Process for preparing high-protein yeast extract from mixed organic matters

Abstract

The invention relates to a process for preparing a high-protein yeast extract from mixed organic matters, and belongs to the technical field of yeast extracts. According to the process provided by the invention, the yeast emulsion and the mixed organic matter are sequentially subjected to hydrolysis for four times, temperature control treatment and centrifugal separation to obtain clear liquid A and heavy liquid B, the heavy liquid B is treated to obtain byproduct cell walls, and the clear liquid A is treated to obtain a semi-finished product C; and finally, carrying out spray drying or single-effect concentration to obtain powdery high-protein yeast extract or pasty high-protein yeast extract. According to the present invention, the specific preparation method effectively improves the proliferation and the activity of the yeast, the uniform and stable yeast emulsion and the pure natural yeast extract are obtained, the utilization rate of the yeast is significantly improved, and the requirements of consumers on the pure natural food are met.

Description

Technical Field

[0001] The invention belongs to the technical field of yeast extracts and relates to a process for preparing high-protein yeast extracts by using mixed organic matter. Background Art

[0002] In recent years, with the improvement of people's living standards, people have put forward new requirements for the content of their diet. All kinds of food are increasingly developing in the direction of natural, convenient, delicious and multifunctional. Food seasonings have also shifted from the previously used brewed seasonings or chemical seasonings to the production of natural compound seasonings with more advanced tastes. At the same time, the seasoning market is also developing towards mid-to-high-end, delicious, convenient, natural and nutritious compound seasonings.

[0003] Since yeast extract contains amino acids and polypeptides, as well as a variety of effective ingredients such as nucleotides, vitamins, organic acids and minerals, it is rich in nutrition and has good processing performance. In some food processing, it often plays an effective role in enhancing the deliciousness and mellowness of the product, while alleviating the saltiness and sourness of the product and masking the odor. Yeast extract has been well applied in many food processing industries.

[0004] At present, some yeast extracts on the market are produced through a process of protease enzymolysis, reaction between processing aids, food additives and other food auxiliary materials, separation, concentration or drying to obtain yeast extracts. The yeast extracts are rich in various amino acids, have a more delicious taste, and have a strong ability to enhance the umami flavor of food. However, proteases, food additives, processing aids or other auxiliary materials are added in the preparation process, and the ingredients in the product are complex, which cannot meet consumers' pursuit of pure natural food, and the utilization rate of yeast is low. Summary of the invention

[0005] The purpose of the present invention is to provide a process for preparing a high-protein yeast extract using mixed organic matter. The present invention effectively improves the proliferation and activity of yeast through a specific preparation method, obtains a uniform and stable yeast emulsion and a pure natural yeast extract, significantly improves the utilization rate of yeast, and meets the needs of consumers for pure natural food.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A process for preparing high-protein yeast extract by using mixed organic matter, the process comprising the following steps:

[0008] S1, adding yeast emulsion and mixed organic matter accounting for ≥7% of the dry weight of yeast into a hydrolysis tank, and performing hydrolysis four times in sequence to obtain a hydrolysis solution;

[0009] S2, controlling the temperature of the hydrolyzed solution and centrifuging it to obtain a clear solution A and a heavy solution B;

[0010] S3, drying, crushing and packaging the heavy liquid B through a drum to obtain a by-product cell wall;

[0011] S4, concentrating the clear liquid A through triple effect to obtain semi-finished product C;

[0012] S5, spray-drying and packaging the semi-finished product C according to process 1 to obtain a powdery high-protein yeast extract;

[0013] S6. The semi-finished product C is concentrated and packaged according to process 2 to obtain a paste-like high-protein yeast extract.

[0014] Furthermore, the preparation method of the yeast emulsion in step S1 is:

[0015] Activating edible yeast to obtain yeast liquid, inoculating it into a culture medium at a volume ratio of 0.05-0.10:1, and then culturing it in a fermenter to obtain a yeast liquid, filtering out the culture medium residue after high-speed centrifugation to obtain preliminary yeast bodies, resuspending it in deionized water to obtain a suspension, centrifuging and concentrating it again to obtain concentrated yeast bodies, suspending the concentrated yeast bodies in a buffer, adjusting the pH to 6-6.5, adding 0.5-1wt% of glucose in the yeast emulsion, stirring at a speed of 20-40rmp at 28-30°C for 1-2h to perform activation treatment, and obtaining a yeast emulsion;

[0016] Furthermore, the edible yeast is selected from one or more of baker's yeast and brewer's yeast.

[0017] Furthermore, the activation step involves adding edible yeast to 30-35° C. warm water at a mass ratio of 1:10, and simultaneously adding glucose accounting for 1-2% of the mass of the warm water, stirring evenly at a speed of 20-40 rpm, and standing for 10-15 minutes to obtain a yeast solution.

[0018] Furthermore, the pH of the culture medium is 5.5-6, and the raw materials of the culture medium include 8-12g / L malt extract, 15-25g / L glucose, 4-6g / L ammonium sulfate, 0.5-1g / L potassium dihydrogen phosphate, 0.1-0.5g / L magnesium sulfate and the remainder deionized water, and the culture medium needs to be sterilized for 15-20min under the conditions of 121°C and 15pis high-pressure steam sterilizer before use.

[0019] Furthermore, the parameters of the fermentation tank culture are: temperature of 28-30°C, rotation speed of 200-300 rpm, time of 12-24 hours, and oxygen is introduced at a ventilation rate of 1-1.5 vvm during the culture period.

[0020] Furthermore, the speed and time of the high-speed centrifugation are 8000-10000 rpm and 10-15 min respectively; the speed and time of the secondary centrifugation and concentration are 3000-5000 rpm and 5-10 min respectively; and the concentration refers to concentration until the dry weight of yeast accounts for 15-20% of the mass of the suspension.

[0021] Furthermore, the buffer used for suspending the yeast cells in the buffer is 20 nM PBS, and the dry matter content in the yeast emulsion is 15-17%.

[0022] Furthermore, the mixed organic matter in step S1 is obtained by mixing ethyl acetate and alcohol in a volume ratio of 7:3, and the alcohol is 95% edible alcohol.

[0023] Furthermore, the four hydrolysis steps in step S1 are as follows: firstly, the first hydrolysis is carried out at 35-40°C for 2.5-3.5 hours to obtain hydrolyzate 1; the second hydrolysis is carried out at 40-45°C for 4.5-5.5 hours to obtain hydrolyzate 2; the third hydrolysis is carried out at 45-50°C to obtain hydrolyzate 3; and finally, the fourth hydrolysis is carried out at 50-55°C for 4.5-5.5 hours to obtain hydrolyzate 3.

[0024] Furthermore, the temperature control treatment in step S2 refers to heating the hydrolyzate to 85-95°C, keeping it warm for 25-35 minutes, and then cooling it to 50-60°C; the centrifugal parameters are: centrifugal speed ≧5000rpm, centrifugal flow rate ≦5m 3 / h.

[0025] Furthermore, the parameters of the drum drying in step S3 are: steam pressure of 1.0-1.5 MPa, feed volume of 2.5-3 m 3 / h; the pulverization is passed through a 60-mesh sieve of a pulverizer; the concentration temperature of the triple-effect concentration in step S4 is 50-60°C, and the semi-finished product is obtained by concentrating to a dry matter content of 40-45%; the spray drying parameters in step S5 are: the inlet air temperature is 170-180°C, the outlet air temperature is 100-110°C, and the feed amount is 0.5-0.7m 3 / h, the atomizer speed is 14500rpm; the temperature of the single-effect concentration in step S6 is 60-70°C, and the concentration is stopped when the dry matter content is 60-65%.

[0026] Beneficial effects of the present invention:

[0027] (1) The present invention prepares yeast emulsion by a specific preparation method, which effectively improves the proliferation and activity of yeast and the uniform stability of yeast emulsion. The obtained yeast emulsion can participate in the reaction at an appropriate concentration during the hydrolysis process, which helps to promote the effective progress of the subsequent hydrolysis reaction and avoids the problem of low reaction efficiency caused by too thin a concentration.

[0028] (2) The present invention adds a certain proportion of mixed organic matter to the cultivated edible yeast, and then performs four hydrolysis, temperature control treatment, and centrifugal separation in sequence to obtain a clear liquid A and a heavy liquid B, and then processes the heavy liquid B to obtain a byproduct cell wall, and processes the clear liquid A to obtain a semi-finished product C, and finally spray-drying or single-effect concentration to obtain a powdered high-protein yeast extract or a paste-like high-protein yeast extract. In addition to the mixed organic matter, no other protease, food additive, processing aid or other auxiliary material is added, and the mixed organic matter has been completely volatilized during the concentration and drying process. The obtained yeast extract is a pure yeast extract of full yeast components, which can effectively meet consumers' demand for pure natural food.

[0029] (3) The extract obtained by the present invention accounts for about 65% of the total yeast content, and the byproduct cell wall can be used for the production of high-content yeast β-glucan, which greatly improves the utilization rate of yeast. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0031] Figure 1 The present invention is a process flow chart for preparing high-protein yeast extract using mixed organic matter. DETAILED DESCRIPTION

[0032] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0033] Example 1

[0034] A process for preparing a high-protein yeast extract by using mixed organic matter, the process of this embodiment comprises the following steps:

[0035] S1, 10m 3 Yeast emulsion and 107 kg of mixed organic matter were added to a hydrolysis tank, at which time the dry matter content of the yeast emulsion was 15.5%, and hydrolysis was performed four times in sequence to obtain a hydrolysis solution;

[0036] S2, controlling the temperature of the hydrolyzed solution and centrifuging it to obtain a clear solution A and a heavy solution B;

[0037] S3, drying, crushing and packaging the heavy liquid B through a drum to obtain a by-product cell wall;

[0038] S4, concentrating the clear liquid A through triple effect to obtain semi-finished product C;

[0039] S5, spray-drying and packaging the semi-finished product C according to process 1 to obtain a powdery high-protein yeast extract;

[0040] S6. The semi-finished product C is concentrated and packaged according to process 2 to obtain a paste-like high-protein yeast extract.

[0041] The preparation method of the yeast emulsion in step S1 of this embodiment is:

[0042] The edible yeast is activated to obtain a yeast liquid, which is inoculated into a culture medium at a volume ratio of 0.075:1 and then placed in a fermenter for cultivation to obtain a yeast liquid, and the culture medium residue is filtered out after high-speed centrifugation to obtain a preliminary yeast body, which is then resuspended in deionized water to obtain a suspension, and is centrifuged and concentrated again to obtain a concentrated yeast body, and the concentrated yeast body is suspended in a buffer solution, and after the pH is adjusted to 6.25, glucose accounting for 0.75 wt% of the yeast emulsion is added, and the yeast emulsion is activated by stirring at a speed of 30 rmp at 29° C. for 1.5 hours to obtain a yeast emulsion.

[0043] The edible yeast of the present embodiment is baker's yeast.

[0044] The activation in this embodiment is to add edible yeast into 32.5°C warm water at a mass ratio of 1:10, and add glucose accounting for 1.5% of the mass of the warm water, stir evenly at a speed of 30 rpm, and stand for 12.5 minutes to obtain yeast solution.

[0045] The pH of the culture medium of this embodiment is 5.75. The raw materials of the culture medium include 10 g / L malt extract, 20 g / L glucose, 5 g / L ammonium sulfate, 0.75 g / L potassium dihydrogen phosphate, 0.3 g / L magnesium sulfate and the remainder deionized water. The culture medium needs to be sterilized for 17.5 min under the conditions of 121°C and 15 pis high-pressure steam sterilizer before use. The malt extract was purchased from Lanzhou Waterless Biotechnology Co., Ltd.

[0046] The parameters of the fermentation tank culture in this example are: temperature of 29° C., rotation speed of 250 rpm, culture time of 18 h, and oxygen is introduced at a ventilation rate of 1.25 vvm during the culture period.

[0047] The speed and time of high-speed centrifugation in this embodiment are 9000 rpm and 12.5 min respectively; the speed and time of centrifugation for re-centrifugation and concentration are 4000 rpm and 7.5 min respectively; and concentration refers to concentration until the dry weight of yeast accounts for 17.5% of the mass of the suspension.

[0048] In this example, the buffer used to suspend the yeast cells in the buffer is 20 nM PBS.

[0049] The mixed organic matter in step S1 of this embodiment is obtained by mixing ethyl acetate and alcohol in a volume ratio of 7:3, and the alcohol is 95% edible alcohol.

[0050] The four hydrolysis steps in step S1 of this embodiment are as follows: firstly, the first hydrolysis is carried out at 37.5°C for 3 hours to obtain hydrolyzate 1; the second hydrolysis is carried out at 42.5°C for 5 hours to obtain hydrolyzate 2; the third hydrolysis is carried out at 47.5°C to obtain hydrolyzate 3; and finally, the fourth hydrolysis is carried out at 52.5°C for 5 hours to obtain hydrolyzate 3.

[0051] The temperature control treatment in step S2 of this embodiment refers to heating the hydrolyzate to 90°C, keeping it warm for 30 minutes, and then cooling it to 55°C; the centrifugal parameters are: centrifugal speed of 5000rpm, centrifugal flow rate of 5m 3 / h.

[0052] In this embodiment, the parameters of drum drying in step S3 are: steam pressure of 1.25 MPa, feed volume of 2.75 m 3 / h; crushed and passed through a 60-mesh sieve of a crusher; the concentration temperature of the triple-effect concentration in step S4 is 55°C, and the semi-finished product is obtained by concentrating to a dry matter content of 42.5%; the spray drying parameters in step S5 are: the inlet air temperature is 175°C, the outlet air temperature is 105°C, and the feed amount is 0.6m 3 / h, the atomizer speed is 14500rpm; the temperature of the single-effect concentration in step S6 is 65°C, and the concentration is stopped when the dry matter content is 62.5%.

[0053] The index detection of this embodiment is shown in Table 1 below:

[0054] Table 1

[0055]

[0056] Example 2

[0057] A process for preparing a high-protein yeast extract by using mixed organic matter, the process of this embodiment comprises the following steps:

[0058] S1, 15m 3 Yeast emulsion and 169 kg of mixed organic matter were added to a hydrolysis tank, at which time the dry matter content of the yeast emulsion was 16.03%, and hydrolysis was performed four times in sequence to obtain a hydrolyzed solution;

[0059] S2, controlling the temperature of the hydrolyzed solution and centrifuging it to obtain a clear solution A and a heavy solution B;

[0060] S3, drying, crushing and packaging the heavy liquid B through a drum to obtain a by-product cell wall;

[0061] S4, concentrating the clear liquid A through triple effect to obtain semi-finished product C;

[0062] S5, spray-drying and packaging the semi-finished product C according to process 1 to obtain a powdery high-protein yeast extract;

[0063] S6. The semi-finished product C is concentrated and packaged according to process 2 to obtain a paste-like high-protein yeast extract.

[0064] The preparation method of the yeast emulsion in step S1 of this embodiment is:

[0065] The edible yeast is activated to obtain a yeast liquid, which is inoculated into a culture medium at a volume ratio of 0.075:1 and then placed in a fermenter for cultivation to obtain a yeast liquid, and the culture medium residue is filtered out after high-speed centrifugation to obtain a preliminary yeast body, which is then resuspended in deionized water to obtain a suspension, and is centrifuged and concentrated again to obtain a concentrated yeast body, and the concentrated yeast body is suspended in a buffer solution, and after the pH is adjusted to 6.25, glucose accounting for 0.75 wt% of the yeast emulsion is added, and the yeast emulsion is activated by stirring at a speed of 30 rmp at 29° C. for 1.5 hours to obtain a yeast emulsion.

[0066] The edible yeast of the present embodiment is baker's yeast.

[0067] The activation in this embodiment is to add edible yeast into 32.5°C warm water at a mass ratio of 1:10, and add glucose accounting for 1.5% of the mass of the warm water, stir evenly at a speed of 30 rpm, and stand for 12.5 minutes to obtain yeast solution.

[0068] The pH of the culture medium of this embodiment is 5.75. The raw materials of the culture medium include 10 g / L malt extract, 20 g / L glucose, 5 g / L ammonium sulfate, 0.75 g / L potassium dihydrogen phosphate, 0.3 g / L magnesium sulfate and the remainder deionized water. The culture medium needs to be sterilized for 17.5 min under the conditions of 121°C and 15 pis high-pressure steam sterilizer before use. The malt extract was purchased from Lanzhou Waterless Biotechnology Co., Ltd.

[0069] The parameters of the fermentation tank culture in this example are: temperature of 29° C., rotation speed of 250 rpm, culture time of 18 h, and oxygen is introduced at a ventilation rate of 1.25 vvm during the culture period.

[0070] The speed and time of high-speed centrifugation in this embodiment are 9000 rpm and 12.5 min respectively; the speed and time of centrifugation for re-centrifugation and concentration are 4000 rpm and 7.5 min respectively; and concentration refers to concentration until the dry weight of yeast accounts for 17.5% of the mass of the suspension.

[0071] In this example, the buffer used to suspend the yeast cells in the buffer is 20 nM PBS.

[0072] The mixed organic matter in step S1 of this embodiment is obtained by mixing ethyl acetate and alcohol in a volume ratio of 7:3, and the alcohol is 95% edible alcohol.

[0073] The four hydrolysis steps in step S1 of this embodiment are as follows: firstly, the first hydrolysis is carried out at 37.5°C for 3 hours to obtain hydrolyzate 1; the second hydrolysis is carried out at 42.5°C for 5 hours to obtain hydrolyzate 2; the third hydrolysis is carried out at 47.5°C to obtain hydrolyzate 3; and finally, the fourth hydrolysis is carried out at 52.5°C for 5 hours to obtain hydrolyzate 3.

[0074] The temperature control treatment in step S2 of this embodiment refers to heating the hydrolyzate to 90°C, keeping it warm for 30 minutes, and then cooling it to 55°C; the centrifugal parameters are: centrifugal speed of 5000rpm, centrifugal flow rate of 5m 3 / h.

[0075] In this embodiment, the parameters of drum drying in step S3 are: steam pressure of 1.25 MPa, feed volume of 2.75 m 3 / h; crushed and passed through a 60-mesh sieve of a crusher; the concentration temperature of the triple-effect concentration in step S4 is 55°C, and the semi-finished product is obtained by concentrating to a dry matter content of 42.5%; the spray drying parameters in step S5 are: the inlet air temperature is 175°C, the outlet air temperature is 105°C, and the feed amount is 0.6m 3 / h, the atomizer speed is 14500rpm; the temperature of the single-effect concentration in step S6 is 65°C, and the concentration is stopped when the dry matter content is 62.5%.

[0076] The index detection of this embodiment is shown in Table 2 below:

[0077] Table 2

[0078]

[0079]

[0080] Example 3

[0081] A process for preparing a high-protein yeast extract by using mixed organic matter, the process of this embodiment comprises the following steps:

[0082] S1, 14m 3 Yeast emulsion and 153 kg of mixed organic matter were added to a hydrolysis tank, at which time the dry matter content of the yeast emulsion was 15.53%, and hydrolysis was performed four times in sequence to obtain a hydrolysis solution;

[0083] S2, controlling the temperature of the hydrolyzed solution and centrifuging it to obtain a clear solution A and a heavy solution B;

[0084] S3, drying, crushing and packaging the heavy liquid B through a drum to obtain a by-product cell wall;

[0085] S4, concentrating the clear liquid A through triple effect to obtain semi-finished product C;

[0086] S5, spray-drying and packaging the semi-finished product C according to process 1 to obtain a powdery high-protein yeast extract;

[0087] S6. The semi-finished product C is concentrated and packaged according to process 2 to obtain a paste-like high-protein yeast extract.

[0088] The preparation method of the yeast emulsion in step S1 of this embodiment is:

[0089] The edible yeast is activated to obtain a yeast liquid, which is inoculated into a culture medium at a volume ratio of 0.075:1 and then placed in a fermenter for cultivation to obtain a yeast liquid, and the culture medium residue is filtered out after high-speed centrifugation to obtain a preliminary yeast body, which is then resuspended in deionized water to obtain a suspension, and is centrifuged and concentrated again to obtain a concentrated yeast body, and the concentrated yeast body is suspended in a buffer solution, and after the pH is adjusted to 6.25, glucose accounting for 0.75 wt% of the yeast emulsion is added, and the yeast emulsion is activated by stirring at a speed of 30 rmp at 29° C. for 1.5 hours to obtain a yeast emulsion.

[0090] The edible yeast of the present embodiment is baker's yeast.

[0091] The activation in this embodiment is to add edible yeast into 32.5°C warm water at a mass ratio of 1:10, and add glucose accounting for 1.5% of the mass of the warm water, stir evenly at a speed of 30 rpm, and stand for 12.5 minutes to obtain yeast solution.

[0092] The pH of the culture medium of this embodiment is 5.75. The raw materials of the culture medium include 10 g / L malt extract, 20 g / L glucose, 5 g / L ammonium sulfate, 0.75 g / L potassium dihydrogen phosphate, 0.3 g / L magnesium sulfate and the remainder deionized water. The culture medium needs to be sterilized for 17.5 min under the conditions of 121°C and 15 pis high-pressure steam sterilizer before use. The malt extract was purchased from Lanzhou Waterless Biotechnology Co., Ltd.

[0093] The parameters of the fermentation tank culture in this example are: temperature of 29° C., rotation speed of 250 rpm, culture time of 18 h, and oxygen is introduced at a ventilation rate of 1.25 vvm during the culture period.

[0094] The speed and time of high-speed centrifugation in this embodiment are 9000 rpm and 12.5 min respectively; the speed and time of centrifugation for re-centrifugation and concentration are 4000 rpm and 7.5 min respectively; and concentration refers to concentration until the dry weight of yeast accounts for 17.5% of the mass of the suspension.

[0095] In this example, the buffer used to suspend the yeast cells in the buffer is 20 nM PBS.

[0096] The mixed organic matter in step S1 of this embodiment is obtained by mixing ethyl acetate and alcohol in a volume ratio of 7:3, and the alcohol is 95% edible alcohol.

[0097] The four hydrolysis steps in step S1 of this embodiment are as follows: firstly, the first hydrolysis is carried out at 37.5°C for 3 hours to obtain hydrolyzate 1; the second hydrolysis is carried out at 42.5°C for 5 hours to obtain hydrolyzate 2; the third hydrolysis is carried out at 47.5°C to obtain hydrolyzate 3; and finally, the fourth hydrolysis is carried out at 52.5°C for 5 hours to obtain hydrolyzate 3.

[0098] The temperature control treatment in step S2 of this embodiment refers to heating the hydrolyzate to 90°C, keeping it warm for 30 minutes, and then cooling it to 55°C; the centrifugal parameters are: centrifugal speed of 5000rpm, centrifugal flow rate of 5m 3 / h.

[0099] In this embodiment, the parameters of drum drying in step S3 are: steam pressure of 1.25 MPa, feed volume of 2.75 m 3 / h; crushed and passed through a 60-mesh sieve of a crusher; the concentration temperature of the triple-effect concentration in step S4 is 55°C, and the semi-finished product is obtained by concentrating to a dry matter content of 42.5%; the spray drying parameters in step S5 are: the inlet air temperature is 175°C, the outlet air temperature is 105°C, and the feed amount is 0.6m 3 / h, the atomizer speed is 14500rpm; the temperature of the single-effect concentration in step S6 is 65°C, and the concentration is stopped when the dry matter content is 62.5%.

[0100] The index detection of this embodiment is shown in Table 3 below:

[0101] Table 3

[0102]

[0103] Example 4

[0104] A process for preparing a high-protein yeast extract by using mixed organic matter, the process of this embodiment comprises the following steps:

[0105] S1, 12.5m 3 Yeast emulsion and 135 kg of mixed organic matter were added to a hydrolysis tank, at which time the dry matter content of the yeast emulsion was 15.37%, and hydrolysis was performed four times in sequence to obtain a hydrolysis solution;

[0106] S2, controlling the temperature of the hydrolyzed solution and centrifuging it to obtain a clear solution A and a heavy solution B;

[0107] S3, drying, crushing and packaging the heavy liquid B through a drum to obtain a by-product cell wall;

[0108] S4, concentrating the clear liquid A through triple effect to obtain semi-finished product C;

[0109] S5, spray-drying and packaging the semi-finished product C according to process 1 to obtain a powdery high-protein yeast extract;

[0110] S6. The semi-finished product C is concentrated and packaged according to process 2 to obtain a paste-like high-protein yeast extract.

[0111] The preparation method of the yeast emulsion in step S1 of this embodiment is:

[0112] The edible yeast is activated to obtain a yeast liquid, which is inoculated into a culture medium at a volume ratio of 0.075:1 and then placed in a fermenter for cultivation to obtain a yeast liquid, and the culture medium residue is filtered out after high-speed centrifugation to obtain a preliminary yeast body, which is then resuspended in deionized water to obtain a suspension, and is centrifuged and concentrated again to obtain a concentrated yeast body, and the concentrated yeast body is suspended in a buffer solution, and after the pH is adjusted to 6.25, glucose accounting for 0.75 wt% of the yeast emulsion is added, and the yeast emulsion is activated by stirring at a speed of 30 rmp at 29° C. for 1.5 hours to obtain a yeast emulsion.

[0113] The edible yeast of the present embodiment is baker's yeast.

[0114] The activation in this embodiment is to add edible yeast into 32.5°C warm water at a mass ratio of 1:10, and add glucose accounting for 1.5% of the mass of the warm water, stir evenly at a speed of 30 rpm, and stand for 12.5 minutes to obtain yeast solution.

[0115] The pH of the culture medium of this embodiment is 5.75. The raw materials of the culture medium include 10 g / L malt extract, 20 g / L glucose, 5 g / L ammonium sulfate, 0.75 g / L potassium dihydrogen phosphate, 0.3 g / L magnesium sulfate and the remainder deionized water. The culture medium needs to be sterilized for 17.5 min under the conditions of 121°C and 15 pis high-pressure steam sterilizer before use. The malt extract was purchased from Lanzhou Waterless Biotechnology Co., Ltd.

[0116] The parameters of the fermentation tank culture in this example are: temperature of 29° C., rotation speed of 250 rpm, culture time of 18 h, and oxygen is introduced at a ventilation rate of 1.25 vvm during the culture period.

[0117] The speed and time of high-speed centrifugation in this embodiment are 9000 rpm and 12.5 min respectively; the speed and time of centrifugation for re-centrifugation and concentration are 4000 rpm and 7.5 min respectively; and concentration refers to concentration until the dry weight of yeast accounts for 17.5% of the mass of the suspension.

[0118] In this example, the buffer used to suspend the yeast cells in the buffer is 20 nM PBS.

[0119] The mixed organic matter in step S1 of this embodiment is obtained by mixing ethyl acetate and alcohol in a volume ratio of 7:3, and the alcohol is 95% edible alcohol.

[0120] The four hydrolysis steps in step S1 of this embodiment are as follows: firstly, the first hydrolysis is carried out at 37.5°C for 3 hours to obtain hydrolyzate 1; the second hydrolysis is carried out at 42.5°C for 5 hours to obtain hydrolyzate 2; the third hydrolysis is carried out at 47.5°C to obtain hydrolyzate 3; and finally, the fourth hydrolysis is carried out at 52.5°C for 5 hours to obtain hydrolyzate 3.

[0121] The temperature control treatment in step S2 of this embodiment refers to heating the hydrolyzate to 90°C, keeping it warm for 30 minutes, and then cooling it to 55°C; the centrifugal parameters are: centrifugal speed of 5000rpm, centrifugal flow rate of 5m 3 / h.

[0122] In this embodiment, the parameters of drum drying in step S3 are: steam pressure of 1.25 MPa, feed volume of 2.75 m 3 / h; crushed and passed through a 60-mesh sieve of a crusher; the concentration temperature of the triple-effect concentration in step S4 is 55°C, and the semi-finished product is obtained by concentrating to a dry matter content of 42.5%; the spray drying parameters in step S5 are: the inlet air temperature is 175°C, the outlet air temperature is 105°C, and the feed amount is 0.6m 3 / h, the atomizer speed is 14500rpm; the temperature of the single-effect concentration in step S6 is 65°C, and the concentration is stopped when the dry matter content is 62.5%.

[0123] The index detection of this embodiment is shown in Table 4 below:

[0124] Table 4

[0125]

[0126] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A process for preparing high-protein yeast extract by using mixed organic matter, characterized in that: The process comprises the following steps: S1, adding yeast emulsion and mixed organic matter accounting for ≥7% of the dry weight of yeast into a hydrolysis tank, and performing hydrolysis four times in sequence to obtain a hydrolysis solution; S2, controlling the temperature of the hydrolyzed solution and centrifuging it to obtain a clear solution A and a heavy solution B; S3, drying, crushing and packaging the heavy liquid B through a drum to obtain a by-product cell wall; S4, concentrating the clear liquid A through triple effect to obtain semi-finished product C; S5, spray-drying and packaging the semi-finished product C according to process 1 to obtain a powdery high-protein yeast extract; S6. The semi-finished product C is concentrated and packaged according to process 2 to obtain a paste-like high-protein yeast extract.

2. The process for preparing high-protein yeast extract by using mixed organic matter according to claim 1, characterized in that: The preparation method of the yeast emulsion in step S1 is: Activating edible yeast to obtain yeast liquid, inoculating it into a culture medium at a volume ratio of 0.05-0.10:1, and then culturing it in a fermenter to obtain a yeast liquid, filtering out the culture medium residue after high-speed centrifugation to obtain preliminary yeast bodies, resuspending it in deionized water to obtain a suspension, centrifuging and concentrating it again to obtain concentrated yeast bodies, suspending the concentrated yeast bodies in a buffer, adjusting the pH to 6-6.5, adding 0.5-1wt% of glucose in the yeast emulsion, stirring at a speed of 20-40rmp at 28-30°C for 1-2h to perform activation treatment, and obtaining a yeast emulsion; The edible yeast is selected from one or more of baker's yeast and brewer's yeast.

3. The process for preparing high-protein yeast extract by using mixed organic matter according to claim 2, characterized in that: The activation step is to add edible yeast into 30-35° C. warm water at a mass ratio of 1:10, and simultaneously add glucose accounting for 1-2% of the mass of the warm water, stir evenly at a speed of 20-40 rpm, and stand for 10-15 minutes to obtain yeast solution.

4. The process for preparing high-protein yeast extract by using mixed organic matter according to claim 2, characterized in that: The speed and time of the high-speed centrifugation are 8000-10000 rpm and 10-15 min respectively; the speed and time of the secondary centrifugation concentration are 3000-5000 rpm and 5-10 min respectively; the concentration refers to concentration until the dry weight of yeast accounts for 15-20% of the mass of the suspension.

5. The process for preparing high-protein yeast extract by using mixed organic matter according to claim 2, characterized in that: The buffer used for suspending the yeast cells in the buffer is 20 nM PBS, and the dry matter content in the yeast emulsion is 15-17%.

6. The process for preparing high-protein yeast extract by using mixed organic matter according to claim 1, characterized in that: The mixed organic matter in step S1 is obtained by mixing ethyl acetate and alcohol in a volume ratio of 7:3, and the alcohol is 95% edible alcohol.

7. The process for preparing high-protein yeast extract by using mixed organic matter according to claim 1, characterized in that: The four hydrolysis steps in step S1 are as follows: firstly, the first hydrolysis is carried out at 35-40°C for 2.5-3.5 hours to obtain hydrolyzate 1; the second hydrolysis is carried out at 40-45°C for 4.5-5.5 hours to obtain hydrolyzate 2; the third hydrolysis is carried out at 45-50°C to obtain hydrolyzate 3; and finally, the fourth hydrolysis is carried out at 50-55°C for 4.5-5.5 hours to obtain hydrolyzate 3.

8. The process for preparing high-protein yeast extract by using mixed organic matter according to claim 1, characterized in that: The temperature control treatment in step S2 refers to heating the hydrolyzate to 85-95°C, keeping it warm for 25-35 minutes, and then cooling it to 50-60°C; the centrifugal parameters are: centrifugal speed ≧5000rpm, centrifugal flow rate ≦5m 3 / h.

9. The process for preparing high-protein yeast extract by using mixed organic matter according to claim 1, characterized in that: The parameters of the drum drying in step S3 are: steam pressure of 1.0-1.5 MPa, feed volume of 2.5-3 m 3 / h; the pulverization is passed through a 60-mesh sieve of a pulverizer; the concentration temperature of the triple-effect concentration in step S4 is 50-60°C, and the semi-finished product is obtained by concentrating to a dry matter content of 40-45%; the spray drying parameters in step S5 are: the inlet air temperature is 170-180°C, the outlet air temperature is 100-110°C, and the feed amount is 0.5-0.7m 3 / h, the atomizer speed is 14500rpm; the temperature of the single-effect concentration in step S6 is 60-70°C, and the concentration is stopped when the dry matter content is 60-65%.

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