Grain-flavor liquor and preparation method thereof

Abstract

The present application relates to the technical field of liquor preparation, in particular to a grain-flavor liquor and a preparation method thereof. The preparation method of the grain-flavor liquor comprises the processes of mixing, slow fire frying, mixing with koji, saccharification, spraying wheat oligopeptide, fermentation, distillation and the like. The grain is fried to be cooked by the slow fire frying method, and the processes of soaking and steaming in the traditional solid-state liquor brewing are abandoned, so that the aroma of the grain is completely stimulated. Meanwhile, the fermentation is carried out after spraying the wheat oligopeptide solution in the pit, so that the number of probiotics in the pit is significantly increased, and a microbial basis for the generation of aroma substances is laid. The test proves that the content of ethyl hexanoate in the grain-flavor liquor prepared by the present application is significantly increased, the contents of ethyl acetate and ethyl heptanoate are significantly reduced, new flavor components are generated, and the obtained grain-flavor liquor has the characteristics of smelling, drinking and tasting aroma, highlights the unique flavor and quality of the grain-flavor liquor, and is suitable for high-quality liquor preparation and application.

Description

Technical Field

[0001] This invention relates to the field of baijiu (Chinese liquor) preparation technology, specifically to a grain-aroma baijiu and its preparation method. Background Technology

[0002] The brewing process of baijiu (Chinese liquor) is influenced by many factors, and the taste and quality of baijiu are determined by the interaction of these factors. Among these influencing factors, the pretreatment method of raw materials directly affects the yield and quality of baijiu. A reasonable selection of raw material pretreatment methods can not only ensure both quality and quantity but also further guarantee the production of high-quality baijiu, achieving the goal of high yield and high quality.

[0003] In the process of baijiu brewing, the influence of raw materials on the body of the baijiu is self-evident. Starch, protein, and other organic compounds in the brewing raw materials undergo synthesis, decomposition, and transformation under the action of microorganisms, producing a rich variety of aroma and flavor substances. These substances interact to create the unique style and taste of strong-aroma baijiu. In strong-aroma baijiu, the main raw material is sorghum, supplemented by rice, glutinous rice, barley, wheat, and corn. Sorghum imparts aroma, glutinous rice imparts smoothness, wheat imparts mellowness, barley imparts softness, rice imparts purity, and corn imparts sweetness. Currently, many scholars mainly focus on the impact of differences in the type, quality, and origin of brewing raw materials on the quality of baijiu, while neglecting the influence of raw material pretreatment methods on the quality of baijiu.

[0004] Raw material processing is particularly important in food processing. Appropriate processing methods can alter the characteristics of raw materials, maximizing factory utilization and reducing grain waste. This is also true in the brewing of baijiu (Chinese liquor). In the traditional fermentation process of strong-aroma baijiu in my country, the brewing raw materials are mostly pre-cooked grains. Solid-state fermentation combined with continuous fermentation technology ensures the quality of the baijiu to a certain extent. Currently, the main methods for maturing brewing raw materials are soaking and steaming. However, soaking the grains makes them susceptible to contamination by other microorganisms, and the large grain size during steaming leads to incomplete starch gelatinization. This results in a distilled spirit with a strong fermented mash flavor and a bland taste, affecting the overall flavor and quality of the baijiu. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a method for preparing grain-aroma baijiu. The grain-aroma baijiu prepared by this method has a significantly increased content of ethyl hexanoate, a significantly reduced content of ethyl acetate and ethyl heptanoate, and produces new flavor components (such as dioctyl adipate, acetal, palmitic acid, etc.). The prepared baijiu has the characteristics of being fragrant in smell, fragrant in taste, and fragrant in aftertaste, highlighting the unique flavor and quality of grain-aroma baijiu.

[0006] The present invention also aims to provide a grain-aroma type of baijiu prepared by the above preparation method.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A method for preparing grain-aroma baijiu includes the following steps:

[0009] (1) Mix the grain raw materials in proportion, and then stir-fry them over a low heat to obtain cooked food;

[0010] (2) The cooked material obtained in step (1) is mixed with yeast and saccharified, then put into a cellar for fermentation, and finally distilled to obtain the grain-aroma type liquor;

[0011] The simmering process involves frying at 80–100°C for 30–50 minutes; before fermentation, a wheat oligopeptide solution with a mass concentration of 1%–5% is sprayed onto the bottom and sides of the fermentation pit.

[0012] As a preferred embodiment, the grain raw materials consist of sorghum, barley, wheat, glutinous rice, and corn; the mass ratio of sorghum, barley, wheat, glutinous rice, and corn in the grain raw materials is (34-38):(20-24):(16-20):(14-18):(6-10). More preferably, the mass ratio of sorghum, barley, wheat, glutinous rice, and corn in the grain raw materials is 36:22:18:16:8.

[0013] As a preferred embodiment, the grain raw materials are pre-crushed before mixing; the particle size of the grain raw materials obtained after crushing is 40-60 mesh.

[0014] As a preferred embodiment, the mixing of koji is done by adding sweet wine koji to the cooked material and stirring evenly; the added mass of sweet wine koji is 0.1%-0.3% of the cooked material; the saccharification is done by placing the cooked material after mixing of koji at a temperature of 25-30°C for 24-32 hours.

[0015] As a preferred option, the spraying mass of wheat oligopeptide solution is 0.1% to 0.5% per 100 kg of grain raw material.

[0016] This invention employs fermentation technology in cellars, where the cellar is the core carrier for baijiu fermentation, providing a suitable environment for microbial metabolism and ensuring that the aroma components produced by metabolism do not volatilize. Different types of baijiu use different cellars; this invention does not impose any particular limitation on the cellar, but rather uses cellars of the dimensions and materials suitable for grain-aroma baijiu fermentation that meet the fermentation requirements. As a preferred embodiment, the cellar is a square cellar, 4-5 meters long and 3-4 meters wide, made of mud.

[0017] As a preferred embodiment, the fermentation time is 60 to 90 days; the fermentation process involves sealing the pit with yellow mud, and no temperature control is performed during the fermentation process.

[0018] As a preferred embodiment, the distillation is carried out by steam distillation; the temperature of the distilled liquor is 25℃~30℃, and the intermediate liquor with an alcohol content of 50%vol~55%vol is taken, which is the grain-aroma type of baijiu.

[0019] As a preferred option, the wheat oligopeptides used in the wheat oligopeptide solution have a molecular weight of 1000-5000 Da.

[0020] A grain-aroma type of baijiu prepared using the above-described preparation method.

[0021] The grain-aroma type baijiu and its preparation method provided by this invention have the following beneficial effects:

[0022] The preparation method of grain-aroma baijiu of the present invention includes processes such as mixing, simmering over a low flame, mixing with yeast, saccharification, spraying with wheat oligopeptides, fermentation, and distillation. In the above processes of the present invention, on the one hand, the grain is cooked by simmering over a low flame, eliminating the soaking and steaming processes in traditional solid-state brewing, thereby fully stimulating the aroma of the grain. On the other hand, the present invention involves spraying a wheat oligopeptide solution into the fermentation pit before grain fermentation, which promotes the proliferation of probiotics, significantly increasing the number of probiotics in the fermentation pit, and laying the microbial foundation for the production of aroma substances.

[0023] Experiments have shown that, compared to traditional grain soaking and steaming processes, the grain-aroma baijiu prepared by this invention exhibits a significant increase in ethyl hexanoate content and a significant decrease in ethyl acetate and ethyl heptanoate content, while also generating a variety of novel flavor components (such as dioctyl adipate, acetal, and palmitic acid). Furthermore, sensory evaluation reveals that the grain-aroma baijiu prepared by this invention possesses a fragrant aroma, a pleasant taste, and a lingering aftertaste, effectively highlighting the unique flavor and quality of grain-aroma baijiu, and demonstrating promising application prospects in the field of high-quality baijiu production. Attached Figure Description

[0024] Figure 1 This diagram shows the network analysis results of dominant microbial genera during fermentation in the pit under the process conditions of non-sprayed oligopeptide (A) in Comparative Example 2 and sprayed oligopeptide (B) in Example 1. Detailed Implementation

[0025] The present invention will now be further described with reference to the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments. Unless otherwise defined, the technical terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art. Unless otherwise specified, the experimental reagents used in the following embodiments are conventional biochemical reagents; the experimental methods, unless otherwise specified, are conventional methods.

[0026] In the following examples, the wheat oligopeptide solution used had a mass concentration of 1% to 5%, and the solvent used in preparing the wheat oligopeptide solution was distilled water. The relative molecular weight of the wheat oligopeptides was 1000 Da to 5000 Da. The sweet wine starter was sourced from Angel Yeast (ingredients are rice flour and rhizobium), with a specification of 10 kg, and the standard implemented was QB / T 4577.

[0027] Example 1

[0028] A method for preparing grain-aroma baijiu includes the following steps:

[0029] (1) Take sorghum, barley, wheat, glutinous rice and corn as grain raw materials, grind them to 40-60 mesh respectively, and then mix the five raw materials evenly in a ratio of 36:22:18:16:8. Stir-fry the mixed grain raw materials at 90℃ for 40 minutes to obtain cooked material, which will then enter the subsequent production process.

[0030] (2) Add 0.2 wt% of sweet wine yeast to the cooked material obtained in step (1) and stir evenly. After mixing with yeast, place the cooked material at 27℃ for saccharification for 28 hours, and then proceed with the subsequent fermentation process in the fermentation pit. Before fermentation in the pit, spray the bottom and sides of the pit with a wheat oligopeptide solution with a mass concentration of 3% (wheat oligopeptide molecular weight is 1000Da~5000Da). The total mass of wheat oligopeptide solution sprayed per 100kg of grain raw material is 0.3%. After spraying, fermentation is carried out in the pit. The pit used during fermentation is a square pit with a length of 5 meters, a width of 4 meters, and a depth of 3 meters. The pit is made of mud. The fermentation time is 80 days. During fermentation, the pit is sealed with yellow mud, and no temperature control is performed during fermentation. After fermentation, steam distillation is carried out. The distillation temperature is 28℃. Take the intermediate wine with an alcohol content of 52% vol, which is the grain-aroma type of baijiu.

[0031] Example 2

[0032] A method for preparing grain-aroma baijiu includes the following steps:

[0033] (1) Take sorghum, barley, wheat, glutinous rice and corn as grain raw materials, grind them to 40-60 mesh respectively, and then mix the five raw materials evenly in a ratio of 36:22:18:16:8. Stir-fry the mixed grain raw materials at 90℃ for 40 minutes to obtain cooked material, which will then enter the subsequent production process.

[0034] (2) Add 0.3 wt% of sweet wine yeast to the cooked material obtained in step (1) and stir evenly. After mixing with yeast, place the cooked material at 30℃ for saccharification for 24 hours, and then proceed with the subsequent fermentation process in the fermentation pit. Before fermentation in the pit, spray the bottom and sides of the pit with a 5% wheat oligopeptide solution (wheat oligopeptide molecular weight is 1000Da~5000Da). The total mass of wheat oligopeptide solution sprayed per 100kg of grain raw material is 0.1%. After spraying, the grain is fermented in the pit. The pit used during fermentation is a square pit with a length of 5 meters, a width of 4 meters, and a depth of 3 meters. The pit is made of mud. The fermentation time is 80 days. During the fermentation process, the pit is sealed with yellow mud, and the fermentation temperature is not controlled. After fermentation, steam distillation is carried out. The temperature of the distilled liquor is 30℃. Take the intermediate liquor with an alcohol content of 52% vol, which is the grain-aroma type of baijiu.

[0035] Example 3

[0036] A method for preparing grain-aroma baijiu includes the following steps:

[0037] (1) Take sorghum, barley, wheat, glutinous rice and corn as grain raw materials, grind them to 40-60 mesh respectively, and then mix the five raw materials evenly in a ratio of 36:22:18:16:8. Stir-fry the mixed grain raw materials at 90℃ for 40 minutes to obtain cooked material, which will then enter the subsequent production process.

[0038] (2) Add 0.1 wt% of sweet wine yeast to the cooked material obtained in step (1) and stir evenly. After mixing with yeast, place the cooked material at 25℃ for saccharification for 32 hours, and then proceed with the subsequent fermentation process in the fermentation pit. Before fermentation in the pit, spray the bottom and sides of the pit with a wheat oligopeptide solution with a mass concentration of 1% (wheat oligopeptide molecular weight is 1000Da~5000Da). The total mass of wheat oligopeptide solution sprayed per 100kg of grain raw material is 0.5%. After spraying, the grain is fermented in the pit. The pit used during fermentation is a square pit with a length of 5 meters, a width of 4 meters, and a depth of 3 meters. The pit is made of mud. The fermentation time is 80 days. During the fermentation process, the pit is sealed with yellow mud, and the fermentation temperature is not controlled. After fermentation, steam distillation is carried out. The distillation temperature is 28℃. Take the intermediate wine with an alcohol content of 52% vol, which is the grain-aroma type of baijiu.

[0039] Comparative Example 1

[0040] A method for preparing a grain-aroma type of baijiu (Chinese liquor) is described. The operation steps (2) are basically the same as in Example 1, except that in this comparative example, during fermentation, step (1) involves soaking and steaming the grain raw materials to obtain cooked grains. The soaking process is as follows: the grains are submerged in 95°C hot water for 20cm above the surface and soaked for 15min. The steaming process is as follows: initial steaming for 7min at 0.14MPa; then steaming for 17min at 0.05MPa.

[0041] Comparative Example 2

[0042] A method for preparing a grain-aroma type of liquor, the operation steps are basically the same as those in Example 1, the difference being that in this comparative example, during fermentation, in step (2), before fermentation, the fermentation pit is not sprayed with wheat oligopeptide solution, and the other operations are the same as in Example 1.

[0043] Comparative Example 3

[0044] A method for preparing grain-aroma baijiu (Chinese white liquor) is basically the same as that in Example 1, except that in this comparative example, during fermentation, step (2) is as follows: 0.2 wt% of sweet wine yeast is added to the cooked material obtained in step (1) and stirred evenly. After mixing with yeast, the cooked material is placed at 27°C for saccharification for 28 hours. Then, wheat oligopeptide solution is directly sprayed onto the saccharified cooked material. The spraying amount of wheat oligopeptide solution is 0.3% per 100 kg of grain raw material, and the subsequent fermentation process is carried out. Before fermentation in the fermentation pit, the fermentation pit is no longer sprayed with wheat oligopeptide solution, and the remaining operations are the same as in Example 1.

[0045] Experimental Example 1

[0046] In this experiment, a triple quadrupole gas chromatography-mass spectrometry (TSQ 8000) system was used to analyze the flavor compounds and volatile components of the grain-aroma baijiu prepared in Example 1 and Comparative Example 1. The analytical conditions were as follows: temperature program: initial temperature 40℃, hold for 5 min, then increase to 70℃ at 5℃ / min, then to 180℃ at 8℃ / min, and finally to 220℃ at 12℃ / min, hold for 8 min. Compounds were searched and analyzed using the Xcalibur software spectral library, and the relative content of each volatile substance was determined by peak area normalization. The analytical results of the flavor compounds are shown in Table 1.

[0047] Table 1

[0048]

[0049]

[0050]

[0051] Table 1 shows that the content of ethyl hexanoate (pineapple-like aroma, sweet and refreshing taste) increased significantly, while the content of ethyl acetate (banana-apple-like aroma, pungent taste, with astringency) and ethyl heptanoate (apple-like aroma, with a fatty odor) decreased significantly. Furthermore, novel flavor components (such as dioctyl adipate, acetal, and palmitic acid) were produced. Sensory evaluation revealed that the resulting grain-aroma baijiu possesses a fragrant aroma, a fragrant taste, and a lingering aftertaste, highlighting the unique flavor and quality of grain-aroma baijiu.

[0052] Experimental Example 2

[0053] Since Comparative Example 3 involved directly spraying wheat oligopeptides into the cooked feed, it was verified that their interaction with microorganisms in the initial stage was weak and unable to effectively promote microbial fermentation and improve the aroma of the baijiu. Therefore, this method was no longer used for fermentation. The microbial network in Comparative Example 3 was not analyzed further.

[0054] This experiment analyzed the microbial components of the grain-aroma baijiu obtained in Example 1 and Comparative Example 2 of the present invention, and then constructed a microbial network. Figure 1 The results of the comparison between Comparative Example 2 (Group A) and Example 1 (Group B) in terms of microbial networks are presented.

[0055] Depend on Figure 1 It can be seen that group A and group B have 62 and 56 valid connection nodes, respectively, and 158 and 234 stable correlations. Further correlation analysis yielded the following results:

[0056] ① Network analysis revealed that the microbial network in group B exhibited a higher degree of aggregation compared to group A. This suggests that microorganisms in group B tend to form densely connected network structures rather than exhibiting a scattered relationship. This network structure may reflect a more complex and stable coexistence relationship within the microbial community.

[0057] ② The analysis of microbial connections revealed that in group B, the connections between bacteria were stronger than those between fungi. This suggests that bacteria play a more important role in the microbial network in group B, possibly closely related to the fermentation process and product formation.

[0058] ③ Correlation analysis revealed that the same microorganism exhibited different correlations in groups A and B, indicating that the interactions between microorganisms were influenced by environmental factors. For example, Aspergillus was significantly correlated only with Kazachstania in group A, while it also showed significant correlations with other microorganisms such as Lactobacillus, Saccharomyces, and Bacteroides in group B.

[0059] ④ Analysis of the effects of oligopeptides revealed that the microbial community in the fermentation pits formed a more stable community structure under the influence of oligopeptides, providing a microbial basis for the production of grain-aroma baijiu. This suggests that the interactions between microorganisms have a significant impact on the quality and characteristics of baijiu, and that oligopeptides may play a key role in regulating these interactions.

[0060] In summary, this invention, by spraying wheat oligopeptides into the fermentation pits, effectively promotes the bio-fermentation of probiotics during the preparation of baijiu (Chinese liquor), increases the variety of probiotics, and enriches the flavor of the baijiu. These analytical results contribute to a deeper understanding of the interactions between microorganisms under different conditions and provide guidance for the regulation and optimization of microbial communities during baijiu production.

[0061] In summary, the results of this invention demonstrate that the grain-aroma baijiu prepared by this invention utilizes a gentle roasting method to cook the grains, eliminating the soaking and steaming processes found in traditional solid-state brewing, thus fully stimulating the aroma of the grains. Simultaneously, the fermentation process, involving spraying a wheat oligopeptide solution into the fermentation pit, significantly increases the number of beneficial bacteria in the pit, laying the microbial foundation for the generation of aroma compounds. Experiments show that the grain-aroma baijiu prepared by this invention exhibits a significant increase in ethyl hexanoate content and a significant decrease in ethyl acetate and ethyl heptanoate content, resulting in novel flavor components. Further sensory evaluation reveals that the grain-aroma baijiu obtained by this invention possesses a fragrant aroma, a pleasant taste, and a lingering aftertaste, highlighting the unique flavor and quality of grain-aroma baijiu and showing promising application prospects in the preparation of high-quality baijiu.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing grain-aroma type baijiu, characterized in that, Includes the following steps: (1) Mix the grain raw materials in proportion, and then stir-fry them over a low heat to obtain cooked food; (2) The cooked material obtained in step (1) is mixed with yeast and saccharified, then put into a cellar for fermentation, and finally distilled to obtain the grain-aroma type liquor; The grain raw materials consist of sorghum, barley, wheat, glutinous rice, and corn; the mass ratio of sorghum, barley, wheat, glutinous rice, and corn in the grain raw materials is (34~38):(20~24):(16~20):(14~18):(6~10); the simmering process is carried out at 80~100℃ for 30~50 minutes; the mixing process involves adding sweet wine yeast to the cooked material and stirring evenly; the added mass of sweet wine yeast is 0.1%-0.3% of the cooked material; the saccharification process involves placing the cooked material after mixing with yeast at 25~30℃ for 24~32 hours; before fermentation, the bottom and sides of the fermentation pit are sprayed with a wheat oligopeptide solution with a mass concentration of 1%~5%; the wheat oligopeptides used in the wheat oligopeptide solution have a molecular weight of 1000~5000 Da.

2. The method for preparing grain-aroma baijiu according to claim 1, characterized in that, The grain raw materials are pre-crushed before mixing; the particle size of the grain raw materials obtained after crushing is 40-60 mesh.

3. The method for preparing grain-aroma baijiu according to claim 1 or 2, characterized in that, For every 100 kg of grain raw material, the corresponding spraying mass of wheat oligopeptide solution is 0.1%~0.5%.

4. The method for preparing grain-aroma baijiu according to claim 1 or 2, characterized in that, The cellar is a square cellar with a length of 4-5 meters and a width of 3-4 meters; the cellar is made of mud.

5. The method for preparing grain-aroma baijiu according to claim 1 or 2, characterized in that, The fermentation time is 60 to 90 days; the fermentation pit is sealed with yellow mud during the fermentation process, and no temperature control is performed during the fermentation process.

6. The method for preparing grain-aroma baijiu according to claim 1 or 2, characterized in that, The distillation is carried out by steam distillation; the temperature of the distilled liquor is 25℃~30℃, and the intermediate liquor with an alcohol content of 50%vol~55%vol is taken, which is the grain-aroma type of baijiu.

7. A grain-aroma type of baijiu prepared by the preparation method according to any one of claims 1 to 6.

Images