Chinese yam protein polypeptide and preparation method thereof

Abstract

The invention discloses a Chinese yam protein polypeptide and a preparation method thereof, and the extraction method of Chinese yam mucoprotein comprises the following steps: cleaning Chinese yam, peeling, protecting color, and homogenizing to obtain Chinese yam slurry; the Chinese yam pulp is diluted and then gelatinized, then amylase is added for enzymolysis, centrifugation is conducted, and supernate is collected; adjusting the pH value of the supernatant to 2-4, standing, centrifuging, and collecting precipitate to obtain Chinese yam protein; the preparation method comprises the following steps: adding Chinese yam protein and trypsin into water, carrying out first enzymolysis, adding papain, carrying out second enzymolysis, carrying out enzyme deactivation treatment, and carrying out freeze drying; according to the preparation method, specific protein can be extracted from Chinese yam through limitation of specific processes and parameters, then the protein is subjected to a specific enzymolysis process, the Chinese yam protein polypeptide is prepared, and the Chinese yam protein polypeptide has lower molecular weight, is beneficial to being absorbed by a body, has excellent oxidation resistance and can be used for preparing the Chinese yam protein polypeptide. The anti-aging purpose can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of polypeptides, and in particular to a yam protein polypeptide and a preparation method thereof. Background Art

[0002] Yam, cut off the root, wash the soil, scrape off the skin with a bamboo knife, dry or bake, that is hairy yam. Choose thick hairy yam, soak it in clean water, add slight heat, cover it with a quilt, keep it moist and stuffy, then put it on a wooden board and rub it into a cylindrical shape, cut the two ends evenly, dry it and polish it, that is, light yam. Functions and indications: invigorate the spleen, nourish the lungs, consolidate the kidneys, and benefit the essence. Treat spleen deficiency diarrhea, chronic dysentery, asthenia cough, thirst, spermatorrhea, leucorrhea, and frequent urination. Invigorate the spleen and nourish the stomach, promote fluid and benefit the lungs, invigorate the kidneys and astringe the essence. It is used for spleen deficiency, poor appetite, chronic diarrhea, lung deficiency, wheezing and coughing, kidney deficiency, spermatorrhea, leucorrhea, frequent urination, and deficiency heat and thirst. Fried yam with bran invigorates the spleen and strengthens the stomach. It is used for spleen deficiency, poor appetite, diarrhea, loose stools, and excessive leucorrhea. ① "Shennong's Herbal Classic": It is used to treat injuries, replenish deficiency, remove cold and heat evil spirits, replenish the middle and strengthen the body, grow muscles, and make the ears and eyes smarter after long-term use. ② "Bielu": It is used to treat wind in the head and face, wind head (also known as "head wind"), dizziness, lower qi, stop waist pain, treat asthenia and emaciation, replenish the five internal organs, eliminate irritability and heat, and strengthen the key. ③ "Yao Xing Lun": It replenishes the five labors and seven injuries, removes cold wind, stops waist pain, calms the mind, replenishes the insufficient heart qi, and is used in addition to the weak body of the patient. ④ "Dietary Therapy Materia Medica": It treats headaches and helps yin strength. ⑤ "Rihuazi Materia Medica": It helps the five internal organs, strengthens the bones and muscles, improves the will and calms the mind, and treats spermatorrhea and forgetfulness. ⑥ Zhu Zhenheng: It can be pounded and applied to the swelling and hard poison, and it can dissipate. ⑦ "Shanghan Yunyao": It replenishes deficiency and clears away heat. ⑧ "Compendium of Materia Medica": It can benefit the kidney qi, strengthen the spleen and stomach, stop diarrhea, resolve phlegm and saliva, and moisturize the skin and fur.

[0003] Yam is rich in protein, but the protein has the disadvantages of poor solubility and difficulty in absorption. Therefore, it is particularly important to fully utilize the protein in yam and achieve certain effects.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The purpose of the present invention is to provide a yam protein polypeptide and a preparation method thereof. The preparation method of the present invention extracts specific protein from yam through a specific process, and adopts a specific enzymatic hydrolysis process to prepare a polypeptide with excellent antioxidant properties.

[0006] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0007] The first aspect of the present invention provides a method for preparing yam protein polypeptide, and the method for extracting yam mucin comprises the following steps:

[0008] (a) washing, peeling, color-protecting and homogenizing yam to obtain yam slurry;

[0009] (b) diluting the yam slurry and gelatinizing it, then adding amylase to perform enzymolysis, centrifuging, and collecting the supernatant;

[0010] (c) adjusting the pH value of the supernatant to 2-4, allowing the supernatant to stand, centrifuging, and collecting the precipitate to obtain yam protein;

[0011] (d) adding yam protein and trypsin to water for a first enzymolysis, then adding papain for a second enzymolysis, then performing enzyme inactivation treatment and freeze-drying to obtain the yam protein polypeptide.

[0012] Preferably, in step (b), the dilution factor is 15 to 20 times.

[0013] Preferably, in step (b), the amount of amylase added is 1% to 4% of the mass of the yam pulp.

[0014] Preferably, in step (b), the gelatinization temperature is 90-100°C; the enzymatic hydrolysis temperature is 50-60°C, and the time is 1-3 hours.

[0015] Preferably, in step (c), the standing time is 12 to 24 hours.

[0016] Preferably, in step (c), the centrifugal speed is 4000-4500 rpm.

[0017] Preferably, in step (d), the mass ratio of yam protein, trypsin, papain and water is 1:(0.005-0.02):(0.01-0.02):(5-15).

[0018] Preferably, in the step (d), the first enzymolysis temperature is 36-38° C., the pH value is 7.5-8.0, and the enzymolysis time is 1-3 h.

[0019] Preferably, in step (d), the second enzymolysis temperature is 50-55° C., the pH value is 6.8-7.2, and the enzymolysis time is 1-3 h.

[0020] The second aspect of the present invention provides a yam protein polypeptide prepared by the above preparation method.

[0021] Compared with the prior art, the beneficial effects of the present invention include at least:

[0022] The preparation method of the present invention can extract specific protein from yam by limiting specific processes and parameters, and then subject the protein to a specific enzymatic hydrolysis process to prepare a yam protein polypeptide. The yam protein polypeptide has a lower molecular weight than protein, which is conducive to being absorbed by the body. At the same time, the yam protein polypeptide has excellent antioxidant properties and can achieve the purpose of anti-aging. DETAILED DESCRIPTION

[0023] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0024] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0025] The embodiment of the present invention provides a method for preparing yam protein polypeptide, and the method for extracting yam mucin comprises the following steps:

[0026] (a) washing, peeling, color-protecting and homogenizing yam to obtain yam slurry;

[0027] (b) diluting the yam slurry and gelatinizing it, then adding amylase to perform enzymolysis, centrifuging, and collecting the supernatant;

[0028] (c) adjusting the pH value of the supernatant to 2-4, allowing the supernatant to stand, centrifuging, and collecting the precipitate to obtain yam protein;

[0029] (d) adding yam protein and trypsin to water for a first enzymolysis, then adding papain for a second enzymolysis, then performing enzyme inactivation treatment and freeze-drying to obtain the yam protein polypeptide.

[0030] The preparation method of the present invention can extract specific protein from yam by limiting specific processes and parameters, and then subject the protein to a specific enzymatic hydrolysis process to prepare a yam protein polypeptide. The yam protein polypeptide has a lower molecular weight than protein, which is conducive to being absorbed by the body. At the same time, the yam protein polypeptide has excellent antioxidant properties and can achieve the purpose of anti-aging.

[0031] In some embodiments, in step (b), the dilution factor is 15 to 20 times.

[0032] In some embodiments, in step (b), the amount of amylase added is 1% to 4% of the mass of the yam pulp.

[0033] In some embodiments, in step (b), the gelatinization temperature is 90-100°C; the enzymatic hydrolysis temperature is 50-60°C, and the time is 1-3 hours.

[0034] In some embodiments, in step (c), the standing time is 12 to 24 hours.

[0035] In some embodiments, in step (c), the centrifugal speed is 4000-4500 rpm.

[0036] In some embodiments, in step (d), the mass ratio of yam protein, trypsin, papain and water is 1:(0.005-0.02):(0.01-0.02):(5-15).

[0037] In some embodiments, in step (d), the first enzymatic hydrolysis temperature is 36-38° C., the pH value is 7.5-8.0, and the enzymatic hydrolysis time is 1-3 hours.

[0038] In some embodiments, in step (d), the second enzymolysis temperature is 50-55° C., the pH value is 6.8-7.2, and the enzymolysis time is 1-3 hours.

[0039] Another embodiment of the present invention provides a yam protein polypeptide prepared by the above preparation method.

[0040] The technical solution of the present invention is further described in detail below through specific embodiments.

[0041] Example 1

[0042] This embodiment is a method for preparing yam protein polypeptide, and the yam mucin extraction method comprises the following steps:

[0043] (a) washing, peeling, color-protecting and homogenizing yam to obtain yam slurry;

[0044] (b) diluting the yam pulp by 15 times and then gelatinizing it, then adding α-amylase for enzymolysis, centrifuging, and collecting the supernatant, wherein the gelatinization temperature is 90° C.; the enzymolysis temperature is 50° C., the time is 1 hour; and the amount of α-amylase added is 4% of the mass of the yam pulp;

[0045] (c) adjusting the pH value of the supernatant to 2, standing for 24 hours, centrifuging at 4000 rpm, collecting the precipitate, and obtaining yam protein;

[0046] (d) adding yam protein and trypsin to water for a first enzymolysis according to a mass ratio of yam protein, trypsin, papain and water of 1:0.02:0.01:5, then adding papain for a second enzymolysis, then performing enzyme inactivation treatment and freeze-drying to obtain the yam protein polypeptide, wherein the first enzymolysis temperature is 37°C, the pH value is 7.5, and the enzymolysis time is 1 hour; the second enzymolysis temperature is 55°C, the pH value is 6.8, and the enzymolysis time is 3 hours.

[0047] Example 2

[0048] This embodiment is a method for preparing yam protein polypeptide, and the yam mucin extraction method comprises the following steps:

[0049] (a) washing, peeling, color-protecting and homogenizing yam to obtain yam slurry;

[0050] (b) diluting the yam pulp by 20 times and then gelatinizing it, then adding α-amylase for enzymolysis, centrifuging, and collecting the supernatant, wherein the gelatinization temperature is 100° C.; the enzymolysis temperature is 60° C., the time is 3 h; and the amount of α-amylase added is 1% of the mass of the yam pulp;

[0051] (c) adjusting the pH value of the supernatant to 4, standing for 12 hours, centrifuging at 4500 rpm, collecting the precipitate, and obtaining yam protein;

[0052] (d) adding yam protein and trypsin to water for a first enzymolysis according to a mass ratio of yam protein, trypsin, papain and water of 1:0.005:0.02:15, then adding papain for a second enzymolysis, and then performing enzyme inactivation treatment and freeze-drying to obtain the yam protein polypeptide, wherein the first enzymolysis temperature is 37°C, the pH value is 8.0, and the enzymolysis time is 3 hours; the second enzymolysis temperature is 50°C, the pH value is 7.2, and the enzymolysis time is 1 hour.

[0053] Example 3

[0054] This embodiment is a method for preparing yam protein polypeptide, and the yam mucin extraction method comprises the following steps:

[0055] (a) washing, peeling, color-protecting and homogenizing yam to obtain yam slurry;

[0056] (b) diluting the yam pulp by 18 times and then gelatinizing it, then adding α-amylase for enzymolysis, centrifuging, and collecting the supernatant, wherein the gelatinization temperature is 90° C.; the enzymolysis temperature is 55° C., the time is 2 h; and the amount of α-amylase added is 2% of the mass of the yam pulp;

[0057] (c) adjusting the pH value of the supernatant to 3, standing for 18 hours, centrifuging at 4200 rpm, collecting the precipitate, and obtaining yam protein;

[0058] (d) adding yam protein and trypsin to water for a first enzymolysis according to a mass ratio of yam protein, trypsin, papain and water of 1:0.01:0.015:10, then adding papain for a second enzymolysis, and then performing enzyme inactivation treatment and freeze-drying to obtain the yam protein polypeptide, wherein the first enzymolysis temperature is 37° C., the pH value is 7.5, and the enzymolysis time is 2 h; the second enzymolysis temperature is 52° C., the pH value is 7.0, and the enzymolysis time is 2 h.

[0059] Comparative Example 1

[0060] This comparative example is a method for preparing a yam protein polypeptide, and the yam mucin extraction method comprises the following steps:

[0061] (a) washing, peeling, color-protecting and homogenizing yam to obtain yam slurry;

[0062] (b) diluting the yam pulp by 18 times and then gelatinizing it, then adding α-amylase for enzymolysis, centrifuging, and collecting the supernatant, wherein the gelatinization temperature is 90° C.; the enzymolysis temperature is 55° C., the time is 2 h; and the amount of α-amylase added is 2% of the mass of the yam pulp;

[0063] (c) adjusting the pH value of the supernatant to 5, standing for 18 hours, centrifuging at 4200 rpm, collecting the precipitate, and obtaining yam protein;

[0064] (d) adding yam protein and trypsin to water for a first enzymolysis according to a mass ratio of yam protein, trypsin, papain and water of 1:0.01:0.015:10, then adding papain for a second enzymolysis, and then performing enzyme inactivation treatment and freeze-drying to obtain the yam protein polypeptide, wherein the first enzymolysis temperature is 37° C., the pH value is 7.5, and the enzymolysis time is 2 h; the second enzymolysis temperature is 52° C., the pH value is 7.0, and the enzymolysis time is 2 h.

[0065] Comparative Example 2

[0066] This comparative example is a method for preparing a yam protein polypeptide, and the yam mucin extraction method comprises the following steps:

[0067] (a) washing, peeling, color-protecting and homogenizing yam to obtain yam slurry;

[0068] (b) diluting the yam pulp by 18 times and then gelatinizing it, then adding α-amylase for enzymolysis, centrifuging, and collecting the supernatant, wherein the gelatinization temperature is 90° C.; the enzymolysis temperature is 55° C., the time is 2 h; and the amount of α-amylase added is 2% of the mass of the yam pulp;

[0069] (c) adjusting the pH value of the supernatant to 3, standing for 18 hours, centrifuging at 4200 rpm, collecting the precipitate, and obtaining yam protein;

[0070] (d) adding yam protein and trypsin to water for a first enzymolysis according to a mass ratio of yam protein, pepsin, papain and water of 1:0.01:0.015:10, then adding papain for a second enzymolysis, and then performing enzyme inactivation treatment and freeze-drying to obtain the yam protein polypeptide, wherein the first enzymolysis temperature is 37° C., the pH value is 2.5, and the enzymolysis time is 2 h; the second enzymolysis temperature is 52° C., the pH value is 7.0, and the enzymolysis time is 2 h.

[0071] Comparative Example 3

[0072] This comparative example is a method for preparing a yam protein polypeptide, and the yam mucin extraction method comprises the following steps:

[0073] (a) washing, peeling, color-protecting and homogenizing yam to obtain yam slurry;

[0074] (b) diluting the yam pulp by 18 times and then gelatinizing it, then adding α-amylase for enzymolysis, centrifuging, and collecting the supernatant, wherein the gelatinization temperature is 90° C.; the enzymolysis temperature is 55° C., the time is 2 h; and the amount of α-amylase added is 2% of the mass of the yam pulp;

[0075] (c) adjusting the pH value of the supernatant to 3, standing for 18 hours, centrifuging at 4200 rpm, collecting the precipitate, and obtaining yam protein;

[0076] (d) adding yam protein and trypsin to water for enzymatic hydrolysis in a mass ratio of yam protein, trypsin and water of 1:0.01:10, then performing enzyme inactivation treatment and freeze-drying to obtain the yam protein polypeptide, wherein the enzymatic hydrolysis temperature is 37° C., the pH value is 7.5, and the enzymatic hydrolysis time is 2 h.

[0077] Comparative Example 4

[0078] This comparative example is a method for preparing a yam protein polypeptide, and the yam mucin extraction method comprises the following steps:

[0079] (a) washing, peeling, color-protecting and homogenizing yam to obtain yam slurry;

[0080] (b) diluting the yam pulp by 18 times and then gelatinizing it, then adding α-amylase for enzymolysis, centrifuging, and collecting the supernatant, wherein the gelatinization temperature is 90° C.; the enzymolysis temperature is 55° C., the time is 2 h; and the amount of α-amylase added is 2% of the mass of the yam pulp;

[0081] (c) adjusting the pH value of the supernatant to 3, standing for 18 hours, centrifuging at 4200 rpm, collecting the precipitate, and obtaining yam protein;

[0082] (d) adding yam protein and papain to water in a mass ratio of yam protein, papain and water of 1:0.015:10 for enzymolysis, then performing enzyme inactivation treatment and freeze-drying to obtain the yam protein polypeptide, wherein the enzymolysis temperature is 52° C., the pH value is 7.0, and the enzymolysis time is 2 h.

[0083] Experimental example

[0084] The yam protein polypeptides prepared in Example 3 and Comparative Examples 1 to 4 were obtained respectively;

[0085] The antioxidant properties of the above-mentioned yam protein polypeptide were tested according to the method in GB / T 39100-2020, and the test results are shown in Table 1;

[0086] Table 1

[0087] Group DPPH(AO value) Example 3 0.871 Comparative Example 1 1.138 Comparative Example 2 0.984 Comparative Example 3 1.306 Comparative Example 4 1.252

[0088] From Table 1, we can see that:

[0089] Compared with the comparative example, the above-mentioned protein polypeptide prepared in the embodiment of the present invention has more excellent antioxidant performance and can better remove DPPH free radicals.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A method for preparing yam protein polypeptide, characterized in that: The method for extracting yam mucin comprises the following steps: (a) washing, peeling, color-protecting and homogenizing yam to obtain yam slurry; (b) diluting the yam slurry and gelatinizing it, then adding amylase to perform enzymolysis, centrifuging, and collecting the supernatant; (c) adjusting the pH value of the supernatant to 2-4, allowing the supernatant to stand, centrifuging, and collecting the precipitate to obtain yam protein; (d) adding yam protein and trypsin to water for a first enzymolysis, then adding papain for a second enzymolysis, then performing enzyme inactivation treatment and freeze-drying to obtain the yam protein polypeptide.

2. The method for preparing yam protein polypeptide according to claim 1, characterized in that: In the step (b), the dilution factor is 15 to 20 times.

3. The method for preparing yam protein polypeptide according to claim 1, characterized in that: In the step (b), the amount of amylase added is 1% to 4% of the mass of the yam pulp.

4. The method for preparing yam protein polypeptide according to claim 1, characterized in that: In the step (b), the gelatinization temperature is 90-100° C.; the enzymatic hydrolysis temperature is 50-60° C., and the time is 1-3 hours.

5. The method for preparing yam protein polypeptide according to claim 1, characterized in that: In the step (c), the standing time is 12 to 24 hours.

6. The method for preparing yam protein polypeptide according to claim 1, characterized in that: In the step (c), the centrifugal speed is 4000-4500 rpm.

7. The method for preparing yam protein polypeptide according to claim 1, characterized in that: In the step (d), the mass ratio of yam protein, trypsin, papain and water is 1: (0.005-0.02): (0.01-0.02): (5-15).

8. The method for preparing yam protein polypeptide according to claim 1, characterized in that: In the step (d), the first enzymolysis temperature is 36-38° C., the pH value is 7.5-8.0, and the enzymolysis time is 1-3 hours.

9. The method according to claim 1, characterized in that: In the step (d), the second enzymolysis temperature is 50-55° C., the pH value is 6.8-7.2, and the enzymolysis time is 1-3 hours.

10. The yam protein polypeptide prepared by the preparation method according to any one of claims 1 to 9.