Saccharomyces cerevisiae for brewing brandy and application thereof

Abstract

The invention relates to the technical field of microorganisms and wine brewing, and discloses saccharomyces cerevisiae for brewing brandy and application of the saccharomyces cerevisiae. The saccharomyces cerevisiae provided by the invention has excellent aroma-producing and acid-producing properties, and has good tolerance to organic acids, glucose, pH, temperature and the like. By adopting the saccharomyces cerevisiae disclosed by the invention, high-quality brandy with richer flower fragrance, wine fragrance and sweet fragrance can be brewed, and a good foundation is provided for production and development of the high-quality brandy with distinct local characteristics.

Description

Technical Field

[0001] This invention relates to the fields of microbiology and brewing technology, and more specifically to brewing yeast for brandy production and its applications. Background Technology

[0002] Brandy is a distilled spirit made from grapes and other fruits through fermentation and distillation. In recent years, the Chinese brandy market has been expanding year by year, and with the increasing demand for high-end spirits, brandy has gradually gained market recognition.

[0003] Brandy base spirits are the foundation of brandy production, and their quality directly impacts the final product. Fermentation is a crucial process in brandy production, where yeast converts the sugars in fruit juice into alcohol and carbon dioxide, while simultaneously producing various flavor compounds. During fermentation, the choice of yeast significantly influences the quality of the base spirits, further affecting the quality and flavor of the brandy. The same raw materials fermented with different yeasts can yield different brandy base spirits, with varying expressions of volatile components such as esters and terpenes. Furthermore, unlike winemaking, fermented base spirits require distillation, aging, and blending to obtain brandy. The quality of the base spirits obtained during fermentation directly affects the effectiveness of subsequent processes, ultimately influencing the flavor and quality of the brandy.

[0004] In order to improve the quality of domestic brandy and highlight local characteristics, it is urgent to develop fermentation bacteria suitable for local brandy brewing and production. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems of existing technologies, such as the lack of distinctive local characteristics and style in domestically produced brandy, which makes it difficult to improve quality. This invention provides a brewing yeast for brandy production and its application. The brewing yeast provided by this invention is a local yeast with excellent aroma-producing properties, which helps to develop brandy products with a local style.

[0006] To achieve the above objectives, the present invention provides, on the one hand, a strain of brewing yeast ( Saccharomyces cerevisiae The preservation number of the brewing yeast is CGMCC No. 25848.

[0007] A second aspect of the present invention provides a microbial agent comprising the brewing yeast described in the first aspect.

[0008] The third aspect of this invention provides the application of the brewing yeast described in the first aspect, or the microbial agent described in the second aspect, in the brewing of brandy or brandy raw wine.

[0009] The fourth aspect of this invention provides the use of the brewing yeast described in the first aspect, or the microbial agent described in the second aspect, in improving the flavor and / or aroma style of brandy or brandy raw spirits.

[0010] The fifth aspect of this invention provides a method for brewing brandy raw materials, the method comprising: (1) The brewing yeast described in the first aspect is inoculated into fruit juice and / or fruit pulp, and fermented under brewing conditions to obtain brandy raw wine; or (2) The microbial agent described in the second aspect is inoculated into fruit juice and / or fruit pulp, and fermented under brewing conditions to obtain brandy raw wine.

[0011] The sixth aspect of the present invention provides a method for brewing brandy, the method comprising distilling the raw wine obtained by the method of the fifth aspect to obtain a distilled spirit.

[0012] The seventh aspect of the present invention provides the use of the brewing yeast described in the first aspect, or the microbial agent described in the second aspect, or the method described in the fifth or sixth aspect, in enhancing at least one of the floral, alcoholic, and sweet aromas of brandy.

[0013] Through the above technical solution, the present invention can achieve at least the following beneficial effects: (1) The brewing yeast provided by the present invention has the advantages of fast fermentation speed, high tolerance to acid stress and outstanding aroma production characteristics, and is especially suitable for use in the brewing of high-quality brandy raw materials from fruits with high acid content (such as grapes).

[0014] (2) The brewing yeast provided by the present invention is a local strain isolated from the local grape producing area. Experimental verification shows that it helps to improve the characteristics, flavor and quality of local brandy.

[0015] (3) Compared with existing commercially available fermentation bacteria, the brandy raw wine prepared using the brewing yeast provided by the present invention has richer floral, wine and sweet aromas, and the aroma is more complex, providing a foundation for the production of high-quality local brandy. Attached Figure Description

[0016] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein... Figure 1 This describes the colony morphology of the *Saccharomyces cerevisiae* on WL medium according to the present invention. Figure 2A This is the pH tolerance curve of the brewing yeast of the present invention; Figure 2B This is the organic acid tolerance curve of the brewing yeast of the present invention; Figure 2CThis is the temperature tolerance curve of the brewing yeast of the present invention; Figure 2D This is the glucose tolerance curve of the brewing yeast of the present invention; Figure 3 The sensory evaluation results are for brandy obtained by distillation of raw spirits brewed using the brewing yeast 60282 of the present invention and commercial yeast QA23.

[0017] Biological Preservation The brewing yeast provided by this invention is classified and named as follows: Saccharomyces cerevisiae It was deposited on September 30, 2022, at the China General Microbiological Culture Collection Center (CGMCC), located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, with accession number CGMCC No. 25848. Detailed Implementation

[0018] In this invention, unless otherwise specified, "(the brewing yeast provided by this invention)" refers to brewing yeast CGMCC No. 25848, and brewing yeast BC60282 (abbreviated as 60282) is the number assigned to this strain by the inventors during the research process. The two are the same strain, and their preservation number and (the number during the research process) can be used interchangeably in the following text.

[0019] Through long-term production and research, the inventors discovered that the fermentation of raw brandy in domestically produced brandy currently relies heavily on commercial yeasts. While commercial yeasts offer advantages such as stable fermentation and reliable performance, ensuring a certain level of product quality, their lack of specificity makes it difficult to fully express the local style of brandy, easily leading to product homogenization and hindering the production and development of high-quality domestic brandy. In contrast, local yeasts possess unique regional characteristics and flavor potential, capable of endowing brandy with more distinctive flavors. However, the development of local yeasts specifically for brandy raw materials is currently relatively limited, restricting further improvements in the flavor and characteristics of domestically produced brandy. Developing targeted local yeasts is crucial for creating brandy products with a Chinese style, helping to enhance the market competitiveness and brand value of domestically produced brandy.

[0020] During their research, the inventors of this invention isolated and cultured a large amount of wine yeast from naturally fermented Frey grape must in the Penglai production area, and ultimately obtained a wine yeast that possesses both good stress resistance and acid production capabilities, and can significantly enhance the aroma quality of brandy. Saccharomyces cerevisiae )BC60282.

[0021] Specifically, the brewing yeast BC60282 provided by this invention exhibits high stress resistance and can grow and ferment normally under conditions of pH 1.5 and 12 g / L organic acid (calculated as tartaric acid). This brewing yeast can also initiate fermentation at lower temperatures, thus ensuring the normal production of brandy raw materials. Further research has found that, in the production of brandy raw materials using Frei grapes from the Penglai region, the brewing yeast BC60282 of this invention, compared with the commercial yeast QA23, has advantages such as faster fermentation speed, higher acid content, and higher ester content. Furthermore, the brandy distilled from the raw material fermented using BC60282 has richer floral, alcoholic, and sweet aromas, with greater aroma complexity, providing a strong foundation for the production and development of high-quality local brandy.

[0022] Based at least on the above findings, the first aspect of the present invention provides a strain of brewing yeast, the brewing yeast having the preservation number CGMCC No. 25848.

[0023] A second aspect of the present invention provides a microbial agent comprising the brewing yeast described in the first aspect.

[0024] The microbial agent provided by this invention can be used for brewing. According to some preferred embodiments of the invention, the microbial agent may further include auxiliary materials acceptable for the brewing process, such as auxiliary materials used to aid yeast fermentation and growth. According to a preferred embodiment of the invention, the microbial agent may further include at least one of pectinase, a nitrogen source, and yeast polysaccharides. The method provided by this invention does not impose particular limitations on the amount of auxiliary materials used, and can be adjusted according to actual conditions (e.g., raw material characteristics, auxiliary material characteristics, product requirements, etc.). The nitrogen source can be a common nitrogen source in the art, such as peptone, yeast extract, etc.

[0025] The third aspect of this invention provides the application of the brewing yeast described in the first aspect, or the microbial agent described in the second aspect, in the brewing of brandy or brandy raw wine.

[0026] In this invention, "brandy" refers to a distilled spirit made from fruit (usually grapes) or fruit juice / pulp through fermentation, distillation, aging, and blending. "Brandy raw material spirit (also referred to as "raw material spirit" in this invention)" refers to the liquid obtained after fermentation of the raw material, which has not undergone distillation, aging, or blending. Generally, the aroma and flavor of the raw material spirit have a significant impact on the aroma and flavor of the brandy; brandy made from raw material spirits with rich and complex aromas also has a better aroma and flavor. Moreover, through distillation and aging, the aromatic substances in the raw material spirit further react, resulting in a better aroma and flavor in the brandy. Typically, the final brandy contains more and a wider variety of aromatic substances than the raw material spirit.

[0027] The inventors of this invention discovered in their research that the brandy raw material obtained by fermentation using the brewing yeast of this invention has a higher content of aroma substances, a richer aroma, and improved flavor quality compared to that obtained by fermentation using conventional commercially available strains.

[0028] Therefore, the fourth aspect of the present invention provides the use of the brewing yeast described in the first aspect, or the microbial agent described in the second aspect, in improving the flavor and / or aroma style of brandy or brandy raw spirit.

[0029] Preferably, improving the flavor and / or aroma style of brandy or brandy base spirit includes increasing the content of aroma substances, increasing the richness of aroma, and improving flavor quality, at least one of these.

[0030] The fifth aspect of this invention provides a method for brewing brandy raw materials, the method comprising: (1) The brewing yeast described in the first aspect is inoculated into fruit juice and / or fruit pulp, and fermented under brewing conditions to obtain brandy raw wine; or (2) The microbial agent described in the second aspect is inoculated into fruit juice and / or fruit pulp, and fermented under brewing conditions to obtain brandy raw wine.

[0031] According to a preferred embodiment of the present invention, the fruit juice and / or pulp contains 100-500 g / L of reducing sugar (calculated as glucose) and 1-15 g / L of total acid (calculated as tartaric acid).

[0032] For example, the reducing sugar (calculated as glucose) content in the fruit juice and / or pulp may be 100g / L, 150g / L, 200g / L, 250g / L, 300g / L, 320g / L, 340g / L, 350g / L, 360g / L, 380g / L, 400g / L, 420g / L, 440g / L, 450g / L, 460g / L, 480g / L, or 500g / L, or may be a range consisting of any two of the above values, or any intermediate value within that range.

[0033] Preferably, the reducing sugar (calculated as glucose) content in the fruit juice and / or pulp is 100-400 g / L.

[0034] For example, the total acid (calculated as tartaric acid) content in the fruit juice and / or pulp may be 1 g / L, 2 g / L, 3 g / L, 4 g / L, 5 g / L, 6 g / L, 7 g / L, 8 g / L, 9 g / L, 10 g / L, 11 g / L, 12 g / L, 13 g / L, 14 g / L, or 15 g / L, or may be a range consisting of any two of the above values, or any intermediate value within that range.

[0035] Preferably, the total acid (calculated as tartaric acid) content in the fruit juice and / or pulp is 1-8 g / L.

[0036] In the method provided by this invention, the juice / purse used can be prepared from any fruit in the art that can be used for brandy production, such as grapes, apples, cherries, strawberries, pears, peaches, apricots, etc. According to some preferred embodiments of the invention, the fruit used to prepare the juice and / or purse is grapes.

[0037] Preferably, the grape variety is selected from at least one of Frei, Longyan, Marselan, Cabernet Sauvignon, Merlot, Cabernet Franc, Syrah, Pinot Noir, D'Ambrosial, Sauvignon Blanc, Riesling, and Chardonnay.

[0038] According to a particularly preferred embodiment of the present invention, the fruit used to prepare the juice and / or pulp is grapes produced in the Penglai production area, preferably of the Frei grape variety.

[0039] According to a preferred embodiment of the present invention, the inoculum amount of the brewing yeast is 10. 5 -10 10 CFU / mL, or the amount of the inoculum is such that the inoculum size of *Saccharomyces cerevisiae* is 10. 5 -10 10 CFU / mL. "10" 5 -10 10 "CFU / mL" refers to the concentration of Saccharomyces cerevisiae in the inoculated system reaching 10 CFU / mL. 5 -10 10 The order of magnitude of CFU / mL, for example, 10 5 The order of magnitude of CFU / mL refers to the concentration of Saccharomyces cerevisiae in the system after inoculation being greater than or equal to 1 × 10⁻⁶. 5 CFU / mL to less than 1×10 6 CFU / mL. That is, in a preferred embodiment of the present invention, the inoculum amount of the brewer's yeast is greater than or equal to 1 × 10⁻⁶. 5 Up to 10 11 CFU / mL.

[0040] Preferably, the inoculation amount of the brewing yeast is 10. 5 -10 7 CFU / mL.

[0041] According to a preferred embodiment of the present invention, the brewing conditions include a fermentation temperature of 10-40°C.

[0042] For example, the fermentation temperature can be 10℃, 12℃, 14℃, 16℃, 18℃, 20℃, 22℃, 24℃, 26℃, 28℃, 30℃, 32℃, 34℃, 36℃, 38℃, or 40℃, or it can be any range consisting of any two of the above values, or any intermediate value within that range.

[0043] Preferably, the fermentation temperature is 13-40℃.

[0044] In some preferred embodiments, the brewing conditions may also include an (initial) pH of 1.5-7.

[0045] For example, the (initial) pH can be 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, or it can be a range consisting of any two of the above values, or any intermediate value within that range.

[0046] Preferably, the (initial) pH is 2.5-7, more preferably 3-7.

[0047] The sixth aspect of the present invention provides a method for brewing brandy, the method comprising distilling the raw wine obtained by the method of the fifth aspect to obtain a distilled spirit.

[0048] The method provided by this invention can employ techniques commonly used in the art for distilling raw wines to prepare the distilled spirits used in brandy. For example, the distillation method may include pot still distillation, column distillation, etc. The specific distillation method can be adjusted according to actual circumstances, such as by considering the characteristics of the raw materials and the needs of the product.

[0049] Preferably, the method may further include storing the distilled spirit.

[0050] In this invention, distilled spirits can be stored using conventional methods and conditions for preparing brandy in the art. For example, distilled spirits can be stored in containers such as oak barrels or earthenware jars.

[0051] The seventh aspect of the present invention provides the use of the brewing yeast described in the first aspect, or the microbial agent described in the second aspect, or the method described in the fifth or sixth aspect, in enhancing at least one of the floral, alcoholic, and sweet aromas of brandy.

[0052] The present invention will be described in detail below through embodiments. It should be understood that the following embodiments are only used to further explain and illustrate the content of the present invention by way of example, and are not intended to limit the present invention.

[0053] Unless otherwise specified, the methods used in the following examples are conventional methods. Unless otherwise specified, the reagents and materials used in the following examples are commercially available products purchased from reputable chemical or biological reagent / material suppliers, and all reagents are of analytical grade.

[0054] The culture medium formulations used in the following examples are as follows: YPD liquid culture medium: yeast extract, 10 g / L; glucose, 20 g / L; peptone, 20 g / L; natural pH. After preparation, sterilize at 121°C for 15 min.

[0055] YPD solid medium: Add 1.5 g / L agar to the YPD liquid medium before sterilization.

[0056] WL nutrient agar medium: yeast extract 4 g / L; ferric chloride 0.0025 g / L; glucose 50 g / L; manganese sulfate 0.0025 g / L; potassium chloride 0.425 g / L; bromocresol green 0.022 g / L; calcium chloride 0.125 g / L; agar 20 g / L; magnesium sulfate 0.125 g / L; acid-hydrolyzed casein 5 g / L; potassium dihydrogen phosphate 0.55 g / L; pH 5.5 ± 0.2. After preparation, autoclave at 121℃ for 15 min.

[0057] WL culture plates: After sterilization, pour the culture medium into plates when it has cooled to a temperature that is not too hot to touch (about 50°C), and then let it cool and solidify.

[0058] The grape juice preparation method used in the following examples is as follows: The grapes used are from the Penglai production area. They are pressed, filtered through gauze to remove solids such as skins and seeds, and then filtered to remove bacteria.

[0059] Example 1 This example illustrates the screening, identification, and preservation of Saccharomyces cerevisiae CGMCC No. 25848.

[0060] (a) Strain screening and identification Laboratory-scale fermentation was conducted using Frei grapes from the Penglai production area. Unsterilized Frei grapes were crushed and added to a fermentation vessel along with the skins, seeds, and juice, and fermented at a constant temperature of 18°C. The reducing sugar content was measured during fermentation, and samples were taken at different stages based on the consumption of reducing sugars. The samples were serially diluted and spread onto WL agar plates. After single colonies grew, strains with good growth and distinct characteristics were selected. The pH tolerance, organic acid tolerance, temperature tolerance, glucose tolerance, and hydrogen sulfide production of the selected strains were evaluated. Finally, a strain of *Saccharomyces cerevisiae* with good tolerance and no hydrogen sulfide production was obtained, designated BC60282.

[0061] The strain underwent morphological observation and molecular biological identification. The specific identification methods and results are as follows: (1) Morphological observation methods and results: Single colonies of BC60282 were picked and inoculated onto WL culture plates by streak method. After 48 hours of incubation at 30℃, the colony morphology was observed.

[0062] Figure 1 The colony morphology of strain BC60282 on WL culture plates is shown. As can be seen from the figure, the grown colonies are round, milky white, glossy, and have neat edges.

[0063] (2) Molecular biological identification methods and results: Identification was performed using 5.8S-ITS rDNA gene amplification and sequencing. Total DNA of the strain was used as a template, and PCR amplification was performed using the amplification system and procedure shown in Table 1 below, using universal primers for fungal ITS rDNA.

[0064] Table 1 PCR amplification system and procedure

[0065] The amplified PCR products were sent for sequencing, which was performed by Sangon Biotech (Shanghai) Co., Ltd. The ITS rDNA sequencing results of strain BC60282 were compared with data from NCBI. The results showed that this strain was compatible with... Saccharomyces cerevisiae It has 100% homology, and based on physiological and biochemical identification results, it is comprehensively identified as *Saccharomyces cerevisiae*. Saccharomyces cerevisiae ).

[0066] (II) Preservation of bacterial strains On September 30, 2022, the above-screened brewing yeast ( Saccharomyces cerevisiae BC60282 is deposited at the China General Microbiological Culture Collection Center (CGMCC), located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, with accession number CGMCC No. 25848.

[0067] Example 2 This example illustrates the stress resistance of Saccharomyces cerevisiae CGMCC No. 25848.

[0068] (a) Evaluation Methods Single colonies of strain 60282 were inoculated into 96-well plates containing sterile YPD liquid medium and incubated overnight at 30°C with shaking at 200 rpm to activate the strain. The stress resistance of this strain was then assessed using the following method.

[0069] (1) pH tolerance evaluation: The pH of YPD liquid medium was adjusted with hydrochloric acid to prepare YPD medium with different pH values. In the experimental group, activated strains from 96-well plates were transferred at an inoculum of 3% (v / v) to YPD liquid medium at pH 1.5, pH 2, pH 2.5, pH 3, pH 3.5, pH 4, pH 4.5, and pH 5. Simultaneously, the control group was transferred to unadjusted YPD liquid medium at the same inoculum (pH was measured to be approximately 6). After inoculation, the plates were cultured overnight at 30°C with shaking at 200 rpm, and OD was measured using a microplate reader. 600 The pH tolerance value is calculated according to the following formula I, and the pH tolerance curve of Saccharomyces cerevisiae 60282 is plotted based on the calculation results.

[0070] pH tolerance = experimental group OD 600 Value / Control Group OD 600 Value × 100% Formula I (2) Evaluation of organic acid tolerance: Tartaric acid was added to YPD liquid medium to prepare YPD liquid medium with different tartaric acid concentration gradients. In the experimental group, activated strains from 96-well plates were transferred at an inoculum of 3% (v / v) to YPD medium containing 4 g / L, 6 g / L, 8 g / L, 10 g / L, and 12 g / L tartaric acid, respectively. Simultaneously, the control group was transferred to YPD liquid medium without tartaric acid at the same inoculum. After inoculation, the plates were cultured overnight at 30℃ with shaking at 200 rpm, and the OD was measured using a microplate reader. 600 The organic acid tolerance value is calculated according to the following formula II, and the organic acid tolerance curve of Saccharomyces cerevisiae 60282 is plotted based on the calculation results.

[0071] Organic acid tolerance = experimental group OD 600 Value / Control Group OD 600 Value × 100% Formula II (3) Temperature tolerance evaluation: Activated strains from 96-well plates were transferred to YPD medium at an inoculum of 3% (v / v). The experimental groups were cultured overnight at 10℃, 13℃, 18℃, and 32℃ with shaking at 200 rpm, respectively. Meanwhile, the control group was cultured overnight at 30℃ with shaking at 200 rpm. OD was measured using a microplate reader. 600 The temperature tolerance value is calculated according to Formula III below, and the temperature tolerance curve of Saccharomyces cerevisiae 60282 is plotted based on the calculation results.

[0072] Temperature tolerance = experimental group OD 600 Value / Control Group OD 600 Value × 100% Formula III (4) Glucose tolerance evaluation: Glucose was added to YPD liquid medium to prepare YPD liquid medium with different glucose concentration gradients. In the experimental group, activated strains from 96-well plates were inoculated at 3% (v / v) into YPD medium with glucose concentrations of 200 g / L, 300 g / L, 400 g / L, and 500 g / L, respectively. Simultaneously, the control group was inoculated into YPD liquid medium with a glucose concentration of 20 g / L at the same inoculation rate. After inoculation, the plates were cultured overnight at 30°C with shaking at 200 rpm, and OD was measured using a microplate reader. 600 The glucose tolerance value was calculated according to the following formula IV, and the glucose tolerance curve of Saccharomyces cerevisiae 60282 was plotted based on the calculation results.

[0073] Glucose tolerance = experimental group OD 600 Value / Control Group OD 600 Value × 100% Formula IV (II) Evaluation Results Figures 2A-2D The pH tolerance curve, organic acid tolerance curve, temperature tolerance curve and glucose tolerance curve of strain 60282 are shown in the figure.

[0074] As shown in the figure, strain 60282 can grow and ferment normally under conditions of pH 1.5, 12 g / L organic acid, and 500 g / L glucose. This strain can also initiate fermentation at lower temperatures (e.g., 10°C), ensuring the normal brewing and production of the raw wine.

[0075] Example 3 This example illustrates the fermentation effect and acid and aroma production properties of brewing yeast CGMCC No. 25848 on brandy raw materials.

[0076] A small-scale fermentation experiment was conducted using sterilized Frei grape juice to test the fermentation effect and acid and aroma production properties of the *Saccharomyces cerevisiae* 60282 screened in Example 1. The specific methods are as follows: Saccharomyces cerevisiae 60282 and commercial Saccharomyces cerevisiae QA23, stored at -80℃, were subcultured on YPD solid and liquid media, respectively. Strains were picked from YPD plates and inoculated into Erlenmeyer flasks containing 100 mL of sterilized liquid YPD medium. The flasks were then incubated on a shaker (180 rpm, 30℃) for 24 h to serve as activated seed culture for inoculation. (The text abruptly ends here, likely due to an incomplete sentence or missing information.) 6 CFU / mL was inoculated into 300 mL of sterilized Frei grape juice (500 mL Erlenmeyer flask), sealed with a fermentation plug, and incubated statically at 14°C for 10-14 days until the final sugar content was <4 g / L, at which point fermentation was terminated to obtain the raw wine.

[0077] The winemaking characteristics were tested using the following methods: Ethanol, fructose, glucose, glycerol: liquid chromatography (GB / T 15038-2006); Content of volatile aroma compounds such as esters, higher alcohols, and organic acids: The types and contents of various volatile aroma compounds in the wine obtained above were detected using an Agilent 6890 gas chromatograph (GC) and an Agilent 5975 mass spectrometer (MS) (Agilent, USA). Specific conditions were as follows: a capillary column (HP-INNOWAX Polyethylene Glycol 60 m × 0.25 mm × 0.25 μm, J&W Scientific, USA) was used with high-purity helium as the carrier gas at a flow rate of 1 mL / min; headspace solid-phase microextraction was performed manually in splitless mode, inserted into the GC inlet, with an inlet temperature of 250℃ and thermal desorption for 25 min. The column oven temperature program was: 40℃ for 5 min, then increased to 200℃ at a rate of 3℃ / min and held for 2 min. The mass spectrometer interface temperature is 280℃, the ion source temperature is 230℃, the ionization mode is EI, the ion energy is 70 eV, and the mass scan range is 20-450 amu.

[0078] The comparison results of brewing characteristics between brewing yeast 60282 and commercial yeast QA23 are shown in Table 2-3.

[0079] Table 2. Physicochemical properties of the fermented raw materials of Saccharomyces cerevisiae 60282 and the control commercial strain QA23

[0080] Table 3. Concentration of aroma compounds in the fermented raw wine of Saccharomyces cerevisiae 60282 and control commercial strain QA23

[0081] Table 2 shows that at the end of fermentation, the final sugar content of the raw liquor brewed by 60282 was 2.89 g / L, indicating that fermentation was complete (<4 g / L). Table 3 shows that the acid content of the raw liquor brewed by 60282 was 1.7 times that of commercial yeast, and the ester content was significantly higher. The higher acid content in the brandy raw liquor contributes to the synthesis of more esters during distillation, thus improving the flavor and quality of the brandy.

[0082] Example 4 This example illustrates the effect of brewer's yeast CGMCC No. 25848 on the aroma style of brandy.

[0083] Fermentation experiments were conducted in a 50 L fermenter to compare the aroma profiles of the original brandy obtained by distillation after fermentation of Frei grape juice using strain 60282 and commercial yeast QA23.

[0084] The specific method is as follows: 60282 and commercial brewer's yeast QA23, stored at -80℃, were subcultured on YPD solid and liquid media, respectively. Strains were picked from YPD plates and inoculated into Erlenmeyer flasks containing 50 mL of sterilized liquid YPD medium. The flasks were then cultured on a shaker (180 rpm, 30℃) for 24 h to obtain activated seed culture for inoculation. (The text abruptly ends here, likely due to an incomplete sentence or missing information.) 6 Inoculations of 60282 and QA23 were performed at CFU / mL in 5 L of Frei grape juice, respectively. After standing for 24 h and warming, activated seed culture was obtained. The activated seed culture was added to a 50 L fermentation tank for fermentation. Fermentation ended when the reducing sugar concentration was <4 g / L, and the mixture was filtered to obtain the raw wine. The raw wine was then distilled using a double distillation method. First, the raw wine was distilled to obtain crude brandy. Then, the crude brandy was distilled again, and after removing the heads and tails, raw brandy with an alcohol content of 65% v / v was obtained.

[0085] For the original brandy samples obtained, a professional sensory evaluation was conducted with reference to the national brandy standard GB / T11856.2-2023 Quality Requirements for Spirits Part 2: Brandy. Ten experts were invited to conduct the evaluation, all of whom are national-level wine tasters from universities and enterprises, which have high authority and rationality.

[0086] The average scores given by the tasters for the tested wines are shown in the following results. Figure 3 The sensory evaluation results show that the original brandy distilled from the wine made by strain 60282 has higher floral, alcoholic, and sweet aromas, demonstrating good winemaking potential.

[0087] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A strain of brewer's yeast ( Saccharomyces cerevisiae ), characterized in that, The preservation number of the brewing yeast is CGMCC No. 25848.

2. A microbial agent, characterized in that, The microbial agent comprises the brewing yeast as described in claim 1.

3. The application of the brewing yeast of claim 1 or the microbial agent of claim 2 in the brewing of brandy or brandy raw wine.

4. The use of the brewing yeast of claim 1, or the microbial agent of claim 2, in improving the flavor and / or aroma style of brandy or brandy raw spirit.

5. A method for brewing brandy raw materials, characterized in that, The method includes: (1) The brewing yeast of claim 1 is inoculated into fruit juice and / or fruit pulp, and fermented under brewing conditions to obtain brandy raw wine; or (2) The microbial agent described in claim 2 is inoculated into fruit juice and / or fruit pulp, and fermented under brewing conditions to obtain brandy raw wine.

6. The method according to claim 5, wherein, The fruit juice and / or pulp contain 100-500 g / L of reducing sugar and 1-15 g / L of total acid.

7. The method according to claim 5 or 6, wherein, The fruit used to prepare the juice and / or pulp is grape, preferably the grape variety is selected from at least one of Frei, Longan, Marselan, Cabernet Sauvignon, Merlot, Cabernet Franc, Syrah, Pinot Noir, Tampifet, Sauvignon Blanc, Riesling and Chardonnay; And / or, the inoculation amount of the brewing yeast is 10. 5 -10 10 CFU / mL, or the amount of the inoculum is such that the inoculum size of *Saccharomyces cerevisiae* is 10. 5 -10 10 CFU / mL; And / or, the brewing conditions include: a fermentation temperature of 10-40°C.

8. A method for brewing brandy, characterized in that, The method includes distilling the raw wine obtained by the method of any one of claims 5-7 to obtain distilled wine.

9. The method according to claim 8, wherein, The method also includes storing the distilled spirit.

10. The use of the brewing yeast of claim 1, or the inoculant of claim 2, or the method of any one of claims 5-8 in enhancing at least one of the floral, alcoholic, and sweet aromas of brandy.

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