Antioxidant stable preservation method for millet wine

Abstract

The invention provides an anti-oxidation stable preservation method for millet wine, and aims to improve the anti-oxidation capability and flavor stability of the millet wine in the storage process, the method specifically comprises the following steps: S1, compounding anti-oxidation components; adding a natural composite antioxidant liquid consisting of tea polyphenol, a grape seed extract and a ginger polyphenol extract into the fermented millet wine, uniformly stirring, and primarily filtering; s2, performing cold stabilization treatment, and performing two-stage filtration and clarification; s3, micro-aerobic sterilization: carrying out low-temperature rapid sterilization by adopting a micro-aerobic flash evaporation technology at 55 + / -2 DEG C and retaining active ingredients; s4, nitrogen filling and sealing filling are carried out, nitrogen replacement is carried out before filling, the dissolved oxygen concentration in a bottle is smaller than or equal to 0.5 mg / L, and sealing packaging is carried out in a clean environment; and S5, storing in a dark place, namely storing the product in a dark environment with the temperature of 10-15 DEG C and the humidity of lower than 60%. The method can effectively inhibit oxidation reaction of the millet wine, prevent precipitation and discoloration, improve sensory quality and nutritional activity, and is suitable for industrial preservation of various millet wine.

Description

Technical Field

[0001] This invention relates to the field of food preservation technology, and in particular to a method for the antioxidant and stable preservation of millet wine. Background Technology

[0002] Millet wine is a traditional alcoholic beverage made from millet, rich in various nutrients such as B vitamins, polyphenols, and amino acids. However, millet wine is susceptible to oxidation during storage, leading to darkening of color, deterioration of flavor, and loss of nutrients, severely impacting its commercial value. Existing storage methods often employ high-temperature sterilization or chemical additives, which pose nutritional risks or safety hazards. Therefore, there is an urgent need for a storage method that combines antioxidant properties, stability, and safety to improve the storage quality and flavor stability of millet wine. Summary of the Invention

[0003] To address the aforementioned technical shortcomings, this invention employs a modified technical solution: a method for the antioxidant and stable preservation of millet wine, comprising the following specific steps.

[0004] S1. Antioxidant compound: Add the following combination of natural antioxidants to the fermented millet wine and mix well;

[0005] S2. Cold stabilization treatment: Place the millet wine with added antioxidants under refrigeration conditions at 0-4℃ and let it stand for 24 hours to settle proteins and impurities, thereby enhancing the clarity and stability of the wine.

[0006] S3. Micro-oxygen sterilization: Low-temperature rapid sterilization is performed using micro-oxygen flash evaporation technology at 55℃±2℃ for 15 seconds, preserving aroma and nutritional active ingredients while sterilizing.

[0007] S4. Nitrogen-filled and sealed filling: Use nitrogen to replace the air in the bottle until the dissolved oxygen concentration is ≤0.5 mg / L, and then seal and fill.

[0008] S5. Store away from light. After filling, store the product in a light-protected environment with a constant temperature of 10-15℃ and a relative humidity of less than 60%.

[0009] As a further preferred embodiment of the present invention, in step S1, a composite antioxidant solution is prepared with the following concentrations: tea polyphenols: 0.02-0.03% by volume of millet wine; grape seed extract: 0.01-0.02% by volume; ginger polyphenol extract: 0.01-0.15% by volume. The antioxidants are dissolved in an appropriate amount of sterile purified water and then slowly added dropwise to the fermented and pre-filtered wine. The mixture is stirred at 100-150 rpm for 5-10 minutes to ensure full dissolution and uniform distribution. After completion, the mixture is allowed to stand for 2 hours for preliminary filtration using a 0.45 μm microporous membrane.

[0010] As a further preferred embodiment of the present invention, in step S2, the processed millet wine is transferred to a refrigerated tank and refrigerated at 0-4°C for 24-36 hours. During refrigeration, natural settling is adopted. After the refrigeration is completed, a second filtration process is performed using a two-stage filtration system: the first stage is coarse filtration using a 5μm filter cartridge to remove large particles; the second stage is fine filtration using a 0.22μm microporous membrane to remove tiny impurities and large molecular colloids. After filtration, the wine should be clear and transparent with no visible suspended matter.

[0011] As a further preferred embodiment of the present invention, in step S3, a micro-oxygen flash sterilization device is used. The device is equipped with a temperature control and instantaneous heating-cooling system. The sterilization parameters are controlled as follows: sterilization temperature: 55℃±2℃; holding time: 15 seconds; heat exchange method: a plate heat exchanger is used to achieve rapid heating and cooling; oxygen control: the dissolved oxygen in the wine is maintained at ≤1mg / L throughout the process to avoid oxidation reaction. After sterilization, the wine is immediately cooled to room temperature through the cooling pipeline, controlled between 15-20℃, and then enters the aseptic filling preparation stage.

[0012] As a further preferred embodiment of the present invention, in step S4, dark glass bottles or UV-resistant food-grade PET bottles are used; aluminum foil anti-oxidation bottle caps with sealing gaskets are selected; the containers are disinfected before filling by spraying with 75% ethanol and irradiating with ultraviolet light; vacuum pretreatment is performed; before filling, nitrogen is used to replace the air in the bottle: nitrogen is purged for 2-3 seconds to replace the air in the bottle; the dissolved oxygen in the bottle is reduced to ≤0.5 mg / L; immediately after filling, a capping machine is used to seal the bottle, and the capping force is controlled at 20-25 N·cm. All processes are carried out in a clean filling room with an air cleanliness level of less than 100,000.

[0013] As a further preferred embodiment of the present invention, in step S5, after bottling, the millet wine is uniformly labeled with light-proof tags and packed into corrugated cardboard boxes or light-proof packaging boxes. The storage environment is set as follows: temperature: 10℃-15℃; relative humidity: <60%; light-proof environment: fully enclosed cold storage room or underground wine cellar; the oxygen content of the ambient air is maintained at the normal level, and sensory indicators such as color, aroma, and taste are sampled every 3 months; alcohol content, pH, dissolved oxygen value, and antioxidant indicators are tested every 6 months.

[0014] Beneficial effects

[0015] This invention provides a method for the antioxidant and stable preservation of millet wine. It has the following beneficial effects:

[0016] By combining natural antioxidants (tea polyphenols, grape seed extract, and ginger polyphenols), this method effectively inhibits oxygen free radical reactions without altering the flavor and nutritional structure of the millet wine, preventing oxidation, discoloration, and flavor changes during storage, and extending the sensory quality stability period to over 12 months. This method uses 55℃ low-temperature micro-oxygen flash evaporation technology instead of traditional high-temperature sterilization, achieving not only highly efficient inhibition of harmful microorganisms but also avoiding thermal degradation of aroma substances, vitamins, amino acids, and other active ingredients, thus ensuring the unique smooth taste and nutritional value of the millet wine. Through a "cold stabilization treatment + dual-stage precision filtration" process, unstable substances such as proteins, polysaccharides, and pigments are significantly removed from the wine, making it less prone to flocculation, sedimentation, or turbidity during storage, thus improving its appearance. All antioxidants used are natural extracts, avoiding the use of chemical preservatives. The method is green and environmentally friendly, and the product better meets modern consumers' demands for "additive-free" and "healthy and natural" products, giving it strong market competitiveness. By employing a triple protection measure of nitrogen replacement, oxygen-proof bottle cap, and light-proof packaging, the dissolved oxygen inside the bottle is controlled at ≤0.5 mg / L, effectively isolating the wine from the continuous damage caused by oxygen in the air and improving the overall storage stability. After 6-12 months of storage, the alcohol content, pH value, sensory quality, and antioxidant capacity of the millet wine treated by the method of this invention remain stable. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0018] This invention provides a technical solution: a method for the antioxidant and stable preservation of millet wine, the specific steps of which include the following:

[0019] S1. Antioxidant compound: Add the following combination of natural antioxidants to the fermented millet wine and mix well;

[0020] S2. Cold stabilization treatment: Place the millet wine with added antioxidants under refrigeration conditions at 0-4℃ and let it stand for 24 hours to settle proteins and impurities, thereby enhancing the clarity and stability of the wine.

[0021] S3. Micro-oxygen sterilization: Low-temperature rapid sterilization is performed using micro-oxygen flash evaporation technology at 55℃±2℃ for 15 seconds, preserving aroma and nutritional active ingredients while sterilizing.

[0022] S4. Nitrogen-filled and sealed filling: Use nitrogen to replace the air in the bottle until the dissolved oxygen concentration is ≤0.5 mg / L, and then seal and fill.

[0023] S5. Store away from light. After filling, store the product in a light-protected environment with a constant temperature of 10-15℃ and a relative humidity of less than 60%.

[0024] In step S1, a compound antioxidant solution is prepared with the following concentrations: tea polyphenols: 0.02-0.03% by volume of millet wine; grape seed extract: 0.01-0.02% by volume; ginger polyphenol extract: 0.01-0.15% by volume. The antioxidants are dissolved in an appropriate amount of sterile purified water and then slowly added dropwise to the fermented and pre-filtered wine. Stirring is carried out at 100-150 rpm for 5-10 minutes to ensure full dissolution and uniform distribution. After completion, the mixture is allowed to stand for 2 hours for preliminary filtration using a 0.45μm microporous membrane.

[0025] In step S2, the processed millet wine is transferred to a refrigerated tank and refrigerated at 0-4℃ for 24-36 hours. During refrigeration, natural settling is allowed. After the settling is complete, a second filtration process is performed using a two-stage filtration system: the first stage is coarse filtration using a 5μm filter cartridge to remove large particles; the second stage is fine filtration using a 0.22μm microporous membrane to remove tiny impurities and large molecular colloids. After filtration, the wine should be clear and transparent with no visible suspended matter.

[0026] In step S3, a micro-oxygen flash sterilization device is used. The device is equipped with a temperature control and instantaneous heating-cooling system. The sterilization parameters are controlled as follows: sterilization temperature: 55℃±2℃; holding time: 15 seconds; heat exchange method: plate heat exchanger is used to achieve rapid heating and cooling; oxygen control: the dissolved oxygen in the wine is maintained at ≤1 mg / L throughout the process to avoid oxidation reaction. After sterilization, the wine is immediately cooled to room temperature through the cooling pipeline, controlled between 15-20℃, and then enters the aseptic filling preparation stage.

[0027] In step S4, dark glass bottles or UV-resistant food-grade PET bottles are used; aluminum foil anti-oxidation bottle caps with internal sealing gaskets are selected; the containers are sterilized before filling by spraying with 75% ethanol and irradiating with ultraviolet light; vacuum pretreatment is performed, and nitrogen is used to replace the air in the bottle before filling: nitrogen is purged for 2-3 seconds to replace the air in the bottle; the dissolved oxygen in the bottle is reduced to ≤0.5 mg / L; after filling, the bottle is immediately sealed with a capping machine, and the capping force is controlled at 20-25 N·cm. All processes are carried out in a clean filling room with an air cleanliness level below 100,000.

[0028] In step S5, after bottling, all millet wines are uniformly labeled with light-proof tags and packed into corrugated cardboard boxes or light-proof packaging boxes. The storage environment is set as follows: temperature: 10℃-15℃; relative humidity: <60%; light-proof environment: fully enclosed cold storage room or underground wine cellar; the oxygen content of the ambient air is maintained at the normal level, and sensory indicators such as color, aroma, and taste are sampled every 3 months; alcohol content, pH, dissolved oxygen value, and antioxidant indicators are tested every 6 months.

[0029] Example 1: Antioxidant and Stable Preservation of Sweet Millet Wine (Small Batch, 10 L)

[0030] Raw material preparation:

[0031] 10 liters of fermented and pre-filtered millet wine

[0032] Tea polyphenols (food grade, purity ≥98%): 3 mL (0.03%)

[0033] Grape seed extract (proanthocyanidin content ≥95%): 2 mL (0.02%)

[0034] Ginger polyphenol extract (polyphenol content ≥30%): 1.5 mL (0.015%)

[0035] Operating steps:

[0036] Antioxidant compound

[0037] The three natural antioxidants mentioned above were diluted 10 times with sterile purified water and added to 10 L of millet wine by continuous, slow dripping, with the stirring speed set at 120 rpm for 8 minutes. After standing for 2 hours, the mixture was filtered through a 0.45 μm microporous membrane to obtain a preliminarily clarified wine.

[0038] Cold stabilization treatment

[0039] The first-filtered wine was placed in a 5°C refrigerator and refrigerated for 30 hours. After natural settling, it was then passed through the following channels:

[0040] First stage: 5 μm filter element;

[0041] Second stage: 0.22 μm microporous membrane filtration to obtain a highly clear wine.

[0042] Micro-oxygen sterilization

[0043] Sterilization was performed using a micro-oxygen flash evaporation device with the following parameters: 55℃, holding time for 15 seconds, rapid heating and cooling via a plate heat exchange system; dissolved oxygen was controlled to be ≤1.0 mg / L throughout the process, and the temperature was cooled to 18℃ after sterilization.

[0044] Nitrogen filling

[0045] Brown glass bottles (500 mL × 20 bottles) were used. They were disinfected with ethanol spray and ultraviolet irradiation beforehand. The air inside the bottles was replaced with nitrogen (nitrogen filling for 2 seconds). The dissolved oxygen inside the bottles was measured to be ≤0.5 mg / L, and the screw cap sealing force was 22 N·cm.

[0046] Store away from light

[0047] Packed and stored in a cellar-style cold storage room with a temperature control of 12℃, humidity of 55%, and no ultraviolet light, the samples showed good sensory properties after six months, with no deterioration in flavor, sedimentation, or color change.

[0048] Example 2: Large-scale industrial production of dry millet wine (1000 L)

[0049] Raw material preparation:

[0050] Fermented and pre-filtered millet wine: 1000 liters

[0051] Tea polyphenols: 200 mL (0.02%)

[0052] Grape seed extract: 150 mL (0.015%)

[0053] Ginger polyphenol extract: 120 mL (0.012%)

[0054] Operating steps:

[0055] Antioxidant compound

[0056] The antioxidants were dissolved in 2 L of sterile water and added to the wine tank using a peristaltic pump while simultaneously stirring at low speed (industrial stirrer, 120 rpm, 10 minutes). After standing for 4 hours, the mixture was filtered through a plate and frame filter with a 0.45 μm filter membrane.

[0057] Cold stabilization treatment

[0058] The wine was transferred to a stainless steel refrigerated tank and kept at 2°C for 36 hours using an industrial cooling system. After settling, it was filtered sequentially.

[0059] Filter cartridge: 5 μm;

[0060] Fine filtration system: 0.22 μm cartridge filter membrane;

[0061] Micro-oxygen sterilization

[0062] Two-section plate heat exchange equipment is adopted:

[0063] Heat to 55℃, then hold for 15 seconds;

[0064] Meanwhile, the atmosphere is controlled by nitrogen inert protection (oxygen concentration at the inlet of the wine is 0.8 mg / L).

[0065] The exported wine is cooled to 20°C and prepared for bottling.

[0066] Nitrogen filling

[0067] The product is filled using 500 mL dark-colored PET bottles with aluminum foil caps. The production line is equipped with vacuum pre-extraction and double-head nitrogen purging (3 seconds / bottle). After capping, the oxygen content is tested to be ≤0.4 mg / L, and the filling cleanliness meets the 100,000-level GMP workshop standard.

[0068] Store away from light

[0069] The products are packed and stored in a temperature-controlled warehouse (13℃) with humidity maintained at 58%. The boxes are equipped with a UV-blocking layer. Products are sampled quarterly, and after 6 months, the DPPH free radical scavenging rate remains above 95%, and the wine is clear and free of sediment.

[0070] Example 3: Millet health wine (medium quantity, 100 L) for adding medicinal and edible ingredients

[0071] Raw material preparation:

[0072] Millet wine: 100 L

[0073] Tea polyphenols: 25 mL (0.025%)

[0074] Grape seed extract: 20 mL (0.02%)

[0075] Ginger polyphenols: 10 mL (0.01%)

[0076] Ingredients that are both food and medicine: Polygonatum sibiricum and concentrated wolfberry extract (added at a ratio of 1:500)

[0077] Operating steps:

[0078] Antioxidant compound

[0079] The three antioxidants were added to the wine along with a mixture of wolfberry and Solomon's seal (the ratio was 0.5L of sterile water). The mixture was mechanically stirred at 120 rpm for 6 minutes and then allowed to stand for 2 hours. The initial filtration was performed using a 0.45 μm filter membrane.

[0080] Cold stabilization treatment

[0081] Settling in a 4°C refrigerated container for 24 hours, then filtering:

[0082] First stage: 5 μm filter element;

[0083] Second stage: 0.22 μm fine filtration membrane;

[0084] Micro-oxygen sterilization

[0085] An experimental flash evaporation apparatus was used, with a flash temperature of 55℃ for 15 seconds, followed by rapid cooling to 16℃. Nitrogen was injected at the apparatus inlet to maintain a low-oxygen environment (≤1 mg / L).

[0086] Nitrogen-filled sealed filling

[0087] Brown ceramic bottles are used for filling. The process involves manual nitrogen filling for 2 seconds followed by screw capping, sealing the bottle mouth with a light-proof film, and bottling after vacuum pre-extraction. The oxygen concentration is ≤0.5 mg / L.

[0088] Store away from light

[0089] Placed in a laboratory underground wine cellar, with the temperature controlled at 11℃ and the humidity at 55%, tested after 6 months:

[0090] The total polyphenol content remains above 90%;

[0091] No flavor changes or sedimentation.

[0092] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or basic characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

[0093] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for antioxidant and stable preservation of millet wine, characterized in that, The specific steps include the following: S1. Antioxidant compound: Add the following combination of natural antioxidants to the fermented millet wine and mix well; S2. Cold stabilization treatment: Place the millet wine with added antioxidants under refrigeration conditions at 0-4℃ and let it stand for 24 hours to settle proteins and impurities, thereby enhancing the clarity and stability of the wine. S3. Micro-oxygen sterilization: Low-temperature rapid sterilization is performed using micro-oxygen flash evaporation technology at 55℃±2℃ for 15 seconds, preserving aroma and nutritional active ingredients while sterilizing. S4. Nitrogen-filled and sealed filling: Use nitrogen to replace the air in the bottle until the dissolved oxygen concentration is ≤0.5 mg / L, and then seal and fill. S5. Store away from light. After filling, store the product in a light-protected environment with a constant temperature of 10-15℃ and a relative humidity of less than 60%.

2. The method for antioxidant and stable preservation of millet wine according to claim 1, characterized in that, In step S1, a compound antioxidant solution is prepared with the following concentrations: tea polyphenols: 0.02-0.03% by volume of millet wine; grape seed extract: 0.01-0.02% by volume; ginger polyphenol extract: 0.01-0.15% by volume. The antioxidants are dissolved in an appropriate amount of sterile purified water and then slowly added dropwise to the fermented and pre-filtered wine. Stirring is carried out at 100-150 rpm for 5-10 minutes to ensure full dissolution and uniform distribution. After completion, the mixture is allowed to stand for 2 hours for preliminary filtration using a 0.45μm microporous membrane.

3. The method for antioxidant and stable preservation of millet wine according to claim 1, characterized in that, In step S2, the processed millet wine is transferred into a refrigerated tank and the refrigeration conditions are set at 0-4℃ for 24-36 hours. During the refrigeration period, natural sedimentation is adopted. After the refrigeration is completed, a second filtration process is carried out using a two-stage filtration system: the first stage is coarse filtration: 5μm filter cartridge filtration to remove large particles. Second-stage fine filtration: 0.22μm microporous membrane filtration to remove tiny impurities and large molecular colloids. The filtered wine should be clear and transparent with no visible suspended matter.

4. The method for antioxidant and stable preservation of millet wine according to claim 1, characterized in that, In step S3, a micro-oxygen flash sterilization device is used. The device is equipped with a temperature control and instantaneous heating-cooling system. The sterilization parameters are controlled as follows: sterilization temperature: 55℃±2℃; holding time: 15 seconds; heat exchange method: plate heat exchanger is used to achieve rapid heating and cooling; oxygen control: the dissolved oxygen in the wine is maintained at ≤1 mg / L throughout the process to avoid oxidation reaction. After sterilization, the wine is immediately cooled to room temperature through the cooling pipeline, controlled between 15-20℃, and then enters the aseptic filling preparation stage.

5. The method for antioxidant and stable preservation of millet wine according to claim 4, characterized in that, In step S4, use dark glass bottles or UV-resistant food-grade PET bottles; select aluminum foil anti-oxidation bottle caps with sealing gaskets; and sterilize the containers before filling by spraying with 75% ethanol and irradiating with ultraviolet light. Before filling, the bottles are purged with nitrogen for 2-3 seconds to replace the air inside. The dissolved oxygen level inside the bottle is reduced to ≤0.5 mg / L. After filling, the bottles are immediately sealed with a capping machine with a capping force controlled at 20-25 N·cm. All processes are carried out in a clean filling room with an air cleanliness level below 100,000.

6. The method for antioxidant and stable preservation of millet wine according to claim 1, characterized in that, In step S5, after bottling, all millet wines are uniformly labeled with light-proof tags and packed into corrugated cardboard boxes or light-proof packaging boxes. The storage environment is set as follows: temperature: 10℃-15℃; relative humidity: <60%; light-proof environment: fully enclosed cold storage room or underground wine cellar; the oxygen content of the ambient air is maintained at the normal level, and sensory indicators such as color, aroma, and taste are sampled every 3 months; alcohol content, pH, dissolved oxygen value, and antioxidant indicators are tested every 6 months.