Compound yeast suitable for fermentation of sugar raw material wine and application thereof

Abstract

The application provides a compound yeast suitable for fermentation of a sugar raw material wine and application. The compound yeast comprises a yeast mixture and nutrients, the yeast mixture comprises at least one alcohol-producing yeast, at least one ester-producing yeast and at least one beta-phenylethanol-producing yeast, wherein the alcohol-producing yeast comprises Saccharomyces cerevisiae; the ester-producing yeast is at least selected from one of the following: Saccharomyces cerevisiae, Hansenula and Pichia fermentans; the beta-phenylethanol-producing yeast is at least selected from one of the following: Pichia kudriavzevii and Kluyveromyces; and the nutrients comprise a nitrogen source, a phosphorus source, inorganic salts and vitamins. The compound yeast of the application can be used for fermentation in a fermentation system with a sugar concentration of 240 g / L or more, and in the case of improving the fermentation efficiency, a fermentation product with a higher wine degree is obtained. Meanwhile, the flavor of the fermentation product can be enriched, and the fermentation wine with higher production efficiency and better quality is obtained.

Description

Technical Field

[0001] This invention relates to the field of wine fermentation technology, and more specifically, to a compound yeast suitable for fermenting wine from sugary raw materials and its application. Background Technology

[0002] Baijiu is a traditional Chinese distilled spirit with a long history of fermentation. It uses koji (large koji, small koji, or bran koji) as the saccharification and fermentation agent, employing a dual solid-state fermentation process where grains (sorghum, rice, glutinous rice, corn, etc.) undergo both saccharification and fermentation simultaneously. This is followed by solid-state distillation, storage, and blending, ultimately resulting in a distilled spirit containing thousands of trace components. In China, particularly in Guangdong and Guangxi, as well as in many countries rich in sugar resources such as Russia, Brazil, and Thailand, sugar-rich raw materials are commonly used for alcoholic or beverage fermentation. Common sugar-rich raw materials include sugarcane juice, malt extract, molasses, hydrolyzed starch, and sucrose. Vodka, whiskey, and rum from different countries and regions also utilize sugar-rich fermentation processes.

[0003] Traditional fermentation processes use a single type of alcohol yeast or baker's yeast for fermentation, with a sugar concentration below 240g / l. The problems include low alcohol content, generally around 12%, long fermentation cycle, and a monotonous flavor in the fermented wine.

[0004] With the continuous improvement of living standards, people's demand for alcoholic beverages, including the demand for flavor, is constantly increasing. Existing flavored compound yeast mainly solves the problem of high-alcohol fermentation using sugar raw materials. By selecting yeasts with excellent fermentation ability and special flavor, and combining them with appropriate fermentation nutrients, it can quickly ferment in a fermentation system with a sugar concentration of more than 240g / L, and the fermentation alcohol content can reach up to 21%, thereby greatly improving the fermentation efficiency. At the same time, the fermentation of flavored yeast can ensure the flavor quality of the fermented wine. Summary of the Invention

[0005] The main objective of this invention is to provide a compound yeast suitable for fermenting wines made from sugary raw materials and its application, so as to solve the problem of low fermentation efficiency under high sugar concentration conditions in the prior art.

[0006] To achieve the above objectives, according to a first aspect of the present invention, a compound yeast suitable for fermenting wines made from sugary raw materials is provided. The compound yeast comprises a yeast mixture and nutrients. The yeast mixture includes at least one alcohol-producing yeast, at least one ester-producing yeast, and at least one β-phenylethanol-producing yeast. The alcohol-producing yeast includes *Saccharomyces cerevisiae* with accession number CCTCC NO:M 2021171. The ester-producing yeast is selected from at least one of the following: *Saccharomyces cerevisiae* with accession number CCTCC NO:M2020118, *Hansenula polymorpha* with accession number CCTCC NO:M 2020174, and *Pichia pastoris* with accession number CCTCC NO:M2017780. The β-phenylethanol-producing yeast is selected from at least one of the following: *Pichia pastoris kudriezweig* with accession number CCTCC NO:M2021124 and *Kluyveromyces kluyveromyces* with accession number CCTCC NO:M 2020173. The nutrients include nitrogen sources, phosphorus sources, inorganic salts, and vitamins.

[0007] Further, by weight, the compound yeast comprises: 35-60 parts yeast, 20-35 parts nitrogen source, 10-15 parts phosphorus source, 5-15 parts inorganic salt, and 0.1-3 parts vitamin, wherein the nitrogen source is selected from at least one of the following: yeast extract, corn steep liquor powder, maltodextrin, and urea; the phosphorus source is selected from at least one of the following: ammonium dihydrogen phosphate, ammonium sulfate, and diammonium hydrogen phosphate; the inorganic salt is selected from at least one of the following: ammonium dihydrogen phosphate, magnesium sulfate, zinc sulfate, and calcium chloride; and the vitamin is selected from at least one of the following: VB1, calcium pantothenate, VB3, VB7, and inositol; preferably, in the yeast mixture, the weight percentage of alcohol-producing yeast is 30-50%, the weight percentage of ester-producing yeast is 3-5%, and the weight percentage of β-phenylethanol yeast is 2-8%.

[0008] Furthermore, the amino acid content in the yeast extract is 3–10 wt%.

[0009] To achieve the above objectives, according to a second aspect of the present invention, an application of the above-mentioned compound yeast for fermentation of saccharide raw materials is provided.

[0010] Furthermore, the sugar raw material is selected from hydrolyzed sugar, sucrose, or concentrated fruit juice; preferably, the initial fermentation sugar concentration of the sugar raw material is 240g / L-330g / L.

[0011] Furthermore, the fermentation of sugar raw materials includes fermenting sugar raw materials with compound yeast, wherein the amount of compound yeast added is 0.2-1% based on the mass-volume content of dry weight and fermentation liquid volume.

[0012] Furthermore, the fermentation temperature for sugary raw materials is 25-30℃.

[0013] Furthermore, the fermentation time for sugary raw materials is 3-15 days.

[0014] Furthermore, the alcohol content (v / v) of the fermentation product is 14-21%, the total ester content is 0.1g / L-0.5g / L, and the β-phenylethanol content is 0.05g / L-0.2g / L.

[0015] Furthermore, fermentation products include: alcoholic beverages, distilled spirits, or alcohol.

[0016] By applying the technical solution of this invention, the compound yeast of this invention contains yeast and nutrients with excellent fermentation ability and the ability to produce esters or β-phenylethanol. This compound yeast can ferment in a fermentation system with a sugar concentration of 240 g / L or higher, obtaining fermented products with higher alcohol content while improving fermentation efficiency. At the same time, it can enrich the flavor of the fermented products, resulting in fermented wine of higher quality with higher production efficiency. Detailed Implementation

[0017] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0018] As mentioned in the background section, the main problem with existing fermentation processes for sugary raw materials is that traditional fermentation processes utilize a single type of alcoholic yeast or baker's yeast, thus only suitable for fermenting sugary raw materials with a sugar concentration below 240 g / L, and resulting in low alcohol content, generally around 12%. Furthermore, traditional fermentation processes are inefficient and have long fermentation cycles. The flavor of the fermented wine also suffers from uniformity, affecting the sensory characteristics of the final product. Therefore, in this application, the inventors have improved the yeast used for fermentation. The compound yeast formula of this invention solves the technical problem of difficulty in efficiently fermenting sugary raw materials with a sugar concentration above 240 g / L in the prior art. Using the yeast of this invention, which has the ability to produce alcohol and esters, can improve the metabolism of fructose in sugary raw materials, thereby increasing the fermentation efficiency of the yeast and obtaining fermented products with higher alcohol content; while using yeast with the ability to produce β-phenylethanol can enhance the flavor of the fermented product. Therefore, the compound yeast of this invention can obtain fermented products with higher alcohol content and unique flavors even when using high-concentration sugary raw materials. Based on these research results, the applicant has proposed the technical solution of this application.

[0019] In a first typical embodiment of the present invention, a compound yeast suitable for fermenting wine from sugary raw materials is provided. The compound yeast comprises a yeast mixture and nutrients. The yeast mixture includes at least one alcohol-producing yeast, at least one ester-producing yeast, and at least one β-phenylethanol-producing yeast. The alcohol-producing yeast includes *Saccharomyces cerevisiae* with accession number CCTCC NO:M2021171. The ester-producing yeast is selected from at least one of the following: *Saccharomyces cerevisiae* with accession number CCTCC NO:M 2020118, *Hansenula polymorpha* with accession number CCTCC NO:M 2020174, and *Pichia pastoris* with accession number CCTCC NO:M2017780. The β-phenylethanol-producing yeast is selected from at least one of the following: *Pichia pastoris kudriezweig* with accession number CCTCC NO:M 2021124 and *Kluyveromyces kluyveromyces* with accession number CCTCC NO:M 2020173. The nutrients include nitrogen sources, phosphorus sources, inorganic salts, and vitamins.

[0020] The compound yeast of this invention is composed of a variety of yeasts and nutrients. The selected yeasts are selected yeast species with excellent fermentation capabilities, possessing the ability to produce alcohol, esters, or β-phenylethanol. This compound yeast can efficiently ferment sugar raw materials with a sugar concentration of 240 g / L or higher, improving production efficiency and solving the problem of monotonous flavor in traditional processes. Furthermore, the application of this compound yeast can increase the alcohol content of fermented wines. If subsequent distillation is required, this also significantly reduces energy consumption in the distillation process.

[0021] The proportions of each component in the above-mentioned compound yeast are crucial to its function, and any proportion that achieves the technical effect of this invention can be applied to this invention. In a preferred embodiment, the above-mentioned compound yeast, by weight, comprises: 35-60 parts yeast, 20-35 parts nitrogen source, 10-15 parts phosphorus source, 5-15 parts inorganic salt, and 0.1-3 parts vitamin, wherein the nitrogen source is selected from at least one of the following: yeast extract, corn steep liquor powder, maltodextrin, and urea; the phosphorus source is selected from at least one of the following: ammonium dihydrogen phosphate, ammonium sulfate, and diammonium hydrogen phosphate; the inorganic salt is selected from at least one of the following: ammonium dihydrogen phosphate, magnesium sulfate, zinc sulfate, and calcium chloride; and the vitamin is selected from at least one of the following: VB1, calcium pantothenate, VB3, VB7, and inositol; preferably, in the yeast mixture, the weight percentage of alcohol-producing yeast is 30-50%, the weight percentage of ester-producing yeast is 3-5%, and the weight percentage of β-phenylethanol yeast is 2-8%. The compound yeast components and their proportions mentioned above in this invention jointly affect the fermentation process of sugary raw materials. Compared with the traditional fermentation method that uses only a single yeast, the use of selected yeast and related nutrients to provide power for yeast growth and fermentation can better and more efficiently ferment high-concentration sugary raw materials.

[0022] Any yeast extract and inorganic salt that can achieve the technical effects of this invention can be used in this invention. In a preferred embodiment, the amino acid content in the yeast extract is 3-10 wt%. Yeast extracts containing a high amino acid content serve as nutrients, providing a rich and sufficient nitrogen source for yeast fermentation in compound yeast, and further supporting flavor enhancement during the fermentation process as an organic raw material.

[0023] In a second typical embodiment of the present invention, an application of the above-mentioned compound yeast in the fermentation of sugary raw materials is provided. Applying the above-mentioned compound yeast to the fermentation of sugary raw materials allows it to fully exert its function, providing support for the efficient production of fermented wines made from sugary raw materials.

[0024] Any sugary raw material that can be fermented using the compound yeast of this invention is applicable to this invention. In a preferred embodiment, the sugary raw material is selected from hydrolyzed sugar, sucrose, or concentrated fruit juice; the initial fermentation sugar concentration of the sugary raw material is 240 g / L-330 g / L. Many alcoholic or beverage fermentations are obtained through the fermentation of sugary raw materials. Traditional fermentation can ferment sugary raw materials with a sugar concentration below 240 g / L to achieve low alcohol content, while the compound yeast of this invention can efficiently ferment sugary raw materials with a sugar concentration above 240 g / L, greatly improving the technical limitations of sugary raw material fermentation.

[0025] In a preferred embodiment, the fermentation of the saccharide raw material includes mixing the saccharide raw material with a compound yeast and then fermenting it. Any amount of compound yeast added that achieves the fermentation effect of this invention is applicable to this invention. In a preferred embodiment, the amount of compound yeast added, based on the mass-volume content of dry weight and fermentation liquid, is 0.2-1%. Further limiting the amount of compound yeast added not only considers cost-saving economics but also provides strong data support for more efficient utilization of the compound yeast.

[0026] During fermentation, any fermentation time and temperature suitable for using the compound yeast of this invention are applicable to this invention. In a preferred embodiment, the fermentation temperature for sugary raw material fermentation is 25-30°C; the fermentation time for sugary raw material fermentation is 3-15 days. Using the compound yeast of this invention can shorten the fermentation time, improve fermentation efficiency, and provide favorable technical support for improving the production efficiency of subsequent fermented wines.

[0027] The product obtained by fermentation using the compound yeast of this invention has an alcohol content (v / v) of 14-21%, a total ester content of 0.1 g / L-0.5 g / L, and a β-phenylethanol content of 0.05 g / L-0.2 g / L. The preferred yeast species in the compound yeast of this invention possess the ability to produce esters or β-phenylethanol and have excellent fermentation capabilities. This not only increases the total ester and β-phenylethanol content in the fermentation product, enriching the flavor of the fermented wine, but also further increases the alcohol content of the fermentation product, resulting in a fermented wine with a higher alcohol content.

[0028] The fermentation product obtained by this invention can be any type of alcoholic beverage. In a preferred embodiment, the fermentation product includes: alcoholic beverages, distilled spirits, or alcohol. Using the compound yeast of this invention to prepare fermented beverages can yield fermentation products with higher alcohol content. If further preparation into distilled spirits is required, energy can be saved for subsequent distillation.

[0029] The present application will be further described in detail below with reference to specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed in this application. It should be noted that the yeasts used in the following embodiments are all known public yeasts, and the specific types are as follows:

[0030] Alcohol-producing yeasts include Saccharomyces cerevisiae with accession number CCTCC NO:M 2021171;

[0031] The ester-producing yeast is selected from at least one of the following: Saccharomyces cerevisiae with accession number CCTCC NO:M 2020118, Saccharomyces hansenii with accession number CCTCC NO:M 2020174, and Saccharomyces ferrugines with accession number CCTCC NO:M2017780.

[0032] The β-phenylethanol-producing yeast is selected from at least one of the following: Pichia kudricazwiel, with accession number CCTCC NO: M 2021124, and Kluyveromyces, with accession number CCTCC NO: M 2020173.

[0033] The yeast extract used in the following examples is Angel Yeast Co., Ltd.'s commercially available product, Angel Yeast Extract Powder FM803, product number 81000799.

[0034] Example 1

[0035] A compound yeast was prepared by mixing yeast and nutrients in the following proportions: 50 parts yeast, 30 parts nitrogen source, 10 parts phosphorus source, 8 parts inorganic salts, and 2 parts vitamins. The yeast consisted of *Saccharomyces cerevisiae* (CCTCC NO: M 2021171) at 40% by weight, *Kluyveromyces kluyveromyces* (CCTCC NO: M 2020173) at 7% by weight, and *Pichia pastoris* (CCTCC NO: M2017780) at 2% by weight. The nutrients included yeast extract, corn steep liquor, ammonium dihydrogen phosphate, magnesium sulfate, zinc sulfate, vitamin B1, calcium pantothenate, vitamin B3, and vitamin B7. Hydrolyzed sugar was used as the fermentation raw material, with an initial fermentation sugar concentration of 300 g / L. The compound yeast was added at 0.4% of the fermentation system. Fermentation was carried out at 25–30℃ for 7 days. The fermentation results are shown in Table 1.

[0036] Table 1. Fermentation results at an initial sugar concentration of 300 g / L

[0037]

[0038] The fermentation alcohol concentration reached 17.5%, which is 25-45% higher than the 12-14% fermentation concentration in traditional processes, greatly improving the fermentation efficiency. This increased alcohol concentration reduces energy consumption in the subsequent distillation process, ultimately resulting in a 45% alcohol distillate. The fermented liquor contains 0.35 g / L of total esters and 0.1 g / L of β-phenylethanol.

[0039] Example 2

[0040] A compound yeast was prepared by mixing yeast and nutrients in the following proportions: 47 parts yeast, 33 parts nitrogen source, 12 parts phosphorus source, 6 parts inorganic salts, and 2 parts vitamins. The yeast consisted of *Saccharomyces cerevisiae* (CCTCC NO: M2021171) at 42% by weight, *Pichia pastoris* (CCTCC NO: M2021124) at 2% by weight, and *Pichia pastoris Fiber* (CCTCC NO: M2017780) at 3% by weight. The nutrients included yeast extract, urea, ammonium dihydrogen phosphate, magnesium sulfate, zinc sulfate, and vitamins. Hydrolyzed sugar was used as the fermentation raw material, with an initial fermentation sugar concentration of 330 g / L. The compound yeast was added at 0.6% of the fermentation system. Fermentation was carried out at 25℃ for 14 days. The fermentation results are shown in Table 2.

[0041] Table 2. Fermentation results at an initial sugar concentration of 330 g / L

[0042]

[0043] The fermentation alcohol concentration reaches 20%, which is 42-66% higher than the 12-14% fermentation concentration in the traditional process. This increases the fermentation efficiency of the wine by more than 50%. The increased alcohol fermentation concentration reduces energy consumption in the subsequent distillation process. The final fermented liquid is distilled to a 45% alcohol content distilled wine. The total ester content in the fermented wine is 0.22g / l, and the β-phenylethanol content is 0.07g / l.

[0044] Example 3

[0045] A compound yeast was prepared by mixing yeast and nutrients in the following proportions: 35 parts yeast, 34.5 parts nitrogen source, 15 parts phosphorus source, 15 parts inorganic salts, and 0.5 parts vitamins. The yeast consisted of *Saccharomyces cerevisiae* (CCTCC NO: M2021171) at 30% by weight, *Kluyveromyces kluyveromyces* (CCTCC NO: M 2020173) at 2% by weight, and *Saccharomyces cerevisiae* (CCTCC NO: M 2020118) at 3% by weight. The nutrients included yeast extract, urea, ammonium dihydrogen phosphate, magnesium sulfate, zinc sulfate, and vitamins. Hydrolyzed sugar was used as the fermentation raw material, with an initial fermentation sugar concentration of 330 g / L. The compound yeast was added at 0.6% of the fermentation system. Fermentation was carried out at 25℃ for 14 days. The fermentation results are shown in Table 3.

[0046] Table 3. Fermentation results at an initial sugar concentration of 330 g / L

[0047]

[0048] The fermentation alcohol concentration reached 18.2%, which is 30-51% higher than the 12-14% fermentation concentration in the traditional process. Increasing the alcohol fermentation concentration reduces energy consumption in the subsequent distillation process. The final fermentation liquid is distilled to a distilled spirit with an alcohol content of 45%. The total ester content in the fermented spirit is 0.11 g / L, and the β-phenylethanol content is 0.06 g / L.

[0049] Example 4

[0050] A compound yeast was prepared by mixing yeast and nutrients in the following proportions: 60 parts yeast, 24.5 parts nitrogen source, 10 parts phosphorus source, 5 parts inorganic salts, and 0.5 parts vitamins. The yeast consisted of *Saccharomyces cerevisiae* (CCTCC NO: M2021171) at 50% by weight, *Kluyveromyces kluyveromyces* (CCTCC NO: M 2020173) at 5% by weight, and *Hansenula polymorpha* (CCTCC NO: M 202017) at 5% by weight. The nutrients included yeast extract, urea, ammonium dihydrogen phosphate, magnesium sulfate, zinc sulfate, and vitamins. Hydrolyzed sugar was used as the fermentation raw material, with an initial fermentation sugar concentration of 330 g / L. The compound yeast was added at 0.6% of the fermentation system. Fermentation was carried out at 25℃ for 14 days. The fermentation results are shown in Table 4.

[0051] Table 4. Fermentation results at an initial sugar concentration of 330 g / L

[0052]

[0053] The fermentation alcohol concentration reached 18.5%, which is 32-54% higher than the 12-14% fermentation concentration in the traditional process. The increased alcohol fermentation concentration reduces energy consumption in the subsequent distillation process. The final fermentation liquid is distilled to a distilled spirit with an alcohol content of 45%. The total ester content in the fermented spirit is 0.22 g / L, and the β-phenylethanol content is 0.07 g / L.

[0054] Example 5

[0055] A compound yeast was prepared by mixing yeast and nutrients in the following proportions: 47 parts yeast, 33 parts nitrogen source, 12 parts phosphorus source, 6 parts inorganic salts, and 2 parts vitamins. The compound yeast consisted of 41% *Saccharomyces cerevisiae* (CCTCC NO: M 2021171), 2% *Pichia pastoris* (CCTCC NO: M 2021124), and 4% *Saccharomyces cerevisiae* (CCTCC NO: M 2020118). The nutrients included yeast extract, urea, ammonium dihydrogen phosphate, magnesium sulfate, zinc sulfate, and vitamins. Hydrolyzed sugar was used as the fermentation raw material, with an initial fermentation sugar concentration of 330 g / L. The compound yeast was added at 1% of the fermentation system. Fermentation was carried out at 30℃ for 8 days. The fermentation results are shown in Table 5.

[0056] Table 5. Fermentation results at an initial sugar concentration of 330 g / L

[0057]

[0058] The fermentation alcohol concentration reaches 19.3%, which is 37-60% higher than the 12-14% fermentation concentration in traditional processes, increasing the fermentation efficiency of the wine by more than 50%. The increased alcohol fermentation concentration reduces energy consumption in the subsequent distillation process. The final fermentation liquid is distilled to a distilled wine with an alcohol content of 45%. The total ester content in the fermented wine is 0.13g / l, and the β-phenylethanol content is 0.06g / l.

[0059] Comparative Example 1 (fermentation using traditional methods)

[0060] A compound yeast was prepared by using 50 parts yeast, 30 parts nitrogen source, 10 parts phosphorus source, 8 parts inorganic salt, and 2 parts vitamin. The yeast was baker's yeast (preservation number CCTCC NO: M 205129). Hydrolyzed sugar was used as the fermentation raw material. The initial fermentation sugar concentration was 330 g / L. The compound yeast was added at 0.6% of the fermentation system. The fermentation temperature was 25℃ and the fermentation time was 14 days. The fermentation results are shown in Table 6.

[0061] Table 6. Fermentation results of Comparative Example 1

[0062]

[0063] The fermentation alcohol concentration reached 12%, and the final fermentation liquid was distilled to a distilled spirit with an alcohol content of 45%. The total ester content in the fermented spirit was 0.02 g / L, and the β-phenylethanol content was undetectable.

[0064] Comparative Example 2

[0065] A compound yeast was prepared by mixing yeast and nutrients in the following proportions: 60 parts yeast, 23 parts nitrogen source, 9 parts phosphorus source, 5 parts other inorganic salts, 2 parts trace vitamins, and 1 part antibacterial agent. The yeasts were brewer's yeast (CCTCC NO: M2017148) and grape juice yeast (CCTCC NO: M2016418). The nutrients included urea, ammonium dihydrogen phosphate, magnesium sulfate monohydrate, zinc sulfate monohydrate, biotin, vitamin B1, calcium pantothenate, and 800,000 units of penicillin. Hydrolyzed sugar was used as the fermentation raw material, with an initial fermentation sugar concentration of 330 g / L. The compound yeast was added at 0.6% of the fermentation system. Fermentation was carried out at 25℃ for 14 days. The fermentation results are shown in Table 7.

[0066] Table 7 Fermentation results of Comparative Example 2

[0067]

[0068]

[0069] The fermentation alcohol concentration reached 16.5%, and the final fermentation liquid was distilled to a distilled spirit with an alcohol content of 45%. The total ester content in the fermented spirit was 0.05 g / L, and the β-phenylethanol content was undetectable.

[0070] Comparative Example 3

[0071] A compound yeast was prepared by mixing yeast and nutrients in the following proportions: 68 parts yeast, 17 parts nitrogen source, 8 parts phosphorus source, 6 parts inorganic salts, and 1 part vitamin. The yeast consisted of *Saccharomyces cerevisiae* (CCTCC NO: M 2021171) at 60% by weight, *Kluyveromyces kluyveromyces* (CCTCC NO: M 2020173) at 4% by weight, and *Pichia pastoris* (CCTCC NO: M2017780) at 4% by weight. The nutrients included yeast extract, urea, ammonium dihydrogen phosphate, magnesium sulfate, zinc sulfate, and vitamins. Hydrolyzed sugar was used as the fermentation raw material, with an initial fermentation sugar concentration of 330 g / L. The compound yeast was added at 0.6% of the fermentation system. Fermentation was carried out at 25℃ for 14 days. The fermentation results are shown in Table 8.

[0072] Table 8. Fermentation results at an initial sugar concentration of 330 g / L

[0073]

[0074] The fermentation alcohol concentration reaches 15.5%, and the final fermentation liquid is distilled to a distilled spirit with an alcohol content of 40%. The total ester content in the fermented spirit is 0.15 g / L, and the β-phenylethanol content is 0.02 g / L.

[0075] Comparative Example 4

[0076] A compound yeast was prepared by mixing yeast and nutrients in the following proportions: 47 parts yeast, 33 parts nitrogen source, 12 parts phosphorus source, 6 parts inorganic salts, and 2 parts vitamins. The compound yeast consisted of 35% *Saccharomyces cerevisiae* (CCTCC NO: M 205129), 8% *Saccharomyces cerevisiae* (CCTCC NO: M2018677), and 4% *Pichia pastoris* (CCTCC NO: M2017780). The nutrients included yeast extract, urea, ammonium dihydrogen phosphate, magnesium sulfate, zinc sulfate, and vitamins. Hydrolyzed sugar was used as the fermentation raw material, with an initial fermentation sugar concentration of 330 g / L. The compound yeast was added at 0.6% of the fermentation system. Fermentation was carried out at 25℃ for 14 days. The fermentation results are shown in Table 9.

[0077] Table 9. Fermentation results at an initial sugar concentration of 330 g / L

[0078]

[0079] The fermentation alcohol concentration reached 14.2%, and the final fermentation liquid was distilled to a distilled spirit with an alcohol content of 45%. The total ester content in the fermented spirit was 0.02 g / L, and the β-phenylethanol content was undetectable.

[0080] As can be seen from the above description, the above embodiments of the present invention achieve the following technical effects: the compound yeast of the present invention can ferment sugar raw materials with high sugar concentration more thoroughly under high fermentation efficiency, with less residual sugar content, and obtain fermentation products with higher alcohol concentration than traditional processes, and provide convenience for the production of subsequent alcoholic beverage products.

[0081] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A compound yeast suitable for fermenting wines made from sugary raw materials, characterized in that, The compound yeast includes a yeast mixture and nutrients, wherein the yeast mixture is an alcohol-producing yeast, an ester-producing yeast and a β-phenylethanol-producing yeast. The alcohol-producing yeast is *Saccharomyces cerevisiae* with accession number CCTCC NO:M 2021171; the ester-producing yeast is selected from the following: *Saccharomyces cerevisiae* with accession number CCTCC NO:M 2020118, *Hansenula polymorpha* with accession number CCTCC NO:M2020174, and *Pichia pastoris* with accession number CCTCC NO:M2017780; the β-phenylethanol-producing yeast is selected from the following: *Pichia pastoris kudriezweig* with accession number CCTCC NO:M 2021124 and *Kluyveromyces kluyveromyces* with accession number CCTCC NO:M 2020173. The nutrients include nitrogen sources, phosphorus sources, inorganic salts, and vitamins; The compound yeast, by weight, comprises: 35-60 parts of the yeast mixture, 20-35 parts of the nitrogen source, 10-15 parts of the phosphorus source, 5-15 parts of the inorganic salts, and 0.1-3 parts of the vitamins. The nitrogen source is selected from at least one of the following: yeast extract, corn steep liquor powder, and maltodextrin; The phosphorus source is selected from at least one of the following: ammonium dihydrogen phosphate and diammonium hydrogen phosphate; The inorganic salt is selected from at least one of the following: ammonium dihydrogen phosphate, magnesium sulfate, zinc sulfate, and calcium chloride; The vitamins are selected from at least one of the following: VB1, calcium pantothenate, VB3, VB7 and inositol; In the yeast mixture, the weight percentage of the alcohol-producing yeast is 30-50%, the weight percentage of the ester-producing yeast is 3-5%, and the weight percentage of the β-phenylethanol yeast is 2-8%.

2. The compound yeast according to claim 1, characterized in that, The amino acid content in the yeast extract is 3-10 wt%.

3. An application of the compound yeast described in claim 1 or 2 for fermentation of saccharide raw materials.

4. The application according to claim 3, characterized in that, The sugar raw material is selected from hydrolyzed sugar, sucrose, or concentrated fruit juice.

5. The application according to claim 4, characterized in that, The initial fermentation sugar concentration of the sugar raw material is 240g / L-330g / L.

6. The application according to claim 3, characterized in that, The fermentation of the sugar raw material includes mixing the sugar raw material with the compound yeast and then carrying out the fermentation, wherein the amount of the compound yeast added is 0.2-1% based on the mass-volume content of the dry weight and the fermentation liquid volume.

7. The application according to claim 3, characterized in that, The fermentation temperature for the sugary raw material is 25-30℃.

8. The application according to claim 3, characterized in that, The fermentation time for the sugary raw materials is 3-15 days.

9. The application according to claim 3, characterized in that, The alcohol content (v / v) of the fermentation product is 14-21%, the total ester content is 0.1g / L-0.5g / L, and the β-phenylethanol content is 0.05g / L-0.2g / L.

10. The application according to claim 3, characterized in that, Fermentation products include: alcoholic beverages or alcohol.

11. The application according to claim 10, characterized in that, The alcoholic beverages include distilled spirits.

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