Preparation method of rice peptide drink

Abstract

The invention provides a preparation method of a rice peptide drink, which is characterized by comprising the following steps: step 1, carrying out freeze-drying treatment, microwave-assisted pretreatment, mechanical pulverization and sieving on rice to obtain rice meal; step 2, adding the sieved rice flour into water, stirring, adding a compound enzyme, adjusting the pH value, and continuously stirring for enzymolysis; filtering is performed; performing ultrafiltration on the filtrate, and collecting filtrate and filtrate; performing vacuum drying on the filtrate to obtain a rice starch hydrolysate; step 3, adding the filtrate serving as a raw material into water, stirring, adding bacillus subtilis and recombinant bacillus subtilis, fermenting, filtering, performing supercritical extraction on filtrate, and collecting extract liquor, namely rice peptide liquor; step 4, sterilizing the rice peptide liquid, inoculating lactobacillus plantarum and bifidobacterium lactis into the rice peptide liquid, and fermenting; and step 5, cooling, blending, filtering, homogenizing and sterilizing to obtain the rice peptide drink. The rice peptide drink prepared by the preparation method provided by the invention is good in quality, good in taste and high in preparation efficiency.

Description

Technical Field

[0001] The invention belongs to the field of biotechnology, and in particular relates to a preparation method of a rice peptide drink. Background Art

[0002] Rice is one of the world's most important food crops, its main components being starch and protein. Rice protein, due to its high nutritional value and hypoallergenic properties, is widely used in functional foods and health supplements. Rice peptides, small molecule peptides derived from rice protein through enzymatic hydrolysis or other treatments, possess numerous physiological activities, including antioxidant, antihypertensive, and anti-inflammatory properties, and are considered a highly promising functional food ingredient.

[0003] However, there are some challenges and shortcomings in the preparation methods of rice peptides in the prior art: First, there's the challenge of separating starch and protein: The starch and protein in rice are tightly bound together. While traditional separation methods, such as alkaline hydrolysis, can effectively separate the two, they can lead to protein denaturation, amino acid racemization, and even the production of toxic substances. Furthermore, the alkaline hydrolysis process is complex, consumes large amounts of chemicals, and produces large amounts of wastewater, placing a burden on the environment.

[0004] Second, there are the limitations of enzymatic hydrolysis: Enzymatic hydrolysis has been widely researched and applied due to its mild conditions and high product safety. However, traditional enzymatic hydrolysis suffers from low hydrolysis efficiency, long reaction times, and a strong bitter taste. In particular, the bitter peptides produced during rice protein hydrolysis severely impact the flavor and application range of rice peptides.

[0005] Third, improving the bitter taste: The bitter taste of rice peptides mainly comes from the hydrophobic amino acids produced during the hydrolysis process. Existing methods to improve the bitter taste include multi-step enzymatic hydrolysis and adsorbent treatment, but these methods are complex, costly, and have limited effectiveness. Summary of the Invention

[0006] Technical problem: In order to solve the defects of the existing technology, the present invention provides a preparation method of rice peptide drink. Through the innovative enzymatic hydrolysis method and the application of engineered bacteria, the rice peptide and quality are improved, the production cost is reduced, the flavor of the rice peptide is improved, and the application of rice peptide in functional foods and health products is promoted.

[0007] Technical solution: The present invention provides a method for preparing a rice peptide drink, comprising the following steps: Step 1: freeze-drying, microwave-assisted pretreatment, mechanical grinding, and sieving the rice to obtain rice flour; Step 2: adding the sifted rice flour to water, stirring, adding a complex enzyme, adjusting the pH, and continuing stirring to allow enzymatic hydrolysis; filtering; ultrafiltration of the filtrate, collecting the filtrate and the filtrate; and vacuum drying the filtrate to obtain a rice starch hydrolysate; Step 3: The filtrate is used as the raw material, which is added into water and stirred, and then Bacillus subtilis is added. (Bacillus subtilis) and fermenting with recombinant Bacillus subtilis, filtering, subjecting the filtrate to supercritical extraction, and collecting the extract to obtain the rice peptide solution; Step 4: sterilize the rice peptide solution and add Lactobacillus plantarum (Lactobacillus plantarum) and Bifidobacterium lactis (Bifidobacterium lactis) Inoculate into rice peptide solution and ferment; Step 5: cooling, blending, filtering, homogenizing, and sterilizing to obtain the rice peptide drink.

[0008] As an improvement, in step 1, during the freeze-drying process, the freezing temperature is -40°C to -20°C, the time is 6-8h, the vacuum degree is 0.1-10pa, the sublimation drying temperature is 20°C to 40°C, and the time is 8-12h; the microwave-assisted pretreatment temperature is 500-1000w, and the time is 2-5min; the mechanical crushing is to use a planetary ball mill to crush the rice, the grinding medium is stainless steel balls with a diameter of 0.5-2mm, the ball-to-material ratio is 5:1 to 10:1, the ball mill speed is 1000-2000 rpm, the crushing time is 30-60 minutes, and the output particle size is 10-50 μm; the screening is a 100-120 mesh sieve. The rice is freeze-dried to remove moisture and maintain its structural integrity; freeze-drying can reduce the impact of moisture on the subsequent crushing process and help maintain protein stability; the freeze-dried rice is microwave-pretreated to further enhance the destruction of cell structure and facilitate subsequent mechanical crushing; the grinding media of the ball mill impacts and rubs the rice particles under high energy, achieving efficient crushing.

[0009] As another improvement, in step 1, a trace amount of vitamin C is added to the rice, with the added amount of vitamin C being 0.01% to 0.1% of the rice mass. The addition of vitamin C can improve the antioxidant capacity of rice protein and protect the rice protein and rice peptides during the preparation process on the one hand, and can enhance the enzymatic hydrolysis process and improve the enzymatic hydrolysis efficiency on the other hand.

[0010] As another improvement, in step 2, the complex enzyme is α-amylase, pullulanase and cellulase, the amount of α-amylase, pullulanase and cellulase is 2-4% of the weight of the rice, the amount of α-amylase is 60-70% of the weight of the complex enzyme, the amount of pullulanase is 20-30% of the weight of the complex enzyme, and the balance is cellulase; the enzymatic hydrolysis temperature is 50-60°C, the pH is 4.5 to 5.5, and the time is 2-4 hours. A specific enzyme combination is used to enzymatically hydrolyze the rice, completely enzymatically hydrolyzing the starch without destroying the protein: α-amylase is used to hydrolyze the α-1,4-glycosidic bonds of starch, breaking it down into smaller dextrins and maltose; pullulanase is used to hydrolyze the α-1,6-glycosidic bonds and further decompose amylopectin; cellulase is used to hydrolyze cellulose to help release starch granules, but does not act on protein.

[0011] As another improvement, in step 2, the ultrafiltration treatment uses an ultrafiltration membrane with a molecular weight cutoff of 10,000-50,000 Da. During the enzymatic hydrolysis process, the protein is not degraded by the complex enzyme and remains in the reaction system as a macromolecular mass. Filtration removes impurities, and ultrafiltration retains the unhydrolyzed rice protein. The hydrolyzed rice starch is collected in the ultrafiltrate, and vacuum drying is performed to obtain the rice starch hydrolyzate.

[0012] As another improvement, in step 3, the fermentation temperature is 50-60°C, the pH is 8.0-9.0, the fermentation shaker speed is 120-160 r / min, and the fermentation time is 4-6 hours. Bacillus subtilis can efficiently produce a variety of proteases, such as alkaline protease (Alcalase)、 Flavor protease (Flavourzyme) , complex protease (Protamex) and trypsin analogs, thereby enabling rice proteolysis, while recombinant Bacillus subtilis can efficiently produce leucine aminopeptidase and proline aminopeptidase, thereby achieving debittering treatment; Bacillus subtilis (Bacillus subtilis) and recombinant Bacillus subtilis (Recombinant Bacillus subtilis) The fermentation conditions are the same and there will be no mutual influence. The synergistic enzymatic hydrolysis and debittering treatment are carried out in the same fermentation process, which not only can achieve the effect of protein degradation, but also avoids the mutual influence of adding other microorganisms, ensures the fermentation efficiency and debittering effect, simplifies the multi-step treatment process, reduces equipment and operation steps, improves the enzymatic hydrolysis and debittering effect, and improves the enzymatic hydrolysis efficiency.

[0013] As another improvement, in step 3, the fermentation auxiliary material includes 10-20 parts of peptone, 10-20 parts of rice starch hydrolysate, 5-10 parts of (NH4)2SO4, 5-10 parts of NaCl, 2-4 parts of K2HPO4, and 2-4 parts of CaCl2; the amount of fermentation auxiliary material added is 4-8% of the mass of the raw material filtrate added in step 3, and Bacillus subtilis (Bacillus subtilis) The amount of added is 2-3% of the mass of the raw material filtrate added in step 3, and the amount of added recombinant Bacillus subtilis is 1-2% of the mass of the raw material filtrate added in step 3. The fermentation auxiliary material provides nutrients suitable for microbial growth, such as a carbon source, a nitrogen source, and trace elements. At the same time, the rice starch hydrolyzate in step 2 is directly used to provide a carbon source for the fermentation auxiliary material, reducing the use of other raw materials and lowering costs.

[0014] As another improvement, in step 3, the supercritical extraction conditions are: temperature 40-60°C, pressure 20-40 MPa, and time 1-2 hours. Supercritical extraction technology is used to remove residual enzymes and impurities to obtain purified rice peptides.

[0015] As another improvement, in step 4, when inoculating, Lactobacillus plantarum (Lactobacillus plantarum) and Bifidobacterium lactis (Bifidobacterium lactis) Pre-culture to reach the logarithmic growth phase, Lactobacillus plantarum (Lactobacillus plantarum) and Bifidobacterium lactis (Bifidobacterium lactis) The inoculation amount is 5-10% (v / v) of the rice peptide solution; the fermentation temperature is 50-60℃, the pH is 6.5-7.0, the fermentation shaker speed is 120-160r / min, and the time is 12-24h. (Lactobacillus plantarum) and Bifidobacterium lactis (Bifidobacterium lactis) ) for fermentation, which can not only consume excess sugar and improve the taste of rice peptide, but also increase the functionality of the product and regulate gastrointestinal function.

[0016] As another improvement, in step 5, the blending process is to add additives to adjust the taste and flavor of the beverage. The added additives include sweeteners (sucrose, glucose, sugar alcohol, etc.), flavorings (such as spices, fruit juice, etc.), functional ingredients (dietary fiber, vitamins and minerals), thickeners (sodium carboxymethyl cellulose, xanthan gum), stabilizers (gellan gum, agar) and / or antioxidants (microorganism C, vitamin E); the homogenization conditions are: primary homogenization pressure 10-20 MPa, temperature 35-45°C, homogenization time 1-2 minutes, secondary homogenization pressure 30-40 MPa, temperature 35-45°C, homogenization time 1-2 minutes; the sterilization conditions are maintained at 72-75°C for 15-20 seconds, or maintained at 63-65°C for 30 minutes.

[0017] Beneficial effects: The rice peptide beverage prepared by the preparation method provided by the present invention has good quality, good taste and high preparation efficiency. Specifically: First, the rice is freeze-dried to enhance the destruction of the cell structure and facilitate subsequent mechanical crushing, thereby facilitating the full enzymatic hydrolysis of the rice starch. A specific enzyme combination is used to enzymatically hydrolyze the rice, completely hydrolyzing the starch without destroying the protein.

[0018] Second, the fermentation conditions of Bacillus subtilis and recombinant Bacillus subtilis are the same, and the synergistic enzymatic hydrolysis and debittering treatment are carried out in the same fermentation process, which not only achieves the effect of protein degradation, but also avoids the mutual influence of adding other microorganisms, ensures the fermentation efficiency and debittering effect, and simplifies the multi-step treatment process.

[0019] Third, using probiotics (Lactobacillus plantarum and Bifidobacterium lactis) with antioxidant and immune-regulating functions for fermentation can not only consume excess sugar and improve the taste of rice peptides, but also increase the functionality of the product and regulate gastrointestinal function.

[0020] Fourth, the rice peptide drink prepared in the present application has the effects of resisting fatigue, enhancing exercise endurance, promoting muscle growth, improving gastrointestinal function, and assisting in improving sleep, and is suitable for people of all ages. DETAILED DESCRIPTION

[0021] The present invention will be further described below.

[0022] Sources of microorganisms used in this application: The recombinant Bacillus subtilis (recombinant Bacillus subtilis) with high production of leucine aminopeptidase and proline aminopeptidase is homemade, and the method is the same as that of Chinese patent CN105925650A.

[0023] Bacillus subtilis (Bacillus subtilis) , purchased from China Center for Type Culture Collection, strain accession number CCTCC CB 20081782; Lactobacillus plantarum and Bifidobacterium lactis are commercially available. Example

[0024] The preparation method of rice peptide drink comprises the following steps: Step 1: adding a trace amount of vitamin C to rice, wherein the amount of vitamin C added is 0.5% of the weight of the rice; freeze-drying the rice, performing microwave-assisted pretreatment, mechanically grinding the rice, and passing the rice through a 110-mesh sieve to obtain rice flour; During the freeze-drying process, the freezing temperature was -30°C, the time was 7 hours, the vacuum degree was 5 Pa, the sublimation drying temperature was 30°C, and the time was 10 hours; the microwave-assisted pretreatment temperature was 800W, and the time was 3 minutes; the mechanical crushing was to use a planetary ball mill to crush the rice, the grinding medium was a stainless steel ball with a diameter of 1 mm, the ball-to-material ratio was 8:1, the ball mill speed was 1500 rpm, the crushing time was 45 minutes, and the output particle size was 10-50 μm.

[0025] Step 2: adding the sieved rice flour to water with stirring, adding a complex enzyme, adjusting the pH to 5.0, and continuing to stir at 55° C. to allow enzymatic hydrolysis for 3 hours; filtering; ultrafiltration of the filtrate using an ultrafiltration membrane with a molecular weight cutoff of 10,000-50,000 Da, collecting the filtrate and the filtrate; and vacuum drying the filtrate to obtain a rice starch hydrolysate. The complex enzyme comprises alpha-amylase, pullulanase and cellulase, wherein the dosage of the alpha-amylase, pullulanase and cellulase is 3% of the mass of the rice, the dosage of the alpha-amylase is 65% of the weight of the complex enzyme, the dosage of the pullulanase is 25% of the weight of the complex enzyme, and the remainder is cellulase.

[0026] Step 3: The filtrate is used as the raw material, which is added into water and stirred, and then Bacillus subtilis is added. (Bacillus subtilis) and recombinant Bacillus subtilis, adjusting the pH to 8.5, fermenting at 55°C for 5 hours with a shaker speed of 140 r / min; filtering, and subjecting the filtrate to supercritical extraction at 50°C and 30 MPa for 1.5 hours. The extract is collected as the rice peptide solution; sampling is performed for testing; The fermentation auxiliary materials include 15 parts of peptone, 15 parts of rice starch hydrolysate, 8 parts of (NH4)2SO4, 7 parts of NaCl, 3 parts of K2HPO4, and 3 parts of CaCl2; the amount of the fermentation auxiliary materials added is 6% of the mass of the raw material filtrate added in step 3, and Bacillus subtilis (Bacillus subtilis)The amount of added is 2.5% of the amount of the raw material filtrate added in step 3, and the amount of added recombinant Bacillus subtilis is 1.5% of the amount of the raw material filtrate added in step 3; Step 4: sterilize the rice peptide solution and add Lactobacillus plantarum (Lactobacillus plantarum) and Bifidobacterium lactis (Bifidobacterium lactis) Inoculate into rice peptide solution, adjust pH to 6.8, and ferment at 55°C for 18 h with a shaker speed of 140 r / min. When inoculating, Lactobacillus plantarum (Lactobacillus plantarum) and Bifidobacterium lactis (Bifidobacterium lactis) Pre-culture to reach the logarithmic growth phase, Lactobacillus plantarum (Lactobacillus plantarum) and Bifidobacterium lactis (Bifidobacterium lactis) The inoculum volume was 8% (v / v) of the rice peptide solution; Step 5: cooling, blending, filtering, homogenizing, and sterilizing to obtain the rice peptide drink; The preparation process is to add vitamin E, the addition amount is 0.05% (m / m) of the rice peptide liquid; the homogenization conditions are: primary homogenization pressure 15MPa, temperature 40℃, homogenization time 1.5 minutes, secondary homogenization pressure 35MPa, temperature 40℃, homogenization time 1.5 minutes; the sterilization conditions are maintained at 72-75℃ for 15s. Example

[0027] The preparation method of rice peptide drink comprises the following steps: Step 1: adding a trace amount of vitamin C to rice, wherein the amount of vitamin C added is 0.01% of the mass of the rice; freeze-drying the rice, performing microwave-assisted pretreatment, mechanically grinding the rice, and passing the rice through a 100-mesh sieve to obtain rice flour; During the freeze-drying process, the freezing temperature was -40°C, the time was 6 hours, the vacuum degree was 0.1 Pa, the sublimation drying temperature was 20°C, and the time was 12 hours; the microwave-assisted pretreatment temperature was 500W, and the time was 5 minutes; the mechanical crushing was to use a planetary ball mill to crush the rice, the grinding medium was a stainless steel ball with a diameter of 0.5 mm, the ball-to-material ratio was 10:1, the ball mill speed was 2000 rpm, the crushing time was 30 minutes, and the output particle size was 10-50 μm.

[0028] Step 2: adding the sifted rice flour to water with stirring, adding a complex enzyme, adjusting the pH to 4.5, and continuing to stir at 50° C. for 4 hours for enzymatic hydrolysis; filtering; ultrafiltration of the filtrate using an ultrafiltration membrane with a molecular weight cutoff of 10,000-50,000 Da, collecting the filtrate and the filtrate; and vacuum drying the filtrate to obtain a rice starch hydrolysate; The complex enzyme comprises alpha-amylase, pullulanase and cellulase, wherein the dosage of the alpha-amylase, pullulanase and cellulase is 2% of the mass of the rice, the dosage of the alpha-amylase is 60% of the weight of the complex enzyme, the dosage of the pullulanase is 30% of the weight of the complex enzyme, and the remainder is cellulase.

[0029] Step 3: The filtrate is used as the raw material, which is added into water and stirred, and then Bacillus subtilis is added. (Bacillus subtilis) and recombinant Bacillus subtilis, adjusting the pH to 9.0, fermenting at 50°C for 6 hours with a shaker speed of 120 r / min; filtering, and subjecting the filtrate to supercritical extraction at 40°C and 40 MPa for 2 hours. The extract is collected as the rice peptide solution; sampling is performed for testing; The fermentation auxiliary materials include 10 parts of peptone, 20 parts of rice starch hydrolysate, 5 parts of (NH4)2SO4, 10 parts of NaCl, 2 parts of K2HPO4, and 4 parts of CaCl2; the amount of the fermentation auxiliary materials added is 4% of the mass of the raw material filtrate added in step 3, and Bacillus subtilis (Bacillus subtilis) The amount of added is 3% of the amount of the raw material filtrate added in step 3, and the amount of added recombinant Bacillus subtilis is 1% of the amount of the raw material filtrate added in step 3; Step 4: sterilize the rice peptide solution and add Lactobacillus plantarum (Lactobacillus plantarum) and Bifidobacterium lactis (Bifidobacterium lactis) Inoculate into rice peptide solution, adjust pH to 6.5, and ferment at 50℃ for 24h with a shaker speed of 160r / min. When inoculating, Lactobacillus plantarum (Lactobacillus plantarum) and Bifidobacterium lactis (Bifidobacterium lactis) Pre-culture to reach the logarithmic growth phase, Lactobacillus plantarum (Lactobacillus plantarum) and Bifidobacterium lactis (Bifidobacterium lactis) The inoculum volume was 5% (v / v) of the rice peptide solution; Step 5: cooling, blending, filtering, homogenizing, and sterilizing to obtain the rice peptide drink; The preparation process is to add additives, including sweeteners (sucrose), flavorings (spices), functional ingredients (dietary fiber), thickeners (sodium carboxymethyl cellulose), stabilizers (gellan gum), and antioxidants (microorganism C); the homogenization conditions are: primary homogenization pressure 10 MPa, temperature 45°C, homogenization time 1 minute, secondary homogenization pressure 30 MPa, temperature 35°C, and homogenization time 2 minutes; the sterilization conditions are maintained at 63-65°C for 30 minutes. Example

[0030] The preparation method of rice peptide drink comprises the following steps: Step 1: adding a trace amount of vitamin C to rice, wherein the amount of vitamin C added is 0.1% of the weight of the rice; freeze-drying the rice, performing microwave-assisted pretreatment, mechanically grinding the rice, and passing the rice through a 120-mesh sieve to obtain rice flour; During the freeze-drying process, the freezing temperature was -20°C, the time was 8 hours, the vacuum degree was 10 Pa, the sublimation drying temperature was 40°C, and the time was 8 hours; the microwave-assisted pretreatment temperature was 1000 W, and the time was 2 minutes; the mechanical crushing was to use a planetary ball mill to crush the rice, the grinding medium was a stainless steel ball with a diameter of 2 mm, the ball-to-material ratio was 5:1, the ball mill speed was 1000 rpm, the crushing time was 60 minutes, and the output particle size was 10-50 μm.

[0031] Step 2: adding the sieved rice flour to water and stirring, adding a complex enzyme, adjusting the pH to 5.5, and continuing to stir at 60° C. to allow enzymatic hydrolysis for 2 hours; filtering; ultrafiltration of the filtrate using an ultrafiltration membrane with a molecular weight cutoff of 10,000-50,000 Da, collecting the filtrate and the filtrate; and vacuum drying the filtrate to obtain a rice starch hydrolysate; The complex enzyme comprises alpha-amylase, pullulanase and cellulase, wherein the dosage of the alpha-amylase, pullulanase and cellulase is 4% of the mass of the rice, the dosage of the alpha-amylase is 70% of the weight of the complex enzyme, the dosage of the pullulanase is 20% of the weight of the complex enzyme, and the remainder is cellulase.

[0032] Step 3: The filtrate is used as the raw material, which is added into water and stirred, and then Bacillus subtilis is added. (Bacillus subtilis) and recombinant Bacillus subtilis, adjusting the pH to 8.0, fermenting at 60°C for 4 hours with a shaker speed of 160 r / min; filtering, and subjecting the filtrate to supercritical extraction at 60°C and 20 MPa for 1 hour. The extract is collected as the rice peptide solution; sampling is performed for testing; The fermentation auxiliary materials include 20 parts of peptone, 10 parts of rice starch hydrolysate, 10 parts of (NH4)2SO4, 5 parts of NaCl, 4 parts of K2HPO4, and 2 parts of CaCl2; the amount of fermentation auxiliary materials added is 8% of the mass of the raw material filtrate added in step 3, and Bacillus subtilis (Bacillus subtilis) The amount of the added recombinant Bacillus subtilis is 2% of the amount of the raw material filtrate added in step 3; Step 4: sterilize the rice peptide solution and add Lactobacillus plantarum (Lactobacillus plantarum) and Bifidobacterium lactis (Bifidobacterium lactis)Inoculate into rice peptide solution, adjust pH to 7.0, and ferment at 60℃ for 12h with a shaker speed of 120r / min. When inoculating, Lactobacillus plantarum (Lactobacillus plantarum) and Bifidobacterium lactis (Bifidobacterium lactis) Pre-culture to reach the logarithmic growth phase, Lactobacillus plantarum (Lactobacillus plantarum) and Bifidobacterium lactis (Bifidobacterium lactis) The inoculum volume was 10% (v / v) of the rice peptide solution; Step 5: cooling, blending, filtering, homogenizing, and sterilizing to obtain the rice peptide drink; The blending process involves adding additives, including sweeteners (sugar alcohols), flavorings (juice, etc.), functional ingredients (dietary fiber, vitamins and minerals), thickeners (xanthan gum), stabilizers (agar), and antioxidants (vitamin E). The homogenization conditions are: primary homogenization pressure 20 MPa, temperature 35°C, homogenization time 2 minutes, secondary homogenization pressure 40 MPa, temperature 45°C, homogenization time 1 minute; and sterilization conditions are maintained at 72-75°C for 20 seconds. Example

[0033] The method is basically the same as Example 1, except that: in step 1, vitamin C is not added. Comparative Example 1 The method is basically the same as Example 1, except that: in step 1, rice is mechanically crushed and sieved through a 110 mesh sieve to obtain rice flour.

[0034] Comparative Example 2 The process is basically the same as Example 1, except that in step 2, the complex enzyme is only cellulase.

[0035] Comparative Example 3 The same as Example 1, except that in step 3, only Bacillus subtilis was added. (Bacillus subtilis) , the addition amount is the Bacillus subtilis in Example 1 (Bacillus subtilis) and recombinant Bacillus subtilis (recombinant Bacillus subtilis )The total amount added.

[0036] Comparative Example 4 The same as Example 1, except that in step 3, only recombinant Bacillus subtilis was added. ( Reorganization Bacillus subtilis) , the addition amount is the Bacillus subtilis in Example 1 (Bacillus subtilis) and recombinant Bacillus subtilis (recombinant Bacillus subtilis) The total amount added.

[0037] Comparative Example 5 The method is substantially the same as that of Comparative Example 1, except that step 4 is omitted and step 5 is to directly cool the rice peptide solution, blend, filter, homogenize, and sterilize the solution to obtain the rice peptide drink. The results of comparisons by many people indicate that the mouthfeel is significantly inferior to that of Example 1.

[0038] Experimental Example 1 Test the hydrolysis effect of rice protein by different methods (samples obtained in step 3), the results are shown in Table 1 Table 1 Molecular weight Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 ＞5000 0.26 0.89 0.97 0.56 2.39 3.14 3.66 3.63 5000-3000 0.65 0.97 1.01 0.96 5.81 6.08 6.24 6.15 3000-2000 1.11 1.26 2.18 1.02 8.28 7.97 10.39 9.28 2000-1000 3.21 3.48 3.67 4.01 10.94 13.71 12.68 15.26 1000-500 9.68 9.87 9.13 10.24 11.67 11.18 19.34 18.43 500-180 36.28 36.18 35.86 35.27 26.28 25.11 20.65 21.68 ＜180 48.81 47.35 47.18 47.94 34.63 32.81 27.04 25.57 The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A method for preparing a rice peptide drink, characterized in that: The following steps are involved: Step 1: freeze-drying, microwave-assisted pretreatment, mechanical grinding, and sieving the rice to obtain rice flour; Step 2: adding the sifted rice flour to water, stirring, adding a complex enzyme, adjusting the pH, and continuing stirring to allow enzymatic hydrolysis; filtering; ultrafiltration of the filtrate, collecting the filtrate and the filtrate; and vacuum drying the filtrate to obtain a rice starch hydrolysate; Step 3: The filtrate is used as the raw material, which is added into water and stirred, and then Bacillus subtilis is added. (Bacillus subtilis) and fermenting with recombinant Bacillus subtilis, filtering, subjecting the filtrate to supercritical extraction, and collecting the extract to obtain the rice peptide solution; Step 4: sterilize the rice peptide solution and add Lactobacillus plantarum (Lactobacillus plantarum) and Bifidobacterium lactis (Bifidobacterium lactis) Inoculate into rice peptide solution and ferment; Step 5: cooling, blending, filtering, homogenizing, and sterilizing to obtain the rice peptide drink.

2. The method of claim 1, wherein the rice peptide drink In step 1, during the freeze-drying process, the freezing temperature is -40°C to -20°C, the time is 6-8h, the vacuum degree is 0.1-10pa, the sublimation drying temperature is 20°C to 40°C, and the time is 8-12h; the microwave-assisted pretreatment temperature is 500-1000w, and the time is 2-5min; the mechanical crushing is to use a planetary ball mill to crush the rice, the grinding medium is a stainless steel ball with a diameter of 0.5-2 mm, the ball-to-material ratio is 5:1 to 10:1, the ball mill speed is 1000-2000 rpm, the crushing time is 30-60 minutes, and the output particle size is 10-50 μm; the sieving is a 100-120 mesh sieve.

3. The method of claim 1, wherein the In step 1, a trace amount of vitamin C is added to the rice, and the added amount of vitamin C is 0.01% to 0.1% of the mass of the rice.

4. The method of claim 1, wherein the rice peptide drink In step 2, the complex enzyme is α-amylase, pullulanase and cellulase, the amount of the α-amylase, pullulanase and cellulase is 2-4% of the mass of rice, the amount of the α-amylase is 60-70% of the weight of the complex enzyme, the amount of the pullulanase is 20-30% of the weight of the complex enzyme, and the balance is cellulase; the enzymolysis temperature is 50-60 ° C, the pH is 4.5 to 5.5, and the time is 2-4h.

5. The method of claim 1, wherein: In step 2, in the ultrafiltration treatment, an ultrafiltration membrane with a molecular weight cut-off of 10,000-50,000 Da is used.

6. The method of making a rice peptide drink according to claim 1, wherein In step 3, the fermentation temperature is 50-60°C, the pH is 8.0-9.0, the fermentation shaker speed is 120-160 r / min, and the time is 4-6 hours.

7. The method of making a rice peptide drink according to claim 1, wherein In step 3, the fermentation auxiliary materials include 10-20 parts of peptone, 10-20 parts of rice starch hydrolysate, 5-10 parts of (NH4)2SO4, 5-10 parts of NaCl, 2-4 parts of K2HPO4, and 2-4 parts of CaCl2; the amount of fermentation auxiliary materials added is 4-8% of the mass of the raw material filtrate added in step 3, and Bacillus subtilis (Bacillus subtilis) The amount of added is 2-3% of the amount of the raw material filtrate added in step 3, and the amount of added recombinant Bacillus subtilis is 1-2% of the amount of the raw material filtrate added in step 3.

8. The method of making a rice peptide drink according to claim 1, wherein In step 3, the supercritical extraction conditions are: temperature 40-60°C, pressure 20-40 MPa, and time 1-2 h.

9. The method of making a rice peptide drink according to claim 1, wherein In step 4, during inoculation, plant lactobacillus (Lactobacillus plantarum) and Bifidobacterium lactis (Bifidobacterium lactis) Pre-culture to reach the logarithmic growth phase, Lactobacillus plantarum (Lactobacillus plantarum) and Bifidobacterium lactis (Bifidobacterium lactis) The inoculation amount is 5-10% (v / v) of the rice peptide solution; the fermentation temperature is 50-60℃, the pH is 6.5-7.0, the fermentation shaker speed is 120-160r / min, and the time is 12-24h.

10. The method of making a rice peptide drink according to claim 1, wherein: In step 5, the preparation process is to add additives, which include sweeteners (sucrose, glucose, sugar alcohol, etc.), flavorings (spices, fruit juice, etc.), functional ingredients (dietary fiber, vitamins and minerals), thickeners (sodium carboxymethyl cellulose, xanthan gum), stabilizers (gellan gum, agar) and / or antioxidants (microorganism C, vitamin E); the homogenization conditions are: primary homogenization pressure 10-20 MPa, temperature 35-45°C, homogenization time 1-2 minutes, secondary homogenization pressure 30-40 MPa, temperature 35-45°C, homogenization time 1-2 minutes; the sterilization conditions are kept at 72-75°C for 15-20 seconds, or kept at 63-65°C for 30 minutes.