Brown algae extract helpful for regulating in-vivo fat function

Abstract

The invention provides a brown algae extract helpful for adjusting in-vivo fat functions. The brown algae extract is extracted from brown algae fermentation liquor; the mass ratio of the effective components in the brown algae fermentation liquor is 50-80%; the effective component comprises oligosaccharide with the polymerization degree of 2 to 10. The brown algae extract provided by the invention does not cause toxic reaction to mice, and has food safety. The brown algae extract provided by the invention has relatively good effects of improving abnormal blood fat metabolism of high-fat diet rats and relieving fat accumulation in bodies.

Description

Technical Field

[0001] The invention belongs to the field of organic macromolecular compounds, and specifically relates to a brown algae extract and its application in regulating body fat function. Background Art

[0002] Brown algae extract is a degradation product of alginate. The alginate oligosaccharide contained in the brown algae extract is a low molecular weight polymer composed of 2 to 25 monosaccharides (mannuronic acid, guluronic acid) bonded by glycosidic bonds. Compared with alginate, oligosaccharides have the characteristics of low viscosity, easy solubility in water, easy absorption, strong stability, as well as many biological activities such as food preservation, anticoagulation, anti-tumor, lowering blood pressure, and promoting plant growth. In recent years, it has become a research hotspot in the field of polysaccharides. The performance and structure of brown algae extract are closely related to its preparation and separation methods.

[0003] The production and preparation methods of brown algae extracts are mainly chemical, physical and bio-enzymatic. Among them, bio-enzymatic hydrolysis technology uses enzymes such as alginate lyase, cellulase, protease, pectinase, cell wall-dissolving enzyme to effectively degrade brown algae to obtain brown algae extracts; different types of strains produce different oligosaccharide structures and polymerization ranges, and some process conditions can also control the oligosaccharide content and different polymerization degrees. Appropriate selection of strains and fermentation conditions to obtain brown algae extracts with the function of regulating body fat is a very challenging research direction.

[0004] As a global epidemic, obesity increases the risk of health complications. Epidemiological evidence shows that a high-fat diet promotes the development of obesity and related metabolic disorders, and there is a direct relationship between the fat content in the diet and the degree of obesity. Lipid metabolism is closely related to obesity, and lipid metabolism disorders are one of its pathogenesis, which can cause a variety of diseases such as obesity, hyperlipidemia, and non-alcoholic fatty liver disease; and obesity itself can lead to lipid metabolism disorders, thus forming a vicious circle. In addition, obesity can cause increased levels of TG and TC in plasma and liver, abnormal lipoprotein metabolism in plasma, and then lead to abnormal lipid metabolism. At present, modern medicine mainly evaluates weight loss function from several aspects such as changes in body weight, changes in lipoprotein content, and changes in liver tissue and adipose tissue morphology. Summary of the invention

[0005] In view of the shortcomings of the prior art, the first object of the present invention is to provide a brown algae extract for regulating body fat.

[0006] The second object of the present invention is to provide the application of the brown algae extract.

[0007] The technical solution for achieving the above-mentioned purpose of the present invention is: a brown algae extract that helps regulate the body's fat function, wherein the brown algae extract is extracted from brown algae fermentation broth; the effective ingredients in the brown algae extract account for 50 to 80% by mass; and the effective ingredients include oligosaccharides with a degree of polymerization of 2 to 10.

[0008] The brown algae extract includes active ingredients containing oligosaccharides formed by sugar chains formed by guluronic acid (G) and mannuronic acid (M) with a polymerization degree of 2 to 10 or a hybrid of the two connected by β-1,4 glycosidic bonds; the brown algae extract contains about 10 to 40% by weight of brown algae polysaccharides.

[0009] Wherein, the brown algae extract is prepared by the following steps:

[0010] 1) Bacterial fermentation: Bacillus subtilis is used as the fermentation strain, the strain is activated and enriched, and then inoculated into alginate functional medium, the temperature is controlled at 28° C. to 32° C., the pH is controlled at 6.5-8.0, and the strain is fermented for 20 to 24 hours to obtain a bacterial fermentation liquid;

[0011] 2) Preparation of brown algae extract: prepare 8% to 12% food grade sodium alginate solution, add the bacterial fermentation liquid obtained in step 1), and carry out biological reaction at 30° C. to 35° C. for 28 to 48 hours;

[0012] 3) The brown algae fermentation liquid obtained in step 2) is centrifuged, and insoluble polysaccharides are removed by filtration. The clear liquid obtained by centrifugation is filtered through a membrane to obtain oligosaccharides with a degree of polymerization of 2 to 10, and the obtained solution is spray-dried at below 100° C. to obtain a brown algae extract.

[0013] This project studies the application of brown algae extract in the preparation of products with immune-enhancing functions, so the raw materials must be harmless and edible. Among the fermentable bacteria, Bacillus subtilis is a GRAS strain included in the US FDA and is a food-grade microorganism, so it is used in the preparation of brown algae extract.

[0014] The alginic acid functional medium contains the following components in mass ratio: sodium alginate 3-5 g / L, tryptone 3-5 g / L, glucose 10 g / L, K2 HPO4 5-8 g / L, chloramphenicol 2-10 μg / mL, magnesium sulfate 1-2 g / L, ferrous sulfate 0.1-0.2 g / L, and a pH value of 6.5-7.0. The pH value is adjusted with 1M HCl.

[0015] Preferably, in step 1), the temperature is controlled at 28°C to 30°C, the pH is controlled at 7.0 to 7.5, and the strain is fermented for 20 to 24 hours.

[0016] Wherein, in step 2), the mass ratio of the food-grade sodium alginate solution to the bacterial fermentation liquid is 100:4-5.

[0017] More preferably, in step 2), the biological reaction is carried out at a temperature of 30°C-35°C for 38 to 42 hours.

[0018] Wherein, in step 3), the clear liquid obtained by centrifugation is sequentially passed through a nanofiltration membrane with a molecular weight cutoff of 400Da and an ultrafiltration membrane with a molecular weight cutoff of 2000Da, and the intermediate filtration product is retained.

[0019] The obtained brown algae extract contains alginate oligosaccharides with a polymerization degree of 2 to 10.

[0020] The invention discloses an application of the brown algae extract in preparing a functional product that helps regulate body fat.

[0021] Furthermore, the mass concentration of the brown algae extract in the functional product that helps regulate body fat is 0.01% to 0.2%.

[0022] The beneficial effects of the present invention are:

[0023] The invention adopts fermentation and purification methods to prepare brown algae extract with a polymerization degree of 2 to 10. By optimizing the fermentation process, a yield of 69.1% can be achieved, and the production method is economical and efficient. The obtained brown algae extract will not cause toxic reactions to mice and has food safety.

[0024] The present invention evaluates the weight loss efficacy of different doses of brown algae extract by exploring the changes in body weight, TG, TC, lipoprotein, liver, epididymal adipose tissue and perirenal adipose tissue in obese rats. The experimental results show that taking 2.0g / kg of brown algae extract can significantly reduce the serum total cholesterol level and low-density lipoprotein cholesterol level of rats fed a high-fat diet, significantly reduce the serum triglyceride level; and significantly reduce the perirenal adipocyte area; indicating that the brown algae extract has a good effect on improving the abnormal lipid metabolism of rats fed a high-fat diet and reducing fat accumulation in the body. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Effects of brown algae extract on body weight and food intake in rats fed a high-fat diet.

[0026] Figure 2The effect of brown algae extract on serum and liver biochemical indexes of rats fed a high-fat diet. Figure A shows the changes in serum TG content, Figure B shows the changes in serum TC content, Figure C shows the changes in serum LDL-C content, Figure D shows the changes in serum HDL-C content, Figure E shows the changes in liver TG content, and Figure F shows the changes in liver TC content. Note: "*", "**" and "***" indicate that the differences between the groups are statistically significant (*: P<0.05, **: P<0.01, ***: P<0.001). Note: "*" indicates that the difference between the two groups is significant (P<0.05).

[0027] Figure 3 H&E staining (A) and Oil Red O staining (B) of rat liver tissues. Note: “*”, “**” and “***” indicate that there are statistically significant differences among the groups (*: P<0.05, **: P<0.01, ***: P<0.001).

[0028] Figure 4 The staining images of rat epididymal adipose tissue (A) and perirenal adipose tissue (B) are shown. Note: "*", "**" and "***" indicate that there are statistically significant differences among the groups (*: P<0.05, **: P<0.01, ***: P<0.001). DETAILED DESCRIPTION

[0029] The following examples are used to illustrate the present invention but should not be used to limit the scope of the present invention.

[0030] The strain used in the examples is commercially available Bacillus subtilis, with the accession number ATCC6633.

[0031] In the examples, unless otherwise specified, all means used are conventional techniques in the art; and all raw materials used are commercially available unless otherwise specified.

[0032] Example 1 Preparation of brown algae extract

[0033] 1) Strain fermentation: The commercially available strain of Bacillus subtilis was activated and enriched, inoculated into alginate functional medium, the temperature was controlled at 28°C to 30°C, and the strain was fermented for 24 hours to obtain a strain fermentation liquid.

[0034] The formula of the alginic acid functional medium is as follows: sodium alginate 5g / L, tryptone 5g / L, glucose 10g / L, K2HPO4 5g / L, chloramphenicol 2μg / mL, magnesium sulfate 1g / L, ferrous sulfate 0.1g / L, pH value is 7.0. The pH value is adjusted with 1M HCl.

[0035] The culture medium formula used for activation and enrichment is the same as above, but with the addition of 20 g / L agar.

[0036] 2) Preparation of brown algae extract: prepare 10% food-grade sodium alginate solution, add the bacterial fermentation broth obtained in step 1), and carry out biological reaction at 30° C. to 35° C. for 30 hours. The mass ratio of the food-grade sodium alginate solution to the bacterial fermentation broth is 100:5.

[0037] 3) The brown algae fermentation liquid obtained in step 2) is centrifuged to remove insoluble polysaccharides, and the oligosaccharide polymerization degree is controlled to be 2-10 by membrane filtration, and the obtained solution is spray-dried below 100°C to obtain a brown algae extract. The type of filter membrane is selected according to the molecular weight range, that is, the clear liquid obtained by centrifugation is sequentially passed through a nanofiltration membrane with a molecular weight cutoff of 400Da and an ultrafiltration membrane with a molecular weight cutoff of 2000Da, and the intermediate filtration product is retained. The content of components with a polymerization degree of 2-10 in the obtained brown algae extract is 53.1%. The yield is 57.2%.

[0038] Example 2 Preparation of brown algae extract

[0039] 1) Bacterial fermentation: Commercially available Bacillus subtilis was used to activate and enrich the strain. The strain was inoculated into an alginate functional medium, the temperature was controlled at 30°C-32°C, the pH was controlled at 7.0, and the strain was fermented for 24 hours to obtain a bacterial fermentation liquid. The medium formula was the same as in Example 1.

[0040] 2) Preparation of alginate oligosaccharides: Prepare 10% food-grade sodium alginate solution, add the bacterial fermentation liquid obtained in step 1), and carry out biological reaction at 30°C-35°C for 40 hours.

[0041] 3) The brown algae fermentation liquid obtained in step 2) is centrifuged to remove insoluble polysaccharides, and the clear liquid obtained by centrifugation is filtered through a membrane to obtain oligosaccharides with a degree of polymerization of 2-10, and the obtained solution is spray-dried at below 100° C. to obtain a brown algae extract. The type of the filter membrane is selected according to the molecular weight range, and the oligosaccharides with a degree of polymerization of 2 to 10 are retained in the solution. The mass proportion of oligosaccharides with a degree of polymerization of 2 to 10 in the obtained brown algae extract is about 56.3%.

[0042] The yield was 61.1%.

[0043] Example 3 Preparation of brown algae extract

[0044] 1) Bacterial fermentation: Use the GRAS strain included in the US FDA, food-grade Bacillus subtilis, to activate and enrich the strain. Inoculate it in alginate functional medium, control the temperature at 28°C to 30°C, and ferment the strain for 24 hours to obtain the bacterial fermentation liquid.

[0045] 2) Preparation of brown algae extract: Prepare 10% food-grade sodium alginate solution, add the bacterial fermentation liquid obtained in step 1), and carry out biological reaction at 30°C-35°C for 36 hours.

[0046] 3) The brown algae fermentation liquid obtained in step 2) is centrifuged to remove insoluble polysaccharides, and oligosaccharides with a degree of polymerization of 2 to 10 are retained by membrane filtration, and the obtained solution is spray-dried at below 100° C. to obtain a brown algae extract. The mass ratio of oligosaccharides with a degree of polymerization of 2 to 10 in the obtained brown algae extract is about 55.9%. The yield is 59.4%.

[0047] Test Example: Experiment on the Weight Loss and Body Fat Regulation Effect of Brown Algae Extract

[0048] The brown algae extract prepared in Example 2 was used in the test example and was prepared into solutions of different concentrations using purified water.

[0049] Modeling: 82 SD rats were moved into the barrier room of the animal room and examined for appearance and health. After no abnormalities were found in the examination, 70 rats were randomly selected to switch to a 45% high-fat diet after 3 days of adaptive feeding, and the remaining 12 rats were still fed with a normal standard diet (i.e., the blank control group). After 2 weeks of feeding, the rats fed with a high-fat diet were sorted by weight gain, and the obesity-resistant rats with lower weight gain were eliminated.

[0050] Administration: The 60 obese-sensitive rats screened were randomly divided into 5 groups according to body weight, with 12 rats in each group, including the model group and the brown algae extract four dose groups, and continued to be given 45% high-fat feed, and the blank control group was given maintenance feed according to normal standard feed. According to 0.1mL / 10g body weight, the low, medium, high and extremely high dose groups of brown algae extract were administered 0.1, 0.3, 0.9, and 2.0g / kg respectively (assuming that the rat weight is 200g, a 2mL administration volume is required, and the low-dose group should be given 0.02g of brown algae extract, that is, 0.02g of brown algae extract is dissolved in 2mL of water for gavage. Similarly, the medium-dose group should be given 0.06g of brown algae extract, and 0.06g of brown algae extract is dissolved in 2ml of water for gavage. The remaining two groups of doses are analogous), and the blank group and the model group are given Wahaha purified water. The amount of food given and the amount of food left are recorded every 3 days, the rats are weighed once a week, and the administration volume is adjusted according to the body weight. The test sample is administered for 8 weeks.

[0051] Sample collection: After 7 weeks of gavage with brown algae extract, rats were fasted for 12 hours but not water, and their body weight was measured. One hour after the last gavage with brown algae extract, the animals were anesthetized with isoflurane and sodium pentobarbital, and blood was collected from the abdominal aorta. The collected fresh blood was allowed to stand overnight at 4°C, centrifuged at 1000g for 15 minutes, and the upper serum was drawn into a new centrifuge tube. The remaining serum was stored in a -80°C refrigerator. Rats were dissected to obtain perirenal fat, peritesticular fat, and liver. Part of the liver and fat were cut and fixed in 4% paraformaldehyde, and then H&E staining was performed; part of the liver tissue was then cut and frozen in liquid nitrogen, sliced, and stained with Oil Red O, and the rest of the tissue was stored in an ultra-low temperature refrigerator at -80°C.

[0052] Serum biochemical index detection: According to the instructions of each kit, the total triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) levels in serum were detected using a fully automatic biochemical analyzer.

[0053] Determination of liver TG and TC content: According to the instructions of each kit, a full-wavelength microplate reader was used to determine the TG content in the liver by the GPO-PAP enzymatic method, and the TC content in the liver by the CHOD-PAP method.

[0054] Result processing: The results of the above-mentioned test indicators were statistically analyzed, and a comparative analysis was conducted between the model group and the blank control group, and between each brown algae extract group and the model group.

[0055] Statistical methods: All quantitative data were input into GraphPad Prism 9.1.0 software and statistically analyzed according to the following method: first, the Shapiro-Wilk method was used for normality test. If the data conformed to normal distribution, the Brown-Forsythe method was used for variance homogeneity test. If the variance was homogeneous, one-way analysis of variance (One-Way ANOVA) was performed and further multiple comparison test was performed using Dunnett's test method; if the variance was unequal, Brown-Forsythe and Welch ANOVA analysis was used and further multiple comparison test was performed using Dunnett's T3 test method. If the normality test failed, a nonparametric test was required, and further multiple comparison test was performed using Dunn's test method. The results in the charts are expressed as mean ± standard error.

[0056] Changes in body weight and food intake of experimental rats: Figure 1 AC showed that after 8 weeks of continuous gavage, the body weight of the model group increased by 11.85% compared with the blank group. The weight gain rate of the model group rats was significantly different from that of the blank group (P<0.001). The above results showed that the high-fat diet-induced obesity rat model was successfully established. Figure 1B), the weight of rats in the brown algae extract group and the model group increased compared with the blank group, but the weight gain of the brown algae extract group was lower than that of the model group, and the weight gain of the brown algae extract medium dose group was significantly lower than that of the model group by 9.43% (P<0.05). Figure 1 C), the brown algae extract medium dose group was significantly lower than the model group by 9.52% (P<0.01). Figure 1 E), the brown algae extract medium dose group was significantly reduced by 26.41% compared with the model group (P<0.05).

[0057] Figure 1 D shows the food intake of rats in each group. The metabolic imbalance caused by a high-fat diet will affect the appetite of rats, thereby causing weight changes. Compared with the blank group, the appetite of rats in the model group decreased; compared with the model group, the food intake of rats in the medium and high dose groups of brown algae extract increased slightly, but there was no significant difference in food intake among the groups (P>0.05), indicating that the weight loss caused by the intake of brown algae extract is not caused by regulating the appetite of rats.

[0058] The above results indicate that intervention with brown algae extract in the medium-dose group (0.3 g / kg) helps obese rats lose weight.

[0059] Table 1 Effects of brown algae extract on body weight and food intake of rats fed a high-fat diet

[0060]

[0061] Note: Different letters indicate statistically significant differences among the groups (P<0.05).

[0062] Effects of brown algae extract on serum and liver biochemical indices in rats: Obesity causes lipid metabolism disorders, which further promotes changes in some biochemical indices in plasma, such as high levels of serum total cholesterol (TC), triglycerides (TG) and low-density lipoprotein (LDL), thereby causing coronary heart disease, atherosclerosis and other related chronic diseases. Figure 2AD showed that compared with the blank group, long-term high-fat diet feeding can significantly increase the serum TG level of rats (P<0.001), significantly increase the serum low-density lipoprotein cholesterol (LDL-C) level of rats (P<0.05), and have no significant effect on TC and high-density lipoprotein cholesterol (HDL-C) levels (P>0.05), indicating that long-term feeding of a high-fat diet will lead to increased blood lipids in rats. Compared with the model group, intervention with brown algae extract can reduce the serum TG, TC and LDL-C levels of rats to varying degrees. Among them, the serum TG level of rats in the extremely high-dose brown algae extract group was significantly reduced by 26.45% (P<0.05), the TC level was extremely significantly reduced by 36.25% (P<0.001), and the LDL-C level was extremely significantly reduced by 31.01% (P<0.01). Figure 2 EF showed that compared with the blank group, the TG level in the liver of rats fed with a long-term high-fat diet was significantly increased by 106.82% (P<0.001), and the TC level was significantly increased by 81.69% (P<0.001). Compared with the model group, the brown algae extract in the medium-dose group significantly reduced the TG level in the liver by 43.41% (P<0.001), and the TC level was significantly reduced by 24.23% (P<0.01).

[0063] Table 2 Effects of brown algae extract on serum and liver biochemical parameters in rats fed a high-fat diet

[0064]

[0065]

[0066] Note: Different letters indicate statistically significant differences among the groups (P<0.05).

[0067] Effect of brown algae extract on the pathological morphology of liver tissue in rats fed a high-fat diet: In order to explore the improvement effect of brown algae extract on lipid deposition in the liver of rats fed a high-fat diet, H&E staining and Oil Red O staining of the liver were performed. The lipid deposition and inflammatory infiltration of hepatocytes were observed using an optical microscope using the H&E staining method. Figure 3A shows the pathological changes of rat liver tissue. The liver tissue of the blank group was neatly arranged and intact in structure, and no fatty degeneration and inflammatory cell infiltration were observed in the cells; the liver cells of the rats in the model group were significantly swollen, with obvious fat vacuoles, accompanied by inflammatory cell infiltration, and the liver pathology score was significantly increased compared with the blank group (P<0.001); although the liver cells of the rats in the different doses of brown algae extract groups were also swollen, the pathological structure of the liver tissue was improved to varying degrees, and the fat vacuoles were reduced. Among them, the improvement effect of the medium dose group of brown algae extract on liver tissue was the most obvious. At this dose, the cell structure of the rat liver tissue became more complete, clear, and without obvious degeneration, the infiltration of inflammatory cells was reduced, and the structure of the central vein, hepatic cord, and hepatic sinusoids tended to be normal. Compared with the model group, the liver tissue pathology score was significantly reduced by 30.05% (P<0.05).

[0068] Oil red O staining can be used to visually observe lipid accumulation in rat liver. Figure 3 As shown in B, the lipid droplets in the tissue cells are orange-red and the nucleus is blue. The livers of the rats in the blank group were basically free of red lipid droplets; the livers of the rats in the model group were filled with red lipid droplets due to excessive lipid intake, and the red lipid droplets were diffused over a large area and accumulated together; after intervention with different doses of brown algae extract, the amount of red lipid droplets in the livers of the rats decreased to varying degrees, and the red lipid droplets were irregularly distributed in small granules, but did not completely return to normal levels; among them, the number of red lipid droplets in the livers of the rats in the medium dose group of brown algae extract was the least, and compared with the model group, the area of ​​Oil Red O was significantly reduced by 39.86% (P<0.001).

[0069] In summary, intervention with brown algae extract, especially the medium-dose group of brown algae extract, can reduce the accumulation of lipids in the liver caused by long-term high-fat diet in rats, thereby reducing liver damage.

[0070] Table 3 Effects of brown algae extract on liver tissue of rats fed a high-fat diet

[0071]

[0072]

[0073] Note: Different letters indicate statistically significant differences among the groups (P<0.05).

[0074] Effects of brown algae extract on the pathological morphology of adipose tissue in mice fed a high-fat diet: Figure 4 It can be seen that compared with the blank group, the epididymal fat and perirenal fat cell area of ​​the model group rats became larger, and the number of cells per unit area was less than that of the blank group. Figure 4A), the cell area of ​​the model group was 2.30 times that of the blank group, with a very significant difference between the two (P<0.001); after intervention with different doses of brown algae extract, the area of ​​epididymal adipocytes decreased, and the cell area of ​​the medium dose group of brown algae extract was significantly reduced by 32.13% compared with the model group (P<0.05). Figure 4 B), the cell area of ​​the model group was 2.94 times that of the blank group, with a very significant difference between the two (P<0.001); after intervention with different doses of brown algae extract, the area of ​​perirenal adipocytes decreased, among which the cell area of ​​the medium dose group of brown algae extract was significantly reduced by 39.70% (P<0.001) compared with the model group, and the cell area of ​​the extremely high dose group was significantly reduced by 28.79% (P<0.01) compared with the model group. In summary, intervention with brown algae extract can reduce the accumulation of fat in rats fed a high-fat diet.

[0075] Table 4 Effects of brown algae extract on adipose tissue in rats fed a high-fat diet

[0076]

[0077] Note: Different letters indicate statistically significant differences among the groups (P<0.05).

[0078] The main results of the brown algae extract in regulating body fat are as follows:

[0079] (1) The brown algae extract in the medium-dose group: It can significantly reduce the weight gain of obese rats (9.43%), extremely significantly reduce the weight gain rate (9.52%), and significantly reduce the body fat rate (26.41%); significantly reduce the liver tissue pathology score (30.05%), significantly reduce the Oil Red O staining area (39.86%); significantly reduce the epididymal adipocyte area (32.13%) and perirenal adipocyte area (39.70%); extremely significantly reduce the liver triglyceride level (43.41%); indicating that the intake of medium-dose brown algae extract has a good effect on reducing the weight of obese rats, reducing liver damage, and alleviating fat accumulation in the body.

[0080] (2) The brown algae extract in the very high dose group was able to significantly reduce the serum total cholesterol level (36.25%) and low-density lipoprotein cholesterol level (31.01%) of rats fed a high-fat diet, and significantly reduce the serum triglyceride level (26.45%); it also significantly reduced the area of ​​perirenal adipocytes (28.79%); this indicates that the very high dose of brown algae extract has a good effect on improving the abnormal lipid metabolism and reducing fat accumulation in rats fed a high-fat diet.

[0081] In summary, the medium-dose group and the extremely high-dose group intervention with brown algae extract had good effects on regulating body fat and relieving constipation.

[0082] Although the present invention has been described in detail above, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present invention. Therefore, these modifications or improvements made on the basis of not departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A brown algae extract that helps regulate body fat function, characterized in that: The brown algae extract is extracted from brown algae fermentation liquid; the effective ingredients in the brown algae extract account for 50-80% by mass; and the effective ingredients include oligosaccharides with a degree of polymerization of 2-10.

2. The brown algae extract according to claim 1, characterized in that The brown algae extract is prepared by the following steps: 1) Bacterial fermentation: Bacillus subtilis is used as the fermentation strain, the strain is activated and enriched, and then inoculated into alginate functional medium, the temperature is controlled at 28° C. to 32° C., the pH is controlled at 6.5 to 8.0, and the strain is fermented and cultured for 20 to 24 hours to obtain a bacterial fermentation liquid; 2) Preparation of brown algae extract: prepare 8% to 12% food grade sodium alginate solution, add the bacterial fermentation liquid obtained in step 1), and carry out biological reaction at 30° C. to 35° C. for 28 to 48 hours; 3) The brown algae fermentation liquid obtained in step 2) is centrifuged, and insoluble polysaccharides are removed by filtration. The clear liquid obtained by centrifugation is filtered through a membrane to obtain oligosaccharides with a degree of polymerization of 2 to 10, and the obtained solution is spray-dried at below 100° C. to obtain a brown algae extract.

3. The brown algae extract according to claim 2, characterized in that The alginic acid functional culture medium contains the following components in mass proportions: 3-5 g / L sodium alginate, 3-5 g / L tryptone, 10 g / L glucose, 5-8 g / L K2 HPO4, 2-10 μg / mL chloramphenicol, 1-2 g / L magnesium sulfate, 0.1-0.2 g / L ferrous sulfate, and a pH value of 6.5-7.

0.

4. The brown algae extract according to claim 2, characterized in that In step 1), the temperature is controlled at 28° C. to 30° C., the pH is controlled at 7.0 to 7.5, and the strain is fermented and cultured for 20 to 24 hours.

5. The brown algae extract according to claim 2, characterized in that In step 2), the mass ratio of the food-grade sodium alginate solution to the bacterial fermentation broth is 100:4-5.

6. The brown algae extract according to claim 2, characterized in that In step 2), the biological reaction is carried out at a temperature of 30°C-35°C for 38 to 42 hours.

7. The brown algae extract according to any one of claims 2 to 6, characterized in that In step 3), the supernatant obtained by centrifugation is sequentially passed through a nanofiltration membrane with a molecular weight cutoff of 400Da and an ultrafiltration membrane with a molecular weight cutoff of 2000Da, and the intermediate filtration product is retained.

8. Use of the brown algae extract according to any one of claims 1 to 7 in the preparation of a functional product that helps regulate body fat.

9. The use according to claim 8, characterized in that: The mass percentage concentration of the brown algae extract in the functional product that helps regulate body fat is 0.01% to 0.2%.

Images