A process for debittering wheat protein peptide dreg

Abstract

The present application relates to the technical field of wheat debittering, in particular to a process for debittering wheat protein peptide residue, comprising the following steps: S1. Preparing a peptide residue solution; S2. Adding 15-25 parts of debittering modification liquid to the peptide residue solution and filtering to obtain a preliminary modified peptide residue solution; S3. Adding 5-8 parts of modified flavor protease to the preliminary modified peptide residue solution and stirring, and water-bath heating to obtain a debittered peptide residue solution; S4. Removing the supernatant of the debittered peptide residue solution by using a separatory funnel, pouring the remaining liquid into a centrifuge tube, and taking the peptide residue precipitate after centrifugation; S5. Supercritical carbon dioxide extraction of the peptide residue precipitate, and then freeze-drying by using a freeze dryer to obtain a debittered peptide residue product. The raw material of the present application is wheat protein peptide residue, and the debittering of the wheat protein peptide residue is improved by adding debittering modification liquid and modified flavor protease, and the debittering effect is remarkable and the debittering efficiency is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wheat debittering, in particular to a process for debittering wheat protein peptide residue. BACKGROUND

[0002] Wheat protein powder has a protein content of up to 75-85%, contains fifteen essential amino acids for the human body, is a plant protein resource rich in nutrition, and has viscosity, elasticity, extension line, film forming property and fat absorption. Wheat protein peptide is a small molecular polypeptide material obtained by using multiple enzyme preparations, directional enzyme cutting and specific small peptide separation technology with wheat protein powder as raw material, and has the characteristics of good water solubility, dispersion stability, easy absorption and strong biological activity. Wheat protein peptide is widely used in various industries due to its excellent emulsifying and water holding capacity, such as feed production, skin care products, baking, functional protein beverages and dairy products, condiments, flour products, medical care and other industries. However, a large amount of wheat protein peptide residue containing bitter components is often produced in the production process of wheat protein peptide, which seriously restricts its direct utilization and market acceptance. The existing debittering technology has the problems of low efficiency, high cost, affecting the nutritional components of the product or introducing harmful substances. SUMMARY

[0003] In view of the deficiencies of the prior art, the purpose of the present application is to provide a process for debittering wheat protein peptide residue. The present application preliminarily debitters the peptide residue solution by using debittering modification liquid. The endo-enzyme of the complex flavor protease can cut the peptide bonds inside the polypeptide of the wheat protein peptide residue, and degrade the long-chain peptides into shorter peptide segments. Some of these short-chain peptides contain hydrophobic amino acids, and these peptide segments often have a bitter taste. The exo-enzyme is responsible for cutting and releasing amino acids from the ends of the polypeptide chain. In this way, the exo-enzyme can further degrade the bitter peptides into single amino acids, thereby effectively removing the bitterness.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical scheme:

[0005] A process for debittering wheat protein peptide residue, comprising the following steps:

[0006] S1. Preparing a peptide residue solution: 1-3 parts of wheat protein peptide residue are crushed for 10-15 minutes according to the mass fraction, and 15-25 parts of deionized water are added to prepare a peptide residue solution;

[0007] S2. Adding 15-25 parts of debittering modification liquid to the peptide residue solution and filtering to prepare a preliminarily modified peptide residue solution;

[0008] S3. Adding 5-8 modified flavor protease to the preliminary modified peptide residue solution and stirring, heating in 30-40℃ water bath for 1-3h, obtaining debittered peptide residue solution, adjusting PH value to 6-8;

[0009] S4. Removing supernatant of the debittered peptide residue solution by separating funnel, pouring the remaining liquid into centrifuge tube, centrifuging in centrifuge for 5-15min, and obtaining peptide residue precipitate;

[0010] S5. Supercritical carbon dioxide extraction of the peptide residue precipitate, and then freeze-drying, obtaining debittered peptide residue product;

[0011] Preferably, the preparation of the debittering modification solution comprises the following steps:

[0012] S201. Mixing and stirring 0.5-1 part of yeast, 0.1-0.2 part of distiller's high-activity dry yeast, 8-10 parts of deionized water and 2-3 parts of propyl alcohol solution, and then adding 0.2-1 part of sodium dihydrogen phosphate to obtain a primary modification solution;

[0013] S202. Adding 4-5 parts of activated carbon to the primary modification solution and stirring to fully mix the solution, obtaining a debittering modification solution.

[0014] Preferably, in step S3, the preparation of the modified flavor protease comprises the following steps:

[0015] S301. Inoculating Lactobacillus plantarum onto culture medium and placing in a 35-37℃ constant temperature incubator for 10-12h, picking Lactobacillus plantarum culture on the slant and inoculating into sterilized MRS liquid medium, culturing in a 35-37℃ constant temperature incubator for 10-12h, obtaining Lactobacillus plantarum seed liquid;

[0016] S302. Inoculating Bacillus subtilis onto culture medium and placing in a 35-37℃ constant temperature incubator for 10-12h, picking a ring of bacteria on the slant and inoculating into a shake flask seed culture medium, culturing at 35-37℃ with shaking for 10-12h, obtaining Bacillus subtilis seed liquid;

[0017] S303. Mixing and inoculating 10-15 parts of compound flavor protease, 1.5-4 parts of Lactobacillus plantarum seed liquid and 1-3 parts of Bacillus subtilis seed liquid according to mass fraction, and placing in a constant temperature shaker for 8-10h fermentation culture, obtaining modified flavor protease.

[0018] Preferably, in step S301, the culture medium is MRS solid slant medium.

[0019] Preferably, in step S302, the culture medium is LB solid slant medium.

[0020] Preferably, in step S302, the rotation speed of the oscillator is 120-150 rpm.

[0021] Preferably, in step S303, the temperature of the constant-temperature shaker is 35-37℃, and the rotation speed is 150-200 rpm.

[0022] Preferably, in step S2, the stirring time is 20-25 min, and the rotation speed is 350-450 r / min.

[0023] Preferably, in step S3, the rotation speed of the centrifuge is set to 4000-6000 r / min, and the temperature is 20-30℃.

[0024] Preferably, in step S4, the temperature of the supercritical carbon dioxide extraction is 35-40℃, and the pressure is 7.08-7.88 MPa.

[0025] Preferably, in step S201, the concentration of the propanol solution is 40%.

[0026] Compared with the prior art, the beneficial effects of the present application are:

[0027] 1. The process is simple, which is conducive to enterprise production, greatly reduces production cost, and has obvious industry competitive advantage.

[0028] 2. The present application improves the flavor of the wheat protein peptide residue by adding the debittering modification liquid and the modified flavor protease, and the debittering effect is remarkable, and the added strain can effectively improve the debittering efficiency.

[0029] 3. The compound flavor protease regulates the molecular weight and peptide chain structure of the hydrolyzate through precise hydrolysis, reduces the generation of bitter peptides, and at the same time, the action of exo-enzyme ensures that even if bitter peptides are generated, they can be degraded in time to avoid their residue in the final product. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The process flow chart of the debittering process of the wheat protein peptide residue of the present application;

[0031] Figure 2 The bitterness grade curve graph of the debittered peptide residue product obtained by the present application. DETAILED DESCRIPTION

[0032] The present application will be described in detail below with reference to the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0033] Please refer to Figures 1-2 The present application provides a technical solution:

[0034] Example 1

[0035] A process for debittering wheat protein peptide residue:

[0036] S1. Prepare a peptide residue solution: weigh 1g of wheat protein peptide residue and crush for 10 minutes, then add 150ml of deionized water to prepare a peptide residue solution;

[0037] S2. Preparation of debittering modification liquid:

[0038] S201. Mix and stir 0.5g of yeast, 0.1g of high-activity dry yeast for brewing, 80ml of deionized water, and 20ml of 40% concentration of propyl alcohol solution, then add 0.2g of sodium dihydrogen phosphate to obtain a primary modification liquid;

[0039] S202. Add 4g of activated carbon to the primary modification liquid and stir to fully mix the solution to obtain a debittering modification liquid;

[0040] S3. Add the debittering modification liquid to the peptide residue solution prepared in S1 and filter to obtain a preliminary modified peptide residue solution;

[0041] S4. Preparation of modified flavor protease:

[0042] S401. Inoculate Lactobacillus plantarum onto a culture medium and place it in a 35℃ constant temperature incubator for 10h. Pick the Lactobacillus plantarum culture on the slant and inoculate it into sterilized MRS liquid medium. Incubate it in a 35℃ constant temperature incubator for 10h to obtain Lactobacillus plantarum seed liquid;

[0043] S402. Inoculate Bacillus subtilis onto LB solid slant medium and place it in a 35℃ constant temperature incubator for 10h. Pick a ring of bacteria from the slant and inoculate it into a shake flask seed culture medium. Incubate it at 35℃ with 120rpm shaking for 10h to obtain Bacillus subtilis seed liquid;

[0044] S403. Mix and inoculate 10g of compound flavor protease, 1.5g of Lactobacillus plantarum seed liquid, and 1g of Bacillus subtilis seed liquid. Place it in a constant temperature shaker, set the temperature to 35℃ and the rotation speed to 150rpm, and perform 8h of fermentation culture to obtain modified flavor protease;

[0045] S5. Add 5g of modified flavor protease to the preliminary modified peptide residue solution and stir for 20min at a rotation speed of 350r / min. Heat it in a 30℃ water bath for 1h to obtain debittered peptide residue solution. Adjust the pH value to 6;

[0046] S6. Remove the supernatant of the debittered peptide residue solution by using a separating funnel, pour the remaining liquid into a centrifuge tube, and take the peptide residue precipitate after centrifugation in a centrifuge for 5 min, with the centrifuge set at a speed of 4000 r / min and a temperature of 20℃;

[0047] S7. Perform supercritical carbon dioxide extraction on the peptide residue precipitate, set the temperature to 35℃ and the pressure to 7.08 MPa, and then freeze-dry to obtain the debittered peptide residue product.

[0048] Example 2

[0049] A process for debittering wheat protein peptide residue:

[0050] S1. Prepare a peptide residue solution: weigh 3 g of wheat protein peptide residue, crush for 15 min, and add 250 ml of deionized water to obtain a peptide residue solution;

[0051] S2. Preparation of debittering modification liquid:

[0052] S201. Mix and stir 1 g of yeast, 0.2 g of brewing high-activity dry yeast, 100 ml of deionized water, and 30 ml of 40% concentration of propyl alcohol solution, and then add 1 g of sodium dihydrogen phosphate to obtain a primary modification liquid;

[0053] S202. Add 5 g of activated carbon to the primary modification liquid and stir to fully mix the solution to obtain a debittering modification liquid;

[0054] S3. Add the debittering modification liquid to the peptide residue solution prepared in S1 and filter to obtain a preliminary modified peptide residue solution;

[0055] S4. Preparation of modified flavor protease:

[0056] S401. Inoculate Lactobacillus plantarum onto a culture medium and place it in a 37℃ constant temperature incubator for 12 h, pick the Lactobacillus plantarum culture on the slant, and inoculate it into sterilized MRS liquid medium and culture it in a 37℃ constant temperature incubator for 12 h to obtain Lactobacillus plantarum seed liquid;

[0057] S402. Inoculate Bacillus subtilis onto LB solid slant medium and place it in a 37℃ constant temperature incubator for 12 h, pick a ring of bacterial moss from the slant, inoculate it into a shake flask seed culture medium, and culture it at 37℃ with 150 rpm shaking for 12 h to obtain Bacillus subtilis seed liquid;

[0058] S403. Mix and inoculate 15 g of compound flavor protease, 4 g of Lactobacillus plantarum seed liquid, and 3 g of Bacillus subtilis seed liquid, and place them in a constant temperature shaker, set the temperature to 37℃ and the speed to 200 rpm, and perform 10 h of fermentation culture to obtain modified flavor protease.

[0059] S5. Adding 8g modified flavor protease to the preliminary modified peptide residue solution and stirring for 25min at 450r / min, and adding 3h at 40℃ water bath to obtain the debittered peptide residue solution, adjusting the PH value to 8;

[0060] S6. Removing the supernatant of the debittered peptide residue solution by using a separatory funnel, and pouring the remaining liquid into a centrifuge tube, and taking the peptide residue precipitate after centrifugation for 15min in a centrifuge set at 6000r / min and 30℃;

[0061] S7. Supercritical carbon dioxide extraction of the peptide residue precipitate is set at 40℃ and 7.88MPa, and then freeze-drying is used to obtain the debittered peptide residue product.

[0062] Example 3

[0063] A process for debittering wheat protein peptide residue:

[0064] S1. Preparing a peptide residue solution: 2g of wheat protein peptide residue is crushed for 12min, and 200ml of deionized water is added to prepare a peptide residue solution;

[0065] S2. Preparation of debittering modification solution:

[0066] S201. Mixing and stirring 0.7g of yeast, 0.15g of high-activity dry yeast for brewing, 85ml of deionized water, and 25ml of 40% concentration of propanol solution, and then adding 0.4g of sodium dihydrogen phosphate to obtain a primary modification solution;

[0067] S202. Adding 4.4g of activated carbon to the primary modification solution and stirring to fully mix the solution to obtain a debittering modification solution;

[0068] S3. Adding the debittering modification solution to the peptide residue solution prepared in S1 and filtering to obtain a preliminary modified peptide residue solution;

[0069] S4. Preparation of modified flavor protease:

[0070] S401. Inoculating Lactobacillus plantarum onto a culture medium and placing it in a 36℃ constant temperature incubator for 11h, picking the Lactobacillus plantarum culture on the slant and inoculating it into sterilized MRS liquid medium, and culturing it in a 36℃ constant temperature incubator for 11h to obtain Lactobacillus plantarum seed liquid;

[0071] S402. Inoculate Bacillus subtilis on LB solid slant medium, and place in a 36°C constant temperature incubator for 11h. Pick a ring of bacterial lawn from the slant, and inoculate into a flask of seed culture medium. Incubate at 36°C with 130rpm shaking for 11h to obtain a seed solution of Bacillus subtilis;

[0072] S403. Mix 12g of complex flavor protease, 2g of Lactobacillus plantarum seed solution, and 2g of Bacillus subtilis seed solution, and inoculate in a constant temperature shaker. Set the temperature to 36°C and the rotation speed to 170rpm, and perform 9h of fermentation culture to obtain modified flavor protease;

[0073] S5. Add 6g of modified flavor protease to the preliminary modified peptide residue solution, and stir for 22min at a rotation speed of 400r / min. Heat in a 35°C water bath for 2h to obtain a debittered peptide residue solution, and adjust the pH to 7;

[0074] S6. Remove the supernatant of the debittered peptide residue solution using a separatory funnel, and pour the remaining liquid into a centrifuge tube. Centrifuge for 8min in a centrifuge set to a rotation speed of 5000r / min and a temperature of 25°C, and obtain the peptide residue precipitate.

[0075] S7. Perform supercritical carbon dioxide extraction on the peptide residue precipitate, set the temperature to 36°C and the pressure to 7.28MPa, and then freeze dry to obtain the debittered peptide residue product.

[0076] Example 4

[0077] A process for debittering wheat protein peptide residue:

[0078] S1. Prepare a peptide residue solution: according to the mass fraction, crush 2.5g of wheat protein peptide residue for 14min, and add 220ml of deionized water to obtain a peptide residue solution.

[0079] S2. Preparation of debittering modification liquid:

[0080] S201. Mix and stir 0.9g of yeast, 0.18g of high-activity dry yeast for brewing, 95ml of deionized water, and 28ml of 40% concentration of propyl alcohol solution, and then add 0.8g of sodium dihydrogen phosphate to obtain a primary modification liquid.

[0081] S202. Add 4.7g of activated carbon to the primary modification liquid and stir to mix the solution thoroughly to obtain a debittering modification liquid.

[0082] S3. Add the debittering modification liquid to the peptide residue solution prepared in S1 and filter to obtain a preliminary modified peptide residue solution.

[0083] S4. Preparation of modified flavor protease:

[0084] S401. Lactobacillus plantarum was inoculated on the culture medium and placed in a 36°C constant temperature incubator for 11h. Lactobacillus plantarum cultured on the slope was picked and inoculated into sterilized MRS liquid medium, and cultured in a 36°C constant temperature incubator for 11h to obtain Lactobacillus plantarum seed liquid;

[0085] S402. Bacillus subtilis was inoculated on LB solid slope culture medium and placed in a 36°C constant temperature incubator for 11h. A ring of bacteria was picked from the slope and inoculated into a shake flask seed culture medium, and cultured at 36°C and 140rpm for 11h to obtain Bacillus subtilis seed liquid;

[0086] S403. 14g of compound flavor protease, 3g of Lactobacillus plantarum seed liquid and 2.5g of Bacillus subtilis seed liquid were mixed and inoculated, and then placed in a constant temperature shaker, with the temperature set at 36°C and the rotation speed set at 180rpm, for 9h of fermentation culture to obtain modified flavor protease;

[0087] S5. 7g of modified flavor protease was added to the preliminary modified peptide residue solution and stirred for 24min at a rotation speed of 430r / min, and heated in a 38°C water bath for 2.5h to obtain a debittered peptide residue solution, and the pH value was adjusted to 7;

[0088] S6. The supernatant of the debittered peptide residue solution was removed by a separatory funnel, and the remaining liquid was poured into a centrifuge tube. After centrifugation in a centrifuge for 13min at a rotation speed of 5500r / min and a temperature of 28°C, the peptide residue precipitate was obtained;

[0089] S7. The peptide residue precipitate was subjected to supercritical carbon dioxide extraction at a temperature of 38°C and a pressure of 7.58MPa, and then freeze-dried to obtain a debittered peptide residue product.

[0090] Comparative Example 1

[0091] A process for debittering wheat protein peptide residue:

[0092] S1. Peptide residue solution was prepared: 1g of wheat protein peptide residue was crushed for 10min, and 150ml of deionized water was added to prepare a peptide residue solution;

[0093] S2. Preparation of modified flavor protease:

[0094] S201. Lactobacillus plantarum was inoculated on the culture medium and placed in a 35°C constant temperature incubator for 10h. Lactobacillus plantarum cultured on the slope was picked and inoculated into sterilized MRS liquid medium, and cultured in a 35°C constant temperature incubator for 10h to obtain Lactobacillus plantarum seed liquid;

[0095] S202. Bacillus subtilis is inoculated on LB solid slant medium and cultured in a 35°C constant temperature incubator for 10h, a ring of bacterial lawn is picked from the slant and inoculated into a flask seed culture medium, 35°C, 120rpm shaking culture for 10h to obtain a Bacillus subtilis seed solution;

[0096] S203. 10g of compound flavor protease, 1.5g of Lactobacillus plantarum seed solution and 1g of Bacillus subtilis seed solution are mixed and inoculated, and then placed in a constant temperature shaker, with a temperature setting of 35°C and a rotation speed of 150rpm, for 8h of fermentation culture to obtain modified flavor protease;

[0097] S3. 5g of modified flavor protease is added to the peptide residue solution and stirred for 20min at a rotation speed of 350r / min, and heated in a 30°C water bath for 1h to obtain a debittered peptide residue solution, and the pH value is adjusted to 6;

[0098] S4. The supernatant of the debittered peptide residue solution is removed by a separatory funnel, and the remaining liquid is poured into a centrifuge tube, and the peptide residue precipitate is obtained after centrifugation in a centrifuge for 5min, with a rotation speed setting of 4000r / min and a temperature of 20°C;

[0099] S5. The peptide residue precipitate is subjected to supercritical carbon dioxide extraction, with a temperature setting of 35°C and a pressure of 7.08MPa, and then freeze-dried to obtain a debittered peptide residue product.

[0100] Comparative Example 2

[0101] A process for debittering wheat protein peptide residue:

[0102] S1. Preparation of peptide residue solution: 1g of wheat protein peptide residue is crushed for 10min, and 150ml of deionized water is added to prepare a peptide residue solution;

[0103] S2 Preparation of debittering modification liquid:

[0104] S201. 0.5g of yeast, 0.1g of high-activity dry yeast for brewing, 80ml of deionized water and 20ml of 40% concentration of propyl alcohol solution are mixed and stirred, and then 0.2g of sodium dihydrogen phosphate is added to obtain a primary modification liquid;

[0105] S202. 4g of activated carbon is added to the primary modification liquid and stirred to fully mix the solution to obtain a debittering modification liquid;

[0106] S3. The debittering modification liquid is added to the peptide residue solution prepared in S1 and filtered to obtain a modified peptide residue solution;

[0107] S5. The modified peptide residue solution was subjected to supercritical carbon dioxide extraction at a temperature of 35℃ and a pressure of 7.08MPa, and then freeze-dried to obtain the debittered peptide residue product.

[0108] Performance testing:

[0109] According to standard GB 31611-2023 "National Food Safety Standard for Plant Protein Peptides for Food Processing", the taste dilution analysis was performed on the peptide residue products without bitterness obtained in Examples 1-4 and Comparative Examples 1-2. Wheat protein peptide residue samples were dissolved in a certain amount of water to prepare a solution of a certain concentration. The amount of water was gradually increased to dilute the sample solution until bitterness was imperceptible. Specific data were analyzed, where "+" indicates detected bitterness and "-" indicates no detected bitterness. The test results are shown in Table 1 below.

[0110] Table 1

[0111]

[0112] Comparative Example 1 lacked the debittering modification solution compared to Example 1, and Comparative Example 2 lacked the modified flavor protease compared to Example 1. Based on the bitterness test results, Example 3 showed the best debittering effect. By considering the different levels of bitterness perception achieved after adding 100-400ml of water, the bitterness perception after adding 300ml of water can be considered as a dividing line, and bitterness levels are classified accordingly. Example 1 is set as level 4, Example 2 as level 3, Example 3 as level 2, Example 4 as level 3, Comparative Example 1 as level 7, and Comparative Example 2 as level 9. A bitterness level line graph is then plotted, as shown below. Figure 2 As shown in the line graph, the debittering effect of Examples 1-4 is significantly greater than that of Comparative Examples 1-2. Therefore, both the debittering modification solution and the modified flavor protease can achieve a relatively significant debittering effect, complementing each other to achieve the optimal technical effect.

[0113] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A process for debittering wheat protein peptide residue, characterized in that, Includes the following steps: S1. Preparation of peptide residue solution: Weigh 1g of wheat protein peptide residue according to the mass fraction, crush it for 10min, and add 150ml of deionized water to prepare peptide residue solution. S2. Preparation of debittering modified solution: S201. Mix and stir 0.5g of yeast, 0.1g of high-activity dry brewing yeast, 80ml of deionized water and 20ml of 40% propanol solution, and then add 0.2g of sodium dihydrogen phosphate to obtain the primary modified solution. S202. Add 4g of activated carbon to the primary modified solution and stir to mix the solution thoroughly to obtain the debittering modified solution; S3. Add the debittering modification solution to the peptide residue solution obtained in S1 and filter to obtain a preliminarily modified peptide residue solution. S4. Preparation of modified flavor protease: S401. Inoculate Lactobacillus plantarum onto the culture medium and incubate at 35℃ for 10 hours. Pick the Lactobacillus plantarum cultured on the slant and inoculate it into sterilized MRS liquid culture medium. Incubate at 35℃ for 10 hours to obtain Lactobacillus plantarum seed culture. S402. Inoculate Bacillus subtilis onto LB solid slant medium and incubate at 35°C for 10 hours. Pick a loopful of bacterial growth from the slant and inoculate it into a shake flask seed culture medium. Incubate at 35°C and 120 rpm for 10 hours to obtain Bacillus subtilis seed culture. S403. Mix 10g of compound flavor protease, 1.5g of Lactobacillus plantarum seed liquid and 1g of Bacillus subtilis seed liquid and inoculate them. Place them in a constant temperature shaker, set the temperature to 35℃ and the rotation speed to 150rpm, and carry out fermentation culture for 8h to obtain modified flavor protease. S5. Add 5g of modified flavor protease to the preliminarily modified peptide residue solution and stir for 20min at a speed of 350r / min. Heat in a water bath at 30℃ for 1h to obtain the debittered peptide residue solution. Adjust the pH value to 6. S6. Remove the supernatant of the debittered peptide residue solution using a separatory funnel, pour the remaining liquid into a centrifuge tube, centrifuge for 5 minutes in a centrifuge, and then take the peptide residue precipitate. The centrifuge is set to a speed of 4000 r / min and a temperature of 20℃. S7. The peptide residue precipitate was subjected to supercritical carbon dioxide extraction at a temperature of 35°C and a pressure of 7.08 MPa, and then freeze-dried to obtain the debittered peptide residue product.

Images