A method for preparing a marine composite dietary fiber product

Abstract

The application belongs to the technical field of dietary fiber product preparation, and particularly relates to a preparation method of a marine composite dietary fiber product, mainly comprising the following steps: (1) preparing a fucoidan solution; (2) soaking chitosan in the fucoidan solution prepared in step (1); (3) continuously stirring for 1-6 hours at a temperature of 20-70 DEG C and a stirring speed of 300-700 rpm; (4) after uniform stirring, centrifuging for 10-20 min at a speed of 8000-12000 r / min, and collecting the precipitate; (5) drying the precipitate collected in step (4) in a 50-80 DEG C oven for 4-8 h; (6) repeating steps 3-8 in steps (2)-(5) for 3-8 times, and drying the precipitate in the last time to obtain the marine composite dietary fiber product. The marine composite dietary fiber product can effectively alleviate the inhibition of chitosan on protein digestion, and has the advantages of low investment cost, simple operation and short time consumption.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of dietary fiber product preparation, and particularly relates to a preparation method of a marine composite dietary fiber product. BACKGROUND

[0002] Dietary fiber is a polysaccharide that cannot be digested and absorbed by the gastrointestinal tract and cannot produce energy, but it can improve gastrointestinal function, promote the digestion and absorption of food, regulate intestinal flora, and reduce the risk of chronic diseases and even malignant tumors. Based on the health effects of dietary fiber, modern nutrition has listed it as the seventh nutrient. Composite dietary fiber is a composite organic substance composed of several dietary fibers, which has important significance in reducing blood lipids, reducing weight, and improving constipation, and is therefore widely used in food and other fields, such as the konjac gum and oat dietary fiber added in the fiber dieting product.

[0003] Chitosan (CTS) is the only alkaline polysaccharide in natural polysaccharides, mainly exists in the shell of crustaceans (such as shrimp, crab), is the main substance of chitin deacetylation, and is the second most abundant dietary fiber in nature after cellulose. Therefore, it is widely used in the production of marine composite dietary fiber products. In addition, chitosan is a food additive allowed to be used in GB2760-2014, and is used as a thickening agent and coating agent in the preparation of western-style ham and meat sausages. In addition, due to the film-forming property and antibacterial property of chitosan, it is often made into food packaging film for the preservation of vegetables, meat products, seafood, starch, eggs, milk and bean products, and has been widely used in the food field.

[0004] However, recent research reports indicate that chitosan can interact with proteins and digestive enzymes, affecting protein digestibility and reducing protein hydrolysis degree. As is known to all, protein is the material basis of life, the basic organic matter constituting cells, and the main carrier of life activities. After entering the human body, protein is hydrolyzed into amino acids by gastrointestinal digestion and absorption, and then combined to form various proteins required by the human body, which plays an important role in various functions of the human body. Therefore, how to solve the problem of inhibition of protein digestion by chitosan is imminent.

[0005] Fucoidan (FUC), also known as fucoidan and fucoidan sulfate, is a kind of acidic polysaccharide of marine origin containing fucose and sulfate groups, and also contains a small amount of monosaccharides such as galactose. Current research shows that fucoidan has the effects of anti-inflammatory, antioxidant, anticoagulation, antithrombosis, hypolipidemic, immune regulation and regulation of intestinal flora. Therefore, fucoidan has the potential for wide application in functional foods, health products and dietary supplements. SUMMARY

[0006] [TECHNICAL PROBLEM]

[0007] The technical problem solved by the present application is that in the prior art marine composite dietary fiber product, chitosan interacts with protein and digestive enzymes, affecting the digestion and absorption of protein.

[0008] [Technical scheme]

[0009] To solve the above problems, the present application provides a preparation method of a marine composite dietary fiber product using chitosan and fucoidan as raw materials, and develops a marine composite dietary fiber product that can effectively alleviate the inhibition of chitosan on protein digestion.

[0010] The first object of the present application is to provide a preparation method of a marine composite dietary fiber product, comprising the following steps:

[0011] (1) preparing a fucoidan (FUC) solution;

[0012] (2) soaking chitosan (CTS) in the fucoidan solution prepared in step (1);

[0013] (3) maintaining the temperature at 20-70℃ and the stirring speed at 300-700 rpm, and continuing stirring for 1-6 hours;

[0014] (4) after uniform stirring, centrifuging for 10-20 min at a speed of 8000-12000 r / min, and collecting the precipitate;

[0015] (5) drying the precipitate collected in step (4) for 4-8 hours;

[0016] (6) repeating steps 3-8 in steps (2)-(5) for 3-8 times, and drying the precipitate of the last time to obtain the marine composite dietary fiber product (CTS-FUC).

[0017] In an embodiment of the present application, the concentration of fucoidan in step (1) is 5-80 mg / mL.

[0018] In an embodiment of the present application, the concentration of chitosan in step (2) is 50-100 mg / mL.

[0019] In an embodiment of the present application, the drying method in step (5) is one of oven drying and freeze drying.

[0020] In an embodiment of the present application, the specific process of step (6) is that the precipitate dried in step (5) is soaked in the fucoidan solution again, uniformly stirred, centrifuged, and the precipitate is dried to obtain the marine composite dietary fiber product.

[0021] [Beneficial effects]

[0022] (1) The marine composite dietary fiber product prepared by coating chitosan with fucoidan can effectively alleviate the inhibition of chitosan on protein digestion, and has low input cost, simple operation and short time consumption, compared with chitosan, chitosan and fucoidan mixed powder.

[0023] (2) Compared with no addition of chitosan, the addition of chitosan reduces the degree of hydrolysis of whey protein from 55% to 25%, and compared with the addition of chitosan, the addition of the marine composite dietary fiber product and the addition of chitosan and fucoidan mixed powder both significantly improve the degree of protein hydrolysis, which is increased to 47% and 38% respectively, significantly alleviating the inhibition of chitosan on protein digestion, and the alleviating effect of the marine composite dietary fiber product is better. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The appearance diagram of the marine composite dietary fiber product obtained in Example 1 is shown in the figure.

[0025] Figure 2 The scanning electron microscope diagram (1000x) of the marine composite dietary fiber product obtained in Example 1 is shown in the figure.

[0026] Figure 3 The transmission electron microscope diagram (15000x) of the marine composite dietary fiber product obtained in Example 1 is shown in the figure.

[0027] Figure 4 The surface sulfur element distribution diagram of the marine composite dietary fiber product obtained in Example 1 is shown in the figure.

[0028] Figure 5 The influence of chitosan, chitosan and fucoidan powder and the marine composite dietary fiber product obtained in Example 1 on the degree of hydrolysis of whey protein at the same concentration is shown in the figure. DETAILED DESCRIPTION

[0029] The embodiments of the present application will be described in detail below with reference to the examples, and the specific conditions not noted in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not noted by the manufacturer, and are all conventional products that can be obtained by market purchase.

[0030] The test method of element distribution: the apparent morphology and element distribution on the surface of the composite dietary fiber are evaluated by scanning electron microscope (JSM-7800F) combined with EDS. 2mg of dried composite dietary fiber powder is adhered to the sample table and placed in the ion sputtering instrument, and a layer of conductive gold film is coated thereon. Under the electron beam acceleration voltage of 3kV, the composite dietary fiber is observed and measured at 1000 times magnification.

[0031] Potential test method: Use 1M HCl to adjust the pH of distilled water to 2 as a dispersant, use this dispersant to prepare a solution with a concentration of 1.0 mg / mL of CTS and composite dietary fiber, and use a 20mL syringe to inject the prepared solution into a laser particle size analyzer (Zetasizer 3000HSA) to measure the ζ-potential of the sample surface. Repeat the measurement three times for each sample.

[0032] Example 1

[0033] A method for preparing a marine composite dietary fiber product comprises the following steps:

[0034] (1) Accurately take 3 g of dried fucoidan (FUC) and add it to a 250 mL beaker. Pour in 100 mL of deionized water. Turn on the magnetic stirrer (rotor speed 500 rpm) to stabilize the temperature at 40°C. Dissolve the fucoidan under stirring with the magnetic stirrer to obtain a clear and transparent solution.

[0035] (2) Accurately take 10g of dry chitosan (CTS) and add it to the fucoidan solution for soaking;

[0036] (3) Maintain the temperature of the magnetic stirrer at 40°C and the speed of the magnetic stirrer at 500 rpm for 4 hours;

[0037] (4) Centrifuge for 15 min at 10,000 rpm and collect the precipitate;

[0038] (5) Dry the precipitate in a 60°C oven for 6 h;

[0039] (6) Repeat steps (2) to (5) for 5 times, and dry the precipitate collected for the last time to obtain a marine composite dietary fiber product (CTS-FUC).

[0040] The marine composite dietary fiber product prepared in Example 1 is as follows Figure 1 As shown, it is light yellow powder.

[0041] Figure 2 The scanning electron microscope image (1000×) of the marine composite dietary fiber product obtained in Example 1 is as follows: Figure 2 As shown, the surface of the marine composite dietary fiber product presents an irregular shape.

[0042] Figure 3 The transmission electron micrograph (15000×) of the marine composite dietary fiber product obtained in Example 1 is shown in FIG. Figure 3 As shown, the marine composite dietary fiber product presents an irregular structure.

[0043] Figure 4The surface sulfur element distribution map of the marine composite dietary fiber product obtained in Example 1 is shown in Table 1. Figure 4 As shown in Table 1, the nitrogen element content on the surface of the marine composite dietary fiber product is significantly reduced and the sulfur element content is significantly increased compared with chitosan, and the S element content on the surface of the marine composite dietary fiber product is 2-10%, which proves that the FUC is indeed coated on the surface of the composite dietary fiber.

[0044] Table 1 is the surface element distribution table of the marine composite dietary fiber product obtained in Example 1, as shown in Table 1, the nitrogen element content on the surface of the marine composite dietary fiber product is significantly reduced and the sulfur element content is significantly increased compared with chitosan, and the S element content on the surface of the marine composite dietary fiber product is 2-10%, which proves that the FUC is indeed coated on the surface of the composite dietary fiber.

[0045] Table 1 is the surface element distribution table of the marine composite dietary fiber product obtained in Example 1

[0046]

[0047] Table 2 is the potential table of the marine composite dietary fiber product obtained in Example 1, as shown in Table 2, the surface of the marine composite dietary fiber product has a negative charge, which changes significantly compared with chitosan, and the potential is-60- -20mV, which proves that the FUC is indeed coated on the surface of the marine dietary fiber product.

[0048] Table 2 is the potential table of the marine composite dietary fiber product obtained in Example 1

[0049]

[0050] A method for verifying that the marine composite dietary fiber product relieves the inhibition of whey protein digestion in the gastrointestinal tract by chitosan, comprising the following steps:

[0051] S1, preparing simulated gastric juice, simulated intestinal juice and ninhydrin color developing solution, the method is as follows;

[0052] (1) Simulated gastric juice: accurately weigh 1.0g NaCl, 0.4g KCl, 0.2g NaHCO3 and 0.05g CaCl2·2H2O, dissolve in 300mL deionized water, and use 1mol / L HCl to adjust the pH of the solution to 1.5, add 600mg pepsin (≥400U / mg) to the above solution to obtain simulated gastric juice, and the simulated gastric juice is prepared and used immediately;

[0053] (2) Simulated intestinal juice: accurately weigh 1.8g NaCl, 0.22g KCl and 0.11g CaCl2·2H2O, dissolve in 300mL deionized water, and use 1mol / L NaHCO3 to adjust the pH to 6.5, add 600mg trypsin (4U) and 3600mg choline salt to the above solution to obtain simulated intestinal juice, and the simulated intestinal juice is prepared and used immediately;

[0054] (3) Indole reaction solution: accurately weigh 0.25 g of indole, 0.15 g of fructose, 5 g of Na2HPO4.10H2O and 3 g of KH2PO4, and dilute to 50 mL with deionized water, and store at 4°C in the dark.

[0055] S2, 12 10 mL centrifuge tubes were taken, 8 mg of dried whey protein isolate (WPI), 8 mg of dried chitosan, and 8 mg of dried whey protein isolate (WPI), 8 mg of dried chitosan and 8 mg of dried fucoidan (FUC), and 8 mg of dried whey protein isolate (WPI), 8 mg of dried marine composite dietary fiber product were weighed, respectively, then 8 mL of the above simulated gastric juice was transferred into each centrifuge tube, and after mixing, 1 mol / L hydrochloric acid solution was used to adjust the pH to 1.5, to prepare a mixed solution with a concentration of 1 mg / mL of whey protein isolate, chitosan, fucoidan and marine composite dietary fiber product, respectively, named WPI, CTS+WPI, CTS+FUC+WPI, CTS-FUC+WPI, 4 parallel samples for each sample;

[0056] S3, the centrifuge tubes containing different dietary fiber and whey protein mixtures were placed in a constant temperature oscillator for 60 min (37°C, 140 rpm), 1 mL of each sample was transferred to a 2 mL centrifuge tube and placed in a boiling water bath for 10 min to inactivate the enzyme, then quickly cooled and centrifuged (8000 rpm, 5 min, 4°C) to take the supernatant; then the simulated gastric digestion sample was inactivated with 1 mol / L NaOH solution, the pH was adjusted to 6.5, mixed with simulated intestinal juice at a volume ratio of 1:1, and then the mixture was placed in a constant temperature oscillator for stirring for 120 min (37°C, 140 rpm), 1 mL of each sample was transferred to a 2 mL centrifuge tube and placed in a boiling water bath for 10 min to inactivate the enzyme, then quickly cooled and centrifuged (8000 rpm, 5 min, 4°C) to take the supernatant, and then the protein hydrolysis degree was determined;

[0057] S4, the indole reaction method was used to determine the free amino acid content and whey protein hydrolysis degree of the protein after simulated gastrointestinal digestion, the results are shown in Figure 5 After gastrointestinal digestion, chitosan had a significant inhibitory effect on the hydrolysis of whey protein, and the protein hydrolysis degree decreased from 55% to 25%; the addition of fucoidan powder significantly alleviated the inhibition of chitosan on protein hydrolysis, and the protein hydrolysis degree increased to 38%; in addition, the addition of marine composite dietary fiber product had a more significant effect on alleviating the inhibition of chitosan on protein hydrolysis, and the protein hydrolysis degree increased to 47%.

[0058] The above examples are not intended to limit the scope of the present application, nor are the described steps intended to limit the order in which they are performed. Modifications apparent to one skilled in the art in light of the above teachings are intended to fall within the scope of the claims.

Claims

1. A method for preparing a marine composite dietary fiber product, characterized in that: The steps include: (1) Prepare fucoidan solution; (2) Soaking chitosan in the fucoidan solution prepared in step (1); (3) Continuously stirring the solution of step (2); (4) After stirring evenly, centrifuge and collect the precipitate; (5) Drying the precipitate collected in step (4) for 4-8 hours; (6) Soaking the precipitate obtained in step (5) in the fucoidan solution prepared in step (1), and performing steps (3) to (5) again; repeating step (6) 2-7 times, and drying the final precipitate to obtain a marine composite dietary fiber product; The concentration of fucoidan in step (1) is 5-80 mg / mL; The concentration of chitosan in step (2) is 50-100 mg / mL; The stirring conditions in step (3) are: temperature of 20-70°C, stirring speed of 300-700 rpm, and stirring is continued for 1-6 hours; The centrifugation time in step (4) is 10-20 min, and the rotation speed is 8000-12000 r / min; The drying method in step (5) is one of oven drying and freeze drying.

2. A marine composite dietary fiber product prepared according to the method of claim 1.

3. Use of the marine composite dietary fiber product according to claim 2 in preparing food for alleviating chitosan inhibition of protein digestion in the gastrointestinal tract.

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