it, and centrifuging it to collect the supernatant to obtain a sea grape extract.

[0010] Furthermore, the ratio of the sea grape, ethanol solution and complex enzyme is 1g:40-60mL:0.1-0.2g.

[0011] Furthermore, in step (2), the volume fraction of the ethanol solution is 80-90%.

[0012] Furthermore, in step (2), the heating temperature is 50-55° C., and the heating time is 20-30 min.

[0013] Furthermore, in step (3), the enzymolysis temperature is 45-50° C. and the enzymolysis time is 25-30 min.

[0014] Furthermore, in step (3), the complex enzyme is prepared from pectinase, neutral protease and cellulase in a mass ratio of 1:0.6-0.8:1-2.

[0015] Furthermore, in step (3), the microwave extraction is performed for 1 to 3 minutes.

[0016] Furthermore, in step (4), the filtration is followed by heating to 82-85° C. for 5-10 minutes.

[0017] Furthermore, in step (4), the cooling is performed to room temperature.

[0018] Furthermore, in step (4), the centrifugal speed is 5000-6000 r / min, and the centrifugation time is 5-10 min.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) The preparation method of the sea grape extract of the present invention not only fully extracts effective ingredients such as green algae polysaccharides, but also helps to reduce impurities, improve purity, and increase the activity of substances with antioxidant functions. It is environmentally friendly and pollution-free, and reduces extraction costs.

[0021] (2) The present invention uses a composite enzyme of pectinase, neutral protease and cellulase to improve the enzymatic hydrolysis effect, which is beneficial to fully extract the effective active ingredients in sea grapes.

[0022] (3) The present invention adopts microwave technology to fully mix the complex enzyme with the sea grape, promote the release of substances inside the plant, improve the extraction efficiency of active substances, enhance the antioxidant effect of the sea grape extract, simplify the operation, reduce the impurity content, and be green and environmentally friendly. DETAILED DESCRIPTION

[0023] In order to better understand the technical content of the present invention, specific embodiments are provided below to further illustrate the present invention.

[0024] Unless otherwise specified, the experimental methods used in the embodiments of the present invention are all conventional methods.

[0025] Unless otherwise specified, the materials, reagents, etc. used in the embodiments of the present invention can be obtained from commercial sources.

[0026] Example 1 - Preparation method of sea grape extract

[0027] (1) Wash 10 g of sea grapes with deionized water and crush them.

[0028] (2) adding 400 mL of 80% by volume ethanol solution to the crushed sea grapes in step (1), and heating at 50° C. for 30 min to obtain a sea grape solution.

[0029] (3) Adding 1 g of composite enzyme to the sea grape solution of step (2), performing enzymatic hydrolysis at 45° C. for 25 min; then performing microwave extraction for 1 min at a microwave power of 260 W to obtain a sea grape microwave liquid; the composite enzyme is prepared from pectinase, neutral protease, and cellulase in a mass ratio of 1:0.6:1.3.

[0030] (4) filtering the sea grape microwave liquid in step (3), heating it to 85° C. for 5 min, cooling it to room temperature, centrifuging it at 5000 r / min for 10 min, collecting the supernatant, and obtaining a sea grape extract.

[0031] Example 2 - Preparation of sea grape extract

[0032] (1) Wash 10 g of sea grapes with deionized water and crush them.

[0033] (2) Add 500 mL of 85% by volume ethanol solution to the crushed sea grapes in step (1), and heat at 53° C. for 25 minutes to obtain a sea grape solution.

[0034] (3) Adding 1.5 g of composite enzyme to the sea grape solution of step (2), performing enzymolysis at 45° C. for 25 min; then performing microwave extraction for 2 min at a microwave power of 300 W to obtain a sea grape microwave liquid; the composite enzyme is prepared from pectinase, neutral protease, and cellulase in a mass ratio of 1:0.7:1.6.

[0035] (4) filtering the sea grape microwave liquid in step (3), heating it to 82° C. for 8 min, cooling it to room temperature, centrifuging it at 5500 r / min for 7 min, collecting the supernatant, and obtaining a sea grape extract.

[0036] Example 3 - Preparation of sea grape extract

[0037] (1) Wash 10 g of sea grapes with deionized water and crush them.

[0038] (2) Add 600 mL of 90% by volume ethanol solution to the crushed sea grapes in step (1), and heat at 55° C. for 20 min to obtain a sea grape solution.

[0039] (3) Adding 2 g of composite enzyme to the sea grape solution of step (2), performing enzymolysis at 50° C. for 30 min; then performing microwave extraction for 3 min at a microwave power of 320 W to obtain a sea grape microwave liquid; the composite enzyme is prepared from pectinase, neutral protease, and cellulase in a mass ratio of 1:0.8:2.

[0040] (4) filtering the sea grape microwave liquid in step (3), heating it to 82° C. for 10 min, cooling it to room temperature, centrifuging it at 6000 r / min for 5 min, collecting the supernatant, and obtaining a sea grape extract.

[0041] Comparative Example 1

[0042] The difference between Comparative Example 1 and Example 2 is that the mass ratio of pectinase, neutral protease and cellulase in the complex enzyme is adjusted to 1:1:1, and the other steps are basically the same as those in Example 2.

[0043] (1) Wash 10 g of sea grapes with deionized water and crush them.

[0044] (2) Add 500 mL of 85% by volume ethanol solution to the crushed sea grapes in step (1), and heat at 53° C. for 25 minutes to obtain a sea grape solution.

[0045] (3) Adding 1.5 g of composite enzyme to the sea grape solution of step (2), performing enzymolysis at 45° C. for 25 min; then performing microwave extraction for 2 min at a microwave power of 300 W to obtain a sea grape microwave liquid; the composite enzyme is prepared from pectinase, neutral protease, and cellulase in a mass ratio of 1:1:1.

[0046] (4) filtering the sea grape microwave liquid in step (3), heating it to 82° C. for 8 min, cooling it to room temperature, centrifuging it at 5500 r / min for 7 min, collecting the supernatant, and obtaining a sea grape extract.

[0047] Comparative Example 2

[0048] The difference between Comparative Example 2 and Example 2 is that the microwave power is adjusted to 500 W, and the other steps are basically the same as those of Example 2.

[0049] (1) Wash 10 g of sea grapes with deionized water and crush them.

[0050] (2) Add 500 mL of 85% by volume ethanol solution to the crushed sea grapes in step (1), and heat at 53° C. for 25 minutes to obtain a sea grape solution.

[0051] (3) Adding 1.5 g of composite enzyme to the sea grape solution of step (2), performing enzymolysis at 45° C. for 25 min; then performing microwave extraction for 2 min at a microwave power of 500 W to obtain a sea grape microwave liquid; the composite enzyme is prepared from pectinase, neutral protease, and cellulase in a mass ratio of 1:0.7:1.6.

[0052] (4) filtering the sea grape microwave liquid in step (3), heating it to 82° C. for 8 min, cooling it to room temperature, centrifuging it at 5500 r / min for 7 min, collecting the supernatant, and obtaining a sea grape extract.

[0053] Take the samples of Examples 1 to 3 and Comparative Examples 1 to 2, and use the phenol-sulfuric acid method to determine the polysaccharide content: weigh 1.0, 2.0, 3.0, 4.0, and 5.0 mL of a glucose standard solution with a concentration of 1 mg / mL, add them to a 50 mL volumetric flask to make up the volume, then draw 2 mL of each series of solutions, add them to a stoppered graduated test tube, and perform a colorimetric reaction (add 1.2 mL of a 5% phenol solution, 5.0 mL of concentrated sulfuric acid, stir, and cool to room temperature after boiling in a water bath for 1 hour), test the absorbance at a wavelength of 490 mm, and obtain a series of standard curves; add 2 mL of the samples of Examples 1 to 3 and Comparative Examples 1 to 2 to a stoppered graduated test tube, perform a colorimetric reaction, measure the polysaccharide content, and calculate the polysaccharide extraction rate, extraction rate = polysaccharide content / extraction raw material mass × 100%, the results are shown in Table 1.

[0054] Table 1. Polysaccharide extraction rates of Examples 1 to 3 and Comparative Examples 1 to 2

[0055] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Polysaccharide content (g) 4.62 4.86 4.59 3.67 3.25 Polysaccharide extraction rate / % 46.2 48.6 45.9 36.7 32.5

[0056] As shown in Table 1, the extraction rates of sea grape polysaccharides in Examples 1 to 3 of the present invention are all above 45%. Compared with Comparative Examples 1 to 2, the extraction by the method of the present invention is more complete and the polysaccharide extraction rate is higher.

[0057] The samples of Examples 1 to 3 and Comparative Examples 1 to 2 were taken and the antioxidant properties were tested by free radical scavenging experiment:

[0058] Take 1mL of 20mmol / L DPPH solution and add it to the cuvette, and measure the absorbance (A0) at a wavelength of 517nm; add 0.5mL of 1% sample and 1ml of 20mmol / L DPPH solution to the cuvette, react for 15min, adjust to zero with anhydrous ethanol, take 1ml of the solution in the cuvette, and measure the absorbance (A0) at a wavelength of 517nm. 样品 ), calculate the free radical scavenging rate, scavenging rate = (A0-A 样品 ) / A0×100%, the results are shown in Table 2.

[0059] Table 2. Free radical scavenging rates of Examples 1 to 3 and Comparative Examples 1 to 2

[0060] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Free radical scavenging rate / % 72.3 75.6 73.4 61.2 63.8

[0061] As shown in Table 2, the free radical scavenging rates of Examples 1 to 3 of the present invention are all above 70%, which is about 10% higher than that of Comparative Examples 1 to 2, indicating that the preparation of sea grape extract by the method of the present invention is helpful to improve the antioxidant effect of the sea grape extract.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a sea grape extract having an antioxidant function, characterized in that: The following steps are involved: (1) Wash and crush the sea grapes; (2) adding an ethanol solution to the crushed sea grapes and heating the mixture to obtain a sea grape solution; (3) adding a composite enzyme to the sea grape solution of step (2) for enzymatic hydrolysis; Then, microwave extraction is performed with a microwave power of 260 to 320 W to obtain sea grape microwave liquid; the composite enzyme is prepared from pectinase, neutral protease and cellulase; (4) filtering the sea grape microwave liquid in step (3), heating it, cooling it, and centrifuging it to collect the supernatant to obtain a sea grape extract; The ratio of the sea grape, ethanol solution and complex enzyme is 1g:40-60mL:0.1-0.2g; In step (2), the volume fraction of the ethanol solution is 80-90%; In step (2), the heating temperature is 50-55° C. and the heating time is 20-30 min. In step (3), the enzymolysis temperature is 45-50°C and the enzymolysis time is 25-30 minutes; In step (3), the complex enzyme is prepared from pectinase, neutral protease and cellulase in a mass ratio of 1:0.6-0.8:1-2; In step (3), the microwave extraction is performed for 1 to 3 minutes.

2. The method for preparing a sea grape extract with antioxidant function according to claim 1, characterized in that: In step (4), the filtration is followed by heating to 82-85° C. for 5-10 minutes.

3. The method for preparing a sea grape extract with antioxidant function according to claim 1, characterized in that: In step (4), the cooling is to room temperature.

4. The method for preparing a sea grape extract with antioxidant function according to claim 1, characterized in that: In step (4), the centrifugal speed is 5000-6000 r / min, and the centrifugation time is 5-10 min.