Dietary fiber composition fermented by jujube and preparation method thereof

Abstract

The invention discloses a dietary fiber composition fermented by jujube and a preparation method thereof, and belongs to the technical field of fermented food finishing. The method comprises the following steps: jujube is crushed into fine powder and mixed with water, and then enzymolyzed and separated by biologically active enzymes to obtain a water-soluble dietary fiber mixed liquid and a water-insoluble dietary fiber solid mixture; the water-soluble dietary fiber mixed liquid is fermented to obtain a probiotic dietary fiber fermentation liquid; the water-insoluble dietary fiber solid mixture is oxidized to obtain carboxylated dietary fiber; the probiotic dietary fiber fermentation liquid and the carboxylated dietary fiber are mixed and then added with calcium chloride solution for cross-linking reaction, and then dried by hot air to obtain a dietary fiber composition. The invention uses jujube as a raw material, separates a water-soluble dietary fiber mixed liquid and a water-insoluble dietary fiber solid mixture by enzymolysis treatment, and then treats the two separately and then mixes and cross-links them, and finally obtains a dietary fiber composition with acid corrosion resistance and high temperature resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of fermented food fine processing, and particularly relates to a dietary fiber composition fermented by jujube and a preparation method thereof. Background Art

[0002] Dietary fiber has many important physiological functions and is recommended to be listed as the "seventh nutrient" that is necessary for human health after protein, fat, carbohydrates, minerals, vitamins and water. At present, there is no universal definition of dietary fiber in the world. It is generally believed that dietary fiber refers to the non-starch polysaccharides and lignin in plant foods that cannot be digested by human gastrointestinal digestive enzymes but can be partially fermented and utilized by certain microorganisms in the large intestine. Dietary fiber is divided into water-soluble dietary fiber and water-insoluble dietary fiber according to different solubility. The main components of water-insoluble dietary fiber are cellulose, hemicellulose and lignin; water-soluble dietary fiber includes storage and secretion of certain plant cells and microbial polysaccharides, and its main components are gum substances such as pectin, xanthan gum, gum arabic, guar gum, carrageenan and guaiac gum. According to different sources, dietary fiber can be divided into cereal fiber, fruit fiber, vegetable fiber, biochemical synthesis or conversion fiber and other types of fiber. Cereal fiber mainly includes wheat fiber, oat fiber, corn fiber and rice bran fiber. Fruit fibers include pomace fiber, peel fiber, whole fruit fiber and pectin. Among vegetable fibers, the most studied are beet fiber, carrot fiber and various vegetable powders. Biochemically synthesized or transformed fibers mainly include modified cellulose, resistant dextrin and polydextrose. Other types of fibers mainly refer to fungal fibers, marine fibers, and some mucilage and gum.

[0003] Dietary fiber has the following properties: (1) Low specific gravity, good water holding capacity, strong swelling power and solubility. The chemical structure of dietary fiber contains many hydrophilic groups, which can absorb water equivalent to several times its own weight. Therefore, dietary fiber absorbs water and swells in the stomach and intestines to form a high-viscosity sol or gel, which makes people feel full and inhibits eating. Many studies have shown that the high water holding capacity of dietary fiber increases gastrointestinal motility, inhibits the diffusion rate of nutrients in the intestine, shortens the stagnation time of food in the intestine, and at the same time increases, softens and stimulates the intestine, which is beneficial to increase the speed or volume of defecation and even the number of defecation, reduces the intestinal pressure, produces a laxative effect, and reduces the retention time of harmful substances in the intestine, thereby achieving the effect of regulating intestinal function. (2) Large specific surface area and many active groups. Dietary fiber has a large specific surface area and many active groups, so it can adsorb or chelate cholesterol, bile acid, endogenous and exogenous toxic substances in the intestine, and promote their excretion from the body. (3) It is easy to decompose into short-chain fatty acids. Although dietary fiber cannot be broken down by endogenous enzymes in the small intestine, various microorganisms parasitic in the intestine can break it down to varying degrees, producing short-chain fatty acids, which lower the pH in the colon, promote the growth and proliferation of beneficial intestinal bacteria, inhibit the growth of harmful putrefactive bacteria in the intestine, and balance the changes in the microbial flora in the intestinal system.

[0004] Dietary fiber prepared by fermentation has health benefits such as producing nutrients that are more easily absorbed by the human body, increasing the solubility of dietary fiber, and improving the taste and flavor of dietary fiber. At present, there are not many types of dietary fiber prepared by fermentation. The reason is that the live probiotics contained in the dietary fiber prepared by fermentation will first reach the stomach when it enters the body orally. The strong acid environment of the stomach is not conducive to the survival and reproduction of probiotics, resulting in a serious loss of probiotics when consuming dietary fiber prepared by fermentation.

[0005] Patent CN113287702A discloses a bamboo shoot dietary fiber live bacteria beverage and a preparation method thereof, wherein bamboo shoot dietary fiber is extracted from bamboo shoot residue, and then mixed and homogenized with bamboo shoot juice, glucose, stabilizer and water, sterilized and inoculated with bacteria for fermentation, and refrigerated and cooked after fermentation to obtain a bamboo shoot dietary fiber live bacteria beverage. The invention increases the number of live bacteria in the bamboo shoot dietary fiber live bacteria beverage after fermentation to resist the inactivation when entering the stomach, and ensures that some live bacteria can smoothly reach the intestines and be utilized by a large number of live bacteria. Although this method has a certain improvement in the utilization of live bacteria in the dietary fiber live bacteria beverage prepared by fermentation, liquid beverages containing live bacteria are prone to secondary fermentation of live bacteria, and gases such as carbon dioxide may occur to cause the sealed packaging to swell or even rupture, and secondary fermentation is due to the lack of nutrients, which easily affects the acidity and number of live bacteria of the liquid beverage, thereby resulting in a shorter shelf life of the dietary fiber live bacteria beverage prepared by fermentation, which is not conducive to storage.

[0006] Patent CN114600930A discloses a method for preparing a high-dietary fiber fermented product rich in prebiotics, in which cereal powder obtained by crushing rye and oats and enzyme powder obtained by fermentation and spray drying are mixed into the raw materials required for preparing dough, and a high-dietary fiber fermented product rich in prebiotics is prepared by fermentation. This method requires the fermentation liquid to be spray-dried, and the high temperature of spray drying also has the adverse effect of easily inactivating the fermented live bacteria.

[0007] Patent CN111955649A discloses a method and product for removing the beany smell of soybean meal and soybean dietary fiber based on the fermentation of Poria cocos. The invention mixes the crushed raw material obtained by crushing soybean meal or soybean dietary fiber with deionized water to prepare a raw material matrix. After the raw material matrix is ​​sterilized, the Poria cocos strain is inoculated and ventilated to obtain a fermentation product. The fermentation product is sterilized, dried and stored to obtain the soybean meal or soybean dietary fiber after the smell is removed. The drying temperature required for the final drying and storage of this method is also much higher than the growth temperature of the strain, which is not conducive to the survival of the strain.

[0008] Therefore, it is of great significance to design a dietary fiber prepared by fermentation while reducing the dual effects of gastric acid on the inactivation of active bacteria during consumption and high-temperature drying treatment on the inactivation of bacteria, and to improve the utilization efficiency of the dietary fiber obtained by fermentation. Summary of the invention

[0009] In view of the deficiencies of the prior art, the present invention uses jujube as raw material, separates a water-soluble dietary fiber mixture and a water-insoluble dietary fiber solid mixture through enzymatic treatment, and then treats the two separately and then mixes and cross-links them, finally obtaining a dietary fiber composition with acid corrosion resistance and high temperature resistance, solving the technical problems raised in the background technology. Specifically, the technical solution of the present invention includes the following steps:

[0010] A method for preparing a dietary fiber composition by fermenting jujube, the method comprising the following steps:

[0011] The jujubes are washed and dried to obtain surface moisture, and then crushed into fine powder by a grinder, the fine powder is mixed with water in a mass ratio of 1:20-40 to form a mixed solution, and the mixed solution is mixed with a biologically active enzyme in a mass ratio of 1:0.1%-0.3% to obtain an enzymolysis mixed solution by enzymolysis reaction;

[0012] The enzymatic hydrolysis mixed solution is centrifuged to obtain a water-soluble dietary fiber mixed solution and a water-insoluble dietary fiber solid mixture;

[0013] The water-soluble dietary fiber mixed liquid is inoculated with probiotic seed liquid for anaerobic fermentation to obtain probiotic dietary fiber fermentation liquid;

[0014] The water-insoluble dietary fiber solid mixture is mixed with acetone, stirred and dispersed, and then potassium permanganate is added to oxidize to obtain carboxylated dietary fiber;

[0015] The probiotic dietary fiber fermentation liquid and the carboxylated dietary fiber are mixed, and then a calcium chloride solution is added to carry out a cross-linking reaction. After the cross-linking reaction is completed, the mixture is evaporated with hot air to obtain the dietary fiber composition.

[0016] Furthermore, the biologically active enzyme includes pectinase or α-glucosidase.

[0017] Furthermore, the conditions of the enzymatic hydrolysis reaction include a reaction temperature of 40°C to 50°C, a reaction pH of 4.0 to 5.0, and a reaction time of 2h to 4h.

[0018] Furthermore, the centrifugal separation conditions include a centrifugal speed of 2000 r / min to 5000 r / min and a centrifugal time of 5 min to 10 min.

[0019] Furthermore, the probiotic seed liquid is Lactobacillus acidophilus seed liquid.

[0020] Furthermore, the Lactobacillus acidophilus seed liquid is obtained by culturing Lactobacillus acidophilus with strain preservation number CGMCC No. 1.12735 through MRS liquid culture medium, and the viable cell count of the Lactobacillus acidophilus seed liquid must be at least 1×10 6 CFU / mL.

[0021] Furthermore, the mass ratio of the water-soluble dietary fiber mixed solution: the probiotic seed solution is 1:0.02-0.04.

[0022] Furthermore, the anaerobic fermentation conditions include a fermentation temperature of 30°C to 38°C, a fermentation pH of 4.5 to 5.5 and a fermentation time of 20h to 36h.

[0023] Furthermore, the mass ratio of the water-insoluble dietary fiber solid mixture: acetone: potassium permanganate is 1:3-5:0.1-0.2.

[0024] Furthermore, the oxidation conditions include an oxidation temperature of 30° C. to 40° C. and an oxidation time of 60 min to 90 min.

[0025] Furthermore, the mass ratio of the probiotic dietary fiber fermentation liquid: carboxylated dietary fiber: calcium chloride solution is 1:1:0.01-0.05.

[0026] Furthermore, the concentration of the calcium chloride solution is 0.5% to 1%.

[0027] Furthermore, the conditions of the cross-linking reaction include a cross-linking temperature of 25° C. to 35° C. and a cross-linking time of 1 h to 2 h.

[0028] A dietary fiber composition is prepared by a method for preparing a dietary fiber composition fermented from jujubes.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The present invention uses jujube as a raw material. Jujube has a very high sugar content. During fermentation, there is no need to add additional nutrient matrix such as glucose to promote the fermentation process. The jujube is crushed to prepare a mixed liquid, and then the jujube is decomposed by a biologically active enzyme that decomposes α-glycosidic bonds to obtain water-soluble dietary fiber and water-insoluble dietary fiber. The aqueous solution containing the water-soluble dietary fiber is used as a fermentation base liquid by centrifugation, and the probiotic Lactobacillus acidophilus is inoculated for fermentation to obtain a probiotic dietary fiber fermentation liquid. Then, the water-insoluble dietary fiber is dissolved and dispersed in an acetone solution, and the hydroxyl groups on the water-insoluble dietary fiber are oxidized by oxidation with potassium permanganate under a certain range of conditions, thereby obtaining carboxylated dietary fiber with a carboxyl functional group. Then, the carboxylated dietary fiber is mixed with a probiotic dietary fiber fermentation liquid, and then a calcium chloride solution is added for cross-linking. The three-dimensional network structure of chemical cross-linking formed between the carboxylic acid groups of the carboxylated dietary fiber and calcium ions and the synergistic coordination of hydrogen bonds between molecules promote the embedding protection of the probiotic dietary fiber fermentation liquid, thereby obtaining a dietary fiber composition with acid corrosion resistance and high temperature resistance. It is unexpectedly found that the solid-state dried dietary fiber composition of the present invention still has a good number of viable bacteria after being stored at room temperature (20° C. to 25° C.) for 30 days.

[0031] (2) It can be seen from Comparative Example 1 and Example 6 that since the anaerobic fermentation of brewer's yeast produces a lot of alcohol, if it cannot be discharged in time, the accumulated alcohol has a toxic effect on the brewer's yeast, and the number of live bacteria after the fermentation is low.

[0032] (3) It can be seen from Comparative Example 2 and Example 6 that, due to the strong oxidizing property of potassium permanganate, long-term oxidation may cause more hydroxyl groups on the water-insoluble dietary fiber to be oxidized into carboxyl groups. The increase in the number of carboxyl groups makes the final cross-linking strength high, resulting in the dietary fiber composition being difficult to dissolve and release into the intestine, the number of viable bacteria is low, and the dietary fiber cannot be well utilized.

[0033] (4) It can be seen from Comparative Example 3 and Example 6 that, since cellulase decomposes β-glycosidic bonds, the β-glycosidic bonds on the water-insoluble dietary fiber are decomposed, which increases the solubility of the water-insoluble dietary fiber, making it impossible to obtain a water-insoluble dietary fiber solid mixture by centrifugal separation. The encapsulation and protection of the probiotic dietary fiber fermentation liquid cannot be formed by hydrogen bonding alone. Therefore, after hot air drying and then treatment in a strong acid environment, it is not resistant to acid corrosion and dissolves rapidly. The probiotics are easily corroded and inactivated by strong acid, resulting in a low number of viable probiotics. DETAILED DESCRIPTION

[0034] The technical solution of the present invention will be clearly and completely described below through the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0035] Unless otherwise specified, the raw materials and reagents used in the present invention are commercially available or can be prepared by known methods.

[0036] Lactobacillus acidophilus with strain collection number CGMCC No.1.12735 was purchased from China General Microbiological Culture Collection Center;

[0037] Saccharomyces cerevisiae with strain collection number CICC 1406 was purchased from the China Industrial Microbiological Culture Collection Center;

[0038] MRS liquid culture medium was purchased from Qingdao Haibo Biotechnology.

[0039] Preparation Example 1:

[0040] Preparation of Lactobacillus acidophilus seed solution:

[0041] The Lactobacillus acidophilus strain with the deposit number CGMCC No. 1.12735 was inoculated into the sterilized MRS liquid medium with a sterilized inoculation loop and cultured and activated in the culture phase at 30°C. After 24 hours of culture, the number of viable Lactobacillus acidophilus was detected every 2 hours until it reached 1×10 6 CFU / mL, it can be used as Lactobacillus acidophilus seed liquid.

[0042] Preparation Example 2:

[0043] Preparation of Saccharomyces cerevisiae seed solution:

[0044] The brewer's yeast with the deposit number CICC 1406 was inoculated into the sterilized MRS liquid medium with a sterilized inoculation loop and activated in the culture phase at 30°C. After 24 hours of culture, the number of live yeast cells was detected every 2 hours until it reached 1×10 6 CFU / mL, it can be used as brewer's yeast seed liquid.

[0045] Embodiment 1:

[0046] A method for preparing a dietary fiber composition by fermenting jujube, specifically comprising the following preparation process:

[0047] The commercially available jujube was repeatedly rinsed with clean water to remove surface impurities, and then placed in an electric hot air drying oven to dry the surface moisture of the jujube. The dried jujube was placed in an ultrafine grinder for pulverization, and then passed through a 400 mesh screen to obtain fine powder after pulverization. 100g of fine powder was mixed and stirred with 2000g of deionized water to dissolve to form a mixed solution, 2.1g of pectinase was added to the mixed solution and mixed and stirred, and then the pH was adjusted to 4.0 with hydrochloric acid, and then the temperature was raised to 40°C for timed enzymolysis reaction for 2h. After the enzymolysis was completed, it was placed in a centrifuge and centrifuged at a speed of 2000r / min for 5min to obtain a liquid-solid biphase of a water-soluble dietary fiber mixed solution and a water-insoluble dietary fiber solid mixture.

[0048] 2% of the mass of the water-soluble dietary fiber mixed liquid was inoculated with the Lactobacillus acidophilus seed liquid obtained in Preparation Example 1 into the water-soluble dietary fiber mixed liquid, and then the air in the fermentation environment was replaced with nitrogen until the oxygen content was reduced to 0.1%, and the pH of the fermentation system was controlled at 4.5 with acid, and then the temperature was raised to 30°C, and the fermentation was timed for 20 hours to obtain the probiotic dietary fiber fermentation liquid.

[0049] The water-insoluble dietary fiber solid mixture was dissolved in acetone 3 times its own weight and stirred to disperse evenly, and potassium permanganate 0.01 times the weight of the water-insoluble dietary fiber solid mixture was randomly added and mixed and stirred, and then oxidized for 60 minutes in a temperature environment of 30°C. After the oxidation treatment, sodium sulfite was added to quench the potassium permanganate, and the pH was adjusted to neutral, and then the reaction solution was poured into a dialysis bag for dialysis treatment to obtain carboxylated dietary fiber.

[0050] After the probiotic dietary fiber fermentation liquid and the carboxylated dietary fiber are mixed in equal weight, a calcium chloride solution (the mass concentration of the calcium chloride solution is 0.5%) with a weight of 0.01 times the probiotic dietary fiber fermentation liquid is added, the mixture is stirred for 10 minutes, and then cross-linked for 1 hour in an environment of 25° C. After the cross-linking is completed, the mixture is evaporated to dryness in a hot air environment of 70° C. to obtain a powdered dietary fiber composition.

[0051] Embodiment 2:

[0052] A method for preparing a dietary fiber composition by fermenting jujube, specifically comprising the following preparation process:

[0053] The commercially available jujube was repeatedly rinsed with clean water to remove surface impurities, and then placed in an electric hot air drying oven to dry the surface moisture of the jujube. The dried jujube was placed in an ultrafine grinder for pulverization, and then passed through a 400 mesh screen to obtain fine powder after pulverization. 100g of fine powder was mixed with 2500g of deionized water to form a mixed solution, 2.6g of pectinase was added to the mixed solution, and then the pH was adjusted to 4.0 with hydrochloric acid, and then the temperature was raised to 42°C for a timed enzymolysis reaction for 2h. After the enzymolysis was completed, it was placed in a centrifuge and centrifuged at a speed of 2500r / min for 6min to obtain a liquid-solid biphase of a water-soluble dietary fiber mixed solution and a water-insoluble dietary fiber solid mixture.

[0054] 2.5% of the mass of the water-soluble dietary fiber mixed liquid was inoculated with the Lactobacillus acidophilus seed liquid obtained in Preparation Example 1 into the water-soluble dietary fiber mixed liquid, and then the air in the fermentation environment was replaced with nitrogen until the oxygen content was reduced to 0.1%, and the pH of the fermentation system was controlled at 4.5 with acid, and then the temperature was raised to 32°C, and the fermentation was timed for 24 hours to obtain the probiotic dietary fiber fermentation liquid.

[0055] The water-insoluble dietary fiber solid mixture was dissolved in acetone 3 times its own weight and stirred to disperse evenly, and potassium permanganate 0.15 times the weight of the water-insoluble dietary fiber solid mixture was randomly added and mixed and stirred, and then oxidized for 65 minutes in a temperature environment of 32°C. After the oxidation treatment, sodium sulfite was added to quench the potassium permanganate, and the pH was adjusted to neutral, and then the reaction solution was poured into a dialysis bag for dialysis treatment to obtain carboxylated dietary fiber.

[0056] After the probiotic dietary fiber fermentation liquid and the carboxylated dietary fiber are mixed in equal weight, a calcium chloride solution (the mass concentration of the calcium chloride solution is 0.6%) with a weight of 0.02 times the probiotic dietary fiber fermentation liquid is added, the mixture is stirred for 10 minutes, and then cross-linked for 1 hour in an environment of 25° C. After the cross-linking is completed, the mixture is evaporated to dryness in a hot air environment of 70° C. to obtain a powdered dietary fiber composition.

[0057] Embodiment 3:

[0058] A method for preparing a dietary fiber composition by fermenting jujube, specifically comprising the following preparation process:

[0059] The commercially available jujube was repeatedly rinsed with clean water to remove surface impurities, and then placed in an electric hot air drying oven to dry the surface moisture of the jujube. The dried jujube was placed in an ultrafine grinder for pulverization, and then passed through a 400 mesh screen to obtain fine powder after pulverization. 100g of fine powder was mixed and stirred with 3000g of deionized water to dissolve to form a mixed solution, 6.2g of pectinase was added to the mixed solution and mixed and stirred, and then the pH was adjusted to 4.5 with hydrochloric acid, and then the temperature was raised to 44°C for timed enzymolysis reaction for 3h. After the enzymolysis was completed, it was placed in a centrifuge and centrifuged at a speed of 3000r / min for 7min to obtain a liquid-solid biphase of a water-soluble dietary fiber mixed solution and a water-insoluble dietary fiber solid mixture.

[0060] 3% of the mass of the water-soluble dietary fiber mixed liquid was inoculated with the Lactobacillus acidophilus seed liquid obtained in Preparation Example 1 into the water-soluble dietary fiber mixed liquid, and then the air in the fermentation environment was replaced with nitrogen until the oxygen content was reduced to 0.1%, and the pH of the fermentation system was controlled at 5.0 with acid, and then the temperature was raised to 34°C, and the fermentation was timed for 28 hours to obtain the probiotic dietary fiber fermentation liquid.

[0061] The water-insoluble dietary fiber solid mixture was dissolved in acetone 4 times its own weight and stirred to disperse evenly, and potassium permanganate 0.15 times the weight of the water-insoluble dietary fiber solid mixture was randomly added and mixed, and then oxidized for 70 minutes in a temperature environment of 34°C. After the oxidation treatment, sodium sulfite was added to quench the potassium permanganate, and the pH was adjusted to neutral, and then the reaction solution was poured into a dialysis bag for dialysis treatment to obtain carboxylated dietary fiber.

[0062] After the probiotic dietary fiber fermentation liquid and the carboxylated dietary fiber are mixed in equal weight, a calcium chloride solution (the mass concentration of the calcium chloride solution is 0.7%) with a weight of 0.03 times the probiotic dietary fiber fermentation liquid is added, the mixture is stirred for 10 minutes, and then cross-linked in an environment of 30° C. for 1 hour. After the cross-linking is completed, the mixture is evaporated to dryness in a hot air environment of 80° C. to obtain a powdered dietary fiber composition.

[0063] Embodiment 4:

[0064] A method for preparing a dietary fiber composition by fermenting jujube, specifically comprising the following preparation process:

[0065] The commercially available jujube was repeatedly rinsed with clean water to remove surface impurities, and then placed in an electric hot air drying oven to dry the surface moisture of the jujube. The dried jujube was placed in an ultrafine grinder for pulverization, and then passed through a 400 mesh screen to obtain fine powder after pulverization. 100g of fine powder was mixed with 3500g of deionized water and stirred to dissolve to form a mixed solution, 7.2g of pectinase was added to the mixed solution and mixed, and then the pH was adjusted to 4.5 with hydrochloric acid, and then the temperature was raised to 46°C for timed enzymolysis reaction for 3h. After the enzymolysis was completed, it was placed in a centrifuge and centrifuged at a speed of 3500r / min for 8min to obtain a liquid-solid biphase of a water-soluble dietary fiber mixed solution and a water-insoluble dietary fiber solid mixture.

[0066] 3.5% of the mass of the water-soluble dietary fiber mixed liquid by weight of the Lactobacillus acidophilus seed liquid obtained in Preparation Example 1 was inoculated into the water-soluble dietary fiber mixed liquid, and then the air in the fermentation environment was replaced with nitrogen until the oxygen content was reduced to 0.1%. The pH of the fermentation system was controlled at 5.0 with acid, and then the temperature was raised to 36°C. The fermentation was timed for 32 hours to obtain a probiotic dietary fiber fermentation liquid.

[0067] The water-insoluble dietary fiber solid mixture is dissolved in acetone of 4 times its own weight and stirred to disperse evenly, and potassium permanganate of 0.2 times the weight of the water-insoluble dietary fiber solid mixture is randomly added and mixed and stirred, and then oxidized for 80 minutes in a temperature environment of 36°C. After the oxidation treatment, sodium sulfite is added to quench the potassium permanganate, and the pH is adjusted to neutral, and then the reaction solution is poured into a dialysis bag for dialysis treatment to obtain carboxylated dietary fiber.

[0068] After the probiotic dietary fiber fermentation liquid and the carboxylated dietary fiber are mixed in equal weight, a calcium chloride solution (the mass concentration of the calcium chloride solution is 0.8%) with a mass of 0.04 times the mass of the probiotic dietary fiber fermentation liquid is added, mixed and stirred for 10 minutes, and then cross-linked for 2 hours in an environment of 30° C. After the cross-linking is completed, the powdered dietary fiber composition is evaporated in a hot air environment of 80° C. to obtain a powdered dietary fiber composition.

[0069] Embodiment 5:

[0070] A method for preparing a dietary fiber composition by fermenting jujube, specifically comprising the following preparation process:

[0071] The commercially available jujube was repeatedly rinsed with clean water to remove surface impurities, and then placed in an electric hot air drying oven to dry the surface moisture of the jujube. The dried jujube was placed in an ultrafine grinder for pulverization, and then passed through a 400 mesh screen to obtain fine powder after pulverization. 100g of fine powder was mixed and stirred with 4000g of deionized water to dissolve to form a mixed solution, 12.3g of pectinase was added to the mixed solution and mixed and stirred, and then the pH was adjusted to 5.0 with hydrochloric acid, and then the temperature was raised to 48°C for 4h of timed enzymolysis reaction. After the enzymolysis was completed, it was placed in a centrifuge and centrifuged at a speed of 4000r / min for 9min to obtain a liquid-solid biphase of a water-soluble dietary fiber mixed solution and a water-insoluble dietary fiber solid mixture.

[0072] 4% of the mass of the water-soluble dietary fiber mixed liquid was inoculated with the Lactobacillus acidophilus seed liquid obtained in Preparation Example 1 into the water-soluble dietary fiber mixed liquid, and then the air in the fermentation environment was replaced with nitrogen until the oxygen content was reduced to 0.1%, and the pH of the fermentation system was controlled at 5.5 with acid, and then the temperature was raised to 38°C, and the fermentation was timed for 36 hours to obtain the probiotic dietary fiber fermentation liquid.

[0073] The water-insoluble dietary fiber solid mixture is dissolved in acetone of 5 times its own weight and stirred to disperse evenly, and potassium permanganate of 0.2 times the weight of the water-insoluble dietary fiber solid mixture is randomly added and mixed and stirred, and then oxidized for 90 minutes in a temperature environment of 38°C. After the oxidation treatment, sodium sulfite is added to quench the potassium permanganate, and the pH is adjusted to neutral, and then the reaction solution is poured into a dialysis bag for dialysis treatment to obtain carboxylated dietary fiber.

[0074] After the probiotic dietary fiber fermentation liquid and the carboxylated dietary fiber are mixed in equal weight, a calcium chloride solution (the mass concentration of the calcium chloride solution is 0.9%) with a weight of 0.05 times the probiotic dietary fiber fermentation liquid is added, the mixture is stirred for 10 minutes, and then cross-linked for 2 hours in an environment of 35° C. After the cross-linking is completed, the mixture is evaporated to dryness in a hot air environment of 90° C. to obtain a powdered dietary fiber composition.

[0075] Embodiment 6:

[0076] A method for preparing a dietary fiber composition by fermenting jujube, specifically comprising the following preparation process:

[0077] The commercially available jujube was repeatedly rinsed with clean water to remove surface impurities, and then placed in an electric hot air drying oven to dry the surface moisture of the jujube. The dried jujube was placed in an ultrafine grinder for pulverization, and then passed through a 400 mesh screen to obtain fine powder after pulverization. 100g of fine powder was mixed and stirred with 4000g of deionized water to dissolve to form a mixed solution, 12.3g of pectinase was added to the mixed solution for mixing and stirring, and then the pH was adjusted to 5.0 with hydrochloric acid, and then the temperature was raised to 50°C for 4h of timed enzymolysis reaction. After the enzymolysis was completed, it was placed in a centrifuge and centrifuged at a speed of 5000r / min for 10min to obtain a liquid-solid biphase of a water-soluble dietary fiber mixed solution and a water-insoluble dietary fiber solid mixture.

[0078] 4% of the mass of the water-soluble dietary fiber mixed liquid was inoculated with the Lactobacillus acidophilus seed liquid obtained in Preparation Example 1 into the water-soluble dietary fiber mixed liquid, and then the air in the fermentation environment was replaced with nitrogen until the oxygen content was reduced to 0.1%, and the pH of the fermentation system was controlled at 5.5 with acid, and then the temperature was raised to 38°C, and the fermentation was timed for 36 hours to obtain the probiotic dietary fiber fermentation liquid.

[0079] The water-insoluble dietary fiber solid mixture is dissolved in acetone of 5 times its own weight and stirred to disperse evenly, and potassium permanganate of 0.2 times the weight of the water-insoluble dietary fiber solid mixture is randomly added and mixed and stirred, and then oxidized for 90 minutes in a temperature environment of 40° C. After the oxidation treatment, sodium sulfite is added to quench the potassium permanganate, and the pH is adjusted to neutral, and then the reaction solution is poured into a dialysis bag for dialysis treatment to obtain carboxylated dietary fiber.

[0080] After the probiotic dietary fiber fermentation liquid and the carboxylated dietary fiber are mixed in equal weight, a calcium chloride solution (the mass concentration of the calcium chloride solution is 1%) with a weight of 0.05 times the probiotic dietary fiber fermentation liquid is added, the mixture is stirred for 10 minutes, and then cross-linked for 2 hours in an environment of 35° C. After the cross-linking is completed, the mixture is evaporated to dryness in a hot air environment of 90° C. to obtain a powdered dietary fiber composition.

[0081] Comparative Example 1:

[0082] A method for preparing a dietary fiber composition by fermenting jujube, specifically comprising the following preparation process:

[0083] The Lactobacillus acidophilus seed solution in Example 6 was replaced with the Saccharomyces cerevisiae seed solution in Preparation Example 2, and the other conditions remained the same as in Example 6.

[0084] Comparative Example 2:

[0085] A method for preparing a dietary fiber composition by fermenting jujube, specifically comprising the following preparation process:

[0086] The potassium permanganate oxidation time in Example 6 was further extended to 100 min, and the other conditions remained the same as in Example 6.

[0087] Comparative Example 3:

[0088] A method for preparing a dietary fiber composition by fermenting jujube, specifically comprising the following preparation process:

[0089] The pectinase in Example 6 was replaced by cellulase, and the other conditions remained the same as in Example 6.

[0090] Since cellulase decomposes β-glycosidic bonds, the β-glycosidic bonds on the water-insoluble dietary fiber are decomposed, which increases the solubility of the water-insoluble dietary fiber. As a result, the mixture obtained by the final enzymatic hydrolysis cannot be separated by centrifugation to obtain a water-insoluble dietary fiber solid mixture. The encapsulation and protection effect of the probiotic dietary fiber fermentation liquid cannot be formed by hydrogen bonding alone. Therefore, after hot air drying and then treatment in a strong acid environment, the number of live bacteria is low.

[0091] The viable counts of the probiotic dietary fiber fermentation broths obtained in Examples 1 to 6 and Comparative Examples 1 to 3 were measured, and the results are shown in the following table:

[0092] Sources Viable bacteria count (CFU / mL) Example 1 <![CDATA[3.7×10 8 ]]> Example 2 <![CDATA[5.0×10 8 ]]> Example 3 <![CDATA[5.4×10 8 ]]> Example 4 <![CDATA[5.7×10 8 ]]> Example 5 <![CDATA[6.1×10 8 ]]> Example 6 <![CDATA[6.2×10 8 ]]> Comparative Example 1 <![CDATA[9.1×10 5 ]]> Comparative Example 2 <![CDATA[6.1×10 8 ]]> Comparative Example 3 <![CDATA[6.3×10 8 ]]>

[0093] 1 g of the dietary fiber composition obtained in Examples 1 to 6 and Comparative Examples 1 to 3 was added to 100 mL of an acidic solution having a pH value of 1.5, and the mixture was shaken at 37° C. to observe the dissolution and detect the number of viable bacteria in the dissolved solution. The results are shown in the following table:

[0094]

[0095]

[0096] The dietary fiber compositions obtained in Examples 1 to 6 were stored in an environment of 20 to 25° C., and the number of viable bacteria was tested at 10 days, 20 days, 30 days and 40 days, respectively. The results are shown in the following table:

[0097]

[0098] The above-described embodiments provide a detailed description of the technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected.

Claims

1. A method for preparing a dietary fiber composition by fermenting jujube, characterized in that: The preparation method comprises the following steps: After washing the jujube, the surface moisture is dried, and the jujube is crushed into fine powder by a grinder, the fine powder is mixed with water at a mass ratio of 1:20-40 to form a mixed solution, and the mixed solution is mixed with a biologically active enzyme at a mass ratio of 1:0.1%-0.3% to obtain an enzymolysis mixed solution after enzymolysis reaction; The enzymatic hydrolysis mixed solution is centrifuged to obtain a water-soluble dietary fiber mixed solution and a water-insoluble dietary fiber solid mixture; The water-soluble dietary fiber mixed liquid is inoculated with probiotic seed liquid for anaerobic fermentation to obtain probiotic dietary fiber fermentation liquid; The water-insoluble dietary fiber solid mixture is mixed with acetone, stirred and dispersed, and then potassium permanganate is added for oxidation treatment. After the oxidation treatment is completed, sodium sulfite is added to quench the potassium permanganate, and the pH is adjusted to neutral to obtain a reaction solution, and then the reaction solution is poured into a dialysis bag for dialysis treatment to obtain carboxylated dietary fiber; The probiotic dietary fiber fermentation liquid and the carboxylated dietary fiber are mixed, and then a calcium chloride solution is added to perform a cross-linking reaction. After the cross-linking reaction is completed, the mixture is evaporated with hot air to obtain the dietary fiber composition; The biologically active enzyme is pectinase; The conditions of the enzymatic hydrolysis reaction include a reaction temperature of 40°C to 50°C, a reaction pH of 4.0 to 5.0, and a reaction time of 2h to 4h; The probiotic seed liquid is Lactobacillus acidophilus seed liquid; The mass ratio of the water-soluble dietary fiber mixed solution to the probiotic seed solution is 1:0.02-0.04; The anaerobic fermentation conditions include a fermentation temperature of 30°C to 38°C, a fermentation pH of 4.5 to 5.5, and a fermentation time of 20h to 36h; The mass ratio of the water-insoluble dietary fiber solid mixture: acetone: potassium permanganate is 1:3-5:0.1-0.2; The oxidation conditions include an oxidation temperature of 30°C to 40°C and an oxidation time of 60min to 90min; The mass ratio of the probiotic dietary fiber fermentation liquid: carboxylated dietary fiber: calcium chloride solution is 1:1:0.01-0.

05.

2. A dietary fiber composition prepared by the method for preparing a dietary fiber composition fermented by jujube according to claim 1.

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