A fermented rice wine and a preparation method thereof

Abstract

This invention relates to the field of deep processing technology of Japanese raisin tree (Hovenia dulcis), and particularly to a fermented rice wine made from Japanese raisin tree (Hovenia dulcis) and its preparation method. This invention uses Japanese raisin tree (Hovenia dulcis) extract and glutinous rice as raw materials, employing a multi-stage, multi-level, low-temperature ecological fermentation process. Combined with the natural flavonoid antioxidant properties of the Japanese raisin tree (Hovenia dulcis) extract, this invention solves the problems of traditional rice wine, such as the need for added antioxidants, sterilization, high purine content, bitter taste, and the need for exogenous coloring and sugar addition. Furthermore, the multi-stage, multi-level, low-temperature ecological fermentation process retains all nutrients and simplifies post-processing steps, eliminating the need for sterilization, decoction, coloring, and antioxidant addition, resulting in higher production efficiency and lower production costs. Moreover, the preparation method provided by this invention results in naturally clarified wine without the use of diatomaceous earth or other filter aids during the preparation process. Therefore, the fermented rice wine made from Japanese raisin tree (Hovenia dulcis) provided by this invention has the advantages of being additive-free, low in purines, naturally amber in color, highly nutritious, possessing natural antioxidant and antibacterial properties, and having a superior taste.

Description

Technical Field

[0001] This invention relates to the field of deep processing technology of Japanese raisin tree (Hovenia dulcis), and in particular to a fermented rice wine made from Japanese raisin tree and its preparation method. Background Technology

[0002] Yellow wine, a unique low-alcohol brewed wine in my country, is deeply loved by consumers. However, existing traditional and commercially available yellow wines have many drawbacks in their production methods: First, most yellow wines add caramel coloring to achieve a uniform color; sulfur dioxide is added as an antioxidant and preservative to extend shelf life; and diatomaceous earth is used as a filtration aid in the clarification process. These practices introduce various food additives, which do not meet the current consumer demand for natural and healthy products. Second, traditional yellow wines are mostly fermented at room temperature in a single fermentation process, which easily produces off-flavors. Unfermented wine is prone to bitterness, and the fermentation process destroys the nutrients in the yellow wine. Third, conventional yellow wine raw materials have a high purine content after fermentation, making them unsuitable for people with high uric acid levels, thus limiting their suitable population. Fourth, traditional yellow wine has a limited nutritional profile and low amino acid content, requiring the addition of sugar sources to adjust the taste. Adding fructose or sucrose makes it unsuitable for people controlling their blood sugar levels.

[0003] Currently, there are existing technologies that attempt to ferment and prepare rice wine using Japanese raisin tree as raw material. However, these technologies have not solved the problems mentioned above, such as additive residues, high purine content, additional sterilization and anti-oxidation, and bitter taste. They have also not achieved integrated production of additive-free, low-purine, naturally colored, and highly nutritious products. Furthermore, there are no related improvements for women who enjoy light drinking, people who control their blood sugar, and people with high uric acid levels. Summary of the Invention

[0004] In view of this, the present invention provides a fermented rice wine made from Japanese raisin tree fruit and its preparation method. The fermented rice wine made from Japanese raisin tree fruit provided by the present invention has the advantages of being additive-free, low in purines, having a natural amber color, high in nutrition, having natural antioxidant and antibacterial properties, and having a good taste.

[0005] This invention provides a method for preparing fermented rice wine made from Japanese raisin tree fruit, comprising the following steps: (1) Soak the crushed Japanese raisin tree in water for water extraction and then separate the solid and liquid components to obtain the Japanese raisin tree extract; (2) Soak glutinous rice in water, drain the water, steam and cool it in sequence to obtain cooked glutinous rice; (3) The cooked glutinous rice and the yellow wine compound fermentation strain are mixed for primary saccharification and fermentation, and then the jujube extract is added for secondary alcoholic fermentation. After that, the tertiary aging fermentation, filtration and bottling are carried out in sequence. The yellow wine compound fermentation strain is rice koji, and the jujube fermented yellow wine is obtained.

[0006] Preferably, the primary saccharification fermentation, secondary alcoholic fermentation, and tertiary aging fermentation are carried out under sealed conditions.

[0007] Preferably, the temperature of the first-stage saccharification fermentation is 8-10 degrees Celsius, and the holding time is 8-10 days; the temperature of the second-stage alcoholic fermentation is 10-12 degrees Celsius, and the holding time is 13-15 days; the temperature of the third-stage aging fermentation is 12-15 degrees Celsius, and the holding time is 22-24 days.

[0008] Preferably, in step (1), the water extraction includes soaking and extraction in sequence; the water temperature of the water extraction is 99~100 degrees Celsius and the pressure is normal pressure.

[0009] Preferably, the soaking time is 1.4 to 1.6 hours; the extraction is performed 3 times, and the extraction time for each extraction is 3 hours.

[0010] Preferably, in step (2), the soaking temperature is 20-25 degrees Celsius; the soaking time is 6-8 hours; and the relative humidity of the environment during soaking is 70-80%.

[0011] Preferably, in step (3), the mass ratio of cooked glutinous rice to jujube extract is 4~6:3.

[0012] Preferably, in step (3), the mass ratio of the jujube extract and the rice wine compound fermentation strain is 28~32:1.

[0013] Preferably, in step (3), the fermented wine after the filter residue is further subjected to de-alcoholization; the de-alcoholization temperature is 35~40 degrees Celsius, the vacuum degree is 55~65 Pa, and the time is 30~40 minutes.

[0014] The present invention also provides fermented rice wine made from Japanese raisin tree leaves prepared by the above-described method.

[0015] Compared with the prior art, the present invention has achieved the following beneficial effects: This invention provides a fermented rice wine made from Japanese raisin tree fruit. The fermented rice wine provided by this invention is a traditional rice wine, additive-free, and naturally amber in color. This invention utilizes the natural flavonoid antioxidants in Japanese raisin tree fruit (such as dihydromyricetin, a strong antioxidant) to achieve natural antioxidant and antibacterial effects (e.g., Staphylococcus aureus, Bacillus subtilis). It requires no sterilization or decoction, has no bitterness, and tastes excellent. Furthermore, the aforementioned natural flavonoid antioxidants can effectively eliminate free radicals in the body, prevent cholesterol synthesis and cell degeneration and aging, and improve metabolism. The fermented rice wine provided by this invention has a high amino acid content, is rich in natural glucose, and has extremely low purine content, only about one-tenth that of existing traditional rice wines. It is suitable for a wide range of people, including women, those controlling blood sugar, and those with high uric acid levels. It can also be prepared as a non-alcoholic nutritional beverage, suitable for even more consumers. Specifically, the fermented rice wine made from Japanese raisin tree fruit provided by this invention has the following advantages: 1) Natural and additive-free, healthy and safe: No caramel color, sulfur dioxide, diatomaceous earth and exogenous sugars are added during the entire preparation process. The wine has a natural amber color and does not require artificial coloring. The antioxidant and antibacterial abilities come from the nutritional components of the Japanese raisin tree itself (such as natural flavonoid antioxidants). No antioxidants are added during the fermentation and storage process. It is a pure ecological fermentation with no chemical residues and meets the standards for green and healthy food.

[0016] 2) Natural antioxidant and antibacterial effects, no sterilization required: The extract of Japanese raisin tree is rich in natural flavonoid antioxidants, which can play a role in antibacterial, antioxidant and antiseptic effects. The fermented Japanese raisin tree rice wine has extremely strong stability. No additional sterilization or antioxidants are required to ensure that the product is not easily spoiled. At the same time, the decoction process is eliminated, avoiding the bitter taste of the fermented Japanese raisin tree rice wine.

[0017] 3) Low in purines, suitable for special populations: Compared with traditional rice wine, the rice wine fermented with Japanese raisin tree provided by this invention has an extremely low purine content, with a total purine content of 0.88mg / 100g, which is almost negligible. People with high uric acid can also drink it in moderation. There is no added exogenous fructose or sucrose. The natural glucose content generated by the fermentation of glutinous rice and Japanese raisin tree is moderate, which is friendly to people who control their blood sugar. People who control their blood sugar can drink it, breaking the limitation of the drinking population of traditional rice wine.

[0018] 4) High in nutrition and excellent taste: The fermentation process constructed in this invention results in an amino acid content of over 7% (volume percentage) in the fermented rice wine made from Japanese raisin tree fruit. Its nutritional content is far higher than that of ordinary rice wine. It is rich in natural glucose, has a smooth taste, a balanced sweet and sour flavor, and no bitterness like traditional rice wine without fermentation. It is mellow and smooth, with an alcohol content of around 14% (volume percentage). It can better retain antioxidant components and is especially suitable for women to enjoy when slightly tipsy.

[0019] This invention also provides a method for preparing the fermented rice wine made from jujube as described above. Using jujube extract and glutinous rice as raw materials, this invention employs a multi-stage, low-temperature ecological fermentation process. Leveraging the natural flavonoid antioxidant properties of the jujube extract, it solves the problems of traditional rice wine, such as the need for added antioxidants, sterilization, high purine content, bitter taste, and the need for exogenous coloring and sugar addition. Furthermore, this invention utilizes a multi-stage, low-temperature ecological fermentation process, which preserves all nutrients and simplifies post-processing steps, eliminating the need for sterilization, heating, coloring, and antioxidant addition, resulting in higher production efficiency and lower production costs. Moreover, the preparation method provided by this invention results in naturally clarified wine, without the use of diatomaceous earth or other filter aids during the preparation process. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of this invention, the accompanying drawings used in the embodiments of this invention or in the prior art are briefly described below. For those skilled in the art, other drawings can be derived from the following drawings without creative effort, and all such drawings are within the protection scope of this invention.

[0021] Figure 1 The natural amber-colored appearance of the fermented rice wine made from Japanese raisin tree provided by this invention; Detailed Implementation

[0022] This invention provides a method for preparing fermented rice wine made from Japanese raisin tree fruit, comprising the following steps: (1) Soak the crushed Japanese raisin tree in water for water extraction and then separate the solid and liquid components to obtain the Japanese raisin tree extract; (2) Soak glutinous rice in water, drain the water, steam and cool it in sequence to obtain cooked glutinous rice; (3) The cooked glutinous rice and the yellow wine compound fermentation strain are mixed for primary saccharification and fermentation, and then the jujube extract is added for secondary alcoholic fermentation. After that, the tertiary aging fermentation, filtration and bottling are carried out in sequence to obtain the jujube fermented yellow wine.

[0023] This invention involves soaking crushed Japanese raisin tree fruit in water for water extraction, followed by solid-liquid separation to obtain a Japanese raisin tree fruit extract. In this invention, the Japanese raisin tree fruit can be fresh, ripe fruit. This invention uses ripe, mold-free, fresh Japanese raisin tree fruit to ensure product quality.

[0024] In this invention, the Japanese raisin tree can be pre-treated before use; the pre-treatment may include washing, removing fruit stems, impurities and seeds, and crushing.

[0025] In this invention, the crushing can be carried out under low temperature conditions, which can be 5 to 20 degrees Celsius, specifically 8 degrees Celsius, 10 degrees Celsius, 12 degrees Celsius, 15 degrees Celsius or 18 degrees Celsius.

[0026] In this invention, there are no special requirements for the pulverization process; conventional pulverization methods in the art can be used.

[0027] In this invention, the water can be purified water.

[0028] In this invention, the mass ratio of the Japanese raisin tree fruit to water can be 1:1.5 to 2.5, specifically 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, 1:2.1, 1:2.2, 1:2.3 or 1:2.4.

[0029] In this invention, the water extraction may include sequential soaking and extraction; the water temperature for water extraction may be 99-100 degrees Celsius, and the pressure may be atmospheric pressure; the soaking time may be 1.4-1.6 hours, specifically 1.5 hours; the extraction may be performed three times, with each extraction lasting 3 hours; the equipment for water extraction may be a non-metallic container, specifically an earthenware jar. This invention, through water extraction, can extract effective components, resulting in a jujube extract rich in natural flavonoid antioxidants, glucose, and various amino acids.

[0030] In this invention, the solid-liquid separation can be filtration.

[0031] In this invention, the concentration factor can be 5 to 10 times, specifically 6 times, 7 times, 7.5 times, 8 times, or 9 times. The Japanese raisin tree extract obtained by this invention is rich in natural glucose and flavonoid antioxidants.

[0032] In this invention, the concentration process may further include drying the resulting product; the drying may be spray drying. The dried Hovenia dulcis extract is then tested, pulverized, sieved (80 mesh), and packaged.

[0033] This invention involves soaking glutinous rice in water, draining the water, steaming, and cooling it to obtain cooked glutinous rice. In this invention, the glutinous rice can be japonica glutinous rice.

[0034] In this invention, the water can be clean water.

[0035] In this invention, the soaking temperature can be 20-25 degrees Celsius, specifically 21 degrees Celsius, 22 degrees Celsius, 23 degrees Celsius or 24 degrees Celsius; the soaking time can be 6-8 hours, specifically 6.5 hours, 7 hours or 7.5 hours; the relative humidity of the environment during soaking can be 70-80%, specifically 75%.

[0036] In this invention, the steaming method can be steam steaming; the steaming temperature can be 100 degrees Celsius; the steaming time can be 45 to 60 minutes, specifically 50 minutes or 55 minutes; the thickness of the rice layer can be 3 centimeters; the steaming equipment can be a bamboo container; the relative humidity of the environment during steaming can be 80 to 90%, specifically 85%.

[0037] In this invention, the cooling method can be cooling by spreading out; the final temperature of the cooling can be 20-25 degrees Celsius, specifically 22 degrees Celsius.

[0038] This invention uses high-quality glutinous rice, which is soaked in water until the grains swell, drained, steamed, and cooled to a low temperature to ensure proper gelatinization of the glutinous rice, which is beneficial for subsequent fermentation and saccharification.

[0039] After obtaining the jujube extract and cooked glutinous rice, the present invention mixes the cooked glutinous rice with the yellow wine compound fermentation strain (referred to as the first mixture) for primary saccharification fermentation, then adds the jujube extract for secondary alcoholic fermentation, and then sequentially carries out tertiary aging fermentation, filtration and bottling to obtain the jujube fermented yellow wine.

[0040] In this invention, the rice wine compound fermentation strain can be rice koji; the rice koji can be the rice koji with product standard code QB / T 4577 of Angel Yeast Co., Ltd.

[0041] In this invention, the mass ratio of the jujube extract and the rice wine compound fermentation strain can be 28~32:1, specifically 29:1, 30:1 or 31:1.

[0042] In this invention, the mass ratio of cooked glutinous rice to jujube extract can be 4~6:3, specifically 4.5:3, 5:3 or 5.5:3.

[0043] In this invention, the temperature of the first mixture can be 18 to 22 degrees Celsius, specifically 19 degrees Celsius, 20 degrees Celsius or 21 degrees Celsius, and the relative humidity of the environment can be 60 to 70%, specifically 63%, 65% or 68%.

[0044] In this invention, the temperature of the primary saccharification and fermentation can be 8-10 degrees Celsius, specifically 9 degrees Celsius, and the holding time can be 8-10 days, specifically 9 days. This invention controls the temperature at 8-10 degrees Celsius for low-temperature saccharification and fermentation. During this stage, the starch in the glutinous rice gradually saccharifies, the natural glucose and flavonoids in the jujube are fully dissolved, and the complex fermentation bacteria for rice wine slowly proliferate, initially producing the wine liquid, thus avoiding the bitterness produced by high-temperature fermentation.

[0045] In this invention, the temperature for the secondary alcoholic fermentation can be 10-12 degrees Celsius, specifically 11 degrees Celsius, and the holding time can be 13-15 days, specifically 14 days. This invention fine-tunes the temperature to 10-12 degrees Celsius, continuously carrying out the secondary alcoholic fermentation, controlling the fermentation time to stabilize the final alcohol content of the fermented rice wine at around 14% (volume percentage). The rice wine's compound fermentation bacteria fully decompose the proteins in the raw materials, ensuring an amino acid content of over 7%. The natural pigments from the jujube are slowly released, resulting in a naturally uniform and translucent amber color in the wine. Figure 1 As shown.

[0046] In this invention, the temperature for the three-stage aging fermentation can be 12-15 degrees Celsius, specifically 13 degrees Celsius or 14 degrees Celsius, and the holding time can be 22-24 days, specifically 23 days. This invention adjusts the temperature to 12-15 degrees Celsius for low-temperature three-stage aging fermentation. During this stage, the flavor compounds in the wine are fully integrated, impurities naturally settle and clarify, eliminating the need for diatomaceous earth filtration. Simultaneously, flavonoids continuously exert their antioxidant effects, naturally inhibiting bacteria and preserving freshness, eliminating the need for sterilization and the addition of antioxidants.

[0047] In this invention, the primary saccharification fermentation, secondary alcoholic fermentation, and tertiary aging fermentation can be carried out under sealed conditions. This invention utilizes a fully sealed fermentation process to produce fermented raw wine. The fermented raw wine clarifies naturally, requiring no heating, no added sulfur dioxide, and no diatomaceous earth filtration aid; it is directly bottled after filtration. This invention employs multi-stage continuous fermentation, controlling the fermentation temperature throughout the process within the range of 8-15 degrees Celsius, with uninterrupted continuous operation and no intermediate separation of the raw material and liquid, resulting in high production efficiency.

[0048] In this invention, the filter residue can be filtered; the filtration equipment can include a microporous physical filter; the temperature of the filter residue can be 15-20 degrees Celsius, specifically 16, 17, 18 or 19 degrees Celsius, and the relative humidity of the environment can be 65-70%, specifically 67%.

[0049] In this invention, the fermented wine after the filter residue may further undergo de-alcoholization; the de-alcoholization temperature can be 35-40 degrees Celsius, specifically 36 degrees Celsius, 38 degrees Celsius, or 39 degrees Celsius; the vacuum degree can be 55-65 Pa, specifically 57 Pa, 59 Pa, 60 Pa, 62 Pa, or 64 Pa; and the time can be 30-40 minutes, specifically 32 minutes, 35 minutes, or 38 minutes. This invention, through de-alcoholization, removes alcohol components while retaining all amino acids, natural glucose, and flavonoids, yielding a de-alcoholized fermented jujube wine (a non-alcoholic nutritional beverage).

[0050] In this invention, the bottling temperature can be room temperature; the bottling can be carried out in a Class 1000 sterile workshop. This invention removes only a small amount of lees through physical filtration, without the need for decoction, and directly bottles and seals to obtain the finished product of fermented jujube rice wine.

[0051] In this invention, the apparatus for the preparation method may include a raw material pretreatment tank, a three-stage fermentation tank with a precise temperature control system, a physical filter, and a filling device connected in sequence.

[0052] The three-stage fermentation tank has a built-in precise temperature control system, which can accurately control the fermentation temperature in stages from 8 to 15 degrees Celsius. The inner wall of the tank is equipped with an anti-oxidation coating and a closed fermentation structure to achieve closed and continuous fermentation, completely isolating the tank from other bacteria. It is suitable for multiple multi-stage low-temperature ecological fermentation, ensuring a constant temperature, a closed and pollution-free fermentation process, and achieving natural anti-oxidation and sterilization-free fermentation production.

[0053] The present invention also provides fermented rice wine made from Japanese raisin tree leaves prepared by the above-described method.

[0054] The fermented rice wine made from Japanese raisin tree fruit provided by this invention is a traditional rice wine, additive-free, and naturally amber in color. This invention utilizes the natural flavonoid antioxidants in Japanese raisin tree fruit to achieve natural antioxidant and antibacterial effects, eliminating the need for sterilization or decoction, resulting in a smooth, non-bitter taste. The fermented rice wine made from Japanese raisin tree fruit provided by this invention has a high amino acid content, is rich in natural glucose, and has extremely low purine content, making it suitable for a wide range of people, including women, those controlling blood sugar, and those with high uric acid levels. It can also be prepared as a dealcoholized nutritional product to cater to an even wider consumer base.

[0055] To further illustrate the present invention, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments thereof.

[0056] Example 1: 1) Preparation of Hovenia dulcis extract: Select 15 kg of fresh, ripe Hovenia dulcis, wash and remove fruit stems, impurities and seeds, crush at low temperature (13 degrees Celsius) and then pulverize. Add the obtained Hovenia dulcis powder to 30 kg of purified water, stir and mix for 15 minutes, soak at 100 degrees Celsius for 1.5 hours, then extract with water at 100 degrees Celsius and normal pressure for 3 hours, repeat the water extraction twice, filter to remove residue, concentrate, spray dry to obtain 6 kg of Hovenia dulcis extract. The content of flavonoid antioxidants in the extract meets the standard and is rich in natural glucose.

[0057] 2) Pretreatment of glutinous rice: Take 30kg of high-quality japonica glutinous rice, keep the relative humidity of the environment stable within the range of 70~80%, soak it in water at 22 degrees Celsius for 7 hours, drain the water, keep the relative humidity of the environment stable within the range of 80~90%, steam it at 100 degrees Celsius, cool it down to 22 degrees Celsius, and you will get cooked glutinous rice for later use.

[0058] 3) Three-stage fermentation in earthenware jars: Under conditions of 20 degrees Celsius and a stable relative humidity of 60-70%, 0.2 kg of rice wine compound fermentation starter (Angel QB / T 4577 rice koji) is added to cooked glutinous rice, mixed well, and then transferred to a three-stage fermentation tank; the temperature of the first-stage saccharification fermentation is 9 degrees Celsius, and the fermentation lasts for 9 days; according to the mass ratio of cooked glutinous rice to jujube extract of 5:3, the resulting first-stage fermentation liquid is mixed with jujube extract for the second-stage aging fermentation, which is carried out at a temperature of 11 degrees Celsius for 14 days, until the alcohol content reaches 14% (volume percentage); the temperature of the third-stage aging fermentation is 14 degrees Celsius, and the fermentation lasts for 23 days, to obtain the fermented base wine, which is naturally clear and amber in color.

[0059] 4) Post-processing: Under the conditions of stable temperature in the range of 15~20 degrees Celsius and stable relative humidity in the range of 65~70%, the lees are filtered by a microporous physical filter, and then directly bottled and sealed at room temperature in a 1000-level aseptic workshop to obtain the fermented rice wine of Japanese raisin tree.

[0060] 5) Product testing: The amino acid content of the fermented rice wine prepared in this embodiment is 7.05%, the natural glucose content is 3.3%, there is no exogenous sugar or fructose, the purine content is less than 0.5mg / L, which is almost negligible, there is no caramel color or sulfur dioxide residue, the taste is sweet and sour and mellow, there is no bitterness, and it does not deteriorate or oxidize after being stored at room temperature and away from light for 24 months.

[0061] Example 2: (1) Take the fermented rice wine of Japanese raisin tree prepared in Example 1 and put it into a low temperature vacuum de-alcoholization device for de-alcoholization. Control the de-alcoholization temperature to be 38 degrees Celsius, the vacuum degree to be 60 Pa, and de-alcoholization for 35 minutes to obtain de-alcoholized fermented rice wine of Japanese raisin tree.

[0062] (2) Product testing: The fermented rice wine prepared in this embodiment has an amino acid content of 7.02%, a natural glucose content of 3.2%, no alcohol content, and extremely low purine content (total purine content is 0.88mg / 100g, which is only about one-tenth of that of existing traditional rice wine). It is suitable for children, the elderly, people with alcohol allergies, people with high uric acid, or people who need to control their blood sugar.

[0063] Example 3: The preparation method in this embodiment is the same as that in Example 1, and the purpose is to test stability and repeatability.

[0064] Comparative Example 1: The preparation method of this comparative example is the same as that of Example 1, except that the temperature of the primary saccharification and fermentation is 13 degrees Celsius.

[0065] Comparative Example 2: The preparation method of this comparative example is the same as that of Example 1, except that the temperature of the primary saccharification and fermentation is 6 degrees Celsius.

[0066] Comparative Example 3: The preparation method of this comparative example is the same as that of Example 1, except that the primary saccharification and fermentation time is 15 days.

[0067] Comparative Example 4: The preparation method of this comparative example is the same as that of Example 1, except that the temperature of the secondary alcoholic fermentation is 16 degrees Celsius.

[0068] Comparative Example 5: The preparation method of this comparative example is the same as that of Example 1, except that the temperature of the secondary alcoholic fermentation is 7 degrees Celsius.

[0069] Comparative Example 6: The preparation method of this comparative example is the same as that of Example 1, except that the incubation time for the secondary alcoholic fermentation is 10 days.

[0070] Comparative Example 7: The preparation method of this comparative example is the same as that of Example 1, except that the incubation time for the secondary alcoholic fermentation is 18 days.

[0071] Comparative Example 8: The preparation method of this comparative example is the same as that of Example 1, except that the temperature of the three-stage aging fermentation is 18 degrees Celsius.

[0072] Tests showed that the fermented rice wine prepared from jujube varieties 1 to 8 had high purine content, comparable to traditional rice wine, and contained virtually no flavonoids, thus lacking natural antioxidant capacity.

[0073] Comparative Example 9: The preparation method of this comparative example is the same as that of Example 1, except that the three-stage fermentation is carried out using stainless steel equipment.

[0074] Tests showed that the fermented rice wine made from Japanese raisin tree seeds prepared in Comparative Example 9 did not contain flavonoids and therefore lacked natural antioxidant capacity.

[0075] Comparative Example 10: The preparation method of this comparative example is the same as that of Example 1, except that no Hovenia dulcis extract was added.

[0076] Tests showed that the rice wine prepared in Comparative Example 10 did not contain flavonoids and therefore lacked natural antioxidant capacity.

[0077] Test Example 1: The fermented rice wine made from Japanese raisin tree (Hovenia dulcis) prepared in Example 3 was tested for lead content (Pb), total sugar (fructose, glucose, sucrose, maltose, and lactose), total acid content, alcohol content, formaldehyde, and aflatoxin. The testing procedures were conducted in accordance with GB / T13662-2018, GB / T 27588-2011 "Liqueurs", GB 2762-2022 "National Food Safety Standard - Limits of Contaminants in Food", and GB... The following standards were used: GB 5009.225-2023 "National Food Safety Standard - Determination of Ethanol Concentration in Wine and Edible Alcohol", GB 5009.8-2023 "National Food Safety Standard - Determination of Fructose, Glucose, Sucrose, Maltose and Lactose in Food", and GB 12456-2021 "National Food Safety Standard - Determination of Total Acid in Food". The limit of quantitation for lead was 0.05 mg / kg, and the standard requirement was ≤0.2 mg / kg. The limit of detection for formaldehyde was 0.4 mg / L, and the limit of quantitation for aflatoxin was 0.1 μg / kg. The results are shown in Table 1.

[0078] Table 1. Test results of fermented rice wine made from Japanese raisin tree fruit in Test Example 1:

[0079] As shown in Table 1, the lead, formaldehyde, and aflatoxin content of the fermented rice wine prepared by this invention all meet the standard requirements. Furthermore, the total sugar content is moderate, the acidity is suitable, and the alcohol content is low. The tested items with standard indicators meet the requirements of GB / T 27588-2011 "Liqueurs" and GB 2762-2022 "National Food Safety Standard Limits of Contaminants in Food".

[0080] Test Example 2: The fermented rice wine made from Japanese raisin tree seeds prepared in Example 3 was tested for energy, protein, fat, total carbohydrates, sodium, moisture, and ash. The testing procedures were carried out in accordance with GB 5009.6-2016 "National Food Safety Standard - Determination of Fat in Food", GB 5009.91-2017 "National Food Safety Standard - Determination of Potassium and Sodium in Food", GB 28050-2011 "National Food Safety Standard - General Rules for Nutrition Labelling of Prepackaged Foods", GB 5009.5-2025 "National Food Safety Standard - Determination of Protein in Food", and GB 5009.3-2016 "National Food Safety Standard - Determination of Moisture in Food". The results are shown in Table 2.

[0081] Table 2. Test results of fermented rice wine made from Japanese raisin tree fruit in Test Example 2:

[0082] As can be seen from Table 2, the fermented rice wine made from Japanese raisin tree provided by this invention is rich in various nutrients, has high nutritional value, and is suitable for long-term consumption.

[0083] The embodiments of the present invention have been described above; however, these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. All other embodiments obtained by those skilled in the art based on the above embodiments of the present invention without inventive effort are within the protection scope of the present invention.

Claims

1. A method for preparing fermented rice wine made from Japanese raisin tree fruit, characterized in that, Includes the following steps: (1) The crushed Japanese raisin tree was soaked in water for water extraction and then solid-liquid separation to obtain Japanese raisin tree extract; (2) Soak glutinous rice in water, drain the water, steam and cool it in sequence to obtain cooked glutinous rice; (3) The cooked glutinous rice and the yellow wine compound fermentation strain are mixed for primary saccharification and fermentation, and then the jujube extract is added for secondary alcoholic fermentation. After that, the tertiary aging fermentation, filtration and bottling are carried out in sequence. The yellow wine compound fermentation strain is rice koji, and the jujube fermented yellow wine is obtained.

2. The preparation method according to claim 1, characterized in that, The primary saccharification fermentation, secondary alcoholic fermentation, and tertiary aging fermentation are carried out under sealed conditions.

3. The preparation method according to claim 1 or 2, characterized in that, The temperature for the primary saccharification and fermentation is 8-10 degrees Celsius, and the holding time is 8-10 days. The secondary alcoholic fermentation is carried out at a temperature of 10-12 degrees Celsius for 13-15 days. The temperature for the three-stage aging fermentation is 12-15 degrees Celsius, and the heat preservation time is 22-24 days.

4. The preparation method according to claim 1, characterized in that, In step (1), the water extraction includes soaking and extraction in sequence; the water temperature for the water extraction is 99~100 degrees Celsius and the pressure is normal pressure.

5. The preparation method according to claim 4, characterized in that, The soaking time is 1.4 to 1.6 hours; the extraction is performed 3 times, with each extraction lasting 3 hours.

6. The preparation method according to claim 1, characterized in that, In step (2), the soaking temperature is 20~25 degrees Celsius; The soaking time is 6-8 hours; The relative humidity of the environment during the soaking process is 70-80%.

7. The preparation method according to claim 1, characterized in that, In step (3), the mass ratio of cooked glutinous rice to jujube extract is 4~6:

3.

8. The preparation method according to claim 1, characterized in that, In step (3), the mass ratio of the jujube extract and the rice wine compound fermentation strain is 28~32:

1.

9. The preparation method according to claim 1, characterized in that, In step (3), the process of removing alcohol from the fermented raw wine after filtering the residue also includes the removal of alcohol from the fermented raw wine after filtering the residue. The de-alcoholization process is carried out at a temperature of 35-40 degrees Celsius, a vacuum of 55-65 Pa, and a time of 30-40 minutes.

10. A fermented rice wine made from Japanese raisin tree fruit, characterized in that, The fermented rice wine made from Japanese raisin tree fruit is prepared using the preparation method described in any one of claims 1 to 9.

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