Malt production method and method for improving antioxidant activity of malt

Abstract

To provide a malt production method and a method for improving antioxidant activity of malt.SOLUTION: The present application discloses a malt production method and a method for improving the antioxidant activity of malt, wherein grains are subjected to at least one steeping step, in which the grains are immersed in hydrogen water with a dissolved hydrogen concentration of 0.3 to 1.6 ppm. By using hydrogen rich water in malt production, it is possible to take into account simultaneous improvements to multiple quality indicators at the same time. The positive biological effects of hydrogen rich water are especially significant. The increased content of α-amino nitrogen in the malt brings greater economic benefit to malt producers. Moreover, the colour intensity and turbidity of the malt are significantly reduced, effectively solving the problem of wort often being turbid. The endogenous antioxidant activity of malt, wort and even fermented beverages is increased, as desired by malt producers and the brewing industry. No additional additives are introduced during malt production.SELECTED DRAWING: None

Description

Technical Field

[0001] The present application relates to a method for producing malt and a method for improving the antioxidant activity of malt. More specifically, the present application relates to a method for using hydrogen-rich water in malt production, and to malt and fermented beverages / foods obtained by this method. The present application also particularly relates to the use of hydrogen-rich water in malt production for improving the antioxidant activity of malt.

Background Art

[0002] Grain kernels can be used in beverages and foods in their raw form or as germinated grains. Due to its high enzyme content, malt is more suitable as a fermentation substrate and as a malt flavoring and nutrient added to foods and beverages.

[0003] Approximately 96% of the world's total malt is used in the production of alcohol, approximately 3% is used in the distillation industry, and the remaining amount is used in the food industry such as malt beverages. Malt suitable for alcohol production contains amylase and protease with certain activities. By germinating barley, starch and protein reach a certain degree of solubility under the action of enzymes to form precursors for brewing. Malt production (malt processing) has already become an independent industry. Malt producers purchase grains such as barley, sorghum, wheat and rye, and process them through various steps to form different types of malt suitable for brewing.

[0004] Taking barley as an example, barley undergoes steps such as pre-treatment of green malt, steeping, germination, roasting / drying, etc., and malt is obtained through root removal. Wort is produced by mashing the malt. Wort is the main source of carbohydrates necessary for yeast metabolism during alcohol brewing. The final products, alcohol and carbon dioxide, further give the characteristic fizziness and refreshing taste to beer and also possess a malt flavor. The amylase and protease in malt act synergistically to convert non-fermentable polysaccharides into fermentable carbohydrates, and at the same time, corresponding changes occur in the α-amino nitrogen content, the content of foaming proteins, and the distribution of proteins.

[0005] Malt provides the main chemical components of beer and good characteristic components of beer. Malt suitable for beer production contains amylase and protease. By germinating barley, the starch and protein in the grains reach a certain degree of solubility under the action of enzymes to form precursors for beer. The malt production process uses barley as the raw material and subjects it to steps such as pre-treatment of green malt, steeping, germination, roasting / drying, etc., and root removal. Mashing of malt is an important intermediate process in subsequent beer brewing. During the enzymatic hydrolysis of starch and protein, the amylase and protease in malt act synergistically to convert non-fermentable polysaccharides into fermentable carbohydrates, and corresponding changes occur in the α-amino nitrogen content, the content of foaming proteins, and the distribution of proteins. During the fermentation process, yeast cells utilize fermentable carbohydrates and amino nitrogen and convert them into the alcohol and flavor components of beer through fermentation.

[0006] Malt processing has already become an independent industry. Malt manufacturers purchase grains such as barley, sorghum, wheat, and rye, and process them through various steps to form different types of malt suitable for brewing. Taking barley as an example, barley germinates to become malt, and wort is produced by mashing the malt. Wort is the main source of carbohydrates necessary for yeast metabolism during alcohol brewing. The final products, alcohol and carbon dioxide, further give the characteristic fizziness and refreshing taste to beer, and also have a malt flavor. 96% of the world's total malt is used in the production of alcohol, about 3% is used in the distillation industry, and the remaining amount is used in the food industry such as malt beverages.

[0007] Particularly important steps in traditional malt production include steeping, germination, and kilning. The steeping process includes the step of immersing the grains in water for several hours, followed by a period of air rest to remove the water. Air rest is considered essential because the immersed grains may become oxygen-deficient. Steeping and air rest can be repeated multiple times. Then, the grains are transferred to a germination apparatus. The purpose of germination is to continue the production of enzymes within the grains. These enzymes can break down the strong structure of the grains and thus can be easily used in the processing of food and beverages. Small rootlets are formed during germination. Based on the variety of barley and the type of malt produced, it is possible to control the moisture content by adjusting the steeping process.

[0008] The composition and quality of malt directly affect the flavor and quality of fermented beverages. Important quality indicators of malt include α-amino nitrogen, color, and turbidity. In addition to the influence of the variety and quality of barley itself (such as protein content, particle size, etc.), malt production is an important process that affects the quality indicators of malt. Moreover, beer manufacturers are increasingly recognizing the fact that the change in the flavor of beer over time is caused by a series of oxidation / reduction reactions of oxygen-free radicals and the like. However, no matter how much the total oxygen content related to beer packaging is improved, oxidation can occur at each step from raw materials to packaging, which cannot be avoided. Therefore, at present, more and more attention is being paid to enhancing the antioxidant activity of malt.

[0009] At present, the steeping and germination facilities are well-developed, and the quality of barley raw materials is also stable. Attention is often focused on improving one or more quality indicators, and the goal is to produce high-quality malt. However, when one quality indicator is improved, it is often impossible to simultaneously consider the impact on other quality indicators. For example, in the prior art, it has been reported that by adding riboflavin, the amount of extract extracted by malt steeping increases by 0.6%, and the amount of α-amino nitrogen increases by 27 mg / 100 g (Non-Patent Document 1). However, the addition of riboflavin also increases the color of malt by about 1.5 EBC. This has an adverse effect on wort and beer quality and is something that malt manufacturers very much want to avoid. It has also been reported that by adding mannitol, the amount of extract extracted by malt steeping increases by 1.1%, and the amount of α-amino nitrogen increases by 22 mg / 100 g. However, the addition of mannitol also increases the color intensity of malt by about 0.4 EBC. This is also not desirable.

[0010] Barley and malt contain a large amount of phenols with antioxidant activity and thus have a great influence on the color, aroma, taste, and stability of beer. As endogenous antioxidants, these phenols can act as free radical scavengers, reducing agents, and metal ion chelating agents to contribute to the control of oxidation reactions. It has been found that the polyphenol content tends to increase during the germination of barley. This indicates that the malting process is very important with respect to the increase in antioxidant activity and phenolic compounds.

[0011] It has been reported that exogenous antioxidants are added to enhance the antioxidant efficacy of beer. These exogenous antioxidants include xylooligosaccharide, SOD, taurine, and tea polyphenols, etc. However, these are expensive and also affect the traditional flavor of beer to some extent and thus are not suitable for large-scale use. A method of increasing the phenol content in malt by adding metal ions to the steeping water has also been disclosed in the prior art. As an example, in (Patent Document 1), MgCl2 is added in an impregnated form to a final concentration of 60 ppm at the steeping stage. At the final mashing stage, CaCl2 is added and controlled to a final concentration of 40 ppm. Then, the germination, roasting, and mashing of barley are carried out, and the resulting wort is used as the main starting material for brewing beer. Finally, the total polyphenol content of the finished beer increases by 35% compared to the beer brewed without metal ion treatment.

[0012] In another paper (Non-Patent Document 2), it has been reported that the antioxidant activity of malt is improved by improving roasting. The use of a new roasting process (Manipulated Kilning Regimens: MKR) is achieved by controlling the recirculation rate, fan speed, and air-on temperature, and it is possible to reach stable breakpoints at set temperatures of 45 °C, 55 °C, and 65 °C for the kiln bed. These processes are called MKR(45), MKR(55), and MKR(65). The grain bed is maintained under these conditions for 2 hours (drying time of 14.5 - 16.5 hours). For the same roasting time, when the MKR(65) roasting process is used, it is possible to increase the ABTS free radical scavenging activity of malt by about 20% compared to normal roasting.

[0013] Hydrogen is a biologically safe gaseous signaling molecule. Patent Document 2 discloses a hydrogen-rich liquid plant growth regulator with a hydrogen saturation of 0.1 - 100% and a solvent being Hoagland nutrient solution, Kimura B nutrient solution, TAP nutrient solution, or MS culture medium. Such a regulator gradually releases hydrogen, promotes plant growth / development and formation, and enhances productivity. Another paper (Non-Patent Document 3) discloses the demonstration that the enrichment of hydrogen-oxidizing bacteria by hydrogen generated by nitrogen fixation shows a fertilizing effect on various crops. When hydrogen is supplied to the soil, the ecological niche partitioning of bacteria and fungi changes, affecting the microbial function diversity in multiple aspects.

Prior Art Documents

Patent Documents

[0014]

Patent Document 1

Patent Document 2

Non-Patent Documents

[0015]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0016] This application aims to improve the endogenous antioxidant activity of malt, wort, and even fermented beverages as desired by malt manufacturers and the brewing industry. No additional additives are introduced during malt production. The biological effects of hydrogen, the preferred range of its concentration, and its different effects at different stages of malt production are further investigated.

[0017] This application also aims to improve the quality of malt as desired by malt producers and the brewing industry, taking into account improvements in color intensity, turbidity, and α-amino nitrogen content. Improvement of one quality index does not adversely affect other quality indexes. The biological effects of hydrogen are further utilized safely and reliably. Moreover, no additional additives are introduced during malt production.

Means for Solving the Problems

[0018] To achieve the above object of the present invention, the first aspect of this application discloses a method for producing malt, in which the grain is subjected to at least one steeping step, in which the grain is immersed in hydrogen water having a dissolved hydrogen concentration of 0.3 ppm to 1.6 ppm.

[0019] Furthermore, in at least one steeping step, the grain is immersed in hydrogen water having a dissolved hydrogen concentration of 0.3 ppm to 1.2 ppm, preferably 0.6 ppm to 1.2 ppm.

[0020] Furthermore, after the steeping step, when the grain starts to germinate, hydrogen water having a dissolved hydrogen concentration of 0.3 ppm to 1.6 ppm is used at least once to keep the surface of the grain moist.

[0021] Furthermore, after the steeping step, when the grain starts to germinate, hydrogen water having a dissolved hydrogen concentration of 0.3 ppm to 1.2 ppm, preferably 0.6 ppm to 1.2 ppm is used at least once to keep the surface of the grain moist.

[0022] Furthermore, at least one steeping has a temperature range of 10°C to 20°C, preferably 14°C to 18°C.

[0023] Furthermore, steeping is performed twice, and the grain is immersed in hydrogen water having a dissolved hydrogen concentration of 0.3 ppm to 1.6 ppm in both the first steeping and the second steeping.

[0024] Furthermore, at least one steeping is continued for a period exceeding 3 hours, preferably exceeding 4 hours, more preferably exceeding 5 hours.

[0025] Furthermore, germination has a temperature range of 12 to 25 °C, preferably 14 to 20 °C, more preferably 14 to 18 °C, and most preferably 16 to 18 °C.

[0026] Furthermore, hydrogen water is used at least once at intervals of 20 to 25 hours after germination has started.

[0027] The second aspect of the present application provides the use of the malt production method according to the first aspect for reducing the color intensity of malt.

[0028] The third aspect of the present application provides the use of the malt production method according to the first aspect for reducing the turbidity of malt.

[0029] The fourth aspect of the present application provides the use of the malt production method according to the first aspect for increasing the α - amino nitrogen content of malt.

[0030] The fifth aspect of the present application provides malt obtained by the malt production method according to the first aspect.

[0031] The sixth aspect of the present application provides the use of the malt according to the fifth aspect for preparing a fermented beverage or a fermented food.

[0032] Furthermore, the fermented beverage includes beer, beer - flavored beverage or whiskey.

[0033] The seventh aspect of the present application provides a method for improving the antioxidant activity of malt, in which the grain is subjected to at least one steeping step, in which the grain is immersed in hydrogen water having a dissolved hydrogen concentration of 0.3 to 1.6 ppm.

[0034] Furthermore, in at least one steeping step, the grain is immersed in hydrogen water having a dissolved hydrogen concentration of 0.3 to 1.2 ppm.

[0035] Furthermore, in at least one steeping step, the cereal grains are immersed in hydrogen water having a dissolved hydrogen concentration of 0.6 to 1.2 ppm.

[0036] Furthermore, after the steeping step, when the cereal grains start to germinate, hydrogen water having a dissolved hydrogen concentration of 0.3 to 1.6 ppm, preferably 0.3 to 1.2 ppm, more preferably 0.6 to 1.2 ppm is used at least once to keep the surface of the cereal grains moist.

[0037] Furthermore, at least one steeping has a temperature range of 10°C to 20°C, preferably 14°C to 18°C.

[0038] Furthermore, the steeping is carried out twice, and the cereal grains are immersed in hydrogen water both in the first steeping and the second steeping.

[0039] Furthermore, at least one steeping continues for a period exceeding 3 hours, preferably exceeding 4 hours, more preferably exceeding 5 hours.

[0040] Furthermore, germination has a temperature range of 12 to 25°C, preferably 14 to 20°C, more preferably 14 to 18°C, and most preferably 16 to 18°C.

[0041] Furthermore, hydrogen water is used at least once at intervals of 20 to 25 hours after germination starts.

[0042] Furthermore, the antioxidant activity index of malt includes DPPH free radical scavenging activity.

[0043] Furthermore, the antioxidant activity index of malt includes ABTS free radical scavenging activity.

[0044] Furthermore, the antioxidant activity index of malt includes reducing power.

[0045] Furthermore, the antioxidant activity index of malt includes metal ion chelating ability.

[0046] Furthermore, the antioxidant activity indexes of malt include the total polyphenol content.

[0047] Furthermore, the antioxidant activity indexes of malt include superoxide dismutase activity.

[0048] Furthermore, the antioxidant activity indexes of malt include catalase activity.

[0049] The eighth aspect of the present application provides a method for improving the antioxidant activity of plant raw materials, the method including subjecting the plant raw materials to at least one steeping and / or at least one germination in hydrogen water having a dissolved hydrogen concentration of 0.3 to 1.6 ppm to produce a fermented food or a fermented beverage.

[0050] Furthermore, the plant raw materials are not particularly limited and include leaves, seeds, roots, stems, flowers or fruits.

[0051] Compared with the prior art, the technical solution provided in the present application has the following advantages. 1. By using hydrogen-rich water in malt production, the present application can simultaneously consider the simultaneous improvement of multiple quality indexes. The positive biological effect of hydrogen-rich water is particularly remarkable. The increase in the content of α-amino nitrogen in malt brings greater economic benefits to malt producers. Moreover, the color intensity and turbidity of malt are significantly reduced, effectively solving the problem of wort turbidity.

[0052] 2. The present application also provides the stage of using hydrogen-rich water and the suitable range of hydrogen-rich water concentration, which constitute important guidelines for malt producers.

[0053] 3. Compared with the prior art, the process of introducing hydrogen-rich water in malt production does not involve the introduction of exogenous compounds or exogenous enzyme preparations, and thus has high biological safety.

[0054] 4. The various antioxidant activity indices of malt are effectively improved by using hydrogen-rich water (dissolved hydrogen concentration 0.3 - 1.6 ppm) at least once during the steeping stage in malt production. The positive biological effects of hydrogen-rich water are particularly remarkable.

[0055] 5. This application can simultaneously consider the simultaneous improvement of multiple quality indices and does not involve the introduction of exogenous antioxidants or other compounds.

Embodiments for Carrying out the Invention

[0056] Hereinafter, specific embodiments of this application will be described in detail. However, this application is not limited to the embodiments described below, and it should be understood that the technical concept of this application can be implemented in combination with other well-known technologies or other technologies having the same functions as well-known technologies.

[0057] In the description of the following specific embodiments, many terms indicating directions are used to clearly show the structure and operation mode of this application. However, terms such as "front", "rear", "left", "right", "outer", "inner", "outward", "inward", "axial direction", "radial direction", etc. should be understood as convenient terms rather than restrictive terms.

[0058] In addition, the terms "first" and "second" do not limit the chronological order, quantity or importance, but are merely used for the purpose of description, and should not be construed as suggesting or implying relative importance or implicitly identifying the number of the technical features shown. It is only intended to distinguish one technical feature in the present technical solution from other technical features. Therefore, the features defined by "first" and "second" may include one or more features explicitly or implicitly. In the description of the present application, "a plurality of" means two or more unless explicitly and specifically specified. Similarly, the modifying phrases similar to "a" described in this specification do not indicate a quantitative limitation, but explain the technical features not described in the previous text. Similarly, unless modified by a phrase indicating a specific quantity, the nouns in this specification should be regarded as including both the singular and plural forms, that is, the technical solution may include a single corresponding technical feature, but may also include a plurality of technical features. Similarly, the modifying words similar to "about" and "approximately" described before the numerical value in this specification usually include that numerical value, and its specific meaning should be understood with reference to the context.

[0059] In the present application, it should be understood that "at least one (element)" means one or more, and "a plurality of" means two or more. The notation "and / or" is used to describe the relationship between related objects and indicates that three relationships can exist. For example, "A and / or B" can mean three situations: when A exists alone, when B exists alone, and when both A and B exist, where A and B can be singular or plural. The symbol " / " generally indicates an "or" relationship between the related objects before and after it. "At least one of the following elements (parts)" or similar expressions mean any combination of these elements, including any combination of a single element (part) or a plurality of elements (parts). For example, at least one of a, b, or c can mean a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be singular or plural.

[0060] Unless otherwise clearly stated, each aspect or embodiment defined in this specification can be combined with any other aspect or embodiment. In particular, any of the shown preferred or advantageous features can be combined with any of the other shown preferred or advantageous features.

[0061] Explanation of Terms As used herein, "hydrogen-rich water" (HRW) or "hydrogen water" means water in which a certain amount of hydrogen is mixed. In an environment of atmospheric pressure and 20°C, the maximum concentration of hydrogen dissolved in water is 1.6 ppm (i.e., the saturation concentration), that is, a maximum of 1.6 mg of hydrogen is dissolved per 1 kg of water. As used herein, the source of hydrogen can be hydrogen generated by electrolysis or cylinder gas, which is well known to those skilled in the art.

[0062] As used herein, there is no limitation on the method of aerating the hydrogen into the steeping vessel as long as the diffusion of hydrogen into water is ensured. For example, the gas inlet may be a nozzle or a jet, etc. Another option is to first dissolve hydrogen in water and then inject the hydrogen water into the steeping vessel.

[0063] As used herein, the "hydrogen-rich water concentration" means the dissolved hydrogen concentration in the hydrogen-rich water when first introduced into the steeping vessel. Considering the dissipation of hydrogen and different methods of aerating hydrogen, those skilled in the art can maintain the required dissolved hydrogen concentration by continuous addition of hydrogen or hydrogen water, or by using other methods, so as to reach, for example, a hydrogen-rich water concentration of more than 80%, preferably more than 85%, more preferably more than 90%, and most preferably 95% - 99.9%. It should be noted that considering the limitations related to the dissipation characteristics of hydrogen and the measuring means, the hydrogen-rich water concentrations described herein (for example, 0.3 ppm, 0.4 ppm, 0.5 ppm, 0.6 ppm, 0.7 ppm, 0.8 ppm, 0.9 ppm, 1.0 ppm, 1.1 ppm, 1.2 ppm, 1.3 ppm, 1.4 ppm, 1.5 ppm, 1.6 ppm, etc.) allow for a certain range of numerical fluctuations. Those skilled in the art can understand that a reasonable range of fluctuations near a certain numerical point of the hydrogen-rich water concentration can be considered to exhibit the same level of biological effects.

[0064] As used herein, the "water" in the steeping process can be any aqueous solution or various sources including tap water, pure water, purified water and recycled water, and is not particularly limited thereto. A mixture of water and grain particles can also be regarded as a suspension or an aqueous solution.

[0065] The grain can be derived from any well-known cereal such as barley, rice, sorghum, corn, millet, triticale, rye, spelt and wheat. In a preferred embodiment of the present application, the cereal grain is a barley grain. The grain can be of any variety of barley. The cereal grain may have a relatively low water content before germination. For example, the cereal grain can have a water content of up to 30%, preferably up to 20%, for example up to 15%, for example 5 - 15%. Some cereal grains contain husks, while other cereal grains do not have husks. Before the germination step, the cereal grains having husks can be processed to remove at least a part of the husks. Generally, when cereal grains without husks are used, there is no need for the treatment of removing husks. Examples of cereals without husks include barley and wheat without husks. In a preferred embodiment of the present application, the cereal grain for use in the method of the present application is a barley grain.

[0066] As used herein, the term "adjuvant material" means a carbon-rich starting material added during beer brewing. The adjuvant material can be ungerminated cereal grains and can be ground together with the germinated cereal grains prepared according to the present application. The adjuvant material can also be syrup, sugar, etc.

[0067] As used herein, the terms "moisture content" and "water content" of the grain mean the ratio of H2O (w / w) in the grain. For the water content of barley, the following method can be carried out: First, weigh the weight W0 of an empty weighing bottle, then weigh 5 g of barley, grind them using an EBC standard malt mill, put them into the weighing bottle to obtain the total weight W1, put them into an oven, remove the lid, heat and dry at 105 °C for 2 hours, and then weigh the weight as W2. The calculation formula for the water content is as follows: Water content (%) = (W1 - W2) / (W1 - W0) × 100%.

[0068] As used herein, the term "germinated grain" means a grain in which a visible sprout (preferably at least 1 mm, such as at least 2 mm) and a visible stem have already developed.

[0069] The process of making malt is well-known in the art. Cereals can change their grain structure, composition, and enzyme content by germinating. The malt thus obtained has important uses in foods for animals and humans. Germinated barley is widely used in the brewing and distilling industries.

[0070] As used herein, the terms "liquor steeping", "steeping", and "soaking" mean a process of increasing the water content (about 40 - 45% (w / w)) of cereal grains.

[0071] Steeping can be carried out by any conventional method known to those skilled in the art. The purpose of steeping is to increase the water content of the grains and thus initiate germination. Steeping generally includes one or more steps of immersing the cereal grains in a wet condition, for example, by immersing the cereal grains in water. In this process, immersion or spraying and ventilation are carried out alternately. To increase the moisture content and prepare for the next step of malt production, the moisture content of barley increases from about 11 - 13% to about 40% - 45%. This stage generally lasts for 10 - 45 hours. There are no specific restrictions on the steeping conditions, and well-known conditions can be used. Specifically, liquor steeping and airlest (also called draining) may be carried out alternately. For example, it is also possible to repeatedly carry out the first steeping, the first airlest, the second steeping, the second airlest, the third steeping, and the third airlest, etc. By repeatedly carrying out steeping and airlest, it is possible to ensure that the barley is sufficiently impregnated with water. When the steeping process is completed, fine roots develop, and thereby the barley is converted into green malt having a uniform water content. Then, this green malt is transferred to a germination vessel.

[0072] The actual time for steeping barley varies depending on the type of barley, the quality of the barley, and the water temperature, and thus cannot be universally set. From the perspective of the water absorption degree, the actual time for the first steeping is preferably more than 3 hours, more preferably more than 4 hours, still more preferably more than 5 hours, even more preferably more than 6 hours, and even more preferably more than 8 hours. Further, from the perspective of production efficiency, it is preferably less than 20 hours, preferably less than 15 hours, and more preferably less than 10 hours. The steeping temperature is preferably 10 - 20°C, and more preferably 14 - 18°C.

[0073] From the perspective of the water penetration into barley, the actual time for the air rest after the first steeping is preferably more than 1 hour, more preferably more than 2 hours, still more preferably more than 10 hours, even more preferably more than 12 hours, and even more preferably more than 15 hours. From the perspective of production efficiency, it is preferably less than 24 hours, and more preferably less than 20 hours. In the air rest stage, the water is drained so that the grains are ventilated again. The grains are exposed to air. It should be noted that at this point, the grains should not be immersed in water.

[0074] The actual time for the second steeping can be appropriately set with reference to the amount of water already absorbed by the barley, for example, about 1 - 10 hours, preferably 1 - 6 hours, more preferably 1 - 5 hours, and more preferably 1 - 4 hours. Further, the temperature of the second steeping is not particularly defined, and within the above-exemplified temperature range, it can be the same as the temperature of the first steeping. The second air rest can be carried out with reference to the first air rest, and its temperature and actual time can be appropriately set.

[0075] In a preferred embodiment, in the steeping step, the steeping process is carried out by a multi-stage method of two immersions and two aero-rests, or a multi-stage method of three immersions and three aero-rests, whereby the final moisture content of the grain is controlled to reach 39 - 45% (i.e., the steeping degree). By the above steeping method, it is possible to achieve an appropriate moisture content inside the grain so that the enzymes originally present in the barley are reactivated and important processes related to germination are initiated. Calculation formula for steeping degree: Steeping degree (%) = (mass of the grain after steeping - original mass of the barley + original moisture content of the barley) / mass of the grain after steeping.

[0076] As used herein, the term "initiation of germination" refers to the time point when the grain is transferred to the germination apparatus after the steeping stage is completed, i.e., after germination has started. The implementation time of germination is measured from the time when germination starts; for example, the implementation time of germination is measured from the start of germination until the fine division of the germinated cereal grains begins. In some embodiments, after germination, the cereal grains have a water content of at least 30%, preferably at least 35%, and more preferably at least 40% (e.g., 40% - 45%).

[0077] The germination of the cereal grains can occur at any achievable temperature. However, the cereal grains can preferably germinate at a temperature of at least 10°C. In particular, the cereal grains can germinate at a temperature within the range of 10 - 25°C, preferably 12 - 25°C, preferably 14 - 20°C, preferably 14 - 18°C, preferably 16 - 18°C. It is preferred that the cereal grains have not germinated before the germination step. As should be explained here, for malt producers, the germination rate of malt and whether the root system is robust after germination are not current issues. It is different from the intention of improving the germination ability of seeds for sowing purposes in agriculture.

[0078] During germination, barley is spread on a screen and continuously ventilated. The germ develops, and chemical changes occur inside the barley. This process lasts for 3.5 to 6 days. Eventually, the germ grows to almost the length of the barley, and the roots wither. At this stage, the malt is called green malt. During the germination stage, it is necessary to replenish water to keep the surface of the barley moist. This is called germination water replenishment (water spraying). Germination water replenishment is carried out by methods well known to those skilled in the art. For example, the surface is maintained in a moist state by spraying.

[0079] Kiln drying or roasting is a drying step of the malt. Green malt is heated in a drying furnace to reduce the water content and stop further growth. Most commercial drying furnaces have a minimally flattened green malt bed layer for effective drying, and a reversing machine is used to mix, reverse, or flatten the green malt bed layer. Drying can be carried out at conventional temperatures, for example, at least 40°C, at least 45°C, at least 65°C, at least 75°C, for example, 80 - 90°C, for example, 80 - 85°C. Kiln drying is generally carried out at a high temperature. Practical examples of the kiln drying process are as follows: 16 hours at 45 - 65°C; 2 hours at 75 - 80°C; 3 hours at 83°C. In the kiln drying step, the water content of the wet malt is reduced from about 40% to 4% - 5%.

[0080] As used herein, de-rooting means the use of a vibrating sieve to remove root sprouts from the germination process. The final stage of malt production is to produce dried and brittle golden-colored malt.

[0081] Those skilled in the art will know that the quality indicators of high-quality malt include α-amino nitrogen content, color intensity, and turbidity. The α-amino nitrogen content is measured by the ninhydrin colorimetric method (refer to the beer malt standard QB / T1686 - 2008). Turbidity is measured using a beer turbidity meter. Color intensity is measured using a UV-VIS spectrophotometer.

[0082] The EBC color scale was developed by the Institute of Brewing and the European Brewing Convention. This is a generally recognized method for the colorimetry of beer, wort, caramel solutions, and similarly colored liquids. Its visible units range from 2 to 27. Light yellow wort and light-colored beer are located at the lower end of the color scale, while dark yellow wort, beer, and caramel are located at the upper end of the color scale.

[0083] The conventional mashing test is the standard method for malt quality evaluation recommended by the European Brewing Convention (EBC). A small amount of wort is prepared by this method, and the quality of the malt used is thereby evaluated.

[0084] α-Amino nitrogen in malt is low-molecular-weight nitrogen in certain amino acids and is the main nitrogen source required for the metabolism of brewer's yeast. The higher the content of α-amino nitrogen, the stronger the fermentation performance of the yeast and the faster the beer fermentation.

[0085] Generally, malts with low color intensity are suitable for the brewing of light-colored beer. The level of color intensity is related to both the variety of barley and the malt manufacturing process. Process parameters such as steeping degree, water content during germination, temperature increase rate during germination, and drying and roasting temperature and time generally show a positive correlation with color intensity. The color intensity of light-colored malt is required to be between EBC 2.5 and 5.7. Light-colored beer has become popular, and beer manufacturers are paying more attention to the color intensity of malt. Some beer manufacturers even require the lowest possible color intensity of malt.

[0086] Turbidity is an index for quantifying the clarity and transparency of wort according to the content of turbidity-causing substances. The lower the turbidity, the higher the quality of the malt. Malts with high turbidity result in wort with high turbidity. The substances that cause turbidity in wort mainly include proteins, polyphenols, dextrins, β-glucans, arabinoxylans, etc. In addition to these, certain microbial metabolites and other factors can also cause turbidity in wort. Turbid wort not only affects filtration but also causes a decrease in the biological stability and flavor stability of fermented beer, reducing the quality of the beer. Therefore, malts with low turbidity are preferred by beer manufacturers.

[0087] Those skilled in the art would know that it is possible to obtain wort by the following method: adding auxiliary components to the obtained malt; adding enzymes such as β-glucanase for gelatinization and mashing as needed; removing husks and the like using filtration; adding hops and boiling; and removing solid components such as coagulated proteins using a clarifying agent. In addition, in addition to the malt obtained by the method of the present application, commonly known malts may be used in combination, and this ratio can be adjusted as appropriate.

[0088] As defined herein, food can include substances that can be processed into nutrients for general consumption (these can be at low or high temperatures). As defined herein, beverages can include substances that can be processed into substances suitable for drinking, which can be at low or high temperatures. It is understood that there is some overlap between these two definitions.

[0089] As used herein, the term "fermented food" means a food fermented by yeast or the like. The malt obtained according to the present application can be fermented by adding yeast to wort obtained from a raw material containing malt. If necessary, yeast is removed for production using a filter or the like. Thus, a fermented beverage can be prepared. The present application also provides a method for producing a fermented beverage, characterized by using the malt obtained by the production method of the present application. As used herein, the term "fermented beverage" means a beverage fermented by yeast or the like, such as beer, beer-flavored beverage, or whiskey. These beverages only need to use the malt obtained according to the present application as an ingredient, and they are not particularly defined. These beverages are usually produced by known methods.

[0090] The taste of fresh beer will more easily acquire the preference of consumers. The taste of fresh beer is related to the endogenous antioxidant activity of malt and the antioxidant process carried out throughout the production. The most important endogenous antioxidant components in beer are phenolic substances. These phenolic substances can effectively scavenge various free radicals and, to some extent, suppress the degree and rate of beer deterioration. Malt accounts for 70% - 80% of the source of phenols in beer. Malt with a high phenol content has great significance in enhancing the freshness of beer.

[0091] Depending on the antioxidant mechanism, the antioxidant systems in barley and malt can be classified into an enzymatic antioxidant system and a non-enzymatic antioxidant system. The non-enzymatic antioxidant system mainly depends on an aromatic ring having one or more hydroxyl groups in the phenol, reacts with free radicals, and scavenges free radicals. The enzymatic antioxidant system mainly depends on the actions of superoxide dismutase (SOD) and catalase (CAT). Both SOD and CAT belong to the category of antioxidant enzymes. Barley and malt contain compounds that are easily oxidized and endogenous oxidoreductases as catalysts. During malt production and subsequent mashing, the endogenous oxidoreductases lead to the production of certain precursors for flavor deterioration (i.e., loss of freshness) and the loss of some endogenous antioxidants through a series of reactions.

[0092] In the processes of auto-oxidation reaction and enzymatic reaction, superoxide free radical O2 - is generated from oxygen. These effects are mainly manifested as lipid peroxidation, polysaccharide decomposition, enzyme inactivation and deactivation, etc. during beer brewing. To prevent the accumulation of superoxide, aerobic organisms generate enzymes that catalyze the scavenging of these superoxides, and SOD is one of the important ones among these enzymes. The following reaction will occur under SOD catalysis: 2O2 - + 2H + → H2O2 + O2. Therefore, it is meaningful to have a sufficient amount of SOD in barley and malt. It is possible that SOD has a favorable protective effect in the storage of raw materials and the stabilization of flavor during the shelf life of beer.

[0093] The above reaction will generate hydrogen peroxide. For an aerobic system, it is very important to have enzymes that can scavenge these hydrogen peroxides. CAT is an enzyme in malt that can solve this problem and catalyze the scavenging of the generated H2O2. Through the continuous actions of SOD and CAT, finally H2O and O2 are generated. As a result, oxygen remains in the basal state and does not change into oxygen free radicals that are very harmful to beer brewing.

[0094] As is well known to those skilled in the art, the above antioxidant system can ultimately be manifested as the antioxidant activity of malt, wort, or even the final fermented beverages (such as beer and whisky) through the following indicators as indicators of antioxidant activity, for example, DPPH free radical scavenging activity (DSA), ABTS free radical scavenging activity (ASA), reducing power (RP), metal ion chelating activity (MCA), total polyphenol content (TPC), superoxide dismutase activity, and catalase activity.

[0095] Components and Equipment In addition to the glass equipment commonly used in the laboratory, other instruments and materials include: a stainless steel malt production tank, a constant temperature and humidity incubator (purchased from Tokyo Rika Kikai Co., Ltd.), a hydrogen-rich water electrolysis cup (purchased from Zhejiang Xinyankun Science & Technology Co., Ltd.), and a hydrogen-rich water concentration detection kit (purchased from MiZ Co., Ltd. (Japan)).

[0096] Method for measuring the concentration of hydrogen-rich water: The measurement is carried out using a titration kit for the amount of dissolved hydrogen in hydrogen-rich water, and the hydrogen content of the test solution can be accurately measured in units of 0.1 ppm. The reagent is dropped into the hydrogen-rich water drop by drop. When water contains hydrogen (for example, 0.5 ppm), the colorless water instantly turns blue after each drop is added, and then immediately returns to colorless. In this way, 5 drops can be continuously added, and each time, the water can return from blue to colorless. When the 6th drop is added, the blue water does not return to colorless. This indicates that the hydrogen content of the test solution is 0.5 ppm. In addition, attention should also be paid to the decay rate of the hydrogen concentration in hydrogen-rich water. When measuring the hydrogen concentration using the titration method, the inventors found that there is no obvious change in the hydrogen concentration after standing for 30 minutes. After standing for 50 minutes, the hydrogen concentration decreased to half of the initial concentration. Therefore, electrolysis can be performed again at intervals of 50 - 60 minutes.

[0097] The DPPH free radical scavenging activity (DSA) can be measured by the following method: DPPH is a highly stable free radical. Its ethanol solution has the strongest absorption peak at 517 nm (i.e., purple). When antioxidants are present, the free radicals are scavenged, causing the color of the solution to fade.

[0098] 2 mL of the sample and 2 mL of 0.1 mmol·L -1 DPPH ethanol solution are placed in the same brown centrifuge tube (10 mL), shaken until homogeneous, and left to stand in the dark at room temperature for 30 minutes. Absolute ethanol is used as a blank control, and its absorbance is measured at 517 nm using the following equation:

Equation

[0099] The calibration curve is obtained using water-soluble vitamin E as the standard product. The DSA of the malt sample is expressed as μmol Trolox value·g -1 (μmol TE·g -1 ).

[0100] The ABTS free radical scavenging activity (ASA) can be measured by the following method: ABTS can generate a stable blue-green free radical with a strong absorption peak at 734 nm by oxidation with reagents such as MnO2 and H2O2. Antioxidants react with the above free radicals, causing the color of the system to fade.

[0101] ABTS is dissolved in water to form a solution with a concentration of 14 mmol·L -1 and then, an equal volume of 4.9 mmol·L-1 Mix it with a potassium persulfate solution and let it stand in the dark at room temperature for 12 - 14 hours. This solution is an ABTS free radical cationic stock solution. Dilute a suitable amount of the stock solution with pure water until the absorbance at 734 nm is 0.7 (±0.02). Mix 2.9 mL of the diluted solution with 0.1 mL of the sample liquid, mix them homogeneously, then subject them to reaction in the dark at room temperature for 6 minutes, and measure its absorbance at 734 nm.

[0102] The scavenging rate is calculated according to the following formula: ABTS free radical scavenging rate (%) = (A0 - A x ) / A0 (where: A x is 2.9 mL of ABTS diluted solution + 0.025 mL of sample liquid + 0.075 mL of water; A0 is 2.9 mL of ABTS diluted solution + 0.1 mL of water) and is calculated according to this.

[0103] The calibration curve is obtained using water - soluble vitamin E as the standard product. The ASA of malt is expressed as μmol Trolox value·g -1 (μmol TE·g -1 ).

[0104] The reducing power (RP) can be measured by the following method: The substances in the wort can reduce Fe 3+ to Fe 2+ . For the determination of the reducing power, the amount of Prussian blue Fe4(Fe(CN)6) generated is used as an indicator. This has a maximum absorption peak at 700 nm. A larger absorbance value indicates a stronger reducing power. Wort with a stronger reducing power also has a stronger antioxidant power. The RP of malt is expressed as μmol ascorbic acid value·g -1 (μmol AAE·g -1 ).

[0105] The metal ion chelating activity (MCA) can be measured by the following method: Some antioxidant components have a remarkable chelating effect on metal ions. After adding the ferrozin reagent, the metal ions that are not completely chelated will react with it, and a substance that exhibits a red color with the strongest absorption peak at 562 nm will be produced. The MCA of malt is expressed as μmol EDTA value·g -1 (μmol EDTAE·g -1 ).

[0106] The total polyphenol content (TPC) can be measured by the following method: Polyphenol compounds undergo an oxidative color reaction with the Folin-Ciocalteu reagent under basic conditions to produce a blue product. The color intensity of the blue product is directly proportional to the total polyphenol content and can be quantified by measuring the absorbance at 760 nm. The total polyphenol content of the sample can be calculated by comparing it with the calibration curve drawn for the standard product. The TPC of the malt sample is expressed as mg GAE·g -1 .

[0107] The superoxide dismutase (SOD) activity can be measured by the following method: For the measurement, the NBT photoreduction method is used to measure the enzyme activity level based on the reduction of nitroblue tetrazolium (NBT) inhibited by SOD under light irradiation. In the presence of oxidizing substances, riboflavin can be reduced under light irradiation conditions. The reduced riboflavin is very easily re-oxidized under aerobic conditions to produce O2 - . After the addition of NBT, O2 - can reduce NBT to blue methylhydrazone under light irradiation conditions, where the latter shows the maximum light absorption at 560 nm.

[0108] When SOD is added, SOD will react with O2 -By sweeping away, the photoreduction reaction of NBT can be inhibited, whereby the production ratio of blue methyl hydrazone decreases. Therefore, after the photoreduction reaction, the darker the blue color of the reaction solution, the lower the enzyme activity, and conversely, the higher the enzyme activity. The relative ratio related to the inhibition of NBT photoreduction has a positive correlation with the enzyme activity within a certain range, and based on this, it is possible to calculate the enzyme activity level. Frequently, the amount of enzyme required for 50% inhibition of the NBT photoreduction reaction is defined as 1 enzyme activity unit (U), and the enzyme activity is expressed as U / g of completely dried malt.

[0109] Catalase (CAT) activity can be measured by the following method: The decrease in the amount of H2O2 in the reaction solution is measured to determine CAT activity. The 3 mL reaction system contains 1 mL of 0.3% H2O2 and 1.95 mL of H2O. Finally, 0.05 mL of the enzyme solution is added to initiate the reaction, and 240 the rate of decrease of 240 is measured. At 25 °C, a decrease of 0.01 per minute is defined as 1 enzyme activity unit (U), and the enzyme activity is expressed as U / g of completely dried malt.

Example

[0110] Example A1: Experiment on the production of Yangnongpi No.7 malt (1) Select plump and unblemished Yangnongpi No.7 barley.

[0111] (2) Washing: Weigh 200 g of barley and wash away the impurities on the surface.

[0112] (3) First steeping: Hydrogen-rich water having a dissolved hydrogen concentration of 0.6 ppm was added to the steeping container to completely immerse the barley. The steeping container was placed in a constant temperature and humidity chamber at a temperature of 15°C and a relative humidity of 90%. The implementation time of the first steeping was 4 hours, and the hydrogen-rich water was exchanged every 30 minutes to maintain the hydrogen-rich water concentration. Here, the steeping container can be a steeping tank, which can generally be a known steeping tank, preferably a stainless steel steeping tank. The shape and dimensions of the steeping container can be suitably adjusted according to the general technical knowledge of those skilled in the art.

[0113] (4) First aeration rest: The implementation time of the first aeration rest of the barley exposed to air is 12 hours.

[0114] (5) Second steeping: The same steps as in the first steeping are repeated. The concentration of the hydrogen-rich water is 0.6 ppm. The implementation time of the second steeping is 5 hours. The hydrogen-rich water is exchanged every 30 minutes.

[0115] (6) Second aeration rest: The implementation time of the second aeration rest of the barley exposed to air is 12 hours.

[0116] (7) Germination: The barley germination stage starts after the second aeration rest. Moreover, the measurement of the barley germination time is started. During germination, a certain amount of green malt is collected every day and stored for testing.

[0117] In the germination stage, hydrogen-rich water having a dissolved hydrogen concentration of 0.6 ppm is used for water replenishment to maintain the steeping degree at about 45%. In the germination stage, water is replenished every 24 hours. For example, water can be replenished at the 24th hour, 48th hour, and 72nd hour. The germination stage is set as follows: From the start of germination to the 24th hour, the germination temperature is set at 14°C; from the 24th hour to the 72nd hour, the germination temperature is set at 15°C; from the 72nd hour to the 96th hour, the germination temperature is set at 16°C; and from the 96th hour to the 110th hour, the germination temperature is set at 18°C.

[0118] Germination ends at the 110th hour (4 days + 14 hours), and green malt is obtained.

[0119] (8) The above green malt is dried. The drying stage is set at 45 - 65°C for 16 hours, at 75 - 80°C for 2 hours, and roasted at 83°C for 3 hours.

[0120] (9) Root removal: After roasting is completed, the root buds and leaf buds are removed from the malt, and weighing is performed. At this point, the preparation of the malt is completed.

[0121] Example A2: The same steps as in Example A1 are used. The difference is that hydrogen-rich water with a dissolved hydrogen concentration of 1.2 ppm is used in all of the first steeping, the second steeping, and the germination stages.

[0122] Example A3: The same steps as in Example A1 are used. The differences are that hydrogen-rich water with a dissolved hydrogen concentration of 0.6 ppm is used only in the first steeping, and tap water is used in the second steeping and the germination stages.

[0123] Example A4: The same steps as in Example A1 are used. The differences are that hydrogen-rich water with a dissolved hydrogen concentration of 0.6 ppm is used only in the second steeping, and tap water is used in the first steeping and the germination stages.

[0124] Example A5: The same steps as in Example A1 are used. The differences are that hydrogen-rich water with a dissolved hydrogen concentration of 0.6 ppm is used only in the germination stage, and tap water is used in the first steeping and the second steeping.

[0125] Example A6: The same steps as in Example A1 are used. The differences are that hydrogen-rich water with a dissolved hydrogen concentration of 0.3 ppm is used in the first steeping and the germination stages, and tap water is used in the second steeping.

[0126] Comparative Example A1: The same steps as in Example A1 are used. The difference is that tap water is used in all of the first steeping, second steeping, and germination stages.

[0127] For each of the above Examples and Comparative Examples, two parallel groups can be set up.

[0128] The malt prepared in Examples A1 - A6 and Comparative Example A1 is individually made into a conventional mashed wort, and the following quality indicators shown in Table 1 are measured.

[0129] Overall, during malt production, by using hydrogen-rich water in the steeping and / or germination stages, it is possible to significantly improve the color intensity, turbidity, and α-amino nitrogen of the malt simultaneously. Moreover, there was no adverse effect on any of the quality indicators. Even when the dissolved hydrogen concentration was low (Example A6), compared with the case of using tap water for malt production, the color intensity was reduced by 8.1%, the turbidity was reduced by 7.3%, and the α-amino nitrogen increased by 2.8%.

[0130] The effects regarding the improvement of color intensity, turbidity, and α-amino nitrogen were most remarkable when hydrogen-rich water was used in the steeping and germination stages. The biological effect of hydrogen-rich water in the steeping stage was more obvious than that in the germination stage. When hydrogen-rich water was used only in the germination stage, there was a slight improvement in color intensity, turbidity, and α-amino nitrogen, but it was not significant. This can be confirmed in Examples A3 - A5. In addition, looking at Examples A5 and A6, even when low-concentration hydrogen-rich water (0.3 ppm) was used in the steeping stage, the effects regarding the improvement of color intensity, turbidity, and α-amino nitrogen were clearer than when high-concentration hydrogen-rich water (0.6 ppm) was used in the germination stage.

[0131] The higher the concentration of hydrogen-rich water, the more obvious the biological effects on the color intensity, turbidity, and α-amino nitrogen of malt. Compared with Example A1, the color intensity in Example A2 is further reduced by 14.3%, the turbidity in Example A2 is further reduced by 1.4%, and the α-amino nitrogen in Example A2 is further increased by 7.4%. Malt manufacturers can, if necessary, compare and consider quality indicators against economic efficiency.

[0132]

Table 1

[0133] Therefore, this application can simultaneously improve multiple important quality indicators by using hydrogen-rich water in malt production. The positive biological effects of hydrogen-rich water are particularly remarkable. The reduction of the color intensity and turbidity of malt meets the requirements of beer manufacturers for light-colored beer. The increase in the content of α-amino nitrogen in malt brings greater economic benefits to malt manufacturers. This application also provides the stage for using hydrogen-rich water and the preferred range of hydrogen-rich water concentration, which constitute important guidelines for malt manufacturers.

[0134] Example B1: Yangnongpi No. 7 Malt Production Experiment (1) Select plump and unblemished Yangnongpi No. 7 barley.

[0135] (2) Washing: Weigh 200 g of barley and wash away the impurities on the surface.

[0136] (3) First steeping: Hydrogen-rich water having a dissolved hydrogen concentration of 0.6 ppm was added to the steeping container to completely immerse the barley. The steeping container was placed in a constant temperature and humidity chamber at a temperature of 15°C and a relative humidity of 90%. The implementation time of the first steeping was 4 hours, and the hydrogen-rich water was replaced every 30 minutes to maintain the hydrogen-rich water concentration. Here, the steeping container can be a steeping tank, which can generally be a known steeping tank, preferably a stainless-steel steeping tank. The shape and dimensions of the steeping container can be suitably adjusted according to the general technical knowledge of those skilled in the art.

[0137] (4) First aeration rest: The implementation time of the first aeration rest of the barley exposed to air is 12 hours.

[0138] (5) Second steeping: The same steps as in the first steeping are repeated. The concentration of the hydrogen-rich water is 0.6 ppm. The implementation time of the second steeping is 5 hours. The hydrogen-rich water is replaced every 30 minutes.

[0139] (6) Second aeration rest: The implementation time of the second aeration rest of the barley exposed to air is 12 hours.

[0140] (7) Germination: The barley germination stage starts after the second aeration rest. Moreover, the measurement of the barley germination time is started. During germination, a certain amount of green malt is collected every day and stored for testing.

[0141] In the germination stage, hydrogen-rich water having a dissolved hydrogen concentration of 0.6 ppm is used for water replenishment to maintain a steeping degree of about 45%. In the germination stage, water is replenished every 24 hours. For example, water can be replenished at the 24th hour, 48th hour, and 72nd hour. The germination stage is set as follows: From the start of germination to the 24th hour, the germination temperature is set at 14°C; from the 24th hour to the 72nd hour, the germination temperature is set at 15°C; from the 72nd hour to the 96th hour, the germination temperature is set at 16°C; and from the 96th hour to the 110th hour, the germination temperature is set at 18°C.

[0142] Germination ends at the 110th hour (4 days + 14 hours), and green malt is obtained.

[0143] (8) The above green malt is dried. The drying stage is set at 45 - 65°C for 16 hours, at 75 - 80°C for 2 hours, and roasted at 83°C for 3 hours.

[0144] (9) Root removal: After roasting is completed, the root buds and leaf buds are removed from the malt and weighed. At this point, the preparation of the malt is completed.

[0145] Comparative Example B1: The same steps as in Example B1 are used. The difference is that tap water is used in all of the first steeping, second steeping, and germination stages.

[0146] Example B2: The same steps as in Example B1 are used. The differences are that hydrogen-rich water with a dissolved hydrogen concentration of 0.6 ppm is used only in the first steeping, and tap water is used in the second steeping and germination stages.

[0147] Example B3: The same steps as in Example B1 are used. The differences are that hydrogen-rich water with a dissolved hydrogen concentration of 0.6 ppm is used only in the germination stage, and tap water is used in the first steeping and second steeping.

[0148] Two parallel groups are set up for each of the above.

[0149] The four antioxidant activity indices of the malt formed in Example B1 and Comparative Example B1 above are measured individually. The results are shown in Table 2. The DPPH free radical scavenging activity and ABTS free radical scavenging activity are in the unit of μmol Te / 1 g of malt. The reducing power is in the unit of μmol AAE / 1 g of malt. And the metal chelating activity MCA is in the unit of μmol EDTA / 1 g of malt. The same applies hereinafter.

[0150] From Table 2, it can be seen that in the malt formed in Example B1, the DPPH free radical scavenging activity, ABTS free radical scavenging activity, reducing power RP, and metal chelating activity MCA are all clearly improved by 21.8%, 37.4%, 28.2%, and 19.0% respectively. It is speculated that hydrogen in hydrogen-rich water may be involved as an exogenous hormone that affects the production of malt while promoting important endogenous antioxidant activities in malt.

[0151]

Table 2

[0152] Malt manufacturers and beer manufacturers will consider the issue of the economic cost associated with the use of hydrogen-rich water. The inventors investigated the effect of the hydrogen-rich water usage stage in the malt production process on important antioxidant activity indicators. As described in Examples B1 to B3, the important antioxidant activity indicators of the completed malt products were finally measured. The results are shown in Table 3. As can be seen from this, the use of hydrogen-rich water in the steeping stage contributes most to the improvement of the antioxidant activity of malt. The use of hydrogen-rich water only in the germination stage increases the antioxidant activity of malt, but this increase is very small. When hydrogen-rich water is used in both the steeping and germination stages, the antioxidant activity of the produced malt is high, which is mainly due to the contribution of the steeping stage.

[0153]

Table 3

[0154] Regarding two antioxidant enzymes that malt manufacturers and beer manufacturers are interested in, the inventors separately measured the results related to SOD and CAT in the malt formed in Examples B2 and B3 as shown in Table 4.

[0155] In the process of malt production, the use of hydrogen-rich water in the steeping and / or germination stage increases SOD and CAT activities to varying degrees. However, the increase in antioxidant enzyme activity by hydrogen-rich water only in the germination stage was not as significant as that by hydrogen-rich water in the steeping stage. The improvement of SOD and CAT activities will directly promote the increase in DPPH free radical scavenging activity, ABTS free radical scavenging activity, reducing power, and metal ion chelating activity. This is also consistent with the trend shown in the results of Table 3.

[0156]

Table 4

[0157] Furthermore, in order to verify the effects of different concentrations of hydrogen-rich water on the non-enzymatic antioxidant system and the enzymatic antioxidant system, the inventors set the following Example B4.

[0158] Example B4: The same steps as in Example B1 are used. The difference is that hydrogen-rich water with a dissolved hydrogen concentration of 1.2 ppm is used in all of the first steeping, the second steeping, and the germination stage. Two parallel groups are set.

[0159] Measure the total polyphenol content TPC in the malt formed in Example B4. The results are shown in Table 5.

[0160] Finally, the total polyphenol content of the malt formed in Example B4 increased by 52.7% compared with the malt formed in Comparative Example B1. The dissolved hydrogen in hydrogen-rich water as an exogenous hormone promoted the increase in the content of phenols during germination. Since phenols are closely related to the stability and freshness of beer, phenols are of great concern to beer manufacturers.

[0161] In addition, the SOD and CAT activities of the malt formed in Example B4 are also higher than those in Examples B2 and B3. This indicates that within a suitable range, the higher the concentration of hydrogen-rich water, the more remarkable its biological effect on antioxidant enzymes.

[0162]

Table 5

[0163] The use of hydrogen-rich water during malt production to provide dissolved hydrogen can significantly increase the total polyphenol content and important antioxidant enzyme activities of the malt, and ultimately, it is manifested as an increase in the DPPH free radical scavenging activity, ABTS free radical scavenging activity, reducing power, and metal ion chelating activity of the malt, wort, or even the final fermented beverages (such as beer and whiskey). Thereby, an increase in endogenous antioxidant activity is achieved as desired by malt producers and the brewing industry. Moreover, no additional additives are introduced during malt production, which brings peace of mind and high reliability.

[0164] This specification describes merely preferred specific embodiments of the present application, and the above embodiments are merely used to explain the technical solutions of the present application without limiting the present application. All technical solutions obtainable by those skilled in the art through logical analysis, inference, or limited experiments related to the concept of the present application should be included within the scope of the present application.

Claims

1. A method for improving the antioxidant activity of malt, characterized in that grains are subjected to at least one steeping step, and the grains are immersed in hydrogen water having a dissolved hydrogen concentration of 0.3 to 1.6 ppm, preferably 0.3 to 1.2 ppm, and more preferably 0.6 to 1.2 ppm.

2. The method according to claim 1, characterized in that after the steeping step, the grains start to germinate, and hydrogen water having a dissolved hydrogen concentration of 0.3 to 1.6 ppm, preferably 0.3 to 1.2 ppm, and more preferably 0.6 to 1.2 ppm is used at least once to keep the surface of the grains moist.

3. The method according to claim 1 or 2, characterized in that the steeping is carried out twice, and the grains are immersed in hydrogen water in both the first steeping and the second steeping.

4. The method according to claim 1 or 2, characterized in that the indicators of the antioxidant activity of the malt include DPPH free radical scavenging activity, ABTS free radical scavenging activity, reducing power, and / or metal ion chelating activity.

5. The method according to claim 1 or 2, characterized in that the indicators of the antioxidant activity of the malt include the total polyphenol content.

6. The method according to claim 1 or 2, characterized in that the indicators of the antioxidant activity of the malt include superoxide dismutase activity and catalase activity.

7. A method for producing malt, characterized in that grains are subjected to at least one steeping step, and the grains are immersed in hydrogen water having a dissolved hydrogen concentration of 0.3 to 1.6 ppm, preferably 0.3 to 1.2 ppm, and more preferably 0.6 to 1.2 ppm.

8. The method for producing malt according to claim 7, characterized in that after the steeping step, the grains start to germinate, and hydrogen water having a dissolved hydrogen concentration of 0.3 to 1.6 ppm, preferably 0.3 to 1.2 ppm, and more preferably 0.6 to 1.2 ppm is used at least once to keep the surface of the grains moist.

9. The method for producing malt according to claim 7 or 8, characterized in that the steeping is carried out twice, and the grains are immersed in hydrogen water having a dissolved hydrogen concentration of 0.3 to 1.6 ppm in both the first steeping and the second steeping.

10. Use of the method for producing malt according to any one of claims 7 to 9 for reducing the color intensity of malt, reducing the turbidity of malt, and / or increasing the content of α-amino nitrogen in malt.

11. Malted barley obtained by the method for producing malt according to any one of Claims 7 to 9.

12. Use of the malt according to Claim 11 for preparing a fermented beverage or a fermented food.

13. The use according to Claim 12, wherein the fermented beverage includes beer, beer-flavored beverage or whiskey.

14. A method for enhancing the antioxidant activity of a plant raw material, the method comprising subjecting the plant raw material to at least one immersion and / or at least one germination in hydrogen water having a dissolved hydrogen concentration of 0.3 ppm to 1.6 ppm for producing a fermented food or a fermented beverage.

15. The method according to Claim 14, wherein the plant raw material includes, but is not limited to, leaves, seeds, roots, stems, flowers or fruits.

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