A method for increasing the tetramethylpyrazine content in soy sauce-flavored koji.

Abstract

This invention discloses a method for increasing the tetramethylpyrazine content in a soy sauce-flavored baijiu (a type of starter culture). The method includes adding a plant additive composed of Eucommia ulmoides leaves, Malus spectabilis leaves, Polygonum hydropiper, Astragalus membranaceus, and Angelica dahurica to the raw materials used in preparing the baijiu. The plant additive is formulated in the following proportions by dry weight: Eucommia ulmoides leaves 2-3 parts by weight, Malus spectabilis leaves 1-2 parts by weight, Polygonum hydropiper 1-2 parts by weight, Astragalus membranaceus 1-1.5 parts by weight, and Angelica dahurica 0.5-1 parts by weight. This invention provides a simple, low-cost, and naturally safe method that effectively increases the tetramethylpyrazine content in the baijiu by adding a specific combination of plant materials, thereby improving the fermentation performance of the baijiu and the final flavor quality of the baijiu.

Description

Technical Field

[0001] The present invention belongs to the technical field of Baijiu brewing, and specifically relates to a method for increasing the content of tetramethylpyrazine (TTMP) in Jiangxiang Daqu by adding specific plant materials, which is applicable to the Daqu preparation process of Jiangxiang Baijiu. Background Art

[0002] Jiangxiang Daqu is the key saccharifying and fermenting agent for the production of Jiangxiang Baijiu, and its microbial community and metabolites directly affect the flavor and quality of Baijiu. Tetramethylpyrazine is an important flavor substance in Jiangxiang Baijiu, with a unique nutty and roasted aroma, and makes an important contribution to the richness and layering of the wine body flavor. At present, the preparation of traditional Jiangxiang Daqu mostly relies on the fermentation of microorganisms in the natural environment, and the production amount of tetramethylpyrazine is unstable and the content is generally low. In the prior art, although optimizing process parameters (such as temperature, humidity) or adding exogenous microorganisms can improve flavor substances to a certain extent, there are problems such as high cost, complex process or flavor distortion.

[0003] Therefore, developing an efficient, stable and natural method to directionally increase the content of tetramethylpyrazine in Daqu has important application value. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method with simple operation, low cost and natural safety. By adding a specific combination of plant materials, the content of tetramethylpyrazine in Jiangxiang Daqu can be effectively increased, thereby improving the fermentation performance of Daqu and the flavor quality of the final Baijiu.

[0005] The technical solution adopted by the present invention to solve its technical problems is: A method for increasing the content of tetramethylpyrazine in Jiangxiang Daqu, which includes adding a plant additive composed of Eucommia ulmoides leaves, Malus spectabilis leaves, Polygonum hydropiper, Astragalus membranaceus and Angelica dahurica to the raw materials for preparing Jiangxiang Daqu; wherein, the ratio of each component in the plant additive by dry weight is: Eucommia ulmoides leaves 2-3 parts by weight, Malus spectabilis leaves 1-2 parts by weight, Polygonum hydropiper 1-2 parts by weight, Astragalus membranaceus 1-1.5 parts by weight, Angelica dahurica 0.5-1 part by weight.

[0006] Preferably, the total amount of the plant additive added is 0.5%-3.0% of the total mass of the koji-making raw materials.

[0007] Preferably, the preparation method of the plant additive includes: washing Eucommia ulmoides leaves, Malus spectabilis leaves, Polygonum hydropiper, Astragalus membranaceus and Angelica dahurica respectively, drying them to a water content below 10%, then respectively pulverizing and passing through a 60-mesh sieve, and finally mixing them evenly according to the above ratio.

[0008] Preferably, the plant additive is added during the raw material mixing stage of the koji-making process, and is thoroughly mixed with the main raw material and water. Then, the koji is pressed and shaped, cultured in a room, turned and controlled, and then ripened and dried according to the conventional koji-making process.

[0009] Preferably, the proportions of the components in the plant additive, based on dry weight, are as follows: 2.4-3 parts by weight of Eucommia ulmoides leaves, 1.1-1.6 parts by weight of Crabapple leaves, 1.1-1.6 parts by weight of Polygonum hydropiper, 1-1.3 parts by weight of Astragalus membranaceus, and 0.6-1 parts by weight of Angelica dahurica.

[0010] Preferably, the weight ratio of Eucommia ulmoides leaves, crabapple leaves, Polygonum hydropiper, Astragalus membranaceus and Angelica dahurica is 2.5:1.5:1.0:1.0:0.5.

[0011] The beneficial effects of this invention are: (1) By adding the plant additive of the present invention, the content of tetramethylpyrazine in the finished sauce-flavored koji can be increased by 120%-150% compared with the traditional process, with stable and significant effects.

[0012] (2) This invention uses all natural plant materials without any chemical synthetic additives. The source is stable and the cost is controllable. It conforms to the green and healthy development direction of the food industry and ensures the safety of the product and consumer acceptance.

[0013] (3) The present invention does not require changes to the main equipment, plant and core process framework of existing sauce-flavored koji production. It only adds a mixing step in the mixing process, which is simple to operate and suitable for large-scale production.

[0014] (4) The introduction of plant additives can also moderately optimize the microbial community structure of Daqu, which may have a positive impact on the activity of enzyme systems such as saccharifying enzymes and proteases, thereby comprehensively improving the fermentation performance of Daqu. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention in any way. It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other. It should also be understood that the terminology used in the embodiments of this invention is for describing specific implementation schemes and not for limiting the scope of protection of this invention.

[0016] When a range of values ​​is given, it should be understood that, unless otherwise stated in this invention, the two endpoints of each range and any value between the two endpoints may be selected.

[0017] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly used in the field to which this invention pertains. The terminology used to describe this invention is intended only to describe a particular implementation and is not intended to limit the scope of the teachings. This invention can be implemented using any prior art methods, apparatus, and materials similar to or equivalent to those described, used, or made in the embodiments of this invention.

[0018] Unless otherwise specified, "%" and "parts" as used in this document refer to "mass %" and "mass parts," respectively.

[0019] The term “and / or” as used herein should be understood to mean any one of the options or any combination of two or more of the options.

[0020] As used herein, the term "about" indicates a range of ±20% of the following value. In some embodiments, the term "about" indicates a range of ±10% of the following value. In some embodiments, the term "about" indicates a range of ±5% of the following value.

[0021] The following embodiments are provided to aid in understanding the present invention. However, it should be understood that these embodiments are for illustrative purposes only and do not constitute any limitation. The actual scope of protection of the present invention is set forth in the claims. It should be understood that any modifications and changes can be made without departing from the spirit of the present invention. Unless otherwise specified, the raw materials used in the embodiments are all commercially available products in the art, their specifications are conventional specifications in the art, and the methods used are conventional methods in the art. The instruments and equipment used in the embodiments are conventional instruments and equipment in the art.

[0022] A method for increasing the tetramethylpyrazine content in soy sauce-flavored koji (a type of starter culture) includes adding a plant additive composed of Eucommia ulmoides leaves, Malus spectabilis leaves, Polygonum hydropiper, Astragalus membranaceus, and Angelica dahurica to the raw materials used in preparing the koji. The plant additive is added during the raw material mixing stage of the koji-making process, and is thoroughly mixed with the main raw materials and water. Subsequently, the process follows the conventional soy sauce-flavored koji-making process, including pressing, incubation, turning and regulating, post-fermentation, and drying.

[0023] The core mechanism of this invention lies in the fact that the five selected plant materials are not simply a mixture, but their combination produces a synergistic effect.

[0024] Eucommia ulmoides leaves and Astragalus membranaceus: rich in polysaccharides, flavonoids and various amino acids. On the one hand, they can serve as a nutrient source and promoter for microbial growth, especially providing favorable conditions for the proliferation of tetramethylpyrazine-producing bacteria such as Bacillus; on the other hand, their active ingredients may regulate the metabolic pathways of microorganisms and promote the chemical reaction (such as the Streptoc amino acid reaction) in which precursor substances (such as amino acids and reducing sugars) are converted into tetramethylpyrazine.

[0025] Polygonum hydropiper: It is sometimes used in small amounts in traditional koji making. It contains flavonoids, volatile oils, etc., and has certain antibacterial and fermentation-promoting effects. It helps to form a microecology that is conducive to the growth of target microorganisms and inhibits miscellaneous bacteria.

[0026] Crabapple leaves and angelica: Crabapple leaves contain organic acids, vitamins, etc.; angelica is rich in coumarins and volatile oils. In addition to providing special flavor precursors, they can further enrich the diversity of the microbial system and may participate in or catalyze the synthesis reaction of pyrazines through specific components they contain.

[0027] Through the above combination, the plant additive creates a microenvironment more conducive to the biosynthesis of tetramethylpyrazine during the fermentation of koji, thereby achieving the targeted enrichment of the target flavor substances.

[0028] In a preferred embodiment, the components of the plant additive are proportioned by dry weight as follows: 2-3 parts by weight of Eucommia ulmoides leaves, 1-2 parts by weight of Malus spectabilis leaves, 1-2 parts by weight of Polygonum hydropiper, 1-1.5 parts by weight of Astragalus membranaceus, and 0.5-1 parts by weight of Angelica dahurica; preferably, 2.4-3 parts by weight of Eucommia ulmoides leaves, 1.1-1.6 parts by weight of Malus spectabilis leaves, 1.1-1.6 parts by weight of Polygonum hydropiper, 1-1.3 parts by weight of Astragalus membranaceus, and 0.6-1 parts by weight of Angelica dahurica; more preferably, the weight ratio of Eucommia ulmoides leaves, Malus spectabilis leaves, Polygonum hydropiper, Astragalus membranaceus, and Angelica dahurica is 2.5:1.5:1.0:1.0:0.5.

[0029] In a preferred embodiment, the total amount of the plant additive is 0.5%-3.0% of the total mass of the raw materials for making koji.

[0030] As a preferred embodiment, the preparation method of the plant additive includes: washing and drying Eucommia ulmoides leaves, crabapple leaves, Polygonum hydropiper, Astragalus membranaceus and Angelica dahurica until the moisture content is less than 10%, then pulverizing them and passing them through a 60-mesh sieve, and finally mixing them evenly according to the specified ratio.

[0031] The present invention will be further described below with reference to specific embodiments and comparative examples, but the scope of protection of the present invention is not limited thereto. All embodiments and comparative examples used the same batch of raw materials and were carried out under the same environmental conditions.

[0032] The following examples and comparative examples all used 1000 kg of high-quality wheat from the same batch as the base raw material, and were carried out according to the traditional process of making soy sauce-flavored koji (wheat soaking, mixing, pressing, fermentation in a fermentation chamber for 40 days, and drying). All plant materials were pre-dried and pulverized through a 60-mesh sieve. The tetramethylpyrazine (TTMP) content was determined by GC-MS.

[0033] Example 1 This embodiment provides a method for increasing the tetramethylpyrazine content in soy sauce-flavored koji. A plant additive composed of Eucommia ulmoides leaves, Malus spectabilis leaves, Polygonum hydropiper, Astragalus membranaceus, and Angelica dahurica is added during the raw material mixing stage of the koji-making process. The mass ratio of Eucommia ulmoides leaves, Malus spectabilis leaves, Polygonum hydropiper, Astragalus membranaceus, and Angelica dahurica in the plant additive is 2.5:1.5:1.0:1.0:0.5, and the total addition amount is 1.5% of the wheat mass. After uniform mixing, the mixture is prepared according to the traditional soy sauce-flavored koji preparation process. The test results are shown in Table 1.

[0034] Example 2 In this embodiment, the mass ratio of Eucommia ulmoides leaves, Malus spectabilis leaves, Polygonum hydropiper, Astragalus membranaceus, and Angelica dahurica was 3.0:1.0:2.0:1.2:0.8, and the total amount added was 2.0% of the wheat mass. The rest was the same as in Example 1. The test results are shown in Table 1.

[0035] Comparative Example 1 This comparative example differs from Example 1 in that no plant-based additives were added. The test results are shown in Table 1.

[0036] Comparative Example 2 The difference between this comparative example and Example 1 is that 1.5% of Eucommia ulmoides leaf powder by weight of wheat was added separately. The test results are shown in Table 1.

[0037] Comparative Example 3 The difference between this comparative example and Example 1 is that 1.5% by weight of crabapple leaf powder was added separately. The test results are shown in Table 1.

[0038] Comparative Example 4 The difference between this comparative example and Example 1 is that 1.5% by weight of Polygonum hydropiper powder was added separately. The test results are shown in Table 1.

[0039] Comparative Example 5 The difference between this comparative example and Example 1 is that Astragalus powder, at 1.5% of the wheat mass, was added separately. The test results are shown in Table 1.

[0040] Comparative Example 6 The difference between this comparative example and Example 1 is that 1.5% of angelica root powder by weight of wheat was added separately. The test results are shown in Table 1.

[0041] Comparative Example 7 The difference between this comparative example and Example 1 is the addition of a plant additive at 1.5% of the wheat mass. This plant additive consists of Eucommia ulmoides leaves and Polygonum hydropiper in a mass ratio of 2.5:1.0. The test results are shown in Table 1.

[0042] Comparative Example 8 The difference between this comparative example and Example 1 is the addition of a plant additive at 1.5% of the wheat mass. This plant additive consists of Eucommia ulmoides leaves and Malus spectabilis leaves in a mass ratio of 2.5:1.5. The test results are shown in Table 1.

[0043] Comparative Example 9 The difference between this comparative example and Example 1 is the addition of a plant additive at 1.5% of the wheat mass. This plant additive consists of Eucommia ulmoides leaves, Polygonum hydropiper, and Malus spectabilis leaves in a mass ratio of 2.5:1.0:1.5. The test results are shown in Table 1.

[0044] Comparative Example 10 The difference between this comparative example and Example 1 is the addition of a plant additive at 1.5% of the wheat mass. This plant additive consists of Eucommia ulmoides leaves, Polygonum hydropiper, and Astragalus membranaceus in a mass ratio of 2.5:1.0:1.0. The test results are shown in Table 1.

[0045] Comparative Example 11 The difference between this comparative example and Example 1 is the addition of a plant additive at 1.5% of the wheat mass. This plant additive consists of Eucommia ulmoides leaves, Polygonum hydropiper, Astragalus membranaceus, and Angelica dahurica in a mass ratio of 1.5:1.0:1.0:0.5. The test results are shown in Table 1.

[0046] Comparative Example 12 The difference between this comparative example and Example 1 is the addition of a plant additive at 1.5% of the wheat mass. This plant additive consists of Eucommia ulmoides leaves, Malus spectabilis leaves, Astragalus membranaceus, and Angelica dahurica in a mass ratio of 2.5:1.5:1.0:0.5. The test results are shown in Table 1.

[0047] Table 1. TTMP content of different embodiments and comparative examples

[0048] Results Analysis In Examples 1-2, the increase in TTMP content was significantly higher than in the comparative examples. In this plant-based additive system, Eucommia ulmoides leaves served as the nutritional and metabolic foundation, Polygonum hydropiper regulated the microbial community and created a favorable ecosystem, Malus spectabilis leaves provided flavor precursors and diversity, and Astragalus membranaceus and Angelica dahurica, based on stable pre-fermentation, further provided special active ingredients (such as Astragalus polysaccharides and Angelica dahurica coumarin), finely regulating secondary metabolism and achieving a significant increase in TTMP content. Comparative Examples 2-6, which added single plant powders, showed limited improvement effects and could not solve the problem of low TTMP content. Comparative Example 7, using a combination of Eucommia ulmoides leaves and Polygonum hydropiper , showed a better effect than the sum of the effects of adding either plant alone, indicating that the nutritional matrix provided by Eucommia ulmoides leaves and the traditional fermentation-promoting and microbial community-regulating effects of Polygonum hydropiper produced a synergistic effect. Comparative Example 8, using a combination of Eucommia ulmoides leaves and Malus spectabilis leaves, was less effective than Comparative Example 7, indicating that the flavor precursors of Malus spectabilis leaves require a more complete microbial community and metabolic environment for effective transformation. Comparative Example 9 used a combination of Eucommia ulmoides leaves, Polygonum hydropiper, and Malus spectabilis leaves, increasing the TTMP content to 33.8 mg / kg. The effect of adding Malus spectabilis leaves was significantly better than Comparative Example 7, indicating that the volatile components of Malus spectabilis leaves were effectively utilized by microorganisms in the fermentation microenvironment created by Eucommia ulmoides leaves and Polygonum hydropiper, beginning to transform into heterocyclic compounds such as TTMP. Comparative Example 10 was better than Comparative Example 7, but not as good as Comparative Example 9. This suggests that the addition of Astragalus membranaceus (possibly providing polysaccharides and saponins) has a beneficial effect, but at this stage, the beneficial effect of Malus spectabilis leaves is more crucial than that of Astragalus membranaceus. Compared to Example 1, Comparative Example 10 only lacked Eucommia ulmoides leaves, but its effect was not as good as Comparative Example 9, indicating that Eucommia ulmoides leaves are the "cornerstone" of the entire formula. Without Eucommia ulmoides leaves providing sufficient basic nutrition and core metabolic regulation, the subsequently added Astragalus membranaceus and Angelica dahurica not only cannot exert their beneficial effects, but may even interfere with fermentation due to competition or inhibition. This conversely highlights the indispensable core position of Eucommia ulmoides leaves. The absence of Polygonum hydropiper in Comparative Example 12 resulted in insufficient "microecological regulation" of the fermentation system, which prevented the full activation of the potential of Eucommia ulmoides leaves, crabapple leaves, etc., leading to a bottleneck in TTMP synthesis efficiency.

[0049] Furthermore, as can be seen from Examples 1-2, the introduction of plant additives can moderately optimize the microbial community structure of Daqu, and have a positive impact on the activity of enzyme systems such as saccharifying enzymes and proteases, thereby comprehensively improving the fermentation performance of Daqu.

[0050] The above analysis demonstrates that the specific proportions of the five specific plants claimed in this invention form an organic whole. Arbitrarily reducing the components, especially omitting the core components, will not achieve the optimal technical effect of this invention. This fully proves the non-obviousness of the technical solution.

[0051] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims

1. A method for increasing the content of tetramethylpyrazine in Maotai Daqu, characterized in that, The method includes adding a plant additive composed of Eucommia ulmoides leaves, Malus spectabilis leaves, Polygonum hydropiper, Astragalus membranaceus, and Angelica dahurica to the raw materials for preparing soy sauce-flavored koji; wherein the proportions of each component in the plant additive on a dry weight basis are: 2-3 parts by weight of Eucommia ulmoides leaves, 1-2 parts by weight of Malus spectabilis leaves, 1-2 parts by weight of Polygonum hydropiper, 1-1.5 parts by weight of Astragalus membranaceus, and 0.5-1 parts by weight of Angelica dahurica.

2. The method of claim 1, wherein, The total amount of the plant additives added is 0.5%-3.0% of the total mass of the raw materials for making koji.

3. The method of claim 1, wherein, The preparation method of the plant additive includes: washing and drying Eucommia ulmoides leaves, crabapple leaves, Polygonum hydropiper, Astragalus membranaceus and Angelica dahurica until the moisture content is less than 10%, then pulverizing them and passing them through a 60-mesh sieve, and finally mixing them evenly according to the specified ratio.

4. The method of claim 1, wherein, The plant-based additives are added during the raw material mixing stage of the koji-making process. They are thoroughly mixed with the main raw materials and water, and then the process is carried out according to the conventional koji-making process, including pressing, molding, fermentation, turning and control, post-ripening and drying.

5. The method of claim 1, wherein, The components of the plant additive are in the following proportions on a dry weight basis: 2.4-3 parts by weight of Eucommia ulmoides leaves, 1.1-1.6 parts by weight of Malus spectabilis leaves, 1.1-1.6 parts by weight of Polygonum hydropiper, 1-1.3 parts by weight of Astragalus membranaceus, and 0.6-1 parts by weight of Angelica dahurica.

6. The method of claim 1, wherein, The weight ratio of Eucommia ulmoides leaves, crabapple leaves, Polygonum hydropiper, Astragalus membranaceus, and Angelica dahurica was 2.5:1.5:1.0:1.0:0.5.

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