A yeast extract and a method for preparing the yeast extract by a novel yeast autolysis process and applications thereof
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SOUTH CHINA UNIV OF TECH
- Filing Date
- 2026-04-15
- Publication Date
- 2026-08-07
AI Technical Summary
[0004]酿酒酵母作为酵母抽提物的优质原料，蛋白含量高、易培养、呈味物质释放效率高，但现有针对酿酒酵母的抽提物制备工艺，仍存在外源添加物利用率低、工艺步骤繁琐、产品易残留外源成分的问题
Smart Images
Figure CN122515439A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of biotechnology, specifically relating to a yeast extract and a novel yeast autolysis process for preparing yeast extract, as well as its application. Background Technology
[0002] Yeast extract is a natural seasoning made from yeast through a series of processes including autolysis, enzymatic hydrolysis, separation, and purification. This process releases and degrades the nutrients and flavor compounds within the yeast cells. Yeast extract is rich in components, primarily including amino acids, small peptides, nucleotides, reducing sugars, organic acids, and minerals. Due to its safety, naturalness, and strong flavor, it has become an indispensable raw material in the food industry.
[0003] In existing technologies, the preparation of yeast extracts often employs autolysis using a single protease (such as papain or flavor protease). While this achieves protein degradation, it suffers from limited autolysis efficiency and suboptimal product functional properties. Other methods involve adding chemical substances or autolysis promoters such as inorganic salts or sodium chloride, but excessive amounts can inhibit amino acid formation, and exogenous components are often discarded with the cell residue, making recycling impossible and resulting in raw material waste and significantly increased production costs. While physical methods assisted by enzymatic hydrolysis can improve autolysis efficiency, they are energy-intensive and difficult to adapt to industrial production. Curcumin, as a natural plant extract, is green and safe and can regulate microbial metabolic processes; however, there are currently no reports of combining curcumin with papain for the preparation of yeast extracts through autolysis.
[0004] Saccharomyces cerevisiae, as a high-quality raw material for yeast extracts, is high in protein, easy to cultivate, and has a high efficiency in releasing flavor compounds. However, existing processes for preparing yeast extracts still suffer from low utilization rates of exogenous additives, cumbersome process steps, and the tendency for exogenous components to remain in the product. Therefore, developing a yeast extract preparation method that combines excellent flavor and functional properties to achieve dual optimization of flavor and function, while simultaneously recovering exogenous components, can not only reduce costs but also expand the application areas of yeast extracts. Summary of the Invention
[0005] To address the shortcomings of existing technologies, the primary objective of this invention is to provide a novel method for preparing yeast extracts using a yeast autolysis process. This method involves the combined addition of papain and curcumin to synergistically regulate the yeast autolysis process, achieving both efficient protein degradation and optimized flavor characteristics. This endows the yeast extracts with significant functional properties, expanding its application range in the food seasoning field. Simultaneously, curcumin is recovered from the precipitate after enzyme inactivation and centrifugation, enabling its recycling and reducing production costs.
[0006] A second objective of this invention is to provide a yeast extract.
[0007] A third objective of this invention is to provide an application of yeast extract.
[0008] The primary objective of this invention can be achieved through the following technical solution:
[0009] A novel yeast autolysis process for preparing yeast extract includes the following steps:
[0010] (1) Yeast autolysis: The cultured brewing yeast was washed with water and centrifuged to obtain yeast sludge. Water was then added to prepare a yeast suspension, and the pH was adjusted. Papain and curcumin were added to synergistically promote yeast autolysis and form a yeast autosol solution. The concentration of the yeast suspension was 5% w / v, the amount of papain added was 240~264 U / mL, and the amount of curcumin added was 0.28~0.30% w / v. The pH of the yeast suspension was adjusted to 6~7.
[0011] (2) Inactivation of enzymes: Boil the yeast self solution from step (1) to inactivate enzymes, centrifuge, and obtain supernatant and precipitate (cell residue).
[0012] (3) Concentration and drying: The supernatant is concentrated under vacuum and spray dried to obtain yeast extract;
[0013] (4) Curcumin recovery: The precipitate obtained after centrifugation in step (2) is extracted with ethanol, concentrated under vacuum and freeze-dried to obtain curcumin.
[0014] Further, the *Saccharomyces cerevisiae* described in step (1) is cultured in 10 mL of YPD liquid medium at 30°C and 130-150 rpm for 24 h to form a *Saccharomyces cerevisiae* seed culture; the *Saccharomyces cerevisiae* seed culture is then inoculated with OD... 600 =0.1% biomass was expanded in 50 mL liquid culture medium. The culture medium used for expansion culture was: 1% w / v yeast extract, 1% w / v peptone, 1-2% w / v wheat gluten protein hydrolysate, and 1% w / v sucrose. Fermentation was carried out at 30℃ and 130-150 rpm for 18 h. The preparation method of the wheat gluten protein hydrolysate is as follows: wheat gluten protein and distilled water were mixed at a ratio of 1:10 (m / v), the solution was adjusted to pH 9.0, and preheated in a constant temperature water bath at 80-100℃ for 5-10 min. After cooling to room temperature, 1.0-1.5% trypsin was added and enzymatically hydrolyzed at 50℃ for 24 h. Then, the enzyme was inactivated in a boiling water bath for 15 min. After cooling, the mixture was centrifuged at 4℃ and 8000-10000 rpm for 15-20 min. The supernatant was collected and freeze-dried to obtain the wheat gluten protein hydrolysate.
[0015] Further, in step (1), the centrifugation speed is 8000~10000 rpm, the centrifugation time is 5~10 min; the yeast autolysis temperature is 50~55℃, the yeast autolysis speed is 130~150 rpm, and the yeast autolysis time is 15~17 h.
[0016] Further, in step (2), the enzyme inactivation parameters are: 100℃, 10 min; the centrifugation temperature is 4℃, the centrifugation speed is 8000~10000 rpm, and the centrifugation time is 5~10 min.
[0017] Further, in step (3), the specific parameters of the vacuum concentration are: temperature of 50-60℃, vacuum degree of -0.08--0.10 MPa, and concentration to a solid content of 25%-35%; the inlet air temperature of the spray drying is 140-160℃, and the outlet air temperature is 80-90℃.
[0018] Further, in step (4), the specific method of ethanol extraction is as follows: add 3 to 5 times the mass of the precipitate of 60 to 80% food-grade ethanol solution to the precipitate; stir and extract in a water bath at 50 to 60°C for 30 to 60 min at a speed of 200 to 300 r / min, and centrifuge at 8000 to 10000 rpm for 10 to 15 min.
[0019] Further, in step (4), the specific parameters for vacuum concentration are: vacuum concentration is carried out at 45~50℃ and -0.09~-0.10 MPa to remove ethanol solvent.
[0020] The second objective of this invention can be achieved through the following technical solution:
[0021] A yeast extract was prepared by the above-described method.
[0022] Furthermore, the yeast extract contains ≥330 mg / g of free α-amino nitrogen, ≥90 mg / g of total umami amino acids, and ≥42 mg / g of total sweet amino acids.
[0023] The third objective of this invention can be achieved through the following technical solution:
[0024] Application of a yeast extract in food seasonings.
[0025] Preferably, the food seasoning is crude soy sauce, and the amount of yeast extract added to the crude soy sauce is 0.5~1.0% w / v.
[0026] Compared with the prior art, the present invention has the following advantages and beneficial effects:
[0027] (1) The method for preparing yeast extract by the novel yeast autolysis process described in this invention uses a combination of papain and curcumin to autolyze yeast. Curcumin, as a natural plant extract, is green and safe and can significantly destroy the integrity of yeast cell membrane and reduce cell viability. Papain can promote the full hydrolysis of proteins. The two work together to achieve the accumulation of autolysate, so that the free α-amino nitrogen content is ≥330 mg / g.
[0028] (2) The yeast extract prepared by this invention is rich in umami amino acids and sweet amino acids, with a total umami amino acid content ≥90 mg / g and a total sweet amino acid content ≥42 mg / g. At the same time, it is rich in glutathione and other components, with excellent functional properties, rich aroma, and excellent quality, and has broad market application prospects.
[0029] (3) The present invention uses food-grade ethanol solution to extract curcumin, which has high extraction efficiency, no toxic solvent residue, and the ethanol can be recycled and reused; the recovered curcumin recovery rate is ≥85%, the purity is ≥90%, and it can be directly reused in yeast autolysis system without additional purification, which greatly reduces the raw material production cost.
[0030] (4) The present invention also provides the application of the above-mentioned yeast extract in crude soy sauce, with an addition amount of 0.5~1.0% w / v, which can significantly enhance the umami and mellowness of soy sauce and have a rich sense of layering.
[0031] (5) The process of this invention is simple, the conditions are mild, and it is suitable for industrial production. The yeast extract produced can be widely used in the field of soy sauce and other condiments, which has the dual advantages of improving product quality and reducing production costs, and has broad application prospects. Attached Figure Description
[0032] Figure 1 Bar charts showing the free α-amino nitrogen content of Examples 1-3 and Comparative Examples 1-2;
[0033] Figure 2 The bar chart shows the glutathione content of Examples 1-3 and Comparative Examples 1-2;
[0034] Figure 3 A bar chart showing the sensory scores of crude soy sauce with added Example 1 and commercially available yeast extract;
[0035] Figure 4 Electronic tongue analysis diagram of soy sauce crude oil with added Example 1 and commercially available yeast extract. Detailed Implementation
[0036] The technical solution of the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings, but the scope of protection and implementation of the present invention are not limited thereto.
[0037] Example 1
[0038] The method for preparing yeast extract using the novel yeast autolysis process described in this embodiment includes the following steps:
[0039] (1) Yeast autolysis: The cultured brewer's yeast was washed with water and centrifuged to obtain brewer's yeast sludge. Water was then added to prepare a yeast suspension, the pH was adjusted, and papain and curcumin were added to work synergistically to autolyze the yeast. The brewer's yeast was seed cultured in 10 mL YPD liquid medium at 30℃ and 150 rpm for 24 h. The brewer's yeast seed culture was inoculated with OD. 600 A biomass of 0.1 was cultured in 50 mL of liquid medium for expansion. The medium consisted of 1% w / v yeast extract, 1% w / v peptone, 2% w / v wheat gluten protein hydrolysate, and 1% w / v sucrose. Fermentation was carried out at 30°C and 150 rpm for 18 h. The wheat gluten protein hydrolysate for the culture medium was prepared as follows: wheat gluten protein and distilled water were mixed at a ratio of 1:10 (m / v), and the solution was adjusted to the optimal pH of trypsin at 9.0. The solution was preheated at 80°C for 10 min in a constant temperature water bath, cooled to room temperature, and then 1.0% trypsin was added. Enzymatic hydrolysis was carried out at 50°C for 24 h. The enzyme was then inactivated in a boiling water bath for 15 min. After cooling, the solution was centrifuged at 10,000 rpm for 15 min at 4°C. The supernatant was then freeze-dried to obtain the wheat gluten protein hydrolysate. The resulting brewer's yeast culture was centrifuged at 8,000 rpm for 10 min. The mixture was washed and centrifuged three times. Sterile water was added to the precipitate after centrifugation to make the final yeast suspension 5% w / v. The pH of the yeast suspension was adjusted to 6. The amount of papain added was 264 U / mL. The amount of curcumin added was 0.29% w / v. The yeast was allowed to autolyze at 50°C and 140 rpm for 16 h.
[0040] (2) Enzyme inactivation: Boil the yeast self solution from step (1) to inactivate the enzyme, centrifuge, and obtain the supernatant and precipitate (cell residue). The enzyme inactivation parameters are: 100℃, 10 min.
[0041] (3) Concentration and drying: The supernatant is concentrated under vacuum and spray dried to obtain yeast extract. The vacuum concentration temperature is 55℃, the vacuum degree is -0.09 MPa, and the concentration is carried out until the solid content is 30%; the spray drying inlet air temperature is 150℃ and the outlet air temperature is 85℃.
[0042] (4) Curcumin recovery: The precipitate obtained after centrifugation in step (2) is extracted with ethanol, concentrated and dried to recover curcumin; wherein, the ethanol extraction is carried out by adding 70% food-grade ethanol solution with 4 times the mass of the precipitate to the precipitate for extraction; the ethanol extraction parameters are: 55℃ water bath stirring extraction for 45 min, speed of 250 r / min, centrifugation at 8000 rpm for 15 min; the specific parameters of vacuum concentration are: vacuum concentration at 48℃ and -0.095 MPa to remove ethanol solvent, and freeze-drying to obtain pure curcumin, which is then sealed and protected from light.
[0043] Example 2
[0044] It is basically the same as Example 1, except that:
[0045] In step (1), the pH of yeast autolysis was adjusted to 7, the amount of papain added was 252 U / mL, the amount of curcumin added was 0.28% w / v, the temperature was 53℃, and the autolysis time was 15 h.
[0046] In step (4), ethanol extraction involves adding 3 times the mass of the precipitate to an 80% food-grade ethanol solution and extracting with stirring in a water bath at 60°C for 30 min. The rest of the process is the same as in Example 1.
[0047] Example 3
[0048] It is basically the same as Example 1, except that:
[0049] In step (1), the pH of yeast autolysis was adjusted to 6.5, the amount of papain added was 240 U / mL, the amount of curcumin added was 0.30% w / v, the temperature was 55℃, and the autolysis time was 17 h.
[0050] In step (4), ethanol extraction involves adding 5 times the mass of the precipitate to a 60% food-grade ethanol solution and extracting with stirring in a 50°C water bath for 60 min. The rest of the steps are the same as in Example 1.
[0051] Comparative Example 1
[0052] It is basically the same as Example 1, except that:
[0053] In step (1), only 264 U / mL papain was added during the yeast autolysis stage, and curcumin was not added. All other steps were the same as in Example 1.
[0054] Comparative Example 2
[0055] It is basically the same as Example 1, except that:
[0056] In step (1), only 0.29% curcumin was added during the yeast autolysis stage, and no papain was added. All other steps were the same as in Example 1.
[0057] Functional testing
[0058] The free amino acid composition, free α-amino nitrogen content, glutathione content, curcumin recovery rate, and purity of the yeast extracts prepared in Examples 1-3 and Comparative Examples 1-2 are as follows:
[0059] (1) Free amino acid composition: determined according to national standard GB 5009.124-2016.
[0060] As shown in Table 1, the free amino acid content of all examples was significantly higher than that of Comparative Example 1 and Comparative Example 2. At the same time, the umami amino acid content was ≥90 mg / g and the sweet amino acid content was ≥42 mg / g, indicating that papain and curcumin have a significant synergistic effect and can greatly increase the release of umami amino acids.
[0061] Table 1 shows the free amino acid composition in Examples 1-3 and Comparative Examples 1-2.
[0062]
[0063] (2) Determination of free α-amino nitrogen content: The determination was carried out in accordance with the national standard GB 5009.235-2016.
[0064] like Figure 1 The free α-amino nitrogen content of Examples 1-3 shown was ≥330 mg / g, which was significantly higher than that of Comparative Example 1 and Comparative Example 2. This indicates that compound autolysis can significantly improve the degree of yeast autolysis.
[0065] (3) Glutathione content determination: The content of glutathione was determined using a reduced glutathione content detection kit.
[0066] like Figure 2 The glutathione content of Examples 1-3 shown was significantly higher than that of Comparative Examples 1 and 2. Curcumin and papain played a synergistic role in the yeast autolysis process, increasing the release of flavor substances.
[0067] (4) Determination of curcumin recovery and purity: Curcumin was determined by high performance liquid chromatography (HPLC). The chromatographic conditions were as follows: C18 column (4.6 mm × 250 mm, 5 μm), mobile phase acetonitrile: 2% glacial acetic acid aqueous solution = 60:40 (V / V), detection wavelength 428 nm, flow rate 1.0 mL / min, column temperature 30℃, and injection volume 20 μL. A standard curve was established using curcumin standards, and quantification was performed based on peak area.
[0068] Curcumin recovery rate (%) = Mass of recovered curcumin / Mass of initial added curcumin × 100
[0069] Curcumin purity (%) = mass of curcumin in sample / total mass of sample × 100
[0070] As shown in Table 2, the curcumin recovery rate of both Examples and Comparative Example 2 was ≥85%, and the purity was ≥90%, which can be reused in the yeast autolysis system.
[0071] Table 2 shows the curcumin recovery in Examples 1-3 and Comparative Examples 1-2.
[0072]
[0073] The water retention, lipid binding capacity, emulsifying properties, and foaming properties of the yeast extract prepared in Example 1 and commercially available yeast extracts were determined as follows:
[0074] (4) Water retention determination: Mix 0.1 g of sample with 0.1 g of distilled water, vortex for 10 min, and then centrifuge the mixture at 6000 rpm for 25 min. After discarding the supernatant, place the centrifuge tube in an oven at 50°C for 30 min. Cool and weigh. Water retention is expressed as the amount of distilled water held by 1 g of sample.
[0075] As shown in Table 3, Example 1 has 88% better water retention than commercially available products, indicating that it can better bind water, reduce water separation, improve system stability, and extend product shelf life in liquid foods, condiments, sauces, and meat products.
[0076] (5) Determination of oil-binding capacity: Mix 0.2 g of sample with 2 mL of rapeseed oil and vortex for 30 min. Centrifuge the mixture at 6000 rpm for 25 min, discard the supernatant after centrifugation, and weigh the precipitate. Perform the same operation on the sample tube containing only 2 mL of rapeseed oil, and remove the measured amount of oil from the sample. Oil-binding capacity is expressed as the amount of rapeseed oil bound to 1 g of sample.
[0077] As shown in Table 3, the oil-binding ability of Example 1 is 80% higher than that of commercially available products. It can effectively stabilize the oil phase and improve the smoothness of the mouthfeel. In soy sauce, seasoning sauce and compound seasoning, it can enhance the flavor release and the mellow taste.
[0078] (6) Determination of emulsification properties: Mix 3 mL of sample solution with 1 mL of rapeseed oil and homogenize at 10000 g for 1 min using a homogenizer. After mixing, take 5 μL of emulsion from the bottom of the container at 0 and 10 min respectively, dilute with 0.1% SDS solution to 5 mL, and measure the absorbance at 500 nm. The formulas for calculating the emulsification activity index and emulsification stability index are as follows:
[0079] Emulsifying activity index (m 2 / g)=(2×2.303×A0×N) / (c×φ×10000)
[0080] Emulsion stability index (min) = A0 / (A0 - A 10 )×Δt
[0081] Where A0 is the absorbance measured immediately after the emulsion forms; A 10 The absorbance is measured 10 min after emulsion formation. N is the dilution factor, c is the protein concentration (g / mL), φ is the volume fraction of the oil phase in the emulsion, and Δt is 10 min.
[0082] As shown in Table 3, the emulsification activity index of Example 1 is 159% higher than that of commercially available products, and the emulsification stability is 80% higher. It can significantly improve the emulsification uniformity of the system, prevent layering, sedimentation, and floating oil, and make liquid condiments such as soy sauce more stable and have a finer texture.
[0083] (7) Determination of foam properties: Take 3 mL of sample solution, homogenize it at 15000 g for 2 min using a homogenizer, and record the foam height at 0 and 15 min. The formulas for calculating foaming properties and foam stability are as follows:
[0084] Foaming property (%) = (H0 - H) / H × 100
[0085] Foam stability (%) = H 15 / H0×100
[0086] Where H is the height of the solution before homogenization, H0 is the height of the foam when homogenization stops, and H 15 The height of the foam is the height of the foam after the homogenization process has stopped and the mixture has been left to stand for 15 minutes.
[0087] As shown in Table 3, Example 1 has 72% better foaming properties and 60% better foam stability than commercially available products. In applications such as seasoning liquids, beverages, and soup mixes, it can enhance the taste and flavor dispersion, making the flavor smoother and longer-lasting.
[0088] Table 3 compares the physicochemical properties of Example 1 with those of commercially available yeast extracts.
[0089]
[0090] (8) Application of yeast extract in crude soy sauce
[0091] The yeast extract prepared in Example 1 and a commercially available yeast extract were added to crude soy sauce at a dosage of 0.5% w / v, respectively, stirred evenly, and aged at room temperature for 72 h. Samples were taken for sensory evaluation and electronic tongue analysis.
[0092] like Figure 3 and 4As shown, the soy sauce crude oil with added Example 1 has the best overall flavor. Its umami value, sweetness value, mellowness, and aftertaste persistence are significantly higher than those of the blank group and the commercially available group, and it has no obvious bitterness or off-flavor. This indicates that the yeast extract of the present invention can significantly improve the quality of soy sauce, enhance the flavor layers and palatability, and has extremely high application value in the condiment industry.
[0093] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.
Claims
1. A novel yeast autolysis process for preparing yeast extract, characterized in that, Includes the following steps, (1) Yeast autolysis: The cultured brewing yeast was washed with water and centrifuged to obtain yeast sludge. Water was then added to prepare a yeast suspension, and the pH was adjusted. Papain and curcumin were added to synergistically promote yeast autolysis and form a yeast autosol solution. The concentration of the yeast suspension was 5% w / v, the amount of papain added was 240~264 U / mL, and the amount of curcumin added was 0.28~0.30% w / v. The pH of the yeast suspension was adjusted to 6~7. (2) Enzyme inactivation: Boil the yeast self solution from step (1) to inactivate the enzyme, centrifuge, and obtain the supernatant and precipitate; (3) Concentration and drying: The supernatant is concentrated under vacuum and spray dried to obtain yeast extract; (4) Curcumin recovery: The precipitate obtained after centrifugation in step (2) is extracted with ethanol, concentrated under vacuum and freeze-dried to obtain curcumin.
2. The method for preparing yeast extract using the novel yeast autolysis process according to claim 1, characterized in that, The *Saccharomyces cerevisiae* described in step (1) was cultured in 10 mL of YPD liquid medium for 24 h at 30°C and 130-150 rpm to form a *Saccharomyces cerevisiae* seed culture; the *Saccharomyces cerevisiae* seed culture was then inoculated with OD... 600 =0.1% biomass was expanded in 50mL liquid culture medium. The culture medium used for expansion culture was: 1% w / v yeast extract, 1% w / v peptone, 1-2% w / v wheat gluten protein hydrolysate, and 1% w / v sucrose. Fermentation was carried out at 30℃ and 130-150 rpm for 18h. The preparation method of the wheat gluten protein hydrolysate is as follows: wheat gluten protein and distilled water were mixed at a ratio of 1:10 (m / v), the solution was adjusted to pH 9.0, and preheated in a constant temperature water bath at 80-100℃ for 5-10 min. After cooling to room temperature, 1.0-1.5% trypsin was added and enzymatically hydrolyzed at 50℃ for 24 h. Then, the enzyme was inactivated in a boiling water bath for 15 min. After cooling, the mixture was centrifuged at 4℃ and 8000-10000 rpm for 15-20 min. The supernatant was collected and freeze-dried to obtain the wheat gluten protein hydrolysate.
3. The method for preparing yeast extract using the novel yeast autolysis process according to claim 1, characterized in that, In step (1), the centrifugation speed is 8000~10000 rpm and the centrifugation time is 5~10 min; the yeast autolysis temperature is 50~55℃, the yeast autolysis speed is 130~150 rpm, and the yeast autolysis time is 15~17 h.
4. The method for preparing yeast extract using the novel yeast autolysis process according to claim 1, characterized in that, In step (2), the enzyme inactivation parameters are: 100℃, 10 min; the centrifugation temperature is 4℃, the centrifugation speed is 8000~10000 rpm, and the centrifugation time is 5~10 min.
5. The method for preparing yeast extract using the novel yeast autolysis process according to claim 1, characterized in that, In step (3), the specific parameters of the vacuum concentration are: temperature of 50-60℃, vacuum degree of -0.08--0.10 MPa, and concentration to a solid content of 25%-35%; the inlet air temperature of the spray drying is 140-160℃, and the outlet air temperature is 80-90℃.
6. The method for preparing yeast extract using the novel yeast autolysis process according to claim 1, characterized in that, In step (4), the specific method of ethanol extraction is as follows: add 3 to 5 times the mass of the precipitate of 60 to 80% food-grade ethanol solution to the precipitate; stir and extract in a water bath at 50 to 60°C for 30 to 60 min at a speed of 200 to 300 r / min, and centrifuge at 8000 to 10000 rpm for 10 to 15 min; the specific parameters of vacuum concentration are as follows: vacuum concentration is carried out at 45 to 50°C and -0.09 to -0.10 MPa to remove the ethanol solvent.
7. A yeast extract, characterized in that, It is prepared according to any one of claims 1 to 6.
8. The yeast extract according to claim 7, characterized in that, The yeast extract contains ≥330 mg / g of free α-amino nitrogen, ≥90 mg / g of total umami amino acids, and ≥42 mg / g of total sweet amino acids.
9. The use of a yeast extract according to any one of claims 7 or 8 in a food seasoning.
10. The application of the yeast extract according to claim 9 in a food seasoning, wherein the food seasoning is crude soy sauce, and the amount of yeast extract added to the crude soy sauce is 0.5~1.0% w / v.