CN116349892A

CN116349892A - Bran dietary fiber product with blood lipid reducing effect, preparation and application thereof

Info

Publication number: CN116349892A
Application number: CN202111625416.9A
Authority: CN
Inventors: 张戈; 李会; 祁瑜婷; 高霓思
Original assignee: Wilmar Shanghai Biotechnology Research and Development Center Co Ltd
Current assignee: Wilmar Shanghai Biotechnology Research and Development Center Co Ltd
Priority date: 2021-12-28
Filing date: 2021-12-28
Publication date: 2023-06-30

Abstract

The invention provides bran dietary fiber with blood lipid reducing effect, and preparation and application thereof. The bran dietary fiber product of the present invention is characterized by comprising: the ratio of arabinose to xylose in dietary fiber is 0.75-1.0. The bran dietary fiber provided by the invention has the functions of improving the adsorption capacity of cholate and reducing blood fat.

Description

Bran dietary fiber product with blood lipid reducing effect, preparation and application thereof

Technical Field

The invention relates to a bran dietary fiber product with a blood lipid reducing effect, and a preparation method and application thereof.

Background

Dietary fiber is a seventh nutrient substance for human health, the recommended daily amount of the dietary fiber for adults in each country is 25-35g, but the processing degree of food is finer and finer due to the development of the food industry at present, and the dietary fiber-rich parts such as bran and the like are removed in the processing process due to poor taste, so that the intake of the dietary fiber for people in each country is lower than the recommended value at present. The recommended dietary fiber amount of residents in China is 25 g/day, but the daily intake of dietary fiber amount of the current Chinese population is only 10-13g, and great difference exists between the recommended dietary fiber amount and the recommended dietary fiber amount. In recent years, as people understand dietary fibers more and more deeply, people are aware of the importance of supplementing dietary fibers. Dietary fibers are reported in the literature to be largely classified into non-starch polysaccharides, resistant dextrins, oligosaccharides, and others. The water-soluble dietary fiber may be classified into water-soluble dietary fiber and water-insoluble dietary fiber according to their water-solubility. The main physiological activity functions reported by the dietary fiber at present are as follows: regulating intestinal flora, loosening bowel to relieve constipation, reducing blood sugar and blood lipid, regulating immunity, resisting bacteria and inflammation, resisting tumor, etc.

Rice bran is a byproduct of rice processing, contains rich dietary fibers, and has certain effects of relaxing bowel, reducing blood sugar and blood fat. The function of reducing blood fat in the dietary fiber is mainly realized by adsorbing cholic acid, but most of dietary fiber in rice bran is water-insoluble, the adsorption capacity of the dietary fiber to cholic acid is not very strong, and the dietary fiber has a rough taste, and the taste is poor after the dietary fiber is made into a terminal product, so that the further use of the dietary fiber of the bran is limited. In order to improve some of the properties of dietary fibers, some physical, chemical, biological methods are applied to the modification of dietary fibers. However, reports on improving rice bran cholic acid adsorption and reducing blood fat and improving rice bran fiber sensory properties are not very common.

Disclosure of Invention

The invention aims to improve the adsorption effect of bran fiber on cholic acid, thereby improving the blood lipid reducing function. In some preferred embodiments, the present invention still further improves mouthfeel, and application in products does not affect the organoleptic properties of the product.

The first aspect of the present invention provides a bran dietary fibre product, characterised in that it comprises: the ratio of arabinose to xylose in dietary fiber is 0.75-1.0.

In one or more embodiments, the ratio of arabinose to xylose in the dietary fiber of the bran dietary fiber product is from 0.8 to 1.0.

In one or more embodiments, the ratio of arabinose to xylose in the dietary fiber of the bran dietary fiber product is from 0.85 to 1.0.

In one or more embodiments, the bran dietary fiber product is further characterized by a soluble pentosan content of greater than or equal to 2%.

In one or more embodiments, the soluble pentosan content of the bran dietary fiber product is greater than or equal to 2.5%.

In one or more embodiments, the soluble pentosan content of the bran dietary fiber product is greater than or equal to 3%.

In one or more embodiments, the bran dietary fiber product has a soluble pentosan content of 2-5%.

In one or more embodiments, the bran dietary fiber product has a soluble pentosan content of 2.5-5%.

In one or more embodiments, the bran dietary fiber product has a soluble pentosan content of 3-5%.

In one or more embodiments, the bran dietary fiber product has a soluble pentosan content of 3-4%. In one or more embodiments, the adsorption capacity of cholate of the bran dietary fiber product is greater than or equal to 65mg/g.

In one or more embodiments, the adsorption capacity of cholate of the bran dietary fiber product is greater than or equal to 70mg/g.

In one or more embodiments, the adsorption capacity of cholate of the bran dietary fiber product is greater than or equal to 80mg/g.

In one or more embodiments, the adsorption capacity of cholate of the bran dietary fiber product is greater than or equal to 90mg/g.

In one or more embodiments, the adsorption capacity of cholate of the bran dietary fiber product is 65-100mg/g.

In one or more embodiments, the adsorption capacity of cholate of the bran dietary fiber product is 80-100mg/g.

In one or more embodiments, the particle size of the bran dietary fiber product is above 200 mesh with D90.ltoreq.90 μm.

In one or more embodiments, the bran dietary fiber product is prepared from rice bran meal, wheat bran, or barley bran.

In one or more embodiments, the bran dietary fiber product is a rice bran dietary fiber product.

In one or more embodiments, the bran dietary fiber product is prepared by extruding or steam explosion of the de-oiled bran.

In one or more embodiments, the extrusion temperature is 70-150 ℃, preferably 100-150 ℃, more preferably 130-150 ℃.

In one or more embodiments, it is preferred that the screw speed be in the range of 200 to 400rpm.

In one or more embodiments, the pressure of the steam explosion is from 0.5 to 1.8MPa, preferably from 0.6 to 1.5MPa, more preferably from 0.9 to 1.5MPa.

In one or more embodiments, the time of steam explosion is 80 to 200 seconds, preferably 90 to 150 seconds.

In one or more embodiments, the resulting product is subjected to enzymatic hydrolysis after extrusion or steam explosion.

In one or more embodiments, the enzymatic hydrolysis system comprises an extruded or steam exploded product, water, and a hemicellulase or xylanase. Preferably, the weight ratio of the product obtained to water is 1:3 to 1:8, preferably 1:4 to 1:8.

in one or more embodiments, the enzyme is added to the enzymatic system in an amount of 0.1 to 1g enzyme per 100g product.

In one or more embodiments, the hemicellulase is a hemicellulase HC-90.

In one or more embodiments, the xylanase is xylanase NS-28345.

In one or more embodiments, the enzymatic hydrolysis is ended until the soluble pentosan content of the resulting product is greater than or equal to 2% and the ratio of arabinose to xylose in the dietary fiber is between 0.75 and 1.0.

In one or more embodiments, the enzymatic hydrolysis temperature is 40-60 ℃.

In one or more embodiments, the enzymatic hydrolysis time is 3 to 8 hours.

In a second aspect, the present invention provides a process for the preparation of a bran dietary fiber product, the process comprising: and extruding or steam explosion is carried out on the degreased bran.

In one or more embodiments, the bran is rice bran, wheat bran or barley bran, oat bran, corn bran.

In one or more embodiments, the method further comprises the step of subjecting the extruded or steam exploded product to enzymatic hydrolysis.

In one or more embodiments, the enzymatic hydrolysis system comprises an extruded or steam exploded product, water, and a hemicellulase or xylanase. Preferably, the weight ratio of the product obtained to water is 1:3 to 1:8, preferably 1:4-1:8.

In one or more embodiments, the hemicellulase is a hemicellulase HC-90.

In one or more embodiments, the xylanase is xylanase NS-28345.

In one or more embodiments, the enzymatic hydrolysis temperature is 40-60 ℃.

In one or more embodiments, the enzymatic hydrolysis time is 3 to 8 hours.

In a third aspect, the present invention provides a bran dietary fibre product obtainable by any of the methods of the second aspect of the present invention.

In a fourth aspect, the present invention provides a food product comprising a bran fiber product according to any one of the embodiments of the first or third aspects of the present invention.

In one or more embodiments, the food product is bread, steamed bread, rice, noodles, pastries, biscuits, puffed food, health care beverages or instant products.

In one or more embodiments, the food product is a beverage, more particularly a high fiber beverage, i.e. a beverage having a fiber content of more than 6g/100 g.

In one or more embodiments, the instant product is a solid beverage powder, more particularly a high fiber solid beverage powder.

In a fifth aspect the present invention provides the use of a hemicellulase or xylanase for increasing the cholate adsorption capacity of a bran dietary fiber product, or for preparing a bran dietary fiber product having an increased cholate adsorption capacity.

In one or more embodiments, the enhancing or preparing is carried out using any of the methods described in the second part of the invention.

In one or more embodiments, the hemicellulase is a hemicellulase HC-90 and the xylanase is xylanase NS-28345.

Detailed Description

It is understood that within the scope of the present invention, the above-described technical features of the present invention and technical features specifically described below (e.g., in the examples) may be combined with each other to constitute a preferred technical solution.

The invention discovers that the adsorption capacity of bile acid salt of the dietary fiber of the bran can be obviously improved by controlling the ratio of arabinose to xylose in the dietary fiber of the bran within a certain range, so that the blood lipid reducing capacity of the dietary fiber of the bran is improved. Further controlling the content of soluble pentosan in the bran dietary fiber can further improve the adsorption capacity and the blood lipid reducing capacity of the bran dietary fiber cholate. Further, in order to improve the mouthfeel, the particle size of the bran dietary fiber may be controlled within a range such that the sensory properties of the end product are not affected when the bran dietary fiber is used in the product.

The term "bran" as used herein includes wheat bran and chips left after wheat grains have been ground to flour after fruit is removed, and also includes bran, i.e., husks or husks from the fruit body of rice, wheat, millet, etc. Thus, in some embodiments, the bran dietary fibers of the present invention include rice bran dietary fibers, wheat bran dietary fibers, and barley bran dietary fibers.

The bran dietary fiber product of the present invention is characterized by comprising: the ratio of arabinose to xylose in dietary fiber is 0.75-1.0. Further, the content of soluble pentosan in the dietary fiber is more than or equal to 2 percent.

It is to be understood that the "bran dietary fiber product" as described herein is a mixture of bran dietary fibers, consisting of bran dietary fibers.

Preferably, the ratio of arabinose to xylose is 0.8-1.0. In some embodiments, the ratio of arabinose to xylose is from 0.85 to 1.0.

Preferably, the soluble pentosan content is not less than 2.5%, more preferably not less than 3%. In some embodiments, the soluble pentosan content in the bran dietary fiber product is 2-5%. In some embodiments, the soluble pentosan content in the bran dietary fiber product is 2.5-5%. In some embodiments, the soluble pentosan content in the bran dietary fiber product is 3-5%. In some embodiments, the soluble pentosan content in the bran dietary fiber product is 3-4%.

Preferably, the adsorption capacity of cholate of the bran dietary fiber product is more than or equal to 65mg/g. In some embodiments, the adsorption capacity of cholate of the bran dietary fiber product is greater than or equal to 70mg/g. In some embodiments, the adsorption capacity of cholate of the bran dietary fiber product is greater than or equal to 80mg/g. In some embodiments, the adsorption capacity of cholate of the bran dietary fiber product is greater than or equal to 90mg/g. In some embodiments, the adsorption capacity of cholate of the bran dietary fiber product is 65-100mg/g. In some embodiments, the adsorption capacity of cholate of the bran dietary fiber product is 80-100mg/g.

Preferably, the cholate described herein is sodium cholate.

Preferably, the grain diameter of the bran dietary fiber product is more than 200 meshes, and D90 is less than or equal to 90 mu m.

In a particularly preferred embodiment of the present invention, the bran dietary fiber product of the present invention is characterized in that it comprises: (1) the content of soluble pentosan is more than or equal to 2%; (2) The ratio of arabinose to xylose in dietary fiber is 0.75-1.0. Further preferably, the bran dietary fiber product of the present invention is characterized by comprising: (1) the content of soluble pentosan is more than or equal to 3%; (2) The ratio of arabinose to xylose in dietary fiber is 0.85-1.0. Further preferably, the particle size of the bran dietary fiber product is above 200 mesh and D90.ltoreq.90 μm. Further preferably, the adsorption capacity of the bran dietary fiber product to sodium cholate reaches more than 80mg/g.

The invention finds that the ratio of arabinose to xylose in the bran can be increased to more than 0.75, preferably more than 0.80, more preferably more than 0.85 by adopting a steam explosion or extrusion method.

Thus, the preparation method of the bran dietary fiber product of the present invention comprises the step of extruding or steam explosion of the degreased bran.

In the process described herein, the extrusion temperature is 70-150 ℃, preferably 100-150 ℃, more preferably 130-150 ℃. Preferably, the screw speed is 200-400rpm. The extrusion process of the present invention may be carried out using extruders well known in the art.

In the methods described herein, the pressure of the steam explosion may be from 0.5 to 1.8MPa, preferably from 0.6 to 1.5MPa, more preferably from 0.9 to 1.5MPa. The time of the steam explosion may be 80 to 200 seconds, preferably 90 to 150 seconds.

Further preferably, the present invention has found that enzymatic hydrolysis of the extruded or steam exploded product further increases the ratio of arabinose to xylose and further increases the soluble pentosan content to above 2%, preferably above 2.5%, more preferably above 3%. Herein, the bran is further decomposed by extrusion and steam explosion, which is beneficial to subsequent enzymolysis.

The enzymatic system herein comprises the product of extrusion or steam explosion, water, and hemicellulase or xylanase. The specific conditions for the enzymatic hydrolysis are not particularly limited as long as the content of soluble pentosan and the ratio of arabinose to xylose in the product obtained by the enzymatic hydrolysis are within the ranges defined herein. Thus, during the enzymatic hydrolysis process, samples can be taken at any time to perform the test, and once the soluble pentosan content of the enzymatic hydrolysate and the ratio of arabinose to xylose are within the ranges defined herein, the enzymatic hydrolysis can be stopped.

In an exemplary embodiment, the weight ratio of the extruded or steam exploded product (on a dry weight basis) to water in the enzymatic hydrolysis system is 1:3 to 1:8, preferably 1:4 to 1:8, 8; the addition amount of the enzyme is 0.1-1g enzyme per 100g product; the enzymolysis temperature is 40-60 ℃; the enzymolysis time is 3-8 hours. It is to be understood that the amounts of water and enzyme, the enzymolysis time, the temperature, etc. may be appropriately adjusted depending on the activity of the enzyme used, etc., as long as the soluble pentosan content of the resulting zymolyte and the ratio of arabinose to xylose are within the ranges defined herein.

Exemplary enzymes include hemicellulases and xylanases. An exemplary hemicellulase is hemicellulase HC-90 (available from the enzyme preparation of the world wide company, inc.); an exemplary xylanase is xylanase NS-28345 (available from NoveXin Biotechnology Co., ltd.).

Herein, after extrusion or steam explosion or enzymolysis, the resultant product may be dried.

Preferably, the drying may be vacuum drying. For example, the product or enzymatic hydrolysate obtained by extrusion or steam explosion may be dried in vacuo at 50-70℃to remove water.

In a preferred embodiment, the method of preparing the bran dietary fiber product of the present invention may comprise: extruding or steam explosion is carried out on the degreased bran (preferably rice bran), enzymolysis is carried out on the product obtained by extrusion or steam explosion, and the enzymolysis product is dried, so that the bran dietary fiber product is obtained.

Rice bran is a byproduct obtained during the processing of rice and can be used to prepare rice bran oil. The bran dietary fiber product of the invention is derived from degreased rice bran, namely rice bran meal. The rice bran meal may be a byproduct of the process of producing rice bran oil by the process of puffing leaching, and is typically in the form of a pale yellowish to yellowish brown powder. The bran meal obtained by various methods may be used to prepare the bran dietary fiber product of the present invention. In some embodiments, the rice bran is solvent defatted. For example, the defatted rice bran used in the present invention can be obtained by degreasing using n-hexane, filtering to obtain a residue, and drying the residue. Other defatting of bran can be performed in a similar manner.

In the invention, the wheat bran dietary fiber can be crushed after drying, so that the grain diameter of the obtained wheat bran dietary fiber product is more than 200 meshes, and D90 is less than or equal to 90 mu m. The bran dietary fiber prepared by the method can be used as dietary fiber supplement, added into foods such as bread, steamed bread, rice, noodles, cake, biscuits, puffed foods, health care beverages and instant products, and also used as dietary fiber functional nutritional preparation such as lozenge, capsule, effervescent tablet and the like.

Accordingly, in some embodiments, the present invention provides a food product comprising the bran dietary fibers described herein. In some embodiments, the food product is bread, steamed bread, rice, noodles, pastries, biscuits, puffed food, health care beverages, and instant products. In some embodiments, the food product is a beverage, more particularly a high fiber beverage, i.e., a beverage having a fiber content of 6g/100g or more. In some embodiments, the instant product is a solid beverage powder, more particularly a high fiber solid beverage powder, that is readily dispersible upon reconstitution, has a smooth mouthfeel, is free of gritty feel, and does not affect the overall flavor of the solid beverage product.

Compared with untreated rice bran, the rice bran fiber product obtained by the invention has the following advantages:

1. the content of soluble pentosan in the rice bran fiber is more than or equal to 2 percent, which is far higher than that of an untreated rice bran sample (0.1 percent), and is improved by more than 30 times;

2. the mole ratio of arabinose to xylose in the dietary fiber is 0.8-1.0;

3. the adsorption capacity to cholate is obviously improved to be more than or equal to 65mg/g, and in some embodiments, 80mg/g or more, which is improved by more than 2 times compared with untreated rice bran samples;

4. the granularity is more than 200 meshes, D90 is less than or equal to 90 mu m, and the final taste of the product is not affected when the product is added into the product;

5. the method does not comprise the step of alcohol precipitation treatment of the enzymolysis liquid after enzymolysis is finished.

The invention will be illustrated by way of specific examples. It should be understood that these examples are illustrative only and are not intended to limit the scope of the invention. In the invention, the prepared bran dietary fiber sample can be detected as follows:

1. soluble pentosan detection:

2.0g (accurate to 0.01 g) of the sample was weighed into a triangular flask, 100mL of water was added, and the mixture was extracted by shaking at 30℃for 120min. After shaking up, the mixture was transferred to a centrifuge tube and centrifuged at 4000 Xg for 15min. 10mL of the supernatant was measured, 10mL of 4mol/L hydrochloric acid solution was added, and the mixture was placed in a 25mL stoppered test tube, and the mixture was hydrolyzed in a boiling water bath for 120min after stoppered. After cooling, the filtrate was filtered with filter paper, collected and diluted 6-fold. 3mL of the sample solution was removed and placed in a 10mL tube with a stopper, and 0.3mL of a 1% solution of lichen phenol-absolute ethanol and 3mL of a 0.1% solution of ferric chloride-hydrochloric acid were added in sequence, with a stopper, and mixed well on a vortex mixer. Heating in boiling water bath for 30min, washing with running water, cooling to room temperature, transferring to 10mL volumetric flask, and fixing volume with distilled water. The absorbance at 670nm and 580nm wavelength was measured using a 1cm cuvette and D-xylose as a standard substance, and the soluble pentosan content was calculated.

2. Determination of the ratio of arabinose to xylose:

weighing a certain amount of bran dietary fiber sample, adding 6 times of water, heating to 95 ℃ for gelatinization for 30min, adding 1% high-temperature amylase Termamyl SC for reaction for 1h, cooling to 55 ℃, adjusting pH to 8.5, adding 1% alkaline protease Alcalase for reaction for 4h, centrifuging to remove supernatant, and precipitating and drying. Taking 10mg of dried precipitate, placing into a glass test tube with a plug, adding 20ml of 2M TFA solution, filling nitrogen, sealing, hydrolyzing for 2 hours at 120 ℃, concentrating the hydrolysate under reduced pressure to dryness, adding a small amount of methanol, concentrating under reduced pressure to dryness, repeating for a plurality of times to remove TFA, adding water to dissolve and fix the volume to 10ml, measuring the content of arabinose and xylose in a sample by adopting an ion chromatography, and calculating the molar ratio.

3. Sodium cholate adsorption Capacity determination:

0.1g of the sample is weighed into a 15mL centrifuge tube, 10mL of 2mg/mL sodium cholate 0.15mol/L sodium chloride solution is added, and the adsorption of sodium cholate is balanced by shaking at a constant temperature of 37 ℃ and 120rpm for 2 hours in a constant temperature oscillator. Centrifuge at 3000rpm for 20min. 1mL of the supernatant was taken, 1mL of a 0.3% furfural solution and 6mL of a 45% sulfuric acid solution were added, the mixture was shaken in a constant temperature shaker at 65℃for 30min, the absorbance was measured at 620nm after cooling in ice water, and 1mL of deionized water was used as a blank instead of sodium chloride solution of sodium cholate. And calculating the adsorption capacity of the sample to sodium cholate according to a standard curve of sodium cholate content and absorbance.

4. Particle size distribution measurement:

the sample was tested using a particle size analyzer.

The starting materials and reagents used in the examples and comparative examples were all conventional in the art and were commercially available.

The invention will be further illustrated with reference to specific examples. It is to be understood that these examples are illustrative of the present invention and are not intended to limit the scope of the present invention. The experimental methods, in which specific conditions are not noted in the following examples, are generally conducted under conventional conditions or under conditions recommended by the manufacturer. Percentages and parts are by weight unless otherwise indicated.

Example 1

500g of rice bran meal from which oil is removed is taken and subjected to steam explosion under the condition of 1.5MPa for 90s. 100g of a sample after steam explosion is taken, 600g of distilled water is added for suspension, then 0.1g of hemicellulase HC-90 is added, and the mixture is stirred and hydrolyzed for 4 hours at 50 ℃. And after the enzymolysis is finished, vacuum drying the enzymolysis cereal fiber suspension at 60 ℃ to remove water, and then superfine grinding to more than 200 meshes to obtain a modified rice bran dietary fiber sample.

Example 2

500g of rice bran meal from which oil is removed is taken and subjected to steam explosion, wherein the condition of the steam explosion is 1.2MPa, and the time is 120s. 100g of the sample after steam explosion is taken, 600g of distilled water is added for suspension, then 0.1g of xylanase NS-28345 is added, and the mixture is stirred and hydrolyzed for 5 hours at 40 ℃. And after the enzymolysis is finished, vacuum drying the enzymolysis cereal fiber suspension at 60 ℃ to remove water, and then superfine grinding to more than 200 meshes to obtain a modified rice bran dietary fiber sample.

Example 3

500g of rice bran meal from which oil is removed is taken and subjected to steam explosion, wherein the condition of the steam explosion is 0.9MPa, and the time is 150s. 100g of a sample after steam explosion is taken, 600g of distilled water is added for suspension, then 1g of hemicellulase HC-90 is added, and the mixture is stirred and hydrolyzed for 6 hours at 60 ℃. And after the enzymolysis is finished, vacuum drying the enzymolysis cereal fiber suspension at 60 ℃ to remove water, and then superfine grinding to more than 200 meshes to obtain a modified rice bran dietary fiber sample.

Example 4

2kg of degreased rice bran meal is taken for extrusion treatment, wherein the extrusion discharge temperature is 145 ℃, and the screw speed is 300rpm. 100g of the extruded sample was taken, 600g of distilled water was added to the mixture to suspend the sample, and then 0.5g of xylanase NS-28345 was added to hydrolyze the sample under stirring at 50℃for 4 hours. And after the enzymolysis is finished, vacuum drying the enzymolysis cereal fiber suspension at 60 ℃ to remove water, and then superfine grinding to more than 200 meshes to obtain a modified rice bran dietary fiber sample.

Example 5

2kg of degreased rice bran meal is taken for extrusion treatment, wherein the extrusion discharge temperature is 130 ℃, and the screw speed is 300rpm. 100g of the extruded sample was taken, 600g of distilled water was added to the mixture to suspend the sample, and then 0.5g of hemicellulase HC-90 was added thereto, followed by hydrolysis at 40℃with stirring for 5 hours. And after the enzymolysis is finished, vacuum drying the enzymolysis cereal fiber suspension at 60 ℃ to remove water, and then superfine grinding to more than 200 meshes to obtain a modified rice bran dietary fiber sample.

Example 6

2kg of degreased rice bran meal is taken for extrusion treatment, wherein the extrusion discharge temperature is 140 ℃, and the screw speed is 300rpm. 100g of the extruded sample was taken, 600g of distilled water was added to the mixture to suspend the sample, 1g of xylanase NS-28345 was then added, and the mixture was stirred at 60℃to hydrolyze the sample for 6 hours. And after the enzymolysis is finished, vacuum drying the enzymolysis cereal fiber suspension at 60 ℃ to remove water, and then superfine grinding to more than 200 meshes to obtain a modified rice bran dietary fiber sample.

Example 7

500g of rice bran meal from which oil is removed is taken and subjected to steam explosion under the condition of 0.6MPa for 90s. 100g of a sample after steam explosion is taken, 600g of distilled water is added for suspension, then 1g of hemicellulase HC-90 is added, and the mixture is stirred and hydrolyzed for 6 hours at 50 ℃. And after the enzymolysis is finished, drying the enzymolysis cereal fiber suspension in vacuum at 60 ℃ to remove water, and then crushing the cereal fiber suspension to 200 meshes to obtain a modified rice bran dietary fiber sample.

Example 8

2kg of degreased rice bran meal is taken for extrusion treatment, wherein the extrusion discharge temperature is 70 ℃, and the screw speed is 300rpm. 100g of the extruded sample was taken, 600g of distilled water was added to the mixture to suspend the sample, and then 0.5g of hemicellulase HC-90 was added thereto to hydrolyze the sample at 50℃with stirring for 4 hours. And after the enzymolysis is finished, drying the enzymolysis cereal fiber suspension in vacuum at 60 ℃ to remove water, and then crushing the cereal fiber suspension to 200 meshes to obtain a modified rice bran dietary fiber sample.

Example 9

And (3) taking 2kg of rice bran meal from which oil is removed, performing extrusion treatment, wherein the extrusion discharge temperature is 145 ℃, the screw speed is 300rpm, drying the sample after extrusion, and performing superfine grinding to more than 200 meshes to obtain a modified rice bran dietary fiber sample.

Comparative example 1

Taking 500g of rice bran meal from which oil is removed, and directly carrying out superfine grinding to more than 200 meshes to obtain a rice bran dietary fiber sample.

Comparative example 2

And (3) taking 500g of rice bran meal from which oil is removed, performing steam explosion under the conditions of 0.3MPa for 60s, drying the sample after the explosion is finished, and directly performing superfine grinding on the dried rice bran sample to 100 meshes to obtain a modified rice bran dietary fiber sample.

Comparative example 3

100g of degreased rice bran meal is taken, 600g of distilled water is added for suspension, then 1g of xylanase NS-28345 is added, and the mixture is stirred and hydrolyzed for 4 hours at 50 ℃. And after the enzymolysis is finished, vacuum drying the enzymolysis cereal fiber suspension at 60 ℃ to remove water, and then superfine grinding to more than 200 meshes to obtain a modified rice bran dietary fiber sample.

Comparative example 4

100g of degreased rice bran meal is taken, 600g of distilled water is added for suspension, then 1g of hemicellulase HC-90 is added, and the mixture is stirred and hydrolyzed for 4 hours at 50 ℃. And after the enzymolysis is finished, vacuum drying the enzymolysis cereal fiber suspension at 60 ℃ to remove water, and then superfine grinding to more than 200 meshes to obtain a modified rice bran dietary fiber sample.

Detection example 1

The rice bran dietary fiber samples prepared in examples 1 to 9 and comparative examples 1 to 4 were subjected to physical and chemical index detection, wherein the detection indexes include the content of soluble pentosan, the ratio of arabinose to xylose, the cholate adsorption capacity and the particle size distribution, and the method is as described above, and the results are shown in Table 1.

Table 1: physical and chemical detection and application test of sample

Application example 1

15g of each rice bran dietary fiber sample prepared in the above examples 1-6 and 9 and comparative examples 1-4 is uniformly mixed with 85g of soybean milk powder respectively to prepare a high-fiber soybean milk powder solid beverage, and the dietary fiber content is more than 6g/100g through detection, so that the declaration of dietary fiber-rich dietary fiber specified by national standards is achieved. 15g of the prepared high-fiber soybean milk powder is taken, 100mL of warm boiled water is added, and the mixture is fully stirred and dissolved until no large particle agglomeration exists, and sensory evaluation is carried out. The results are shown in Table 2 below.

Application example 2

The rice bran dietary fiber samples prepared in examples 1 to 6 and 9 and comparative examples 1 to 4 were taken, respectively, and meal replacement powder solid beverages were prepared according to the following formulation proportions, wherein: 45.6% of soybean protein isolate, 20.3% of soybean milk powder, 10% of rice bran dietary fiber sample, 5.1% of maltitol, 5% of inulin, 5% of quinoa flour, 3.8% of MCT powder, 2.5% of maltodextrin, 2.5% of plantain seed husk powder and 0.2% of guar gum, and all the materials are fully and uniformly stirred to obtain meal replacement powder solid beverage aiming at weight management. Taking 20g of the prepared solid beverage, adding 150-200mL of warm boiled water for brewing, and performing sensory evaluation after fully and uniformly stirring. The results are shown in Table 2 below.

Table 2: physical and chemical detection and application test of sample

The structure of dietary fiber in wheat bran is similar to that of rice bran fiber, and the adsorption effect of the wheat bran on cholate can be enhanced by treating the wheat bran by the method, so that the blood lipid reducing effect of the wheat bran is improved.

Claims

1. A bran dietary fiber product characterized by comprising: the mass ratio of arabinose to xylose in the dietary fiber is 0.75-1.0; preferably, the content of soluble pentosan in the bran dietary fiber product is more than or equal to 2 percent.

2. The bran dietary fiber product of claim 1, wherein the mass ratio of arabinose to xylose in the dietary fiber is 0.8-1.0; preferably, the ratio of arabinose to xylose in the dietary fiber is 0.85-1.0.

3. Bran dietary fiber product according to claim 1 or 2, characterized in that the soluble pentosan content in the bran dietary fiber product is not less than 2.5%, preferably not less than 3%;

preferably, the soluble pentosan content in the bran dietary fiber product is 2-5%, preferably 2.5-5%, more preferably 3-4%.

4. A bran dietary fiber product according to any one of claims 1-3, wherein the bran dietary fiber product has one or more of the following characteristics:

the adsorption capacity of cholate of the bran dietary fiber product is more than or equal to 65mg/g, preferably more than or equal to 70mg/g, preferably more than or equal to 80mg/g, preferably more than or equal to 90mg/g; preferably, the adsorption capacity of cholate of the bran dietary fiber product is 65-100mg/g, preferably 80-100mg/g;

the grain diameter of the bran dietary fiber product is more than 200 meshes, and D90 is less than or equal to 90 mu m;

the bran dietary fiber product is prepared from rice bran meal, wheat bran or barley bran; preferably, the bran dietary fiber product is a rice bran dietary fiber product.

5. A method of preparing a bran dietary fiber product, the method comprising: a step of extruding or steam explosion of the degreased bran, and a step of preferably hydrolyzing the product obtained by the extrusion or steam explosion.

6. The method of claim 5, wherein the method has one or more of the following features:

the extrusion temperature is 70-150 ℃, preferably 100-150 ℃, more preferably 130-150 ℃; preferably, the screw speed at extrusion is 200-400rpm;

the pressure of the steam explosion is 0.5-1.8MPa, preferably 0.6-1.5MPa, more preferably 0.9-1.5MPa; preferably, the time of the steam explosion is 80-200s, preferably 90-150s;

in the enzymolysis step, the enzymolysis system contains the product obtained by extrusion or steam explosion, water and hemicellulase or xylanase.

7. The method of claim 5 or 6, wherein the enzymatic hydrolysis is characterized by one or more of the following:

in the enzymolysis system, the weight ratio of the product to water is 1:3 to 1:8, preferably 1:4 to 1:8, 8;

in the enzymolysis system, the addition amount of the enzyme is 0.1-1g of enzyme per 100g of product;

the hemicellulase is hemicellulase HC-90;

the xylanase is xylanase NS-28345;

the enzymolysis is finished until the content of soluble pentosan in the obtained product is more than or equal to 2 percent and the ratio of arabinose to xylose in the dietary fiber is 0.75 to 1.0;

the enzymolysis temperature is 40-60 ℃;

the enzymolysis time is 3-8 hours.

8. A food product comprising the bran dietary fiber product of any one of claims 1-4 or prepared by the method of any one of claims 5-7;

preferably, the food is bread, steamed bread, rice, noodles, pastry, biscuits, puffed food, health drink or instant product;

preferably, the food product is a beverage, preferably a beverage having a fiber content of 6g/100g or more;

preferably, the instant product is a solid beverage powder, more preferably a solid beverage powder having a fiber content of more than 6g/100 g.

9. A method of preparing a food product, the method comprising the steps of preparing a bran dietary fiber product using the method of any one of claims 5-7, and mixing the bran dietary fiber product with other ingredients of the food product to prepare the food product.

10. Use of a hemicellulase or xylanase for increasing the cholate adsorption capacity of a bran dietary fiber product, or for preparing a bran dietary fiber product having increased cholate adsorption capacity;

preferably, the enhancing or preparing is carried out using the method of any one of claims 5-7;

preferably, the hemicellulase is a hemicellulase HC-90 and the xylanase is xylanase NS-28345.