Holothurian antioxidative peptide

[0027] The preparation method of sea cucumber antioxidant polypeptide, the specific steps are as follows:

[0028] (1) Extraction of sea cucumber protein

[0029] The technological conditions of sea cucumber protein extraction are:

[0030] Wash the sea cucumber or sea cucumber viscera 3-5 times, the extraction pH is 7.0, the extraction temperature is 40-80 ℃, the material-to-liquid ratio is 1:4-1:8 (weight ratio), the extraction time is 2-6 h, centrifugation 10000g for 20 minutes, collect the supernatant, filter, concentrate and freeze-dry to obtain sea cucumber protein.

[0031] (2) Enzymatic hydrolysis of sea cucumber protein

[0032] Enzyme was purchased from Shanghai Biological Reagent Company (Shanghai, China).

[0033] Use acid protease to hydrolyze sea cucumber protein, the protein concentration is 30mg / ml, the conditions of enzymatic hydrolysis are pH 3.5, temperature 50℃, enzymolysis time 6h, enzyme to substrate ratio (3000U / g), adjust pH with 2M HCl Stable, after 6 hours of

[0056] Example 1

[0057] Weigh out 5.0 g of sea cucumber protein, dissolve it with deionized water and dilute to 250ml, then adjust its pH to 3.0 with 2mol / L HCl. The solution is heated to 50°C in a water bath, and then the corresponding amount of enzyme is added at the ratio of enzyme-substrate ratio of 3000 U / g, and the enzymolysis time is 6 hours. Then inactivate the enzyme in a boiling water bath for 15 minutes, and then centrifuge at 4000 rpm for 15 minutes after cooling. Collect the supernatant for later use.

[0058] The supernatant is separated by ultrafiltration of the sea cucumber polypeptide solution using a membrane filtration system, and the enzymatic hydrolysis products are separated using ultrafiltration membranes with different molecular weight cut-off ranges to obtain different components of ≥3000 Da, 1500-3000 Da, and ≤1500 Da , Determine its antioxidant activity. The result of the determination is that the components with a molecular weight of less than 15