Preparation method and application method of aspergillus oryzae powder and fermented grain wine prepared from aspergillus oryzae powder

Abstract

The invention discloses a preparation method and an application method of aspergillus oryzae powder and fermented grain wine prepared from the aspergillus oryzae powder, and belongs to the technical field of biological fermentation of wine brewing. The preparation method comprises the following steps: inoculating aspergillus oryzae into a bran culture medium for culturing, and preparing a spore bacterial suspension after a large number of hyphae appear; and inoculating the spore bacterial suspension into a wheat culture medium for culturing, and after a large number of hyphae appear, crushing to prepare the aspergillus oryzae powder. When the prepared aspergillus oryzae powder is used for brewing wine, the yield and the quality of the fermented grain wine can be remarkably improved while nutritional ingredients such as residual starch in the red vinasse and the waste vinasse are efficiently utilized. The obtained fermented grain wine meets the national standard of producing white spirit by a solid-state fermentation method and the production standard of high-quality white spirit, and has important industrial application prospect and popularization value.

Description

Technical Field

[0001] The invention belongs to the technical field of winemaking biological fermentation, relates to use of Aspergillus oryzae in red lees and discarded lees winemaking, relates to a method for improving the yield and quality of lees wine, and specifically relates to a preparation method and an application method of Aspergillus oryzae powder and lees wine prepared therefrom. Background Art

[0002] Red lees is a byproduct of the traditional solid-state winemaking process and is usually considered a low-quality mash due to incomplete fermentation. In the winemaking process, no new grains are added to the red lees in the next round of fermentation. Only after the previous round of distillation is completed, koji is added and the lees are fermented and distilled again, eventually forming discarded lees. Although red lees and discarded lees are considered waste, they still contain a large amount of underutilized nutrients, such as residual starch, protein, cellulose, and a variety of amino acids and vitamins, and have significant potential for high-value utilization.

[0003] my country produces more than 30 million tons of lost lees every year, but the current way of utilizing lost lees is not efficient. At present, the residual starch in lost lees and red lees is mainly utilized by adding medium-high temperature Daqu or high-efficiency brewing lees. However, the red lees wine obtained after fermentation and distillation of red lees is usually only used as a low-end base wine because of its light body and low content of flavor substances. Lost lees also have similar problems. Its wine yield is generally low, and the wine quality is difficult to meet the standards of mid-to-high-end liquor.

[0004] Existing technologies attempt to improve the yield and quality of red glutinous rice and discarded glutinous rice wine by adding saccharification and fermentation agents (such as enzyme preparations, active yeast, Daqu, etc.), yellow water esterification liquid, and adopting processes such as cellar turning and continuous distillation. However, these methods still have significant defects: (1) Low raw material utilization efficiency: the crude fiber, crude fat and crude protein content in red glutinous rice / discarded glutinous rice is high, which is difficult for microorganisms to directly utilize, resulting in the need to add a large amount of additional saccharification and fermentation agents, increasing production costs; (2) Complex processes: operations such as cellar turning and continuous distillation require a lot of manpower and material resources, and the fermentation cycle is long, resulting in low production efficiency; (3) High research costs: Existing technologies have invested a lot in research on strain screening and process optimization, but the actual application effect is limited.

[0005] For example, CN112430513A discloses a method of inoculating Rhizopus oryzae or Aspergillus niger AS3.4309 into bran to make bran koji, mixing it with yeast liquid, and then adding it to the spent lees to ferment for 30-60 days at 25-30°C to produce liquor. Although this method can partially utilize the residual starch in the spent lees to increase the yield, its fermentation cycle is long; the fermentation temperature needs to be precisely maintained at a constant temperature of 25-30°C, and the energy consumption cost is high; the improvement in wine quality is limited, and it is difficult to meet the standards of mid-to-high-end liquor. CN1970718B discloses a method for preparing fortified bran koji using Aspergillus kawachii, which is used for spent lees fermentation and wine making. This method has a complex process and requires multiple inoculation, culturing and drying steps. The operation is cumbersome and time-consuming; it has high requirements for production equipment and technicians, and it is difficult to promote and apply it in small and medium-sized wineries. CN101921689B discloses a secondary fermentation brewing method for Luzhou-flavor liquor with spent grains, which requires the addition of additional ingredients such as tailings, esterification enzyme, yellow water, caproic acid fermentation liquid, etc. after fermentation. This method is too costly and difficult to implement in actual production applications.

[0006] In addition, Aspergillus oryzae is a kind of mold widely present in nature, with strong survival ability, multiple enzyme types and high amylase activity. CN117126707A discloses a medium-high temperature Daqu process and its billet making system for enhancing flavor and quality, mainly by adding Aspergillus oryzae Shanghai Niang 3.042 improved strains in the koji making process, combined with specific mixing and pressing equipment, to improve the quality and aroma production capacity of Daqu. Although this method improves the quality of koji by Aspergillus oryzae strain improvement and equipment optimization, its process has high complexity (multi-stage mixing process and complex billet making system are required), strict parameter control (mixed materials need to accurately maintain 42%-45% water content, fermentation needs "slow before, middle and slow after" gradient temperature control, etc.), dependence on specific strains and equipment, etc., which limits its application in low-cost, large-scale production scenarios. Summary of the invention

[0007] The technical problem to be solved by the present invention is that the existing production method of red lees wine / lost lees wine has the problems of long fermentation cycle, complex process, high cost, limited improvement in wine quality, and difficulty in meeting the application needs of mid-to-high-end liquor.

[0008] Based on the above problems, the main purpose of the present invention is to provide a preparation method and application method of Aspergillus oryzae powder and lees wine prepared therefrom, specifically to use Aspergillus oryzae to improve the yield and quality of lees (discarded lees and red lees) wine, which has the characteristics of simple method, short production cycle, low production site requirements, significant yield and quality improvement effects and easy large-scale production and application.

[0009] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0010] In a first aspect, the present invention provides a method for preparing Aspergillus oryzae powder: Aspergillus oryzae is activated, then inoculated into a bran culture medium for cultivation to prepare a spore suspension; the spore suspension is inoculated into a wheat culture medium for cultivation, and crushed to prepare the Aspergillus oryzae powder.

[0011] In the above preparation method, the Aspergillus oryzae is an environmental microorganism screened from the wine production space, and is an engineering model strain that is not genetically engineered.

[0012] In the above preparation method, the amylase activity of Aspergillus oryzae is greater than 26000 U / g, and the saccharifying enzyme activity is greater than 1200 U / g.

[0013] In the above preparation method, the Aspergillus oryzae activation is as follows: Aspergillus oryzae is inoculated into a PDA solid culture medium and cultured at 28-30° C. until a large number of spores appear on the surface of the mycelium.

[0014] In the above preparation method, the bran culture medium is prepared by passing wheat bran through a sieve of 80-100 meshes, gelatinizing and cooling.

[0015] In the above preparation method, the wheat culture medium is prepared by steaming or soaking whole wheat in boiling water, pressing it into a plum blossom shape, and cooling it.

[0016] In the above preparation method, the culturing is: culturing at 28-30°C until a large amount of hyphae appear.

[0017] In the above preparation method, the bacterial content of the spore suspension is 10 6 ~10 7 CFU / mL.

[0018] In the above preparation method, the inoculation amount of the spore suspension is: based on the mass of wheat in the wheat culture medium, 5 to 10 mL of the spore suspension is inoculated per 100 g of wheat.

[0019] In a second aspect, the present invention provides Aspergillus oryzae powder prepared by the above preparation method.

[0020] In a third aspect, the present invention provides an application method of Aspergillus oryzae powder: using the powder for brewing wine.

[0021] In the above application method, Aspergillus oryzae powder, koji medicine and fermented grains are mixed separately to prepare fermented grains, which are put into a cellar for natural fermentation and then distilled to obtain wine.

[0022] Furthermore, in the fermented mash, the mass of Aspergillus oryzae powder accounts for 0.1-2% of the weight of the mash, and the mass of the koji medicine accounts for 1.5-4% of the weight of the mash.

[0023] Furthermore, the koji medicine is a conventional koji medicine used for fermentation of mash during the production process, and no unnatural enhancers such as yeast are added.

[0024] Furthermore, the fermented grains are red fermented grains or discarded fermented grains.

[0025] Furthermore, the time for natural fermentation in the cellar is 15 to 45 days.

[0026] In the above application method, Aspergillus oryzae powder is added to the koji and mixed evenly to prepare the fortified koji, and then the fortified koji is inoculated into the mash to prepare the fermented mash, which is put into a cellar for natural fermentation and distilled to obtain wine.

[0027] Furthermore, in the fermented mash, the mass of Aspergillus oryzae powder accounts for 0.1-2% of the weight of the mash, and the mass of the koji medicine accounts for 1.5-4% of the weight of the mash.

[0028] Furthermore, the koji medicine is a conventional koji medicine used for fermentation of mash during the production process, and no unnatural enhancers such as yeast are added.

[0029] Furthermore, the fermented grains are red fermented grains or discarded fermented grains.

[0030] Furthermore, the time for natural fermentation in the cellar is 15 to 45 days.

[0031] In a fourth aspect, the present invention provides fermented grains wine prepared by the above-mentioned application method.

[0032] The beneficial effect of the present invention is that through the above-mentioned method, the present invention can efficiently utilize the residual starch and other nutrients in the red lees and discarded lees, while significantly improving the yield and quality of lees wine. The obtained red lees wine and discarded lees wine meet the national standard for the production of liquor by solid-state fermentation method (GB / T 10781.1-2021) and the production standard of high-quality liquor.

[0033] Compared with the prior art, the present invention has the following advantages:

[0034] 1) Both production and quality are improved: the wine yield is significantly higher than that of traditional processes, and the content of esters and alcohols in the wine is also significantly increased;

[0035] 2) The process is simple and easy to promote: the raw materials are easy to obtain (Aspergillus oryzae, bran culture medium, wheat culture medium, etc.), the operation process is simplified, and it is suitable for application in small and medium-sized wineries; no complex equipment is required, and it can be directly used for natural fermentation in the cellar, reducing the equipment investment cost;

[0036] 3) High compatibility with traditional processes: No natural engineered strains are added, and the traditional brewing process of mid- to high-end liquor is not changed;

[0037] 4) Flexible fermentation conditions: It can be directly used for natural fermentation in the cellar, without the need for constant temperature fermentation, and has a wide fermentation temperature range; the fermentation cycle is short, which significantly improves production efficiency compared with existing technologies;

[0038] 5) Significant economic benefits: Turning waste into treasure, achieving high-value utilization of mash resources, with low application cost and high benefits, provides a new green and sustainable waste recycling method for the liquor industry.

[0039] The present invention can help the sustainable development of the liquor industry. The fermented grains liquor prepared by the method of the present invention can be used as base liquor, and high-quality base liquor can create huge economic benefits for enterprises. The present invention not only provides an innovative solution for the efficient utilization of fermented grains, but also provides a new way for the high-value utilization of red fermented grains and discarded fermented grains, and provides a new idea for the liquor industry that adheres to the traditional solid-state fermentation process to maintain integrity and innovation, reduce costs and increase efficiency, and improve quality and efficiency, and has important industry application prospects and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 The temperature conditions for simulating natural fermentation in Example 1 and Example 2;

[0041] Figure 2 The alcohol content of the fermented grains after red glutinous rice fermentation in Example 1;

[0042] Figure 3 The content of main ester flavor substances in the red lees wine obtained in Example 1;

[0043] Among them, (A) is ethyl lactate, (B) is ethyl caproate, (C) is ethyl acetate, and (D) is ethyl butyrate;

[0044] Figure 4 The content of main alcohol flavor substances in the red lees wine obtained in Example 1;

[0045] Wherein, (A) is isoamyl alcohol, (B) is n-butanol, and (C) is n-propanol;

[0046] Figure 5 The alcohol content of the mash after the fermentation of the discarded mash in Example 2;

[0047] Figure 6 The content of main ester flavor substances in the waste wine obtained in Example 2;

[0048] Among them, (A) is ethyl lactate, (B) is ethyl caproate, (C) is ethyl acetate, and (D) is ethyl butyrate;

[0049] Figure 7 The content of main alcohol flavor substances in the waste wine obtained in Example 2;

[0050] Among them, (A) is isoamyl alcohol, (B) is n-butanol, and (C) is n-propanol. DETAILED DESCRIPTION

[0051] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clear, the present application is further described in detail below in combination with the implementation methods. Unless otherwise defined, all scientific and technological terms used herein have the same meanings as understood by ordinary technicians in the field.

[0052] The invention first provides a method for preparing Aspergillus oryzae powder: Aspergillus oryzae is activated, then inoculated into a bran culture medium and cultured at 28-30°C, after a large number of hyphae appear, spores are washed out with sterile water to prepare a spore suspension, wherein the spore suspension has a bacterial content of 10 6 ~10 7 CFU / mL. The spore suspension was inoculated into wheat culture medium and cultured at 28-30°C. The inoculation amount was calculated based on the mass of wheat in the wheat culture medium. 5-10 mL of spore suspension was inoculated per 100 g of wheat. After culturing until a large number of hyphae appeared, the spores were crushed to make Aspergillus oryzae powder.

[0053] In one embodiment of the present invention, the Aspergillus oryzae is an engineering model strain that is screened from environmental microorganisms in the brewing production space and is not genetically engineered. The brewing of high-end liquor has extremely high requirements on the geographical environment and production area. In addition to the natural conditions such as temperature, humidity and wind conditions in a specific environment being suitable for brewing, it is also closely related to environmental microorganisms. The long-term brewing process is also a process of domesticating environmental microorganisms. High-end liquor adheres to the traditional brewing process and refuses to add genetically modified strains from non-natural environments and non-brewing spaces to the brewing mash.

[0054] In one embodiment of the present invention, the amylase activity of the Aspergillus oryzae is greater than 26000U / g, and the saccharifying enzyme activity is greater than 1200U / g. The Aspergillus oryzae of the present invention is for screening environmental microorganisms from the brewing production space, and other non-genetically engineered Aspergillus oryzae not derived from the brewing production space and the Aspergillus oryzae of the present invention may have differences in strains, and the corresponding metabolic capacity of each enzyme also has certain differences. Although the amylase and saccharifying enzyme activities of other Aspergillus oryzae (non-derived from the brewing production space, non-genetically engineered) can meet the limited requirements of the present invention, they belong to strains in the non-brewing natural environment added artificially, and do not meet the production standards of high-end liquor.

[0055] The present invention selects a single Aspergillus oryzae strain, and makes Aspergillus oryzae naturally adapt to evolution through two culture medium cultivations: on the one hand, the bran culture medium can not only provide sufficient nutrient basis for the rapid propagation of Aspergillus oryzae; on the other hand, the bran culture medium is rich in cellulose and hemicellulose, can effectively induce the expression of Aspergillus oryzae cellulase and hemicellulase genes, and synthesizes multiple enzymes (such as amylase, protease, etc.) while promoting its rapid propagation. Through the pre-cultivation of the bran culture medium, Aspergillus oryzae can fully adapt to the complex carbohydrate environment and form a rich enzyme system.

[0056] Wheat culture medium is rich in starch and protein, which is suitable for further fermentation of Aspergillus oryzae. Aspergillus oryzae pre-cultured in bran culture medium has a richer enzyme system. After inoculation into wheat culture medium, it can efficiently decompose starch and protein in wheat and generate more reducing sugars and amino acids, thereby significantly improving fermentation efficiency and product quality.

[0057] The amylase and protease produced by Aspergillus oryzae in the wheat culture medium can break down the starch and protein in the wheat into small-molecule reducing sugars and amino acids. These small molecules not only provide rich nutrients for the growth of Aspergillus oryzae, but also provide more fermentable sugars and flavor precursors for the subsequent fermented mash. During the fermentation of mash, these reducing sugars and amino acids can be further metabolized by microorganisms to produce a variety of flavor compounds, such as alcohols, aldehydes, ketones and esters. The increase of these flavor compounds significantly improves the flavor and quality of mash wine.

[0058] The Aspergillus oryzae of the present invention is cultured in two steps of bran and wheat culture medium to form an "induction-activation" cascade reaction, and the enzyme system produced is more abundant and synergistic, and cannot be reproduced by simple mixing of multiple strains or gene editing. At the same time, the Aspergillus oryzae used in the present invention does not rely on a specific improved strain of Aspergillus oryzae, has high process universality, and significantly reduces production costs.

[0059] In one embodiment of the present invention, Aspergillus oryzae powder (accounting for 0.1-2% of the weight of the mash) and koji medicine (accounting for 1.5-4% of the weight of the mash) are inoculated into the mash (discarded mash or red mash) to make fermented mash, which is put into a cellar for natural fermentation for 15-45 days, and the wine is distilled to obtain mash wine.

[0060] In one embodiment of the present invention, Aspergillus oryzae powder (accounting for 0.1-2% of the weight of the glutinous rice) is added to koji medicine (accounting for 1.5-4% of the weight of the glutinous rice) and mixed evenly to prepare fortified koji medicine, and then the fortified koji medicine is inoculated into the glutinous rice (discarded glutinous rice or red glutinous rice) to prepare fermented glutinous rice, which is put into a cellar for natural fermentation for 15-45 days, and the wine is distilled to prepare glutinous rice wine.

[0061] In one embodiment of the present invention, the koji medicine is a conventional koji medicine used for fermentation of mash during the production process, and no non-natural enhancers such as yeast are added.

[0062] The Aspergillus oryzae powder prepared by the present invention has significant process advantages and cost-effectiveness. When used for winemaking (preparing fermented grains), it can be directly put into a cellar for fermentation without complicated pretreatment or constant temperature fermentation conditions. The Aspergillus oryzae powder can adapt to the natural temperature changes in the cellar, without strictly limiting process conditions and parameters, and greatly reduces the technical difficulty and cost in the production process. The method of use is simple and easy to operate, which not only improves production efficiency, but also brings significant economic benefits to enterprises due to its low production cost and wide application range.

[0063] Those skilled in the art should understand that using the Aspergillus oryzae powder prepared by the present invention for fermentation of fermented grains to improve the yield and quality of fermented grains wine is only a preferred embodiment of the present invention. Based on the same technical principle, using the Aspergillus oryzae powder prepared by the present invention for fermentation of other liquors, or combining it with koji to make enhanced koji for fermentation of liquor, can also achieve the technical effect of improving yield and quality.

[0064] Specific examples will be listed below to explain the scheme of the present invention. It will be appreciated by those skilled in the art that the following examples are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. Where specific techniques or conditions are not indicated in the examples, the techniques or conditions described in the literature in this area or the product instructions are used. Reagents or instruments used that do not indicate manufacturers are all conventional products that can be obtained commercially.

[0065] Example

[0066] 1. Preparation of Aspergillus oryzae powder

[0067] 1. Preparation of culture medium:

[0068] (1) PDA medium: a solid plate medium prepared using a standard formula;

[0069] (2) Bran culture medium: sieve the bran through an 80-mesh sieve to obtain fine powder, weigh 15 g of bran, add 10 mL of water, stir evenly, and sterilize by high pressure at 121° C. for 20 min. After cooling, prepare the bran culture medium;

[0070] (3) Wheat culture medium: Soak wheat in boiling water, press single-grain wheat into plum blossom shape, weigh 50 g of wheat, sterilize at 121°C for 20 min, and cool to make wheat culture medium.

[0071] 2. Screening of Aspergillus oryzae:

[0072] The Aspergillus oryzae was screened from the Daqu produced by the 502 workshop of Yibin Wuliangye Co., Ltd., and its amylase activity was 26754.43 U / g and its saccharifying enzyme activity was 1234.63 U / g.

[0073] 3. Preparation of Aspergillus oryzae powder:

[0074] Aspergillus oryzae was inoculated on PDA medium and cultured at 28°C until spores grew on the surface of mycelium. Then, the spores were inoculated on bran medium with an inoculation loop on a sterile clean bench. After cultured at 28°C until a large number of spores grew on the surface of mycelium, 80 mL of sterile water was added for elution to prepare a spore suspension. The bacterial content was measured to be 1.45×10 6 CFU / mL. Take 5 mL of spore suspension and inoculate it into wheat culture medium, continue to culture at 28°C until a large number of spores appear on the surface of mycelium, and then crush it to obtain Aspergillus oryzae powder.

[0075] 2. Preparation of fermented rice wine

[0076] Example 1 Fermentation and extraction of red lees wine:

[0077] In each test system, 7 kg of red glutinous rice that had been mixed with koji medicine was taken (the amount of koji medicine added was about 2% of the weight of the red glutinous rice), and Aspergillus oryzae powder was added at an inoculation rate of 0.1%, 0.5%, 1%, and 2% (based on the weight of the red glutinous rice), and the Aspergillus oryzae powder addition rate was 0% as the blank control group, and the mixture was mixed well. The mixed glutinous rice was placed in a plastic barrel and sealed with cellar mud. The fermentation conditions simulated the temperature changes of natural fermentation in the cellar (reference Figure 1 Fermentation temperature control curve), fermentation for 20 days. After fermentation, the mash was mixed and sampled for analysis, and 100g of mash was added to 300mL of ultrapure water to distill 80mL of wine.

[0078] Example 2 Fermentation and extraction of discarded lees wine:

[0079] Take 7kg of the discarded dregs after mixing with koji medicine (the amount of koji medicine added is about 2% of the weight of red dregs), add Aspergillus oryzae powder at an inoculation rate of 0.5% (based on the weight of discarded dregs), and use 0% Aspergillus oryzae powder as the blank control group, and mix well. Put the mixed dregs into a plastic barrel and seal it with cellar mud. The fermentation conditions simulate the temperature changes of natural fermentation in the cellar (reference Figure 1 Fermentation temperature control curve), fermentation for 20 days. After fermentation, the mash was mixed and sampled for analysis, and 100g of mash was added to 300mL of ultrapure water to distill 80mL of wine.

[0080] 3. Detection of fermented grain wine

[0081] The alcohol content of fermented mash was detected by headspace solid phase micro-extraction-gas chromatography-flame ionization detection (HS-GC-FID). High Performance Gas Chromatography (HPGC) was used to detect the content of various alcohols, esters and other flavor substances in the wine samples.

[0082] HS-GC-FID method for detecting alcohol content in mash: After fermentation, take out the mash and mix it. Weigh 25g of the mixed mash, add 100mL of distilled water, mix and shake for 30min, centrifuge at 5000g for 5min at 5℃, take the supernatant, and filter through a 0.22μm filter membrane. Pipette 1mL of filtrate into a 20mL headspace sample bottle, balance at 60℃ for 15min, insert the extraction head for adsorption for 45min, and insert the GC injection port for thermal desorption for 3min. GC parameters: DB-WAXUI gas phase capillary column (60m×0.25mm×0.25μm); injection port temperature 230℃, carrier gas is high purity helium (He,>99.999%), flow rate 1mL / min, split ratio 10:1; chromatographic column heating program: 40℃ for 2min, heating to 100℃ at 8℃ / min, heating to 230℃ at 20℃ / min, and holding for 2min. FID parameters: detector temperature 220℃, hydrogen flow rate: 30mL / min; air flow rate: 300mL / min; nitrogen tail gas flow rate: 25mL / min.

[0083] High performance gas chromatography method for detecting flavor substances in wine samples: 1 mL of wine sample was taken, filtered through a 0.22 μm filter membrane, and injected onto a DB-FFAP capillary column (30 m × 0.25 mm × 0.50 μm) on the HPGC sample plate, with high purity helium (He) as the carrier gas, at a flow rate of 1 mL / min, and injected in splitless mode; the heating program was a starting temperature of 40 °C, maintained for 5 min, then increased to 230 °C at 4 °C / min, and maintained for 15 min.

[0084] 1. Detect the alcohol content in the fermented grains according to the above method; wherein, the alcohol content in the fermented grains of red glutinous rice of Example 1 is as follows: Figure 2 As shown in Example 2, the alcohol content in the fermented grains discarded is as follows Figure 5 shown.

[0085] Depend on Figure 2 and Figure 5It can be seen that the use of the Aspergillus oryzae powder of the present invention for fermenting lees to produce wine can significantly increase the yield of alcohol in the lees. When the Aspergillus oryzae powder is added at 0.5%, the yield of red lees wine is increased by 163.16% compared with the blank control group, and the yield of discarded lees wine is increased by 154.01% compared with the blank control group.

[0086] 2. The content of volatile flavor components in the fermented grain wine was detected by the above method; wherein, the alcohol and ester contents of the red lees wine in Example 1 were as follows: Figure 3 , Figure 4 As shown, the alcohol and ester contents of the discarded lees wine in Example 2 are as follows Figure 6 , Figure 7 shown.

[0087] Depend on Figure 3 , Figure 4 and Figure 6 , Figure 7 It can be known that the use of the Aspergillus oryzae powder of the present invention for fermentation of fermented grains to produce wine can significantly improve the coordination of flavor substances in the wine. When the amount of Aspergillus oryzae powder added to the red lees is 0.5%, the main aromatic flavor compound ethyl caproate in the Luzhou-flavor liquor increases by about 321.71%, and ethyl acetate increases by about 1150%, while the content of ethyl lactate that causes the astringent taste of the wine remains basically unchanged, breaking through the pain point of "increasing ethyl lactate and controlling lactate". At the same time, the contents of isopentanol, n-butanol and n-propanol that contribute to the sweetness of liquor increased by 96.16%, 99.41% and 43.69% respectively, and methanol and isobutanol were not detected in both the test group and the control group because they were below the detection limit.

[0088] 3. Compare the results of using the Aspergillus oryzae powder of the present invention for fermentation of lees to produce wine and the existing technology under optimal conditions (reference: Huang Liang, Ren Zhiqiang, Deng Jie, et al. Effect of "gluten koji + yeast" model on fermentation of wine with discarded lees [J]. Modern Food Science and Technology, 2022, 38(11): 73-79. DOI: 10.13982 / j.mfst.1673-9078.2022.11.0077.) to obtain lees wine, as shown in Table 1.

[0089] Table 1 Comparison of different treatment methods on the improvement of various indicators of fermented grain wine

[0090]

[0091] It can be understood by those skilled in the art that the mash used in the test directly affects the flavor composition and content of the resulting wine, so the comparison of data is only valid for the control group set up in the experimental system. Of particular importance, the content (concentration) is largely determined by the amount of wine picked during distillation. Therefore, comparing the differences between the test group and the control group is the main reference for judging the treatment effect. As can be seen from the above table, although the method of reference Huang Liang et al. does not specify the conversion method of the amount of wine or the content, according to the comparison of the data of the test group and the control group disclosed by them, it can be seen that the method has a certain effect on improving the wine yield, but the types and contents of flavor substances are relatively small, indicating that this method has no significant improvement on the quality of discarded mash wine.

[0092] As can be seen from the data in Table 1, the fermented grains liquor obtained by the method of the present invention has significant advantages over the prior art. Specifically, it can not only significantly increase the output of liquor, but also significantly reduce the content of main flavor substances such as ethyl caproate and ethyl acetate in liquor, while having no significant effect on increasing the content of ethyl lactate that affects the quality of Luzhou-flavor liquor, thus significantly improving the quality of fermented grains liquor.

Claims

1. The preparation method of Aspergillus oryzae powder is characterized in that: Aspergillus oryzae is activated, then inoculated into a bran culture medium for cultivation to prepare a spore suspension; the spore suspension is inoculated into a wheat culture medium for cultivation, and crushed to prepare Aspergillus oryzae powder.

2. The preparation method according to claim 1, characterized in that: The Aspergillus oryzae is an environmental microorganism for screening the production space of home-made wine, and its amylase activity is greater than 26000 U / g, and its saccharifying enzyme activity is greater than 1200 U / g.

3. The preparation method according to claim 1, characterized in that: The Aspergillus oryzae activation is to inoculate Aspergillus oryzae into a PDA solid culture medium and culture it at 28-30° C. until a large number of spores appear on the surface of the mycelium.

4. The preparation method according to claim 1, characterized in that: The bran culture medium is prepared by passing wheat bran through a 80-100 mesh sieve, gelatinizing, and cooling; The wheat culture medium is prepared by boiling or soaking whole wheat in boiling water, pressing it into a plum blossom shape, and cooling it; The culturing step is as follows: culturing at 28-30° C. until a large amount of hyphae appear.

5. The preparation method according to claim 1, characterized in that: The bacterial content of the spore suspension is 10 6 ~10 7 CFU / mL; The inoculation amount of the spore suspension is: based on the mass of wheat in the wheat culture medium, 5 to 10 mL of the spore suspension is inoculated per 100 g of wheat.

6. The application method of Aspergillus oryzae powder is characterized in that: The Aspergillus oryzae powder prepared by the preparation method according to any one of claims 1 to 5 is used for brewing wine.

7. The application method according to claim 6, characterized in that: Aspergillus oryzae powder, koji and mash are mixed separately to make fermented mash, which is put into cellar for natural fermentation and then distilled to obtain wine.

8. The application method according to claim 6, characterized in that: Add Aspergillus oryzae powder to the koji and mix well to make a fortified koji, then inoculate the fortified koji into the mash to make fermented mash, put it into a cellar for natural fermentation and distill it to obtain wine.

9. The application method according to claim 7 or 8, characterized in that: In the fermented mash, the mass of Aspergillus oryzae powder accounts for 0.1-2% of the weight of the mash, and the mass of the koji medicine accounts for 1.5-4% of the weight of the mash; The koji medicine is a conventional koji medicine used for fermentation of mash during the production process, and no unnatural enhancers such as yeast are added; The fermented grains are red fermented grains or discarded fermented grains; The time for natural fermentation in the cellar is 15 to 45 days.

10. Fermented wine obtained by the application method according to any one of claims 6 to 9.

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