Method for co-distilling wine by using magnetic field to assist pear and grain and application thereof

Abstract

The present application belongs to the technical field of brewing, and discloses a method for co-brewing and distilling wine by pear and grains with the aid of magnetic field and application. The method comprises the following steps: taking specific weight ratio of sorghum, glutinous rice, rice, wheat and corn as a grain composition, adding pear juice, chaff and Daqu to prepare a steamed grain substrate, and fermenting the substrate in an alternating magnetic field environment with a magnetic field strength of 1-5 mT to obtain co-brewed and distilled wine by pear and grains. The obtained distilled wine has an alcohol yield of ≥30%, a total ester content of ≥2.3% and a tannin content of ≤0.5 g / L. The present application significantly improves the alcohol yield and the content of ester flavor substances by the aid of alternating magnetic field fermentation, effectively reduces the astringency and harmful by-products such as methanol caused by tannin, and makes the finished product have both pear fruit fragrance and grain wine mellow taste, with harmonious flavor and excellent safety indicators. The present application also provides application of the above method in the preparation of pear wine food.

Description

Technical Field

[0001] This invention belongs to the field of brewing technology, specifically a method and application of using a magnetic field to assist in the co-brewing of pears and grains to distill liquor. Background Technology

[0002] Pears are rich in organic acids, sugars, and various phenolic substances. Pear wine, made from pears, is characterized by its refreshing fruity aroma and low alcohol content, making it an important direction for the deep processing of pears. However, pear wine generally suffers from a bland taste and limited flavor due to low microbial metabolic efficiency and insufficient production of core flavor compounds such as esters during fermentation, resulting in limited market acceptance. Traditional Chinese baijiu, made from grains such as sorghum and glutinous rice, dominates the market with its mellow taste and rich flavor, but lacks the freshness of fruit. Theoretically, co-fermenting pears with grains to produce distilled spirits could blend the delicate aroma of pears with the mellowness of baijiu, thereby increasing the added value of pear processing.

[0003] However, existing pear-grain co-fermentation processes still have the following prominent drawbacks: First, the alcohol yield is low. The high organic acid and tannin content in pears inhibits the activity of fermenting microorganisms, leading to a slower metabolic rate and a longer fermentation cycle, while the alcohol yield is generally less than 20%. Some processes attempt to shorten the cycle by increasing the fermentation temperature or the amount of yeast inoculated, but high temperatures easily induce the proliferation of lactic acid bacteria and other miscellaneous bacteria, producing excessive methanol, fusel oils, and other harmful byproducts, and increasing subsequent purification costs.

[0004] Secondly, the synthesis of flavor compounds is insufficient, resulting in poor harmony between pear aroma and wine aroma. Current processes largely rely on a single brewing yeast or a natural fermentation system, limiting the activity of ester synthases. This leads to a significant drop in the production of characteristic pear aroma components such as ethyl hexanoate and ethyl butyrate, resulting in an imbalance in the ester-acid ratio of the wine. To compensate for these aroma deficiencies, some technologies employ the addition of artificial ester flavorings, but these exogenous flavorings still exhibit a certain difference from the flavors of natural fermentation.

[0005] Third, the astringency and astringency caused by tannins are difficult to control effectively. Condensed tannins in pear peel and core continue to dissolve during the winemaking process, and when combined with salivary proteins in the mouth, they produce a rough and dry drinking experience. If the tannin content is reduced by extending the aging process, it would take months or even years, which not only increases storage costs but also makes the wine prone to oxidative rancidity during long-term storage, producing a stale aroma and further deteriorating its quality.

[0006] In summary, existing methods for brewing wine with pears have room for improvement in terms of fermentation efficiency, flavor harmony, astringency control, and safety indicators. A safe brewing method that can simultaneously improve brewing efficiency, enrich natural flavor substances, and reduce tannin content is still needed. Summary of the Invention

[0007] The purpose of this invention is to provide a method and application for distilling pear and grain co-fermentation using a magnetic field. By using an alternating magnetic field of specific intensity, frequency, and processing time, combined with optimized pear and grain raw material ratios and process parameters such as fermentation temperature and pH, a distilled spirit that combines the fresh fruity aroma of pears with the mellow and smooth taste of baijiu can be produced. This solves the problems of insufficient alcohol yield, monotonous flavor, heavy astringency, and poor safety indicators such as methanol in existing pear wine and pear and grain co-fermentation processes. While significantly shortening the fermentation cycle and increasing the alcohol yield, this method effectively increases the content of characteristic flavor substances such as esters and moderately reduces the astringency caused by tannins, so that the finished spirit maintains good flavor harmony under both normal temperature and low temperature storage conditions.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] In a first aspect, the present invention provides a method for co-brewing distilled spirits from pears and grains using a magnetic field, specifically by fermenting the grain substrate in an alternating magnetic field environment with a magnetic field strength of 1~5mT to prepare co-brewing distilled spirits from pears and grains.

[0010] The steamed grain substrate is prepared by adding pear juice to the grain composition, moistening the grain for 20-35 minutes, mixing in rice husks, steaming the grain until the starch gelatinization degree reaches more than 85%, cooling to 22-25℃, adding Daqu (a type of starter culture), and thus obtaining the steamed grain substrate.

[0011] The grain composition is prepared by mixing sorghum, glutinous rice, rice, wheat and corn in a weight ratio of 42~58 : 18~22 : 18~22 : 4~8 : 2~6.

[0012] The weight ratio of corn, pear juice, rice husks, and Daqu (a type of starter culture) in the raw materials is 2~6: 10~20: 20~30: 25~35;

[0013] The distilled spirit made from pears and grains has an alcohol yield of ≥30%, a total ester content of ≥2.3%, and a tannin content of ≤0.5g / L.

[0014] Among them, sorghum, glutinous rice, rice, wheat, corn and rice husks are all measured by dry weight.

[0015] The Daqu is a medium-high temperature Daqu, and its physicochemical indicators meet the following requirements: moisture ≤12%, acidity 1.0~1.2mmol / 10g, starch content ≤57%, saccharification power 500~800mg / g·h, liquefaction power ≥0.8g / g·h, and fermentation power ≥0.8g / g·72h.

[0016] As a limitation of the present invention, the fermentation time of the fermented steamed grain substrate is 25 to 35 days;

[0017] On days 16-20 of fermentation, the fermentation substrate was placed in an alternating magnetic field environment with a magnetic field strength of 1-5 mT and fermentation continued until the fermentation was terminated.

[0018] As another limitation of the present invention, it includes the following steps performed sequentially:

[0019] S1. Preparation of pear juice: Juice snow pears, separate the liquid, and obtain pear juice with a soluble solids content of 12-14% and an acidity of 0.1-0.2%;

[0020] S2. Pear juice soaking: Take the grain composition according to the weight ratio and add it to the pear juice. Soak the grain for 20-35 minutes to allow the grain to absorb the pear juice and soften, and obtain pear grain feed.

[0021] S3. Mixing the fermented grains: Weigh the pear grains and fermented grains at a weight ratio of 1:2~3, add the steamed rice husks, and obtain the fermented grains.

[0022] The steaming process of rice husks is as follows: Soak rice husks in water at a temperature of 80~90℃ for 3 times their weight, place them in a steamer, steam for 30~40 minutes after the steam rises, and then cool them to 22~25℃ to obtain steamed rice husks.

[0023] S4. Steaming and adding koji: Heat the mash until the starch gelatinization reaches more than 85%, then cool it down to 22~25℃ and add koji to obtain the steamed grain base.

[0024] S5. Fermentation and distillation: The steamed grain substrate is placed in a fermentation device and fermented in an alternating magnetic field environment of 1~5mT. After fermentation is completed, mash is obtained. The mash is distilled to produce pear-grain co-fermented distilled liquor.

[0025] As a further limitation of the present invention, no mash is added during the first round of preparation of pear and grain co-fermented distilled liquor, and the mash obtained in step S5 is used in step S3 during subsequent rounds of preparation of pear and grain co-fermented distilled liquor.

[0026] That is, the mash can be mash made from pear grains through fermentation, or it can be the mash obtained from step S5.

[0027] Preferably, the temperature of the distilled mash is 90–105°C.

[0028] As a further limitation of the present invention, in step S5, the fermentation device is a fermentation tank, the temperature of the steamed grain substrate entering the tank is 18~24℃, and the moisture content entering the tank is 55~60%.

[0029] As a further limitation of the present invention, the pear juice is obtained by juicing snow pears and filtering them through a 200-mesh sieve.

[0030] Furthermore, the total acid content of the distilled spirit made from pear grains is ≤4.2g / L.

[0031] Secondly, the present invention also provides the application of the above-mentioned method of using magnetic field-assisted co-fermentation of pear grains for distilling liquor in the preparation of pear wine-flavored food products.

[0032] Furthermore, the pear wine-flavored foods are pear wine-flavored beverages, pear wine-flavored seasonings, and pear wine-flavored baked goods made with pear grains as the base spirit, which is co-distilled with pear grains using the magnetic field as an aid.

[0033] By adopting the above technical solution, the technical progress achieved by this invention compared with the prior art is as follows:

[0034] The present invention relates to a method for brewing pear and grain co-fermentation distilled spirits using a magnetic field-assisted fermentation process. By applying an alternating magnetic field of a specific intensity at a specific fermentation stage, combined with optimized pear and grain ratios and fermentation parameters, a pear and grain compound distilled spirit with high alcohol yield, harmonious flavor, smooth taste, and excellent safety indicators can be produced. This method effectively solves the problems of low fermentation efficiency, monotonous flavor, strong astringency, and poor safety indicators in existing pear wine and pear and grain co-fermentation processes.

[0035] This invention utilizes an alternating magnetic field to assist in brewing, significantly enhancing the activity and metabolic rate of microbial enzymes. At the optimal strength of 3mT, the alcohol yield reaches 32.0%, far exceeding the 27.0% of the group without a magnetic field and the 18.5% of traditional pear wine. The fermentation cycle is controllable, and the equipment utilization rate is greatly improved, meeting the needs of industrial production.

[0036] This invention utilizes a magnetic field to promote the synthesis of core flavor compounds such as esters. Under 3mT conditions, the total ester content reaches 2.8g / L, which is significantly better than the group without a magnetic field and traditional pear wine. At the same time, the co-fermentation of pear and grain achieves an organic fusion of the pear aroma and the mellow taste of grain wine, with a sensory score of 95 points, solving the problem of bland taste and monotonous flavor of traditional pear wine.

[0037] This invention achieves moderate control of tannin content through raw material dilution, magnetic field-assisted biotransformation, and distillation separation. At 3mT, the tannin content is reduced to 0.2g / L, which is far lower than the 1.2g / L of traditional pear wine and the 0.6g / L of the group without magnetic field, completely eliminating astringency and astringency. At the same time, trace amounts of tannin are retained to provide structure and avoid thinness, achieving a "smooth but not bland" taste balance.

[0038] This invention effectively reduces harmful byproducts through substrate optimization and magnetic field metabolic regulation. At 3mT, the methanol content is only 0.14 g / L, significantly lower than the group without a magnetic field and traditional pear wine. The total acid content is controlled to a suitable range of 3.8 g / L, ensuring both flavor and improved drinking safety. The entire method requires no chemical additives, relying solely on physical magnetic fields and process optimization, aligning with green brewing principles. Furthermore, the fermentation process is stable, resulting in high batch-to-batch consistency.

[0039] This invention combines deep processing of pear fruit with traditional baijiu brewing, significantly increasing the added value of pear fruit and solving the industry problems of insufficient pear fruit processing volume and weak deep processing capacity. At the same time, it creates a new category of pear-grain integrated distilled spirits, taking into account the consumption needs of both fruit wine and baijiu, broadening the market audience, enriching the alcohol product system, and has good prospects for industrial application. Attached Figure Description

[0040] Figure 1 This is a standard curve diagram showing the results of detecting tannin content in the comparative example of the effects of this invention. Detailed Implementation

[0041] The present invention will be further described in detail below through specific embodiments. It should be understood that the described embodiments are only for explaining the present invention and do not limit the present invention.

[0042] Unless otherwise specified, the experimental methods used in the following examples are conventional methods in the art. Unless otherwise specified, the materials and reagents used in the following examples are commercially available. In each specific example, the rice husks were pre-treated by steaming. The steaming process was as follows: rice husks were soaked in water at 80°C, 85°C, 87°C, or 90°C, at a temperature three times their weight, placed in a steamer, and steamed for 30 min, 33 min, 35 min, or 40 min after the steam was released. The husks were then cooled to 22°C, 23°C, 24°C, or 25°C to obtain the steamed rice husks. In each example, sorghum, glutinous rice, rice, wheat, corn, and rice husks are all measured by dry weight.

[0043] The Daqu is a medium-high temperature Daqu, and its physicochemical indicators meet the following requirements: moisture ≤12%, acidity 1.0-1.2mmol / 10g, starch content ≤57%, saccharification power 500~800mg / g·h, liquefaction power ≥0.8g / g·h, and fermentation power ≥0.8g / g·72h.

[0044] Example 1

[0045] This embodiment describes a method for distilling liquor using pear and grain in a magnetic field-assisted manner. The main raw materials used are sorghum, glutinous rice, rice, wheat, corn, pear juice, rice husks, and daqu (a type of starter culture) in a weight ratio of 50:20:20:6:4:15:20:30.

[0046] The pear-grain co-fermented distilled spirit is prepared using the above-mentioned raw materials by following the steps in sequence:

[0047] S1. Preparation of pear juice

[0048] Fresh, unblemished Zhaoxian snow pears were selected, washed, cored, and cut into chunks before being juiced using a juicer. The extracted pear juice was filtered through a 200-mesh sieve to remove coarse fiber and pulp, and the filtrate was collected to obtain pear juice. Testing showed that the soluble solids content of the obtained pear juice was 14%, and the acidity was 0.1%, meeting the requirements.

[0049] S2. Pear juice to moisten grains

[0050] A grain composition is prepared by uniformly mixing sorghum, glutinous rice, rice, wheat, and corn. The pear juice obtained in step S1 is then added to the grain composition. The grain composition and pear juice are thoroughly mixed and the grains are soaked for 25 minutes to allow the grains to fully absorb the pear juice and soften, resulting in a pear-based grain feed.

[0051] S3. Mix the fermented mash.

[0052] Take pear-based grains and mix them thoroughly with steamed rice husks (treated to remove impurities and bacteria). Then heat and steam the grains until the starch gelatinization reaches 85% or higher. After steaming, cool the material to 22℃, then add medium-high temperature Daqu (a type of starter culture) with a moisture content ≤12%, acidity 1.0~1.2mmol / 10g, starch content ≤57%, saccharification power 500~800mg / g·h, liquefaction power ≥0.8g / g·h, and fermentation power ≥0.8g / g·72h. Mix thoroughly to obtain the first batch of steamed grain substrate. Place the substrate in a fermentation tank, controlling the initial temperature at 20℃ and the initial moisture content at 60%, and ferment for 30 days. After fermentation, obtain mash A for later use.

[0053] Weigh the pear feed and mash A obtained in step S2 at a weight ratio of 1:2.5. Mix the weighed pear feed and mash together, and then add the rice bran that has been steamed to remove impurities and bacteria. Thoroughly mix the above materials to obtain the mash.

[0054] In the first round, mash A is made from pear grains without adding mash. In subsequent rounds, mash A can be used directly or the mash obtained in step S5 can be used to prepare lees.

[0055] S4. Steamed grain with koji

[0056] The mash obtained in step S3 is heated and steamed until the starch gelatinization degree reaches more than 85%. After steaming, the material is cooled to 22°C, and then Daqu (a type of starter culture) is added and mixed thoroughly to obtain the steamed grain substrate.

[0057] S5. Fermentation and alcohol collection

[0058] The steamed grain substrate obtained in step S4 is placed in a fermentation tank, with the temperature of the substrate at 20°C and the moisture content at 60%. The fermentation tank is placed in an alternating magnetic field environment with a magnetic field strength of 3mT for 30 days of fermentation. After fermentation, mash is obtained. The mash is distilled, and the distillate is collected to produce pear-grain co-fermented distilled spirit, denoted as Pear-Grain Co-fermented Distilled Spirit J1.

[0059] Example 2

[0060] This embodiment is a method for co-brewing distilled liquor with pear and grain using a magnetic field. Except for fermenting the grain substrate in an alternating magnetic field environment with a magnetic field strength of 3mT, the other preparation steps and process parameters are the same as in Embodiment 1. The resulting co-brewing distilled liquor with pear and grain is denoted as Pear and Grain Co-brewing Distilled Liquor J2.

[0061] Example 3

[0062] This embodiment is a method for co-brewing distilled liquor using pear and grain with magnetic field assistance. Except for fermenting the grain substrate in an alternating magnetic field environment with a magnetic field strength of 5mT, the other preparation steps and process parameters are the same as in Embodiment 1. The resulting co-brewing distilled liquor is denoted as Pear and Grain Co-brewing Distilled Liquor J3.

[0063] Example 4

[0064] This embodiment describes a method for distilling liquor using pear and grain in a magnetic field-assisted manner. The main raw materials used are sorghum, glutinous rice, rice, wheat, corn, pear juice, rice husks, and daqu (a type of starter culture) in a weight ratio of 42:22:18:4:2:10:20:25.

[0065] The pear-grain co-fermented distilled spirit is prepared using the above-mentioned raw materials by following the steps in sequence:

[0066] S1. Preparation of pear juice

[0067] Fresh, unblemished Zhaoxian snow pears were selected, washed, cored, and cut into chunks before being juiced using a juicer. The extracted pear juice was filtered through a 200-mesh sieve to remove coarse fiber and pulp, and the filtrate was collected to obtain pear juice. Testing showed that the soluble solids content of the obtained pear juice was 13%, and the acidity was 0.13%, meeting the requirements.

[0068] S2. Pear juice to moisten grains

[0069] A grain composition is prepared by uniformly mixing sorghum, glutinous rice, rice, wheat, and corn. The pear juice obtained in step S1 is then added to the grain composition. The grain composition and pear juice are thoroughly mixed and the grains are soaked for 35 minutes to allow the grains to fully absorb the pear juice and soften, resulting in a pear-based grain feed.

[0070] S3. Mix the fermented mash.

[0071] Weigh the pear feed and mash A obtained in step S2 at a weight ratio of 1:2. Mix the weighed pear feed and mash together, and then add the rice husks that have been steamed to remove impurities and bacteria. Thoroughly mix the above materials to obtain the mash.

[0072] S4. Steamed grain with koji

[0073] The mash obtained in step S3 is heated and steamed until the starch gelatinization degree reaches more than 85%. After steaming, the material is cooled to 22°C, and then Daqu (a type of starter culture) is added and mixed thoroughly to obtain the steamed grain substrate.

[0074] S5. Fermentation and alcohol collection

[0075] The steamed grain substrate obtained in step S4 is placed in a fermentation tank, with the initial temperature controlled at 20°C and the moisture content at 60%. The fermentation tank is placed in an alternating magnetic field environment with a magnetic field strength of 3 mT for fermentation. The total fermentation time is 35 days. On the 20th day of fermentation, the fermentation substrate is placed back into the aforementioned alternating magnetic field environment to continue fermentation until termination. After fermentation, mash is obtained. The mash is distilled, and the distillate is collected to produce pear-grain co-fermented distilled spirit.

[0076] Testing revealed that the pear-grain co-fermented distilled spirit produced in this embodiment had a yield ≥30%, a total ester content ≥2.3%, a tannin content ≤0.5g / L, and a total acid content ≤4.2g / L. The resulting spirit possesses both the delicate aroma of pears and the mellow taste of grain spirits, with significantly reduced astringency and a harmonious flavor profile.

[0077] Example 5

[0078] This embodiment describes a method for distilling liquor using pear and grain in a magnetic field-assisted manner. The main raw materials used are sorghum, glutinous rice, rice, wheat, corn, pear juice, rice husks, and daqu (a type of starter culture) in a weight ratio of 50:20:20:6:4:15:25:30.

[0079] The pear-grain co-fermented distilled spirit is prepared using the above-mentioned raw materials by following the steps in sequence:

[0080] S1. Preparation of pear juice

[0081] Fresh, unblemished Zhaoxian snow pears were selected, washed, cored, and cut into chunks before being juiced using a juicer. The extracted pear juice was filtered through a 200-mesh sieve to remove coarse fiber and pulp, and the filtrate was collected to obtain pear juice. Testing showed that the soluble solids content of the obtained pear juice was 12%, and the acidity was 0.2%, meeting the requirements.

[0082] S2. Pear juice to moisten grains

[0083] A grain composition is prepared by uniformly mixing sorghum, glutinous rice, rice, wheat, and corn. The pear juice obtained in step S1 is then added to the grain composition. The grain composition and pear juice are thoroughly mixed and the grains are soaked for 25 minutes to allow the grains to fully absorb the pear juice and soften, resulting in a pear-based grain feed.

[0084] S3. Mix the fermented mash.

[0085] Weigh the pear feed and mash A obtained in step S2 at a weight ratio of 1:3. Mix the weighed pear feed and mash together, and then add the rice bran that has been steamed to remove impurities and bacteria. Mix the above materials thoroughly to obtain the mash.

[0086] S4. Steamed grain with koji

[0087] The mash obtained in step S3 is heated and steamed until the starch gelatinization reaches over 85%. After steaming, the material is cooled to 24°C, and then Daqu (a type of starter culture) is added and mixed thoroughly to obtain the steamed grain substrate.

[0088] S5. Fermentation and alcohol collection

[0089] The steamed grain substrate obtained in step S4 is placed in a fermentation tank, with the initial temperature controlled at 24°C and the moisture content at 58%. The fermentation tank is placed in an alternating magnetic field environment with a magnetic field strength of 5 mT for fermentation. The total fermentation time is 25 days. On the 16th day of fermentation, the substrate is placed back into the aforementioned alternating magnetic field environment to continue fermentation until termination. After fermentation, mash is obtained. The mash is distilled, and the distillate is collected to produce pear-grain co-fermented distilled spirit.

[0090] Testing revealed that the pear-grain co-fermented distilled spirit produced in this embodiment had a yield ≥30%, a total ester content ≥2.3%, a tannin content ≤0.5g / L, and a total acid content ≤4.2g / L. The resulting spirit possesses both the delicate aroma of pears and the mellow taste of grain spirits, with significantly reduced astringency and a harmonious flavor profile.

[0091] Example 6

[0092] This embodiment describes a method for distilling liquor using pear and grain in a magnetic field-assisted manner. The main raw materials used are sorghum, glutinous rice, rice, wheat, corn, pear juice, rice husks, and daqu (a type of starter culture) in a weight ratio of 58:22:22:8:6:20:30:35.

[0093] The pear-grain co-fermented distilled spirit is prepared using the above-mentioned raw materials by following the steps in sequence:

[0094] S1. Preparation of pear juice

[0095] Fresh, unblemished Zhaoxian snow pears were selected, washed, cored, and cut into chunks before being juiced using a juicer. The extracted pear juice was filtered through a 200-mesh sieve to remove coarse fiber and pulp, and the filtrate was collected to obtain pear juice. Testing showed that the soluble solids content of the obtained pear juice was 14%, and the acidity was 0.1%, meeting the requirements.

[0096] S2. Pear juice to moisten grains

[0097] A grain composition is prepared by uniformly mixing sorghum, glutinous rice, rice, wheat, and corn. The pear juice obtained in step S1 is then added to the grain composition. The grain composition and pear juice are thoroughly stirred and mixed, and the grains are soaked for 20 minutes to allow them to fully absorb the pear juice and soften, resulting in a pear-based grain mixture.

[0098] S3. Mix the fermented mash.

[0099] Weigh the pear feed and mash A obtained in step S2 at a weight ratio of 1:2.5. Mix the weighed pear feed and mash together, and then add the rice bran that has been steamed to remove impurities and bacteria. Thoroughly mix the above materials to obtain the mash.

[0100] S4. Steamed grain with koji

[0101] The mash obtained in step S3 is heated and steamed until the starch gelatinization degree reaches more than 85%. After steaming, the material is cooled to 25°C, and then Daqu (a type of starter culture) is added and mixed thoroughly to obtain the steamed grain substrate.

[0102] S5. Fermentation and alcohol collection

[0103] The steamed grain substrate obtained in step S4 is placed in a fermentation tank, with the initial temperature controlled at 18°C ​​and the moisture content at 55%. The fermentation tank is placed in an alternating magnetic field environment with a magnetic field strength of 3 mT for fermentation. The total fermentation time is 30 days. On the 18th day of fermentation, the substrate is placed back into the aforementioned alternating magnetic field environment to continue fermentation until termination. After fermentation, mash is obtained. The mash is distilled, and the distillate is collected to produce pear-grain co-fermented distilled spirit.

[0104] Testing revealed that the pear-grain co-fermented distilled spirit produced in this embodiment had a yield ≥30%, a total ester content ≥2.3%, a tannin content ≤0.5g / L, and a total acid content ≤4.2g / L. The resulting spirit possesses both the delicate aroma of pears and the mellow taste of grain spirits, with significantly reduced astringency and a harmonious flavor profile.

[0105] Example 7

[0106] This embodiment is a method for co-fermenting pear and grain with a magnetic field to produce distilled liquor. It is basically the same as embodiment 2, except for step S5, which is as follows:

[0107] S5. Fermentation and alcohol collection

[0108] The steamed grain substrate obtained in step S4 is placed in a fermentation tank, with the initial temperature controlled at 20°C and the moisture content at 60%. The fermentation tank is placed in an alternating magnetic field environment with a magnetic field strength of 3 mT for fermentation. The total fermentation time is 30 days. On the 18th day of fermentation, the fermentation substrate is placed in the above-mentioned alternating magnetic field environment to continue fermentation until termination. After fermentation, mash is obtained. The mash is distilled, and the distillate is collected to produce pear-grain co-fermented distilled spirit, denoted as Pear-Grain Co-fermented Distilled Spirit J7.

[0109] In other embodiments, the mash obtained in step S5 can be reused in step S3 as recycled mash to produce pear and grain co-fermented distilled spirits.

[0110] Comparative Example 1

[0111] This comparative example is a traditional pear wine made by Hebei Fenglaiyi Winery Co., Ltd. Its preparation method is to use pear juice as raw material, which is crushed and pressed, clarified, primary fermented, secondary fermented, aged, blended and sterilized.

[0112] Comparative Example 2

[0113] This comparative example is a pear wine prepared by a method without magnetic field assistance. The only difference between this method and Example 1 is that the magnetic field strength is 0.

[0114] Comparative Example 3

[0115] The pear wine prepared by this comparative example using a strong magnetic field-assisted method differs from that in Example 1 only in that the magnetic field strength is 15 mT.

[0116] Comparative Example 4

[0117] The pear wine prepared by this comparative example using a strong magnetic field-assisted method differs from that in Example 7 only in that the magnetic field is a constant magnetic field with a strength of 3 mT.

[0118] Effect Comparison

[0119] In this comparative study, equal amounts of pear wine from Examples 1-3, Example 7, and Comparative Examples 1-4 were taken, and the starch gelatinization degree, alcohol yield, total ester content, methanol content, total acid content, and tannin content were measured sequentially. Sensory evaluation was also conducted, and the results are shown in Table 1.

[0120] The specific testing methods are as follows:

[0121] Alcohol yield: Calculated by testing according to the conventional methods in the distilled spirits industry, the ratio of the volume of the finished alcohol (60% vol) to the mass of the base grains, expressed as % (volume / mass).

[0122] Total ester content: Take 50 mL of wine sample into a reflux bottle, add phenolphthalein indicator, titrate with NaOH standard solution until pink, then add 25 mL of NaOH standard titration solution, reflux in boiling water bath for 30 min, cool, and titrate with sulfuric acid standard solution until the faint red color disappears.

[0123] Calculation formula: X = [(V0 - V1) × C × 88] / 50;

[0124] In the formula, X is the mass concentration of total esters in the sample (calculated as ethyl acetate), g / L;

[0125] C represents the actual concentration of the sulfuric acid standard titration solution, in mol / L;

[0126] V0 is the volume of sulfuric acid standard titration solution consumed by the blank test sample, in mL;

[0127] V1 is the volume of sulfuric acid standard titration solution consumed by the sample, in mL;

[0128] 88 represents the molar mass of ethyl acetate.

[0129] Methanol content: determined in accordance with GB 5009.266-2016 "National Food Safety Standard - Determination of Methanol in Food".

[0130] Total acid content: determined according to the first method (acid-base indicator titration method) in GB 12456-2021 "National Food Safety Standard - Determination of Total Acid in Food".

[0131] Tannin content: The standard method in brewing, the Folin-Ciocalteu colorimetric method, was used for detection. Gallic acid was used as the standard, and a standard curve was prepared as follows: Figure 1 The detection wavelength is 765 nm.

[0132] Sensory evaluation: In accordance with GB / T 33404-2016 "Guidelines for Sensory Evaluation of Baijiu", an evaluation panel composed of 8 professionals with national wine taster qualifications will conduct a comprehensive evaluation based on four dimensions: color (5 points), aroma (15 points), taste (15 points), and typicality (5 points), with a maximum score of 100 points.

[0133] Table 1. Test results of various indicators

[0134]

[0135] This invention utilizes a 1-5 mT alternating magnetic field to assist in the co-fermentation and distillation of pear grains, with Example 2 showing the best results achieved through a 3 mT alternating magnetic field for 30 days of fermentation. Compared to traditional pear wine (Comparative Example 1), the yield increased by 73.0%, the total ester content increased by 115.4%, and the contents of methanol, total acid, and tannins were significantly reduced, resulting in improved sensory scores. Furthermore, in the non-magnetic field fermentation group and the group using a strong magnetic field with the same intensity of constant magnetic field, all indicators were significantly inferior to those in Example 2, demonstrating that the 1-5 mT alternating magnetic field specified in this invention has irreplaceable technical effects.

[0136] In addition, as in Example 7, applying a magnetic field in the middle and late stages of fermentation from day 18 to day 30 also yielded significantly better results than the group without a magnetic field. Although its alcohol yield, total esters and sensory scores were slightly lower than those of Example 2, which applied a magnetic field throughout the entire process, it saved energy and its indicators were higher than those of Examples 1 and 3.

[0137] The above results indicate that alternating magnetic field treatment throughout the process is beneficial to improving the overall quality of pear-grain co-fermented spirits. In particular, it solves the problems of low alcohol yield, monotonous flavor, heavy astringency, and poor safety indicators in existing pear wine and pear-grain co-fermentation processes. It has good prospects for industrial application, especially since applying a magnetic field in the middle and later stages can achieve a balance between good quality and energy saving.

[0138] In other embodiments, the pear-grain co-fermented distilled spirit prepared in the above embodiments is directly added to the raw materials of baked goods such as bread, cakes, biscuits, and pastries, participating in dough preparation or filling formulation, and after baking, the product presents a unique pear wine aroma; or the distilled spirit is encapsulated to make wine aroma microcapsules, and then added to baked goods to achieve slow release and stable release of flavor, and prolong the flavor retention time.

[0139] It should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions described in the above embodiments or make equivalent substitutions for some of the technical features. 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 claims of the present invention.

Claims

1. A method for co-fermenting distilled spirits from pears and grains using a magnetic field, characterized in that, Fermentation of steamed grain substrate in an alternating magnetic field environment with a magnetic field strength of 1~5mT was used to prepare pear-grain co-fermented distilled liquor. The steamed grain substrate is prepared by adding pear juice to the grain composition, moistening the grain for 20-35 minutes, mixing in rice husks, steaming the grain until the starch gelatinization degree reaches more than 85%, cooling to 22-25℃, adding Daqu (a type of starter culture), and thus obtaining the steamed grain substrate. The grain composition is prepared by mixing sorghum, glutinous rice, rice, wheat and corn in a weight ratio of 42~58 : 18~22 : 18~22 : 4~8 : 2~6. The weight ratio of corn, pear juice, rice husks, and Daqu (a type of starter culture) in the raw materials is 2~6: 10~20: 20~30: 25~35; The distilled spirit made from pears and grains has an alcohol yield of ≥30%, a total ester content of ≥2.3%, and a tannin content of ≤0.5g / L.

2. The method for co-fermenting pear and grain with magnetic field assistance to distill liquor according to claim 1, characterized in that, The fermentation time for the fermented grain substrate is 25-35 days. On days 16-20 of fermentation, the fermentation substrate was placed in an alternating magnetic field environment with a magnetic field strength of 1-5 mT and fermentation continued until it was terminated.

3. A method for co-fermenting pear and grain with magnetic field assistance to distill liquor according to claim 1 or 2, characterized in that, This includes the following steps performed sequentially: S1. Preparation of pear juice: Juice snow pears, separate the liquid to obtain pear juice with a soluble solids content of 12-14% and an acidity of 0.1-0.2%; S2. Pear juice soaking: Take the grain composition according to the weight ratio and add the pear juice to soak the grain for 20-35 minutes to allow the grain to absorb the pear juice and soften, thus obtaining pear grain feed; S3. Mixing the fermented grains: Weigh the pear grains and fermented grains at a weight ratio of 1:2~3, add the steamed rice husks, and obtain the fermented grains. S4. Steaming and adding koji: Heat the mash until the starch gelatinization reaches more than 85%, then cool it down to 22~25℃ and add koji to obtain the steamed grain base. S5. Fermentation and distillation: The steamed grain substrate is placed in a fermentation device and fermented in an alternating magnetic field environment of 1~5mT. After fermentation is completed, mash is obtained. The mash is distilled to produce pear-grain co-fermented distilled liquor.

4. The method for co-fermenting pear and grain with magnetic field assistance to distill liquor according to claim 3, characterized in that, No mash is added during the first round of preparation of pear and grain co-fermented distilled spirits. In subsequent rounds of preparation of pear and grain co-fermented distilled spirits, the mash obtained in step S5 is used in step S3.

5. The method for co-fermenting pear and grain with magnetic field assistance to distill liquor according to claim 4, characterized in that, In step S5, the fermentation device is a fermentation tank, the temperature of the steamed grain substrate entering the tank is 18~24℃, and the moisture content entering the tank is 55~60%.

6. The method for co-fermenting pear and grain with magnetic field assistance to distill liquor according to claim 5, characterized in that, The pear juice is obtained by juicing snow pears and filtering them through a 200-mesh sieve.

7. A method for co-fermenting pear and grain with magnetic field assistance to distill liquor according to any one of claims 4 to 6, characterized in that, The total acid content of the distilled spirit made from pear grains is ≤4.2g / L.

8. The application of the method for co-fermenting pear and grain with magnetic field assistance in distilling liquor according to any one of claims 1 to 7, characterized in that, Used to prepare pear wine-flavored foods.

Images