A method for preparing edible yeast peptides using waste beer yeast

Abstract

The present invention relates to a preparation method of edible yeast peptides using waste beer yeast, and belongs to the technical field of food processing. The method converts waste beer yeast into high-purity, low-ash edible yeast peptide powder through plate-frame filter pressing, drum drying, crushing and packaging, cleaning, aging and enzymolysis, enzyme inactivation and standing, activated carbon decolorization, filtration, vacuum concentration, membrane filtration and ultra-high temperature instantaneous sterilization (UHT), spray drying and other steps. The main feature of the present invention is that the ash content in the yeast peptide product is effectively reduced through a specific cleaning and enzymolysis process, while the yield and purity of the yeast peptide are improved. The prepared yeast peptide powder has excellent characteristics such as a peptide content of more than 75%, an ash content of less than 5.25%, a weight-average molecular weight of 380g / mol, and a peptide molecular weight of less than 1000D accounting for more than 95%. The method is simple in process, easy to operate, suitable for industrial production, and has broad market application prospects, especially in the field of functional foods.

Description

Technical Field

[0001] The present invention relates to the field of proteins and peptides, and in particular to a method for preparing edible yeast peptides by using waste beer yeast, in particular to a method for preparing edible yeast peptides by using waste beer yeast, which is a byproduct of beer production in a brewery, as a raw material. Background Art

[0002] Peptides are compounds formed by two or more amino acids connected by peptide bonds. There are three main ways for the human body to obtain peptides: one is through endogenous synthesis in the liver using amino acids as raw materials, the second is the production of food-derived proteins through gastrointestinal digestion, and the third is the direct ingestion of peptide products. Due to the large differences in individual digestive abilities and the different digestion conditions of food-derived proteins after oral administration, direct ingestion of peptide products is an important way for the human body to obtain target peptides. Studies have shown that there is a protective film on the surface of peptides to prevent secondary hydrolysis by various enzymes in the digestive tract, and to enter the human circulation in a complete form and exert its physiological function; and peptides can not only be absorbed by the small intestine through active transport, but also through assisted diffusion without consuming energy.

[0003] Bioactive peptides have the functions of lowering blood pressure, improving immunity, anti-oxidation, promoting digestion and absorption, and anti-diabetes. The mainstream protein raw materials of bioactive peptides include animal protein (such as whey protein, casein, collagen, etc.), plant protein (such as soy protein isolate, soy protein concentrate, pea protein, etc.) and microbial protein. Microbial protein is an emerging source of bioactive peptides, such as yeast protein, which has a reasonable amino acid composition, and its production is not affected by external natural conditions and seasonal factors. The production conditions are easy to control and it is not easy to have risks such as infectious viruses and genetically modified organisms.

[0005] There are few patents on extracting peptides from waste brewer's yeast, and the existing technology has some problems, such as too high ash content, too long enzymatic hydrolysis time, low yeast peptide yield and purity, etc. Therefore, there is a need for an extraction process that reduces the ash content in yeast protein products while increasing the yeast peptide yield and purity. Summary of the invention

[0006] The purpose of the present invention is to provide a method for preparing edible yeast peptides using waste brewer's yeast, which can overcome the problem of too high ash content in yeast protein in waste brewer's yeast during recovery and extraction, and take into account the yield and purity of yeast peptides.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A method for preparing edible yeast peptides using waste beer yeast, characterized in that it comprises the following steps:

[0009] Plate and frame filter press for waste beer yeast: the fermented waste yeast mud is pumped into the plate and frame of the filter, water is added to the autolysis tank and the temperature is raised to 70-90℃, the feed valve is opened, and then the pneumatic diaphragm pump of the raw material tank is turned on to start pumping. The pressure of the autolysis tank shall not exceed 0.15MPa. After 5-10 minutes of plate and frame pressing, it enters the clinker tank to obtain yeast liquid;

[0010] Drum drying: put the yeast liquid in the clinker tank in step 1 into a drum dryer, set the speed to 20-35r / min, the steam pressure to 0.25-0.45MPa, and the drum temperature to 90-140°C;

[0011] Crushing and packaging: Open the finished product bin fan, left or right damper, cyclone fan, and finished product bin fan in sequence. After the crusher runs smoothly, put the drum-dried yeast powder into the feeder. The feeder speed should not exceed 750Hz. Start the packaging scale, adjust the weight of each bag to 25kg, and start receiving the materials.

[0012] Washing: Wash the yeast powder obtained in step (3) with deionized water at a solid-liquid ratio of 1:5-1:20, wash at 40-45°C for 2-4 times, and finally centrifuge at 4000 r / min for 10 min in a high-speed centrifuge, discard the supernatant, and leave the bottom yeast liquid;

[0013] Aging and enzymolysis: The cleaned yeast solution was aged at 80-90°C for 30 min, then the pH of the yeast solution was adjusted to 7.0-8.0 with NaOH, the temperature was adjusted to 53-58°C, and 0.1-0.5% protease was added for enzymolysis for 2-8 hours;

[0014] Enzyme inactivation and static standing: keep the mixture at 85°C for 15 minutes to inactivate the protease, centrifuge it at 5000r / min for 5 minutes, collect the supernatant and obtain the enzymatic hydrolysis product;

[0015] Activated carbon decolorization: Use 3-5% activated carbon at 60°C for 30 minutes to absorb the ash in the yeast solution and reduce the ash content of the product;

[0016] Filtration: Filter the decolorized yeast hydrolysate, including plate and frame filtration, security filtration and nanofiltration;

[0017] Vacuum concentration: vacuum concentrate the filtered yeast solution to evaporate the water, reduce the volume of the system, and concentrate it to 40%-50% of the original volume;

[0018] Membrane filtration + UHT: The yeast solution after vacuum concentration is filtered by membrane, and then heated at 120±3℃ for 20s for ultra-high temperature instantaneous sterilization (UHT) to extend the shelf life of yeast peptides;

[0019] Spray drying finished product: The yeast liquid after UHT treatment is spray dried, the air inlet temperature is set to 178-182℃, the air outlet temperature is set to 90-105℃, the powder is collected and packaged to obtain the final yeast peptide powder.

[0020] As a further embodiment of the present invention, in step (4), the yeast powder is washed three times with deionized water at a solid-liquid ratio of preferably 1:10 at 40-45°C.

[0021] As a further embodiment of the present invention, in step (5), the amount of protease added is preferably 0.2%, and the enzymatic hydrolysis time is preferably 4 h.

[0022] As a further embodiment of the present invention, in step (5), the protease includes: at least one of, including but not limited to, alkaline protease and composite protease, preferably 0.1% each of composite protease and alkaline protease.

[0023] As a further solution of the present invention, it is characterized in that in step (7), the usage amount of the activated carbon is preferably 4%.

[0024] As a further embodiment of the present invention, in step (11), the moisture content of the yeast peptide powder obtained by spray drying is ≤5%.

[0025] As a further embodiment of the present invention, the peptide content of the prepared yeast peptide exceeds 75%, the ash content is ≤5.25%, the weight average molecular weight of the yeast peptide is about 380 g / mol, and the proportion of peptides with a molecular weight less than 1000D exceeds 95%.

[0026] Step (4) and step (7) are deashing operations. The raw material wort for beer fermentation has a high content of mineral components, which makes the ash content of the recovered waste yeast high. The ash content in the waste yeast can be effectively reduced by water washing.

[0027] The beneficial effects of the present invention are:

[0028] The preparation method of yeast peptide proposed in the present invention is to recover waste yeast mud from a beer brewing workshop, and obtain a yeast polypeptide product through a series of cleaning and enzymatic hydrolysis steps. The yeast polypeptide product is light yellow and has a special aroma. The ash content is less than 5% of the yeast peptide powder, the yeast peptide content is more than 75% and the weight-average molecular weight is 380g / mol, and the peptides with a molecular weight below 1000D account for 95.25%. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] In a specific embodiment of the present invention, a preparation method for separating edible yeast peptides from waste beer yeast is provided, and the specific steps are as follows:

[0031] S1. Plate and frame filter press for waste beer yeast: put the fermented waste yeast mud into the plate and frame, add water to the autolysis tank and heat it to 70-90℃, open the feed valve, and then turn on the pneumatic diaphragm pump of the raw material tank to start feeding. The pressure of the autolysis tank shall not exceed 0.15MPa, and it will enter the clinker tank after 5-10min of plate and frame pressing;

[0032] S2. Drum drying; the yeast solution in the clinker tank obtained in step 2 is beaten into the drum, the drum speed is 20-35r / min, the steam pressure is 0.25-0.45MPa, and the drum temperature of No. 1 and No. 2 is set at 90-140 ℃;

[0033] S3. Crushing and packaging: turn on the finished product bin fan, left or right damper, cyclone fan, and finished product bin fan in sequence. After the crusher runs smoothly, put the drum-dried yeast powder into the feeder. The feeder speed should not exceed 750Hz. Start the packaging scale, adjust the weight of each bag to 25kg, and start receiving the materials.

[0034] S4. Washing: Take a portion of the yeast powder obtained in step 4 and wash it 2-4 times at 40-45 ° C with deionized water at a solid-liquid ratio of 1:5-1:20, and centrifuge it at 4000r / min for 10min, pour off the supernatant, leaving the bottom yeast;

[0035] S5. Aging and enzymolysis: The cleaned yeast solution is aged at 80-90°C for 30 min, and then the pH of the yeast solution is adjusted to 7.0-8.0 with NaOH, the temperature is adjusted to 53-58°C, and 0.1-0.5% (preferably 0.2%) of protease (the protease includes but is not limited to alkaline protease, composite protease, etc., and the protease is preferably 0.1% of composite protease and alkaline protease respectively) is added for enzymolysis for 2-8h (preferably 4h);

[0036] S6. Inactivate the enzyme and let it stand: keep the mixture at 85°C for 15 min to inactivate the protease, centrifuge at 5000 r / min for 5 min, collect the supernatant and obtain the enzymatic hydrolysis product;

[0037] S7. Activated carbon decolorization: Use 3%-5% (preferably 4%) activated carbon, keep warm at 60°C for 30 minutes, absorb the ash in the yeast hydrolysate, and achieve the effect of reducing the ash content in the yeast peptide product;

[0038] S8. Filtration: including plate and frame filtration, security filtration and nanofiltration;

[0039] S9. Vacuum concentration to evaporate water, reduce the volume of the system, and concentrate to 40%-50% of the original volume, while preparing for the drying process;

[0040] S10. Membrane filtration + UHT: Sterilize at 120±3℃ for 20s to extend the shelf life of yeast peptides;

[0041] S11. Spray drying finished product: the air inlet temperature is set to 178-182°C, the air outlet temperature is 90-105°C, the powder is collected and packaged to obtain yeast peptide powder.

[0042] Table 1 shows the main experimental materials and manufacturers

[0043] Table 1 Experimental materials and manufacturers

[0044] Reagents Purity and type Manufacturer Deionized water 751628 Thermo Fisher Scientific Alkaline protease A1412 Beijing Rambolide Biotechnology Co., Ltd. Compound protease Protamex1.6 Novozymes (China) Biotech Co., Ltd. Activated carbon XK-FM1 Ningxia Zhulin Activated Carbon Co., Ltd. Sodium hydroxide 99％ Xilong Chemical Industry Co., Ltd. hydrochloric acid 99％ Xilong Chemical Industry Co., Ltd.

[0045] Table 2 shows the main experimental equipment models and manufacturers

[0046] Table 2 Experimental equipment and its information

[0047] Experimental equipment Model / Specification Manufacturer Autolysis tank mixing reducer DRE132M4 SEW-Motor (Suzhou) Co., Ltd. Drum reducer DRE180M4 SEW-Motor (Suzhou) Co., Ltd. Hammer Mill SFSP5630021 Changzhou Youde Machinery Co., Ltd. Rapid Moisture Tester MB23 Ohaus Instruments Ltd. pH Meter ST2100 Ohaus Instruments Ltd. High performance liquid chromatography Agilent1260 Agilent

[0048] The peptide determination in the yeast peptide powder of the present invention is to analyze the content of oligopeptides in the yeast peptides with reference to "6.3 oligopeptides" in the marine fish oligopeptide powder of the national standard of the People's Republic of China GB / T22729-2008. The principle is as follows: low molecular weight protein hydrolysate (including oligopeptides and free amino acids) is soluble in trichloroacetic acid solution, high molecular weight protein is easy to precipitate in trichloroacetic acid, after being dissolved in trichloroacetic acid, the protein and low molecular weight protein hydrolysate are separated by centrifugation, and then the content of protein hydrolysate in the supernatant is determined according to the method specified in CB / T 5009.5, and then the content of free amino acids in the supernatant is measured by an amino acid automatic analyzer, and the difference between the two is the oligopeptide content; the proportion of protein hydrolysate (including oligopeptides and a small amount of free amino acids) with a molecular weight lower than 1000u is determined by high performance gel filtration chromatography with reference to Appendix A of the national standard of the People's Republic of China GB / T 22729-2008; the ash content is determined by reference to the national standard of the People's Republic of China GB 5009.4 National Food Safety Standard Determination of Ash in Food Method 1 Determination of total ash in food for testing.

[0049] Oligopeptide content (on dry basis), % = acid-soluble protein hydrolyzate content in sample (on dry basis), % - free amino acid content in sample (on dry basis), % ash content (g / 100g) = (mass of crucible and ash - mass of crucible) / (mass of crucible and sample - mass of crucible) × 100;

[0050] Embodiment 1:

[0051] An embodiment of the present invention provides a method for preparing edible yeast peptides using waste brewer's yeast, comprising the following steps:

[0052] (1) Recycling of waste beer yeast: Saccharification is carried out according to the feed-water ratio of 1:5.0 for the gelatinization pot and 1:3.5 for the saccharification pot. Oxygen is added to the wort during the whole process of entering the tank, and the compressed air pressure is controlled at 10-12m 3 / h, oxygenate for 15-20min, at 1-3×10 7 / mL ratio of yeast, the temperature is adjusted to 27-30 ℃, the yeast multiplies in large quantities, and finally the waste yeast mud after fermentation is recovered; (2) waste beer yeast plate and frame filtration: the waste yeast mud after fermentation is pumped into the plate and frame, the autolysis tank is heated to 70 ℃ with water, the feed valve is opened, and then the pneumatic diaphragm pump of the raw material tank is opened to start pumping. The pressure of the autolysis tank shall not exceed 0.15MPa. After 5 minutes of plate and frame pressing, it enters the clinker tank; (3) drum drying: the yeast liquid in the clinker tank obtained in step 1 is pumped into the drum, the drum speed is 20-35r / min, and the steam pressure is 0.25-0.4 5MPa, the temperature of No. 1 and No. 2 rollers is 90-140℃; (4) Crushing and packaging: turn on the finished product bin fan, left air door or right air door, cyclone fan, finished product bin fan in sequence, and after the crusher runs smoothly, put the yeast powder dried by the drum into the feeder, the feeder speed does not exceed 750Hz, start the packaging scale, adjust the weight of each package to 25kg, and receive the material; (5) Cleaning: take a part of the yeast powder obtained in step 4, use pure water at a material-liquid ratio of 1:10, clean it 3 times at 40-45℃, and centrifuge it at a speed of 4000r / min for 10min, and discard the supernatant. The yeast on the bottom layer was left behind; (6) Aging and enzymolysis: The cleaned yeast solution was aged at 80-90°C for 30 min, and then the pH of the yeast solution was adjusted to 7.0-8.0 with NaOH, the temperature was adjusted to 53-58°C, and 0.1% alkaline protease and 0.1% composite protease were added for enzymolysis for 4 h; (7) Enzyme inactivation and standing: At 85°C, the protease was inactivated for 15 min, and the solution was centrifuged at 5000 r / min for 5 min, and the supernatant was collected to obtain the enzymolysis product; (8) Activated carbon decolorization: 4% activated carbon was used and the solution was kept at 60°C for 30 mi n, adsorbing ash in yeast hydrolysate to reduce the ash content in yeast peptide products; (9) Filtration: including plate and frame filtration, security filtration and nanofiltration; (10) Vacuum concentration to evaporate water, reduce the volume of the system, and concentrate to 40%-50% of the original volume, while preparing for the drying process; (11) Membrane filtration + UHT: heating at 120±3℃ for 20s to sterilize and extend the shelf life of yeast peptides; (12) Spray drying: the inlet temperature is set to 178-182℃, and the outlet temperature is 90-105℃; (13) Powder collection and packaging to obtain yeast peptide powder.

[0053] After testing, the yeast peptide obtained under this condition has a purity of 75%, an ash content of 5.25%, a weight-average molecular weight of 380 g / mol, and the proportion of peptides with a molecular weight less than 1000D exceeds 95%.

[0054] Embodiment 2:

[0055] An embodiment of the present invention provides a method for preparing edible yeast peptides using waste brewer's yeast, comprising the following steps:

[0056] (1) Recycling of waste beer yeast: The feed ratio is 1:5.0 for the gelatinization pot and 1:3.5 for the saccharification pot. The wort is oxygenated throughout the process of entering the tank and the compressed air pressure is controlled at 10-12m 3 / h, oxygenate for 15-20min, at 1-3×10 7 / mL ratio of yeast, the temperature is adjusted to 27-30 ℃, the yeast multiplies in large quantities, and finally the waste yeast mud after fermentation is recovered; (2) waste beer yeast plate and frame filtration: the waste yeast mud after fermentation is pumped into the plate frame, the autolysis tank is heated to 70 ℃ with water, the feed valve is opened, and then the pneumatic diaphragm pump of the raw material tank is opened to start pumping. The pressure of the autolysis tank shall not exceed 0.15MPa. After 5 minutes of plate and frame pressing, it enters the clinker tank; (3) drum drying: the yeast liquid in the clinker tank obtained in step 1 is pumped into the drum, the drum speed is 20-35r / min, the steam pressure is 0.25- 0.45MPa, the temperature of No. 1 and No. 2 rollers is between 90-140℃; (4) Crushing and packaging: turn on the finished product bin fan, the left damper or the right damper, the cyclone fan, and the finished product bin fan in sequence, and after the crusher runs smoothly, put the yeast powder dried by the drum into the feeder, the feeder speed does not exceed 750Hz, start the packaging scale, adjust the weight of each package to 25kg, and start receiving the material; (5) Cleaning: take a part of the yeast powder obtained in step 4, use pure water at a material-liquid ratio of 1:5, clean it twice at 40-45℃, and centrifuge it at a speed of 4000r / min for 10min , pour off the supernatant and leave the yeast at the bottom; (6) Aging and enzymolysis: The cleaned yeast solution was aged at 80-90°C for 30 minutes, and then the pH of the yeast solution was adjusted to 7.0-8.0 with NaOH, the temperature was adjusted to 53-58°C, and 0.1% alkaline protease was added for enzymolysis for 4 hours; (7) Enzyme inactivation and standing: At 85°C, keep warm for 15 minutes to inactivate the protease, and centrifuge at 5000r / min for 5 minutes, collect the supernatant, and obtain the enzymolysis product; (8) Activated carbon decolorization: Use 3% activated carbon, keep warm at 60°C for 30 minutes, absorb The ash in the yeast hydrolysate is removed to reduce the ash content in the yeast peptide product; (9) Filtration: including plate and frame filtration, security filtration and nanofiltration; (10) Vacuum concentration to evaporate water, reduce the volume of the system, and concentrate to 40%-50% of the original volume, while preparing for the drying process; (11) Membrane filtration + UHT: heat at 120±3℃ for 20s to sterilize and extend the shelf life of the yeast peptide; (12) Spray drying: the inlet temperature is set to 178-182℃, and the outlet temperature is 90-105℃; (13) Powder collection and packaging to obtain yeast peptide powder.

[0057] After testing, the yeast peptide obtained under this condition has a purity of 72%, an ash content of 7.56%, a weight-average molecular weight of 420 g / mol, and the proportion of peptides with a molecular weight less than 1000D exceeds 86%.

[0058] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0059] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0061] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for preparing edible yeast peptides using waste brewer's yeast, characterized in that: The steps include: (1) Plate and frame filter press for waste beer yeast: the fermented waste yeast mud is pumped into the plate and frame of the filter, water is added to the autolysis tank and the temperature is raised to 70-90°C, the feed valve is opened, and then the pneumatic diaphragm pump of the raw material tank is turned on to start pumping. The pressure in the autolysis tank shall not exceed 0.15MPa. After 5-10 minutes of plate and frame pressing, the waste yeast mud enters the clinker tank to obtain yeast liquid; (2) Drum drying: the yeast solution in the clinker tank of step (1) is pumped into a drum dryer, the speed is set to 20-35 r / min, the steam pressure is 0.25-0.45 MPa, and the drum temperature is set to 90-140° C.; (3) Crushing and packaging: Crushing the yeast powder obtained by drum drying to obtain waste beer yeast powder, and packaging it through a feeder. The speed of the feeder shall not exceed 750 Hz, and the weight of each package shall be 25 kg; (4) Cleaning: Clean the yeast powder obtained in step (3) with deionized water at a solid-liquid ratio of 1:5-1:20, at 40-45° C. for 2-4 times, and finally centrifuge at 4000 r / min for 10 min in a high-speed centrifuge, discard the supernatant, and leave the bottom yeast liquid; (5) Aging and enzymolysis: The cleaned yeast solution was aged at 80-90°C for 30 min, then the pH of the yeast solution was adjusted to 7.0-8.0 with NaOH, the temperature was adjusted to 53-58°C, and 0.1-0.5% protease was added for enzymolysis for 2-8 h; (6) Inactivation of enzyme: Keep the mixture at 85°C for 15 min to inactivate the protease, centrifuge it at 5000 r / min for 5 min, collect the supernatant and obtain the enzymatic hydrolysis product; (7) Activated carbon decolorization: Use 3-5% activated carbon at 60°C for 30 minutes to absorb the ash in the yeast solution and reduce the ash content of the product; (8) Filtration: Filter the decolorized yeast solution, including plate and frame filtration, security filtration and nanofiltration; (9) Vacuum concentration: The filtered yeast solution is vacuum concentrated to evaporate the water, reduce the volume of the system, and concentrate it to 40%-50% of the original volume; (10) Membrane filtration + UHT: The yeast solution after vacuum concentration was membrane filtered and then heated at 120 ± 3 °C for 20 s for ultra-high temperature instantaneous sterilization (UHT) to extend the shelf life of the yeast peptide; (11) Spray drying finished product: The yeast solution after UHT treatment is spray dried, the air inlet temperature is set to 178-182°C, the air outlet temperature is set to 90-105°C, the powder is collected and packaged to obtain the final yeast.

2. The preparation method according to claim 1, characterized in that: In step (1), the fermented waste yeast mud is obtained by fermenting the yeast used in Yanjing beer production at a certain inoculation amount.

3. The preparation method according to claim 1, characterized in that: In step (4), the yeast powder is washed three times with deionized water at a solid-liquid ratio of preferably 1:10 at 40-45°C.

4. The preparation method according to claim 1, characterized in that: In step (5), the amount of protease added is preferably 0.2%, and the enzymolysis time is preferably 4 h.

5. The preparation method according to claim 1, characterized in that: In step (5), the protease includes but is not limited to: alkaline protease, composite protease, preferably 0.1% each of alkaline protease and composite protease.

6. The preparation method according to claim 1, characterized in that: In step (7), the amount of activated carbon used is preferably 4%.

7. The preparation method according to claim 1, characterized in that: In step (11), the humidity of the yeast peptide powder obtained by spray drying is ≤5%.

8. The preparation method according to any one of claims 1 to 7, characterized in that: The peptide content of the prepared yeast peptide exceeds 75%, the ash content is ≤5.25%, the weight average molecular weight of the yeast peptide is about 380g / mol, and the proportion of peptides with a molecular weight less than 1000D exceeds 95%.