Wheat dietary fiber and preparation method thereof

Abstract

The invention discloses a preparation method of wheat dietary fibers, which comprises the following steps: carrying out enzymolysis on wheat bran by using bacillus subtilis alpha-amylase and medium-temperature alpha-amylase in a certain proportion, and then carrying out enzymolysis by using neutral protease to obtain an enzymolysis product, namely the wheat dietary fibers. The use amount ratio of the bacillus subtilis alpha-amylase to the medium-temperature alpha-amylase is 1: (1.2-1.8), the total use amount of the bacillus subtilis alpha-amylase and the medium-temperature alpha-amylase accounts for 4-6% of the wheat bran, the enzymolysis time of the bacillus subtilis alpha-amylase and the medium-temperature alpha-amylase is 2.5-4.5 h, the use amount of the neutral protease accounts for 6-10% of the wheat bran, and the enzymolysis time of the neutral protease accounts for 6-10% of the wheat bran. The enzymolysis time of the neutral protease is 2-3.5 h, and the prepared wheat dietary fiber is high in yield, high in purity and few in impurities.

Description

Technical Field

[0001] This application belongs to the field of biomedicine, specifically relating to medicinal wheat dietary fiber and its preparation method. Background Technology

[0002] With increasing awareness of health and environmental protection and the growing acceptance of sustainable development concepts, the market demand for wheat dietary fiber is constantly growing. In the future, with continuous improvements in production technology and the expansion of new application areas, the market prospects for wheat dietary fiber will be even broader. At the same time, with the increasing global emphasis on and demand for environmentally friendly materials, wheat dietary fiber, as a new type of environmentally friendly material, will be applied and promoted in more fields.

[0003] In existing technologies, such as CN113718003A, wheat bran is enzymatically hydrolyzed by mesophilic α-amylase, neutral protease, and pepsin, achieving a wheat dietary fiber yield of 44% and a wheat dietary fiber purity of 92.1%. Although this has reached a relatively good level, there is still room for improvement. Summary of the Invention

[0004] This application provides a method for preparing wheat dietary fiber, which yields wheat dietary fiber with higher yield and purity.

[0005] This application provides a method for preparing wheat dietary fiber, which involves first enzymatically hydrolyzing wheat bran with a certain proportion of Bacillus subtilis α-amylase and mesophilic α-amylase, and then enzymatically hydrolyzing it with neutral protease. The enzymatic hydrolysis product is wheat dietary fiber.

[0006] Preferably, the ratio of Bacillus subtilis α-amylase to mesophilic α-amylase is 1:(1.2-1.8).

[0007] Preferably, the ratio of Bacillus subtilis α-amylase to mesophilic α-amylase is 1:1.5.

[0008] Preferably, the total amount of Bacillus subtilis α-amylase and mesophilic α-amylase added accounts for 4-6% of the weight of wheat bran.

[0009] Preferably, the total amount of Bacillus subtilis α-amylase and mesophilic α-amylase added accounts for 5% of the mass of wheat bran.

[0010] Preferably, the enzymatic hydrolysis time of Bacillus subtilis α-amylase and mesophilic α-amylase is 2.5-4.5 h.

[0011] Preferably, the enzymatic hydrolysis time of Bacillus subtilis α-amylase and mesophilic α-amylase is 3.5 h.

[0012] Preferably, the amount of neutral protease added is 6-10% of the weight of wheat bran, more preferably 8%.

[0013] Preferably, the enzymatic hydrolysis time of the neutral protease is 2-3.5 h, and more preferably 2.75 h.

[0014] The present invention also provides a wheat dietary fiber, which is prepared by any of the methods described above.

[0015] Beneficial effects:

[0016] Through extensive experimental verification, this invention has found that by adding Bacillus subtilis α-amylase and mesophilic α-amylase in a certain ratio, first enzymatically hydrolyzing wheat bran, and then enzymatically hydrolyzing wheat bran with neutral protease, the yield of wheat dietary fiber can be significantly improved compared with existing technologies, the purity of wheat dietary fiber can be increased to 95% or more, and the content of other substances, including protein, fat, ash and phytic acid, is also significantly reduced. Detailed Implementation

[0017] The technical solutions in the embodiments of this application are clearly described below. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0018] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0019] This application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

[0020] This application provides a method for preparing wheat dietary fiber, which involves first enzymatically hydrolyzing wheat bran with a certain proportion of Bacillus subtilis α-amylase and mesophilic α-amylase, and then enzymatically hydrolyzing it with neutral protease. The enzymatic hydrolysis product is wheat dietary fiber.

[0021] In one embodiment of the present invention, the ratio of Bacillus subtilis α-amylase to mesophilic α-amylase is 1:(1.2-1.8); the ratio of Bacillus subtilis α-amylase to mesophilic α-amylase can be 1:1.2, 1:1.5, 1:1.8, preferably 1:1.5.

[0022] In one embodiment of the present invention, the total amount of Bacillus subtilis α-amylase and mesophilic α-amylase added accounts for 4-6% of the wheat bran mass, which can be 4%, 5%, or 6%, preferably 5%.

[0023] In one embodiment of the present invention, the enzymatic hydrolysis time of Bacillus subtilis α-amylase and mesophilic α-amylase is 2.5-4.5 h, which can be 2.5 h, 3.5 h, or 4.5 h, preferably 3.5 h.

[0024] In one embodiment of the present invention, the amount of neutral protease added accounts for 6-10% of the mass of wheat bran, which can be 6%, 8%, or 10%, preferably 8%.

[0025] In one embodiment of the present invention, the enzymatic hydrolysis time of the neutral protease is 2-3.5h, which can be 2h, 2.75h, or 3.5h, preferably 2.75h.

[0026] The present invention also provides a wheat dietary fiber, which is prepared by any of the methods described above.

[0027] The wheat dietary fiber prepared by this invention has a high yield, high purity, and few impurities.

[0028] The sources of raw materials and auxiliary materials in the following specific embodiments and comparative examples are shown in Tables 1 and 2.

[0029] Table 1 Source of Raw Materials

[0030] name Manufacturer / Specifications Distributors and manufacturers bran Hebei Heima Noodles Inner Mongolia Xinonghe Feed Co., Ltd.

[0031] Table 2 Information on excipients (enzymes)

[0032] name Enzyme activity factory mesophilic α-amylase 5000u / g Xingtai Sibeite Biotechnology Co., Ltd. neutral protease 50,000u / g Xingtai Sibeite Biotechnology Co., Ltd. Bacillus subtilis α-amylase 50u / mg Shanghai Yuanye Biotechnology Co., Ltd.

[0033] Example 1

[0034] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 6g of Bacillus subtilis α-amylase and 9g of mesophilic α-amylase, stir and hydrolyze for 3.5 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 24g of neutral protease, stir and hydrolyze for 2.75 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0035] Example 2

[0036] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 6.8g of Bacillus subtilis α-amylase and 8.2g of mesophilic α-amylase, stir and hydrolyze for 3.5 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 24g of neutral protease, stir and hydrolyze for 2.75 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0037] Example 3

[0038] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 5.4g of Bacillus subtilis α-amylase and 9.6g of mesophilic α-amylase, stir and hydrolyze for 3.5 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 24g of neutral protease, stir and hydrolyze for 2.75 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0039] Example 4

[0040] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 4.8g of Bacillus subtilis α-amylase and 7.2g of mesophilic α-amylase, stir and hydrolyze for 3.5 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 24g of neutral protease, stir and hydrolyze for 2.75 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0041] Example 5

[0042] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 7.2g of Bacillus subtilis α-amylase and 10.8g of mesophilic α-amylase, stir and hydrolyze for 3.5 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 24g of neutral protease, stir and hydrolyze for 2.75 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0043] Example 6

[0044] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 6g of Bacillus subtilis α-amylase and 9g of mesophilic α-amylase, stir and hydrolyze for 2.5 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 24g of neutral protease, stir and hydrolyze for 2.75 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0045] Example 7

[0046] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 6g of Bacillus subtilis α-amylase and 9g of mesophilic α-amylase, stir and hydrolyze for 4.5 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 24g of neutral protease, stir and hydrolyze for 2.75 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0047] Example 8

[0048] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 6g of Bacillus subtilis α-amylase and 9g of mesophilic α-amylase, stir and hydrolyze for 3.5 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 18g of neutral protease, stir and hydrolyze for 2.75 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0049] Example 9

[0050] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 6g of Bacillus subtilis α-amylase and 9g of mesophilic α-amylase, stir and hydrolyze for 3.5 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 30g of neutral protease, stir and hydrolyze for 2.75 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0051] Example 10

[0052] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 6g of Bacillus subtilis α-amylase and 9g of mesophilic α-amylase, stir and hydrolyze for 3.5 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 24g of neutral protease, stir and hydrolyze for 2 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0053] Example 11

[0054] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 6g of Bacillus subtilis α-amylase and 9g of mesophilic α-amylase, stir and hydrolyze for 3.5 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 24g of neutral protease, stir and hydrolyze for 3.5 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0055] Comparative Example 1

[0056] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 15g of medium-temperature α-amylase, stir and hydrolyze for 3.5 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 24g of neutral protease, stir and hydrolyze for 2.75 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0057] Comparative Example 2

[0058] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 15g of Bacillus subtilis α-amylase, stir and hydrolyze for 3.5 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 24g of neutral protease, stir and hydrolyze for 2.75 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0059] Comparative Example 3

[0060] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 7.5g of Bacillus subtilis α-amylase and 7.5g of mesophilic α-amylase, stir and hydrolyze for 3.5 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 24g of neutral protease, stir and hydrolyze for 2.75 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0061] Comparative Example 4

[0062] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 5g of Bacillus subtilis α-amylase and 10g of mesophilic α-amylase, stir and hydrolyze for 3.5 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 24g of neutral protease, stir and hydrolyze for 2.75 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0063] Comparative Example 5

[0064] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 3.6g of Bacillus subtilis α-amylase and 5.4g of mesophilic α-amylase, stir and hydrolyze for 3.5 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 24g of neutral protease, stir and hydrolyze for 2.75 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0065] Comparative Example 6

[0066] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 8.4g of Bacillus subtilis α-amylase and 12.6g of mesophilic α-amylase, stir and hydrolyze for 3.5 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 24g of neutral protease, stir and hydrolyze for 2.75 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0067] Comparative Example 7

[0068] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 6g of Bacillus subtilis α-amylase and 9g of mesophilic α-amylase, stir and hydrolyze for 2 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 24g of neutral protease, stir and hydrolyze for 2.75 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0069] Comparative Example 8

[0070] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 6g of Bacillus subtilis α-amylase and 9g of mesophilic α-amylase, stir and hydrolyze for 5 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 24g of neutral protease, stir and hydrolyze for 2.75 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0071] Comparative Example 9

[0072] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 6g of Bacillus subtilis α-amylase and 9g of mesophilic α-amylase, stir and hydrolyze for 2 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 15g of neutral protease, stir and hydrolyze for 2.75 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0073] Comparative Example 10

[0074] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 6g of Bacillus subtilis α-amylase and 9g of mesophilic α-amylase, stir and hydrolyze for 2 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 36g of neutral protease, stir and hydrolyze for 2.75 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0075] Comparative Example 11

[0076] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 6g of Bacillus subtilis α-amylase and 9g of mesophilic α-amylase, stir and hydrolyze for 2 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 24g of neutral protease, stir and hydrolyze for 1.5 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0077] Comparative Example 12

[0078] Weigh 300g of wheat bran, add 10 times the amount of pH 2.0 solution (3000ml), reflux and stir for 1 hour, wash twice with water, filter, add water to the residue to make up to 3300ml, determine the pH, add dilute hydrochloric acid solution to adjust the pH to 6, heat to 65℃, add 6g of Bacillus subtilis α-amylase and 9g of mesophilic α-amylase, stir and hydrolyze for 2 hours under heat preservation, cool to 55℃, add 40% sodium hydroxide solution to adjust the pH to 7, add 24g of neutral protease, stir and hydrolyze for 4 hours under heat preservation, wash with water 5 times, filter with gauze, collect the residue, dry at 120℃ (dry for at least 3 hours), weigh, and calculate the yield.

[0079] The variables in Examples 1-11 and Comparative Examples 1-12 are shown in Table 3.

[0080] Table 3. A list of variables in Examples 1-11 and Comparative Examples 1-12

[0081]

[0082]

[0083] The finished products prepared in Examples 1-11 and Comparative Examples 1-12 were subjected to quality testing. The quality standard of this product specifies the following test items: protein, fat, ash, loss on drying, fiber, and phytic acid.

[0084] Protein detection method: Take 0.2g of sample, 3.0g of anhydrous potassium sulfate, and 0.2g of copper sulfate, weigh accurately, place in a digestion tube, add 6ml of sulfuric acid along the wall accurately, and test according to the method (Chinese Pharmacopoeia 2020 Edition, General Chapter 0731, Method III). The protein content shall not exceed 9.0%.

[0085] Fat content determination method: Take the sample, grind it in a mortar, pass it through a No. 3 sieve, take about 1.0g of fine powder, accurately weigh it, wrap it in defatted weighing paper, place it in a Soxhlet extraction tube, and dry it at 95℃ for 2 hours. Separately, take a Soxhlet extraction flask containing two glass beads, which has been weighed at 95℃, and add 100ml of petroleum ether (30-60℃). Extract accurately for 90 minutes, evaporate the petroleum ether in the extraction flask on a water bath, dry it at 95℃ for 30 minutes, cool it, and accurately weigh it. The fat content should not exceed 7.0%.

[0086] Ash content determination method: Take 5.0g of sample, accurately weigh it, place it in a crucible heated to constant weight at 550℃, and test it according to the method (General Chapter 2302 Ash Content Determination Method 1 of Chinese Pharmacopoeia 2020 Edition). The residual ash content shall not exceed 2.0%.

[0087] Fiber detection method: Take the sample, grind it in a mortar, pass it through a No. 3 sieve, take about 1.0g of fine powder, accurately weigh it, put it in a 500ml stoppered flask, add 25ml of 0.1mol / L phosphate buffer (pH 6.0), incubate in a water bath for 5 minutes, add 100mg of α-amylase, react for 30 minutes, shake once every 5 minutes, cool, add 20ml of water, adjust the pH value to 1.5±0.1 with 0.325mol / L hydrochloric acid solution, add 100mg of pepsin, react in a 40℃ water bath for 60 minutes, shake once every 5 minutes, and adjust the pH value to keep it constant at 1.5. Adjust the pH to 6.8 with 0.275 mol / L sodium hydroxide solution, add 100 mg of trypsin, and react in a 40°C water bath for 60 minutes, shaking every 2 minutes, while adjusting the pH to maintain a constant 6.8. Adjust the pH to 4.5 with 0.325 mol / L hydrochloric acid solution, add 400 ml of 75% ethanol solution (60°C), let stand for 1 hour, filter through a G3 sintered glass crucible that has been weighed to constant weight at 105°C, and dry to constant weight at 105°C. Accurately weigh approximately 150 mg of the residue dried to constant weight, determine the protein content according to the method under the "Tests" section on protein, and determine the ash content of the remaining portion according to the method under the "Tests" section, and calculate using the following formula.

[0088]

[0089] Where: R is the sample weight (g) after digestion and constant weight;

[0090] P represents the protein content (%) of the constant-weight sample after digestion;

[0091] A represents the ash content (%) of the constant-weight sample after digestion;

[0092] W represents the loss on drying (%) of the test sample;

[0093] S represents the weight of the test sample (g).

[0094] Phytic acid detection method: Ultraviolet-visible spectrophotometry (General Chapter 0401, Chinese Pharmacopoeia 2020 Edition).

[0095] The reference solution (% of sodium phytate dodecanoate (C6H6Na)) 12 O 24 P6) Weigh 18 mg of reference standard accurately, place it in a 100 ml volumetric flask, add water to dissolve and dilute to the mark, and shake well.

[0096] For the test solution, take the sample, grind it in a mortar, pass it through a No. 3 sieve, take about 0.5 g of fine powder, accurately weigh it, put it in a 100 ml centrifuge tube, accurately add 20 ml of 0.5 mol / L nitric acid solution, shake and extract for 4 hours, centrifuge for 30 minutes (10000 r / min), take the supernatant, filter it through a G4 sintered glass crucible, and take the filtrate as the test solution.

[0097] For the assay, take six stoppered test tubes and add 1.5 ml of water to each. Then add 1.0, 0.9, 0.8, 0.7, 0.6, and 0.5 ml of 0.5 mol / L nitric acid solution, respectively. Next, accurately add 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5 ml of reference solution, respectively. Then, accurately add 0.3 ml of 0.76 mol / L ferric ammonium sulfate solution (prepared with 0.01 mol / L hydrochloric acid solution) to each tube. Heat in a water bath for 20 minutes and cool. Add 5.0 ml of n-pentanol and 0.1 ml of 10% ammonium thiocyanate solution to each tube and extract by shaking. After standing or centrifugation, collect the n-pentanol phase. Using n-pentanol as a reference solution, measure the absorbance at 500 nm. Plot the difference in absorbance between the blank tube and other tubes on the ordinate and the molar amount of the reference solution on the x-axis to calculate the regression equation.

[0098] Take two more stoppered test tubes and accurately add 0.5 ml of 0.5 mol / L nitric acid solution, 2.0 ml of the test solution, and 0.3 ml of 0.76 mmol / L ferric ammonium sulfate solution to each. Measure the absorbance as described above. Substitute the difference between the blank value and the average absorbance of the two test tubes into the regression equation to calculate the number of moles of the test solution. Calculate the phytic acid content in the test sample using the following formula.

[0099]

[0100] In the formula: N is the number of moles of phytic acid in the test solution (mmol) calculated from the regression equation;

[0101] E represents the volume (ml) of extract added.

[0102] M represents the molar mass of phytic acid, which is 660.02 g / mol.

[0103] P is the weight (g) of the test sample.

[0104] W represents the loss on drying (%) of the test sample;

[0105] V represents the volume (ml) of the test solution added during the determination.

[0106] The yield of the finished products and the content of each substance in the finished products of Examples 1-11 and Comparative Examples 1-12 are shown in Table 2.

[0107] Table 4 shows the yield of the finished products and the content of each substance in the finished products for Examples 1-11 and Comparative Examples 1-12.

[0108]

[0109]

[0110] Observing Table 2 and comparing Example 1 with Comparative Examples 1 and 2, it is evident that using both Bacillus subtilis α-amylase and mesophilic α-amylase simultaneously to enzymatically hydrolyze wheat bran significantly improves the yield compared to hydrolysis by Bacillus subtilis α-amylase and mesophilic α-amylase alone. Simultaneous use of Bacillus subtilis α-amylase and mesophilic α-amylase increases the fiber content to over 95%, while hydrolysis by Bacillus subtilis α-amylase and mesophilic α-amylase alone does not reach 90% fiber content. Furthermore, the contents of other substances, including protein, fat, ash, and phytic acid, are significantly lower when using Bacillus subtilis α-amylase and mesophilic α-amylase simultaneously compared to hydrolysis by Bacillus subtilis α-amylase and mesophilic α-amylase alone. Therefore, under the same conditions, replacing mesophilic α-amylase with Bacillus subtilis α-amylase in the enzymatic hydrolysis of wheat bran can significantly improve the yield of the finished product and the purity of wheat dietary fiber.

[0111] Comparing Examples 1, 2, and 3 with Comparative Examples 3 and 4, it is evident that the yield and fiber content of Examples 1, 2, and 3 are higher than those of Comparative Examples 3 and 4; furthermore, the contents of other substances in Examples 1, 2, and 3, including protein, fat, ash, and phytic acid, are lower than those in Comparative Examples 3 and 4. Therefore, under the same conditions, when the ratio of Bacillus subtilis α-amylase to mesophilic α-amylase is 1:(1.2-1.8), the yield of the finished product and the purity of wheat dietary fiber can be significantly improved.

[0112] Comparing Examples 1, 4, and 5 with Comparative Examples 5 and 6, it is evident that the yield and wheat dietary fiber content of Examples 1, 4, and 5 are significantly higher than those of Comparative Examples 5 and 6; the contents of other components such as protein, fat, ash, and phytic acid are also lower in the former than in the latter. Therefore, under the same conditions, when the amount of Bacillus subtilis α-amylase added is between 0.4% and 0.6%, the yield and purity of the finished product are significantly improved.

[0113] Comparing Examples 1, 6, and 7 with Comparative Examples 7 and 8, it is evident that the yield and wheat dietary fiber content of Examples 1, 6, and 7 are significantly higher than those of Comparative Examples 7 and 8. Furthermore, the contents of other components such as protein, fat, ash, and phytic acid in Examples 1, 6, and 7 are all lower than those in Comparative Examples 7 and 8. Therefore, under the same conditions, when the enzymatic hydrolysis time of Bacillus subtilis α-amylase is between 2.5 and 4.5 hours, the yield of the finished product and the purity of wheat dietary fiber are significantly improved.

[0114] Comparing Examples 1, 8, and 9 with Comparative Examples 9 and 10, it is evident that the yield and wheat dietary fiber content of Examples 1, 8, and 9 are significantly higher than those of Comparative Examples 9 and 10. Furthermore, the contents of other components such as protein, fat, ash, and phytic acid in Examples 1, 8, and 9 are all lower than those in Comparative Examples 9 and 10. Therefore, under the same conditions, when the amount of neutral protease is 6-10%, the yield and purity of the finished product are significantly improved.

[0115] Comparing Examples 1, 10, and 11 with Comparative Examples 11 and 12, it is evident that the yield and wheat dietary fiber content of Examples 1, 10, and 11 are significantly higher than those of Comparative Examples 11 and 12. Furthermore, the contents of other components such as protein, fat, ash, and phytic acid in Examples 1, 10, and 11 are all lower than those in Comparative Examples 11 and 12. Therefore, under the same conditions, when the enzymatic hydrolysis time of neutral protease is 2-3.5 hours, the yield of the finished product and the purity of wheat dietary fiber are significantly improved.

[0116] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of this application, and this application is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this application, and these modifications and improvements are also considered to be within the scope of protection of this invention.

Claims

1. A method for preparing wheat dietary fiber, characterized by, The application relates to a method for preparing wheat dietary fiber. The ratio of the Bacillus subtilis alpha-amylase to the medium-temperature alpha-amylase is 1: (1.2-1.8).

2. The method for preparing wheat dietary fiber according to claim 1, characterized by, The ratio of the Bacillus subtilis alpha-amylase to the medium-temperature alpha-amylase is 1:1.

5.

3. The method for preparing wheat dietary fiber according to claim 1, characterized by, The total amount of the Bacillus subtilis alpha-amylase and the medium-temperature alpha-amylase accounts for 4-6% of the mass of the wheat bran.

4. The method for preparing wheat dietary fiber according to claim 1, characterized by, The total amount of the Bacillus subtilis alpha-amylase and the medium-temperature alpha-amylase accounts for 5% of the mass of the wheat bran.

5. The method for preparing wheat dietary fiber according to claim 1, characterized by, The enzymolysis time of the Bacillus subtilis alpha-amylase and the medium-temperature alpha-amylase is 2.5-4.5h.

6. The method for preparing wheat dietary fiber according to claim 1, characterized by, The enzymolysis time of the Bacillus subtilis alpha-amylase and the medium-temperature alpha-amylase is 3.5h.

7. The method for preparing wheat dietary fiber according to claim 1, characterized by, The adding amount of the neutral protease accounts for 6-10% of the mass of the wheat bran, preferably 8%.

8. The method for preparing wheat dietary fiber according to claim 1, characterized by, The enzymolysis time of the neutral protease is 2-3.5h, preferably 2.75h.

9. The method for preparing wheat dietary fiber according to claim 1, characterized by, 10. Wheat dietary fiber prepared by the method in any one of claims 1-9. ​

Images