Method for preparing low-purine beer based on high-energy fluid mill equipment

Abstract

The invention provides a method for preparing low-purine beer based on high-energy fluid mill equipment, and relates to the field of beer. Comprising the following steps: preparing clarified wort, and pumping the clarified wort into a high-energy fluid mill for treatment to obtain treated wort; the treated wort is subjected to flavor treatment and fermentation treatment, and the low-purine beer is obtained. The method is mainly based on a high-density energy input physical method, purine combined in nucleic acid in wort can be effectively released and is converted into a free state, the utilization rate of purine is increased through fermentation proliferation of yeast, and the purpose of reducing the purine content in a beer product is achieved. The production process flow is simple, the purine reduction effect is obvious, and the prepared beer is excellent in sense, rich in taste level, suitable for industrial production and wide in application prospect.

Description

Technical Field

[0001] The present invention relates to the field of beer, and in particular to a method for preparing low-purine beer based on high-energy fluid mill equipment. Background Art

[0002] Beer is a fermented alcoholic beverage made primarily from malt and water, with hops (including hop products) added, and fermented with yeast. It contains carbon dioxide, forms foam, and has a low alcohol content. Beer contains very little ethanol and is rich in nutrients, so drinking beer is not only not intoxicating but also beneficial to human health in moderation. my country's beer industry is developing rapidly. By 2023, China's total beer output reached 37.89 million kiloliters, with sales revenue of 186.3 billion yuan and total profits of 26 billion yuan, maintaining its position as the world's largest beer producer and consumer for many consecutive years.

[0003] However, the high purine content in beer and the hyperuricemia caused by excessive drinking are currently major issues hindering the development of the beer industry and affecting people's dietary health. Purines in beer primarily come from fermentation raw materials, including barley malt, water, hops, and brewer's yeast. Aside from water, all of these raw materials contain purines, which are primarily present in a bound form to nucleic acids. Research has shown that barley malt has the largest proportion of purines and is the primary source of purines in beer.

[0004] Existing technologies use methods such as enzymatic treatment, adsorption, and acidification to reduce purine content in beer. However, these methods all face numerous challenges: enzymatic treatment can lead to a lighter beer appearance and color. High levels of auxiliary materials during fermentation can reduce the nutritional value of the wort, resulting in insufficient nutrients for yeast growth, which can affect the normal metabolism of the beer and, in turn, its fermentation performance. Treatment with adsorbents can significantly affect the color and flavor of the beer. Acidification is highly corrosive, making safety assessment difficult. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preparing low-purine beer based on a high-energy fluid mill, which can significantly reduce the purine content in beer and retain the original flavor and taste of the beer to the greatest extent, avoiding the problem of beer flavor becoming lighter due to an excessively high proportion of auxiliary materials or the introduction of some chemical substances causing beer flavor deterioration.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A method for preparing low-purine beer based on a high-energy fluid mill comprises the following steps:

[0008] preparing clarified wort, and pumping the clarified wort into a high-energy fluid mill for treatment to obtain treated wort;

[0009] The treated wort is subjected to flavor treatment and fermentation treatment to obtain low-purine beer.

[0010] Furthermore, in the present invention, raw materials and auxiliary materials are weighed according to the weight ratio, wherein the raw materials include 70-90 parts of Vienna malt, 10-20 parts of caramel malt, and 10-20 parts of wheat malt, and the auxiliary materials include 0.05-0.1 parts of aromatic hops, 0.05-0.1 parts of bitter hops, and 0.01-0.05 parts of high-activity brewer's dry yeast;

[0011] The step of preparing clarified wort comprises:

[0012] The Vienna malt, caramel malt and wheat malt are crushed;

[0013] The crushed Vienna malt, caramel malt and wheat malt are mixed with water and saccharified to obtain saccharified liquid;

[0014] The saccharified liquid is filtered to obtain clarified wort.

[0015] Furthermore, in the present invention, the step of subjecting the treated wort to flavor treatment and fermentation treatment to obtain low-purine beer comprises:

[0016] The wort treated by the high-energy fluid mill is heated and boiled, and aromatic hops and bitter hops are added to the boiled wort for flavor treatment;

[0017] The boiled wort is cooled and then fermented by adding highly active brewing dry yeast;

[0018] The fermented beer is filtered to obtain low-purine beer.

[0019] Furthermore, in the present invention, the coarseness to fineness ratio of the malt after the pulverization process is greater than 1:2-3.

[0020] Furthermore, in the present invention, the material-liquid ratio in the saccharification treatment is 1:3-10, and the pH value is 5.2-5.6.

[0021] Furthermore, in the present invention, the saccharification step includes:

[0022] Mixing crushed Vienna malt, caramel malt and wheat malt with water to obtain a mixture;

[0023] The mixture was stirred continuously and kept at 40-50°C for 30-45 minutes;

[0024] Heat to 65-70°C at a rate of 1°C / min and maintain for 65-90 minutes;

[0025] The temperature was raised to 75-78°C at a rate of 1°C / min, and the mixture was allowed to stand for 20-30 minutes after stirring.

[0026] Furthermore, in the present invention, after the filtered beer is allowed to stand for 15-20 minutes, the wort is refluxed and washed until the wort becomes clear.

[0027] Furthermore, in the present invention, the processing parameters of the high-energy fluid mill are: pressure 120-280 MPa, processing times 1-2 times, and flow rate 2-5 T / h.

[0028] Furthermore, in the present invention, the step of adding aromatic hops and bitter hops to the boiled wort for flavor treatment comprises:

[0029] Add Magnum bittering hops within 5-15 minutes of the start of the boil and Hallertauer aroma hops within 20-40 minutes of the end of the boil.

[0030] Furthermore, in the present invention, the step of adding highly active brewing dry yeast for fermentation treatment comprises:

[0031] After the boiled wort is cooled to 12-15°C, yeast is added and sterile air is added until the dissolved oxygen reaches 8-10 mg / L for fermentation.

[0032] When the sugar content drops to 4.3-4.8Brix and the diacetyl content is ≤0.15mg / L, cool down to 0-2℃.

[0033] The present invention has at least the following advantages or beneficial effects:

[0034] The present invention uses a high-energy fluid mill to process wort, mainly using a physical method with high-density energy input, which can effectively release the purine bound to the nucleic acid in the wort and convert it into a free state, which is then absorbed and utilized by yeast in the subsequent fermentation process. During the fermentation process, brewer's yeast needs to absorb the free purine to proliferate, thereby achieving the purpose of reducing the content of purine substances in beer, thereby significantly reducing the purine content in beer. The method of the present application does not require reducing the amount of malt used, nor does it require the addition of additional chemicals. Therefore, the original flavor and taste of the beer can be retained to the greatest extent, avoiding the problem of beer flavor becoming lighter due to an excessively high proportion of auxiliary materials or the introduction of some chemicals causing the beer flavor to deteriorate, and overcoming the defects of the existing high-proportion auxiliary material method, adsorption method and chemical method. The production process of the present invention is simple, the effect of reducing purine is obvious, and the prepared beer has excellent sensory properties and rich taste levels, is suitable for industrial production, and has the advantages of high efficiency, green industrialization and broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 A schematic flow chart of the steps of a method for preparing low-purine beer based on a high-energy fluid mill provided in an embodiment of the application. DETAILED DESCRIPTION

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0039] The inventors analyzed the prior art and found that:

[0040] Patent CN 102433231 A mentions the use of an enzymatic method, a double mash leaching and secondary saccharification process, a 75% adjuvant addition rate, and a high-concentration, high-adjuvant brewing method to optimize existing brewing technology. This method, combined with adsorption technology, low-temperature separation, and high-concentration dilution technology, reduces the purine content in beer to 8-15 mg / L. However, due to the significant reduction in the amount of barley malt used, this method results in a lighter beer appearance and color. It also presents numerous challenges during the fermentation stage. A high adjuvant content results in a low nutrient content in the wort, insufficient nutrients for yeast growth, and thus affects the normal metabolism of the beer and, consequently, its fermentation performance.

[0041] In addition, some researchers are using adsorbents to absorb purines from beer. One study found that activated carbon and artificial zeolite are effective at absorbing purines in beer, with adsorption rates of 85% and 65%, respectively. However, adsorbent treatment significantly affects the color and flavor of beer, and currently, no ideal adsorbent specifically targeting purines exists.

[0042] Furthermore, purines in wort can be degraded by methods such as acidification and the addition of nucleosidase, converting them into free purines. This increases the proportion of free purines in the wort to total purines, which are then assimilated by yeast during fermentation, thereby reducing the total purine content. For example, patent CN 103589548A discloses a method for producing low-purine beer. This method primarily involves adding an acidification step during saccharification to increase the proportion of free purines in the wort, improve the yeast's ability to absorb purines, and thus reduce the residual purine content in the beer. This method involves adding 50% sulfuric acid to the wort to adjust its pH to 1.0, completely freeing the purines in the wort. Solid sodium hydroxide is then added to return the pH to its original value. However, sulfuric acid is extremely corrosive and is generally not used directly as a food additive in the food industry. Its safety remains to be evaluated. Furthermore, the high acidity of sulfuric acid can cause protein coagulation, affecting the subsequent fermentation process and the sensory quality of the beer.

[0043] In summary, the preparation methods involved in the above patents all have certain defects and are not suitable for the preparation of low-purine beer. It is still necessary to continue to develop a low-purine beer preparation method that is highly safe, simple to operate, has excellent sensory quality, and is suitable for industrial application.

[0044] Example

[0045] Please refer to Figure 1 , which is a schematic flow chart of the steps of a method for preparing low-purine beer based on a high-energy fluid mill device in an embodiment of the present invention;

[0046] This embodiment provides a method for preparing low-purine beer based on a high-energy fluid mill, comprising the following steps:

[0047] S1, preparing clarified wort, and pumping the clarified wort into a high-energy fluid mill for treatment to obtain treated wort;

[0048] S2, performing flavor treatment and fermentation treatment on the treated wort to obtain low-purine beer.

[0049] Next, a method for preparing low-purine beer based on a high-energy fluid mill according to this exemplary embodiment will be further described.

[0050] In step S1, before preparing the clarified wort, a certain amount of raw materials and auxiliary materials are weighed according to a weight ratio. The raw materials include 70-90 parts Vienna malt, 10-20 parts caramel malt, and 10-20 parts wheat malt. The auxiliary materials include 0.05-0.1 parts Hallertauer flavor hops, 0.05-0.1 parts Magnum bitter hops, and 0.01-0.05 parts of high-activity brewer's dry yeast (high viability ≥ 90%). The beer is made primarily of Vienna malt, with caramel malt added to enhance the color and aroma of the beer, and wheat malt added to improve the saccharification efficiency and foam performance of the beer.

[0051] As an example, the specific steps of preparing clarified wort include: grinding Vienna malt, caramel malt and wheat malt, and during the grinding, the malt is required to be ground into a ratio of coarse particles to fine particles (including fine powder) greater than 1:2-3.

[0052] Preferably, the ratio of coarse malt to fine malt is 1:3. This degree of grinding ensures good saccharification and filtration efficiency, and prevents overly fine powder from forming sludge and clogging the wort filter when the saccharification effect is poor or the conversion is incomplete, or from entering the wort through the filter layer, resulting in a large amount of suspended particles in the wort.

[0053] Furthermore, crushed Vienna malt, caramel malt, and wheat malt are mixed with water, with the material-to-liquid ratio of malt raw material to water being 1:3-10, preferably 1:5. After mixing, saccharification is performed to obtain a saccharified liquid. The specific steps of the saccharification process include: mixing the crushed Vienna malt, caramel malt, and wheat malt with water to obtain a mixed liquid; continuously stirring the mixed liquid and keeping it at 40-50°C for 30-45 minutes; heating it to 65-70°C at a heating rate of 1°C / min and maintaining it for 65-90 minutes; heating it to 75-78°C at a heating rate of 1°C / min, stopping stirring and letting it stand for 20-30 minutes; and controlling the pH value of the saccharified liquid to 5.2-5.6.

[0054] The saccharified liquid is then filtered to obtain clarified wort. Specifically, the filtered beer is left to rest for 15-20 minutes, and then the wort is refluxed to wash the tank until the wort is clear before proceeding to the next step.

[0055] As an example, in step S1, the clarified wort is pumped into a high-energy fluid mill for processing to obtain treated wort. Specifically, the filtered clarified wort is pumped into the high-energy fluid mill by a centrifugal pump, pressurized to a certain pressure by a plunger high-pressure pump to form a high-speed, high-energy fluid, and passed through a specially designed high-speed vortex kinetic energy reaction chamber. The processing parameters of the high-energy fluid mill are set to: pressure of 120-280 MPa, 1-2 treatment cycles, and flow rate of 2-5 T / h. The processing pressure and number of treatment cycles are related to the release of free purines. Setting these parameters can efficiently and quickly release free purines in the wort, allowing them to be rapidly absorbed.

[0056] In step S2, the treated wort is subjected to flavor treatment and fermentation to obtain low-purine beer. During the fermentation process, the highly active and highly fermented composite brewer's yeast absorbs free purine, which can significantly reduce the purine content in the beer.

[0057] As an example, the wort treated by high-energy fluid mill is heated and boiled, and Magnum aroma hops and Hallertauer bitter hops are added to the boiled wort for flavor treatment.

[0058] Furthermore, hops are added to the boiling wort in two steps: Magnum bitter hops are added within 5-15 minutes after the start of boiling, and Hallertauer aroma hops are added within 20-40 minutes before the end of boiling.

[0059] The boiled wort is then cooled and fermented with a high-activity, high-fermentation composite yeast. The fermentation process is as follows: after the wort cools to 12-15°C, the high-activity, high-fermentation composite yeast is added, and sterile air is introduced to a dissolved oxygen concentration of 8-10 mg / L. Fermentation is then continued, and the wort is cooled to 0-2°C until the sugar content drops to 4.3-4.8 Brix and the diacetyl content is ≤0.15 mg / L.

[0060] Furthermore, the obtained low-purine beer crude liquid is filtered through a diatomaceous earth filter and a PVPP filter to remove suspended matter and sediment in the beer, thereby obtaining the low-purine beer.

[0061] Example 1

[0062] A method for preparing low-purine beer based on a high-energy fluid mill is carried out in the following steps:

[0063] The raw materials and auxiliary materials of the low-purine beer include the following components by weight: 35 kg Vienna malt, 5 kg caramel malt, and 5 kg wheat malt, which are crushed and then added into 225 L of water at a material-liquid ratio of 1:5 for mixing.

[0064] The malt mixture is kept at 40-50°C for 30-45 minutes while being stirred continuously. The temperature is then raised in a water bath at a rate of 1°C per minute to 65-70°C within 20-25 minutes. The temperature is then maintained at 65-90 minutes. The temperature is then raised to 75-78°C. The mixture is allowed to stand for 20-30 minutes without stirring until the reaction is complete. The pH value of the saccharified liquid is controlled at 5.2-5.6.

[0065] The obtained saccharified wort is filtered, and after standing for 15-20 minutes, the wort is refluxed to wash the tank. After reflux until the wort is clear, it proceeds to the next step.

[0066] The clarified malt wort obtained after filtration is pumped through a high-pressure centrifugal pump into a high-energy fluid mill. A plunger high-pressure pump pressurizes the fluid to a certain pressure, creating a high-speed, high-energy fluid. The fluid then passes through a specially designed high-speed vortex kinetic energy reaction chamber. The mill processes the wort at a pressure of 140 MPa, with a single treatment cycle. The mill delivers high-density energy in a short period of time. This high pressure and energy releases most of the purines bound to nucleic acids in the wort, releasing them into free form.

[0067] The wort obtained by high-energy fluid milling was boiled, and 115 g of Magnum bitter hops were added within 5-15 minutes after the start of boiling, and 115 g of Hallertauer aroma hops were added within 20-40 minutes before the end of boiling.

[0068] The boiled wort is cooled, and after the wort is cooled to 12-15°C, a high-activity and high-fermentation composite brewer's yeast is added, and sterile air is filled to make the dissolved oxygen reach 8-10mg / L for fermentation. When the sugar content is reduced to 4.3-4.8Brix and the diacetyl content is ≤0.15mg / L, the temperature is lowered to 0-2°C.

[0069] The low-purine beer crude liquid obtained by fermentation is filtered through a diatomaceous earth filter and a PVPP filter in sequence to remove suspended matter and sediment in the beer, thereby obtaining the low-purine beer.

[0070] Example 2

[0071] A method for preparing low-purine beer based on a high-energy fluid mill is carried out in the following steps:

[0072] The raw materials and auxiliary materials of the low-purine beer include the following components by weight: 35 kg Vienna malt, 5 kg caramel malt, and 5 kg wheat malt, which are crushed and then added into 225 L of water at a material-liquid ratio of 1:5 for mixing.

[0073] The malt mixture is kept at 40-50°C for 30-45 minutes while being stirred continuously. The temperature is then raised in a water bath at a rate of 1°C per minute to 65-70°C within 20-25 minutes. The temperature is then maintained at 65-90 minutes. The temperature is then raised to 75-78°C. The mixture is allowed to stand for 20-30 minutes without stirring until the reaction is complete. The pH value of the saccharified liquid is controlled at 5.2-5.6.

[0074] The obtained saccharified wort is filtered, and after standing for 15-20 minutes, the wort is refluxed to wash the tank. After reflux until the wort is clear, it proceeds to the next step.

[0075] The clarified malt wort, obtained after filtration, is pumped through a high-pressure centrifugal pump into a high-energy fluid mill. A high-pressure plunger pump then pressurizes the fluid to a predetermined pressure, creating a high-speed, high-energy fluid. This fluid then passes through a specially designed high-speed vortex kinetic energy reaction chamber. The mill processes the wort at a pressure of 210 MPa, with a single treatment cycle. The mill delivers high-density energy within a short period of time. This high pressure and energy releases most of the purines bound to nucleic acids in the wort, releasing them into free form.

[0076] The wort obtained by high-energy fluid milling was boiled, and 115 g of Magnum bitter hops were added within 5-15 minutes after the start of boiling, and 115 g of Hallertauer aroma hops were added within 20-40 minutes before the end of boiling.

[0077] The boiled wort is cooled, and after the wort is cooled to 12-15°C, a high-activity and high-fermentation composite brewer's yeast is added, and sterile air is filled to make the dissolved oxygen reach 8-10mg / L for fermentation. When the sugar content is reduced to 4.3-4.8Brix and the diacetyl content is ≤0.15mg / L, the temperature is lowered to 0-2°C.

[0078] The low-purine beer crude liquid obtained by fermentation is filtered through a diatomaceous earth filter and a PVPP filter in sequence to remove suspended matter and sediment in the beer, thereby obtaining the low-purine beer.

[0079] Example 3

[0080] A method for preparing low-purine beer based on a high-energy fluid mill is carried out in the following steps:

[0081] The raw materials and auxiliary materials of the low-purine beer include the following components by weight: 35 kg Vienna malt, 5 kg caramel malt, and 5 kg wheat malt, which are crushed and then added into 225 L of water at a material-liquid ratio of 1:5 for mixing.

[0082] The malt mixture is kept at 40-50°C for 30-45 minutes while being stirred continuously. The temperature is then raised in a water bath at a rate of 1°C per minute to 65-70°C within 20-25 minutes. The temperature is then maintained at 65-90 minutes. The temperature is then raised to 75-78°C. The mixture is allowed to stand for 20-30 minutes without stirring until the reaction is complete. The pH value of the saccharified liquid is controlled at 5.2-5.6.

[0083] The obtained saccharified wort is filtered, and after standing for 15-20 minutes, the wort is refluxed to wash the tank. After reflux until the wort is clear, it proceeds to the next step.

[0084] The clarified malt wort, obtained after filtration, is pumped through a high-pressure centrifugal pump into a high-energy fluid mill. A high-pressure plunger pump then pressurizes the fluid to a predetermined pressure, creating a high-speed, high-energy fluid. This fluid then passes through a specially designed high-speed vortex kinetic energy reaction chamber at a pressure of 280 MPa, with a single treatment cycle. The high-energy fluid mill delivers high-density energy in a short period of time. This high pressure and energy releases most of the purines bound to nucleic acids in the wort, releasing them into free form.

[0085] The wort obtained by high-energy fluid milling was boiled, and 115 g of Magnum bitter hops were added within 5-15 minutes after the start of boiling, and 115 g of Hallertauer aroma hops were added within 20-40 minutes before the end of boiling.

[0086] The boiled wort is cooled, and after the wort is cooled to 12-15°C, a high-activity and high-fermentation composite brewer's yeast is added, and sterile air is filled to make the dissolved oxygen reach 8-10mg / L for fermentation. When the sugar content is reduced to 4.3-4.8Brix and the diacetyl content is ≤0.15mg / L, the temperature is lowered to 0-2°C.

[0087] The low-purine beer crude liquid obtained by fermentation is filtered through a diatomaceous earth filter and a PVPP filter in sequence to remove suspended matter and sediment in the beer, thereby obtaining the low-purine beer.

[0088] Example 4

[0089] A method for preparing low-purine beer based on a high-energy fluid mill is carried out in the following steps:

[0090] The raw materials and auxiliary materials of the low-purine beer include the following components by weight: 35 kg Vienna malt, 5 kg caramel malt, and 5 kg wheat malt, which are crushed and then added into 225 L of water at a material-liquid ratio of 1:5 for mixing.

[0091] The malt mixture is kept at 40-50°C for 30-45 minutes while being stirred continuously. The temperature is then raised in a water bath at a rate of 1°C per minute to 65-70°C within 20-25 minutes. The temperature is then maintained at 65-90 minutes. The temperature is then raised to 75-78°C. The mixture is allowed to stand for 20-30 minutes without stirring until the reaction is complete. The pH value of the saccharified liquid is controlled at 5.2-5.6.

[0092] The obtained saccharified wort is filtered, and after standing for 15-20 minutes, the wort is refluxed to wash the tank. After reflux until the wort is clear, it proceeds to the next step.

[0093] The clarified malt wort, obtained after filtration, is pumped through a high-pressure centrifugal pump into a high-energy fluid mill. A high-pressure plunger pump then pressurizes the fluid to a predetermined pressure, creating a high-speed, high-energy fluid. The fluid then passes through a specially designed high-speed vortex kinetic energy reaction chamber, where the mill processes the wort twice at a pressure of 280 MPa. The mill delivers high-density energy in a short period of time. This high pressure and energy releases most of the purines bound to nucleic acids in the wort, releasing them into free form.

[0094] The wort obtained by high-energy fluid milling was boiled, and 115 g of Magnum bitter hops were added within 5-15 minutes after the start of boiling, and 115 g of Hallertauer aroma hops were added within 20-40 minutes before the end of boiling.

[0095] The boiled wort is cooled, and after the wort is cooled to 12-15°C, a high-activity and high-fermentation composite brewer's yeast is added, and sterile air is filled to make the dissolved oxygen reach 8-10mg / L for fermentation. When the sugar content is reduced to 4.3-4.8Brix and the diacetyl content is ≤0.15mg / L, the temperature is lowered to 0-2°C.

[0096] The low-purine beer crude liquid obtained by fermentation is filtered through a diatomaceous earth filter and a PVPP filter in sequence to remove suspended matter and sediment in the beer, thereby obtaining the low-purine beer.

[0097] Comparative Example 1

[0098] A method for preparing low-purine beer based on a high-energy fluid mill is carried out in the following steps:

[0099] The raw materials and auxiliary materials of the low-purine beer include the following components by weight: 35 kg Vienna malt, 5 kg caramel malt, and 5 kg wheat malt, which are crushed and then added into 225 L of water at a material-liquid ratio of 1:5 for mixing.

[0100] The malt mixture is kept at 40-50°C for 30-45 minutes while being stirred continuously. The temperature is then raised in a water bath at a rate of 1°C per minute to 65-70°C within 20-25 minutes. The temperature is then maintained at 65-90 minutes. The temperature is then raised to 75-78°C. The mixture is allowed to stand for 20-30 minutes without stirring until the reaction is complete. The pH value of the saccharified liquid is controlled at 5.2-5.6.

[0101] The obtained saccharified wort is filtered, and after standing for 15-20 minutes, the wort is refluxed to wash the tank. After reflux until the wort is clear, it proceeds to the next step.

[0102] The clarified wort obtained by filtration is pumped into a high-energy fluid mill through centrifugal high-pressure pumping. The high-energy fluid mill has a processing pressure of 0 MPa and passes through a specially designed high-speed vortex kinetic energy reaction chamber.

[0103] The wort obtained by high-energy fluid milling was boiled, and 115 g of Magnum bitter hops were added within 5-15 minutes after the start of boiling, and 115 g of Hallertauer aroma hops were added within 20-40 minutes before the end of boiling.

[0104] The boiled wort is cooled, and after the wort is cooled to 12-15°C, a high-activity and high-fermentation composite brewer's yeast is added, and sterile air is filled to make the dissolved oxygen reach 8-10mg / L for fermentation. When the sugar content is reduced to 4.3-4.8Brix and the diacetyl content is ≤0.15mg / L, the temperature is lowered to 0-2°C.

[0105] The low-purine beer crude liquid obtained by fermentation is filtered through a diatomaceous earth filter and a PVPP filter in sequence to remove suspended matter and sediment in the beer, thereby obtaining the low-purine beer.

[0106] The free purine and total purine contents of the wort and low-purine beer in the above examples and comparative examples before and after high-energy fluid mill treatment were determined by high-performance liquid chromatography:

[0107] Table 1: Free purine content of wort before and after high-energy fluid mill treatment

[0108]

[0109] Table 2: Free and total purine content of low-purine beer

[0110] Group Free purine (mg / L) Total purine (mg / L) Example 1 8.24 49.64 Example 2 9.08 35.61 Example 3 9.83 30.12 Example 4 8.67 22.76 Comparative Example 1 7.94 61.30

[0111] As can be seen from Table 1, the free purine content of the wort treated by Examples 1-4 of the present invention is significantly higher than that of Comparative Example 1, and as the pressure and number of treatments of the high-energy fluid mill treatment continue to increase, the free purine content released also continues to increase, indicating that the purines in the wort that are most bound to nucleic acids can be effectively released by the high-energy fluid mill equipment to obtain free purine components. At the same time, as can be seen from Table 2, the total purine content of the low-purine beer obtained by the treatment of Examples 1-4 is significantly lower than that of Comparative Example 1, wherein the total purine content of the low-purine beer obtained by the treatment of Example 4 is reduced by 62.87% compared to Comparative Example 1, indicating that the fermentation treatment is finally carried out by inoculating a high-activity and high-fermentation composite brewer's yeast, and the free purine bases are utilized by yeast during the fermentation stage, thereby improving the utilization rate of purine substances, thereby achieving the purpose of reducing purine substances in beer.

[0112] In summary, the present invention mainly uses a physical method of high-density energy input to release the purine bound to nucleic acids in the wort, obtain free purine components, and ferment them through high-activity brewing dry yeast. During the fermentation process, brewing yeast needs to absorb free purines for proliferation, thereby achieving the purpose of reducing the content of purine substances in beer. The low-purine beer malt prepared by this method has a strong aroma, retains the flavor and taste of beer to the greatest extent, overcomes the defects of high-proportion auxiliary material method, adsorption method and chemical method, and has the advantages of high efficiency, greenness and industrialization.

[0113] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing low-purine beer based on a high-energy fluid mill, characterized in that: The steps include: preparing clarified wort, and pumping the clarified wort into a high-energy fluid mill for treatment to obtain treated wort; The treated wort is subjected to flavor treatment and fermentation treatment to obtain low-purine beer.

2. The method for preparing low-purine beer based on high-energy fluid mill equipment according to claim 1, characterized in that, Weigh the raw materials and auxiliary materials according to the weight ratio, wherein the raw materials include 70-90 parts of Vienna malt, 10-20 parts of caramel malt, and 10-20 parts of wheat malt, and the auxiliary materials include 0.05-0.1 parts of aromatic hops, 0.05-0.1 parts of bitter hops, and 0.01-0.05 parts of high-activity brewer's dry yeast; The step of preparing clarified wort comprises: The Vienna malt, caramel malt and wheat malt are crushed; The crushed Vienna malt, caramel malt and wheat malt are mixed with water and saccharified to obtain saccharified liquid; The saccharified liquid is filtered to obtain clarified wort.

3. The method for preparing low-purine beer based on high-energy fluid mill equipment according to claim 2, characterized in that, The step of subjecting the treated wort to flavor treatment and fermentation to obtain low-purine beer comprises: The wort treated by the high-energy fluid mill is heated and boiled, and aromatic hops and bitter hops are added to the boiled wort for flavor treatment; The boiled wort is cooled and then fermented by adding highly active brewing dry yeast; The fermented beer is filtered to obtain low-purine beer.

4. The method for preparing low-purine beer based on high-energy fluid mill equipment according to claim 2, characterized in that, The coarseness-fineness ratio of the malt after the crushing process is greater than 1:2-3.

5. The method for preparing low-purine beer based on high-energy fluid mill equipment according to claim 2, characterized in that, The material-liquid ratio in the saccharification treatment is 1:3-10, and the pH value is 5.2-5.

6.

6. The method for preparing low-purine beer based on high-energy fluid mill equipment according to claim 5, characterized in that: The saccharification step includes: Mixing crushed Vienna malt, caramel malt and wheat malt with water to obtain a mixture; The mixture was stirred continuously and kept at 40-50°C for 30-45 minutes; Heat to 65-70°C at a rate of 1°C / min and maintain for 65-90 minutes; The temperature was raised to 75-78°C at a rate of 1°C / min, and the mixture was allowed to stand for 20-30 minutes after stirring.

7. The method for preparing low-purine beer based on high-energy fluid mill equipment according to claim 3, characterized in that: After the filtered beer is left to rest for 15-20 minutes, the wort is refluxed to wash the tank until the wort is clear.

8. The method for preparing low-purine beer based on high-energy fluid mill equipment according to claim 1, characterized in that: The processing parameters of the high-energy fluid mill are: pressure 120-280 MPa, processing times 1-2 times, and flow rate 2-5 T / h.

9. The method for preparing low-purine beer based on high-energy fluid mill equipment according to claim 3, characterized in that: The step of adding aromatic hops and bitter hops to the boiled wort for flavor treatment comprises: Add Magnum bittering hops within 5-15 minutes of the start of the boil and Hallertauer aroma hops within 20-40 minutes of the end of the boil.

10. The method for preparing low-purine beer based on high-energy fluid mill equipment according to claim 3, characterized in that: The step of adding highly active brewing dry yeast for fermentation treatment comprises: After the boiled wort is cooled to 12-15°C, high-activity brewer's dry yeast is added and sterile air is added until the dissolved oxygen reaches 8-10 mg / L for fermentation. When the sugar content drops to 4.3-4.8Brix and the diacetyl content is ≤0.15mg / L, cool down to 0-2℃.

Images