Navel orange wine brewing process

Abstract

The invention relates to the technical field of fruit wine brewing, in particular to a navel orange wine brewing process which comprises the following steps: performing programmed slow freezing treatment on a navel orange raw material to destroy a cell structure; performing non-sulfur physical sterilization by combining a high-voltage electric field with dry ice; special yeast is inoculated for segmented variable-temperature sealed fermentation, and multiple kinds of fermentation base liquor are collected at different temperature stages; after the fermentation is finished, distilling to obtain a plurality of distilled base wines; after being aged, the base wine is blended into finished wine with different alcohol contents according to a specific proportion; finally, aging is accelerated through alternate cooling and heating treatment. Pure natural and zero-additive brewing is realized, a series of products with distinct navel orange fruity flavor and composite aroma and wide alcohol coverage range can be produced, meanwhile, the ageing period is greatly shortened, and the production efficiency and the added value of raw materials are improved.

Description

Technical Field

[0001] This invention relates to the field of fruit wine brewing technology, specifically to a navel orange wine brewing process. Background Technology

[0002] Navel oranges are an important citrus fruit in my country, rich in nutrients, and the country ranks among the world's top in terms of planting area and yield. However, the fruit ripens within a concentrated period, is prone to rotting, faces significant pressure to sell fresh produce, and suffers substantial post-harvest losses. Currently, navel orange processing is mostly limited to primary products such as juice and jam, with deep processing technologies, especially brewing technology, lagging behind.

[0003] Current fruit wine production largely follows winemaking techniques, resulting in products with limited flavor profiles that fail to highlight the unique characteristics of navel oranges. Traditional processes often employ chemical additives such as sulfur dioxide for sterilization and preservation, potentially leading to residue issues. Furthermore, the natural aging process is lengthy and inefficient. Therefore, there is an urgent need to develop a dedicated navel orange wine brewing method that fully utilizes navel orange resources, preserves its nutrients and unique flavor, and employs a pure and efficient process. Summary of the Invention

[0004] Traditional navel orange wine or similar fruit wine production typically employs winemaking techniques directly (single-temperature fermentation, sulfur-based sterilization, natural aging, etc.), resulting in homogenized flavors, risks of chemical residues, and long production cycles. To address the shortcomings of existing technologies, this invention redesigns the entire process chain from raw material pretreatment to finished product aging. Tailored to the characteristics of navel orange raw materials, it customizes a series of interconnected integrated processes, achieving the comprehensive goals of full utilization of raw materials, unique flavor profiles, zero additives in the process, and significantly improved efficiency.

[0005] This invention is achieved through the following technical solution: A process for brewing navel orange wine is provided, including the following steps: S1. Raw material processing: Select fresh, unrotten navel oranges and wash them.

[0006] S2. Low-temperature freezing: The washed navel oranges are slowly frozen at a temperature of -5℃ to -18℃.

[0007] Preferably, the slow-freezing process involves maintaining temperatures at -5°C, -10°C, -18°C, and -5°C sequentially. This step slowly disrupts the fruit pulp cell structure, facilitating the dissolution of internal substances, increasing juice yield and extraction efficiency, and providing a richer material basis for subsequent fermentation. This is a creative improvement to the raw material pretreatment method.

[0008] S3. Sterilization and Disinfection: The frozen navel oranges are subjected to high-voltage electric field treatment and dry ice disinfection in sequence. The preferred intensity of the high-voltage electric field treatment is 10 kV / cm; high-voltage electric field pulses are used to destroy the cell membranes of microorganisms through electroporation effect; dry ice disinfection involves placing dry ice into a sealed container containing the navel oranges, using the low temperature generated by its sublimation and carbon dioxide gas to isolate oxygen, thereby achieving sterilization and slowing down oxidation. This method avoids the use of chemical sulfur agents, avoids the potential health risks and possible adverse effects on flavor (such as the production of a sulfurous taste) caused by SO2 residues, and realizes the pure natural brewing concept of zero chemical additives.

[0009] S4. Segmented temperature-controlled fermentation: The sterilized whole navel orange fruit is placed in a stainless steel fermentation tank, and yeast strains obtained from the surface of the navel orange peel, which are separated, screened, purified and cultured, are introduced for sealed fermentation. The fermentation process is controlled by segmented temperature control.

[0010] Preferably, the temperature program involves maintaining each of the following temperatures for 24 hours: 10℃, 16℃, 20℃, 25℃, 20℃, 16℃, 10℃, and 5℃. Variable-temperature fermentation helps control the fermentation rate and promotes the formation of more flavor compounds.

[0011] Yeast metabolites vary significantly at different temperatures. Low temperatures (10-16℃) favor the production of fresh fruity esters; medium temperatures (20-25℃) accelerate fermentation, producing more alcohol and alcohols; subsequent cooling (back to 5℃) promotes the fusion and precipitation of flavor compounds. The specialized yeast is a local strain isolated from navel orange peels, better adapted to the navel orange juice environment, and produces a flavor more harmonious with the raw materials. This invention transforms static constant-temperature fermentation into dynamic programmed variable-temperature fermentation (10℃→25℃→5℃), and, in conjunction with specialized yeast from the source of the raw materials, actively guides the generation spectrum of flavor compounds during fermentation. Through a preset temperature curve, it directs yeast metabolism, directionally enriching the characteristic aromas of navel oranges (such as limonene) and producing complex esters (such as ethyl acetate and ethyl hexanoate), thereby creating a unique, multi-layered flavor distinct from other fruit wines.

[0012] S5. Multi-stage extraction and distillation: Collect portions of the fermentation liquid at different temperature stages during the fermentation process.

[0013] Preferably, fermented base liquors a, b, c, and d are collected at the end of the four temperature stages of 20℃, 25℃, 16℃, and 5℃, respectively. After the fermentation cycle (90 days) is completed, the remaining fermentation liquid is distilled.

[0014] Preferably, fractions with alcohol content of approximately 60%, 55%, 50%, and 20% are sequentially extracted in a dedicated fractionator to obtain distilled base spirits A, B, C, and D.

[0015] Distilling at different fermentation stages (at different temperatures) yields base wines (a, b, c, d) with varying flavor profiles (fruit aroma, mellow aroma, acidity, etc.). Precise distillation of fractions with different alcohol strengths (A, B, C, D) effectively separates and removes harmful low-boiling-point substances (such as methanol). This step produces eight base wines with distinct styles and alcohol strengths, forming a rich matrix of flavor base wines and providing a material basis for subsequent blending of diverse products. Simultaneously, by distilling specific fractions, the common challenge of controlling methanol content in fruit wines is solved, improving safety while preserving desired mid-grain flavor compounds.

[0016] S6. Base wine aging: The eight base wines (a, b, c, d, A, B, C, D) obtained in step S4 are aged at 25°C for 30 days to stabilize the wine composition.

[0017] S7. Finished Product Blending: Multiple aged base spirits are blended according to a preset ratio to obtain finished spirits with different alcohol contents and flavors. Exemplary blending schemes include: Honey-flavored (16% vol): fermented base spirits a 50%, b 10%, c 10%, d 10%, and distilled base spirits C 10%, D 10%.

[0018] Smooth type (36% vol): fermented base spirits b 30%, c 20%, d 10%, and distilled base spirits B 20%, D 20%.

[0019] Strong type (58% vol): Distilled base spirits A 50%, B 40%, and fermented base spirits b 5%, c 5%.

[0020] S8. Finished wine aging: The blended finished wine is placed in a stainless steel storage tank and subjected to alternating hot and cold aging processes to accelerate the aging process.

[0021] By allowing each base wine to mature for a short period at a stable temperature (25℃), its internal components are initially integrated and stabilized. The eight base wines are then blended in a scientific ratio. Through the blending of different base wines (fermented wine and distilled wine, with different flavor emphases), a series of products ranging from low alcohol (16% vol) to high alcohol (58% vol) and from honey aroma to robust flavor can be precisely designed and stably produced, meeting the diversified needs of the market and realizing the creative expansion of fruit wine product forms.

[0022] Preferably, the wine is first stored at approximately 0°C for 100 days, and then at approximately 35°C for 100 days, which constitutes one cycle. The total aging period is 400 days (i.e., two cycles). This process simulates the natural temperature changes of the four seasons, which can significantly accelerate the aging of the wine and shorten the aging time.

[0023] The aging process of wine essentially involves chemical reactions such as oxidation, reduction, and esterification, with temperature being a key influencing factor. Periodic alternation of temperature (0℃ to 35℃ cycles) dramatically but in a controlled manner alters the speed of molecular motion and reaction equilibrium, simulating and accelerating the chemical reactions caused by seasonal temperature variations during natural aging. This shortens the natural aging process, which typically takes several years, to approximately 400 days through artificially controlled temperature stress cycling. This significantly improves production efficiency and capital turnover, solving the industry pain points of long aging cycles and high costs associated with fruit wine, and thus possesses significant economic value.

[0024] The beneficial effects of this invention are: I. High raw material utilization rate and increased added value: It effectively utilizes fresh navel oranges, especially those substandard fruits that are not suitable for fresh consumption, solving the problem of unsold goods and transforming primary agricultural products into high-value commodities.

[0025] II. Unique and rich flavor: Through a combination of processes such as slow freezing and cell wall breaking, special yeast, segmented variable temperature fermentation and multi-stage wine extraction, the natural fruit aroma of navel oranges (such as limonene) is extracted and preserved to the greatest extent, while generating complex fermentation aromas such as esters, forming a unique flavor system that harmonizes fruit aroma, fermentation aroma and aging aroma.

[0026] 3. Purely natural and additive-free: The physical sterilization method combining high-voltage electric field and dry ice completely eliminates chemical additives such as sulfur dioxide, achieving pure natural brewing.

[0027] IV. Wide Product Range: Through a combination of fermentation and distillation, and blending of multiple base spirits, a series of products with different alcohol contents and styles (honey-scented, smooth, and robust) ranging from 16 to 58 degrees can be produced to meet the diversified needs of the market.

[0028] V. High aging efficiency: The alternating hot and cold aging technology simulates the natural aging environment, enabling it to achieve the mellow taste that traditional natural aging takes several years to obtain in a relatively short time (such as 400 days), thus improving production efficiency.

[0029] VI. Good nutrient retention: The processing method focuses on preserving the vitamin C, minerals and flavonoids in the navel orange raw materials and peel. Attached Figure Description

[0030] Figure 1 This is a process flow diagram of the present invention.

[0031] Figure 2 This diagram illustrates the source of the base liquor and the blending process of the finished product.

[0032] Figure 3 This is a temperature-time curve for alternating hot and cold aging. Detailed Implementation

[0033] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution. Example

[0034] Cultivation process of orange wine yeast liquid: 1. Select 10 kg of ripe, intact oranges free from pesticide contamination, crush and pulp them. 2. Allow the orange pulp to ferment naturally at 25-30℃ for about 3 days. Once the alcoholic flavor appears, transfer it to a 0℃ environment to stop fermentation. Store for later use.

[0035] 3. Collect the slurry from the filtered orange wine yeast, and perform streak plating isolation culture according to the PDA plate method. Incubate at 28℃ for 2-5 days until single colonies grow.

[0036] 4. Use the TTC colorimetric method to identify yeast colonies with strong metabolic capacity that are deep red and purple.

[0037] 5. Transfer the selected colonies with strong metabolic capacity to orange juice culture medium. Incubate at 28℃ for approximately 7 days. Measure the alcohol content in the orange juice fermentation broth.

[0038] 6. Select strains with strong fermentation power, high alcohol content, and strong alcohol tolerance for large-scale cultivation and preservation.

[0039] 7. Add the expanded culture of orange juice yeast to the sterilized orange jar for fermentation to obtain the fermentation strain. Example

[0040] like Figure 1 As shown, a navel orange wine brewing process is described. In this embodiment, 1000 kg of Fengjie navel oranges are used as raw materials, and the specific brewing steps are as follows: S1. Raw material processing: Select fresh, unrotten, and pest-free navel oranges (including fresh fruits that meet commercial standards and some substandard fruits; fruits that are not properly shaped or have minor scars on the skin but are not rotten), and wash them thoroughly with clean running water to remove surface dirt and impurities.

[0041] S2, Low-temperature freezing: The washed navel oranges were placed in a quick-freezing warehouse for a programmed slow-freezing process: first, they were kept at -5°C for 12 hours, then cooled to -10°C and kept there for 12 hours, then further cooled to -18°C and kept there for 12 hours, and finally warmed up to -5°C and kept there for 12 hours. This slow-freezing process allowed the water inside the fruit cells to slowly form ice crystals, effectively disrupting the cell wall structure and facilitating the subsequent dissolution of flavor compounds and nutrients.

[0042] S3. Sterilization and disinfection: The fruits, after being slow-frozen, were placed in a high-voltage electric field device and treated for 5 minutes under an electric field strength of 10 kV / cm to kill microorganisms on the surface of the fruits using the electroporation effect.

[0043] Subsequently, the fruits, after being treated with a high-voltage electric field, are transferred to a sealed sterilization tank, and food-grade dry ice is added at 1% of the total fruit weight. The dry ice rapidly sublimates, creating a -78°C low-temperature environment to enhance the sterilization effect, and simultaneously generating a high concentration of carbon dioxide gas, which replaces the air inside the tank while sterilizing, effectively slowing down the oxidation of the fruit components.

[0044] S4. Segmented temperature-controlled fermentation: Sterilized whole navel oranges (no need to crush) are directly packed into a 1.5m container. 3 The fermentation tank was filled with a culture medium of navel orange-specific yeast strain (obtained in Example 1), which had been pre-separated, screened, purified, and cultured on a large scale from the surface of the navel orange peel. The inoculation amount was 5% of the total material.

[0045] Seal the fermenter and start the programmed temperature control system for segmented variable-temperature fermentation. The temperature control program is as follows: First stage: Fermentation at 10℃ for 24 hours.

[0046] Second stage: Ferment at 16℃ for 24 hours.

[0047] Third stage: Fermentation at 20℃ for 24 hours. At the end of this stage, about 10% of the total fermentation liquid volume is released from the valve at the bottom of the tank and labeled as fermented base wine a.

[0048] Fourth stage: Fermentation at 25℃ for 24 hours. At the end of this stage, about 10% of the liquid is released and labeled as fermented base wine b.

[0049] Fifth stage: Ferment at 20℃ for 24 hours.

[0050] Stage 6: Fermentation at 16℃ for 24 hours. At the end of this stage, approximately 10% of the liquid is released and labeled as fermented base wine c.

[0051] Stage 7: Ferment at 10℃ for 24 hours.

[0052] Stage 8: Fermentation at 5℃ for 24 hours. At the end of this stage, approximately 10% of the liquid is released and labeled as fermented base wine (d).

[0053] Segmented temperature control aims to regulate yeast metabolic activity through temperature changes, thereby inducing the production of richer flavor compounds.

[0054] S5. Multi-stage extraction and distillation: After the above eight stages of fermentation are completed (a total of 8 days), the fermentation tank continues to be sealed for post-fermentation and aging, with a total fermentation cycle of 90 days.

[0055] After the fermentation cycle is complete, all remaining fermentation broth in the tank is removed and transferred to a stainless steel still for distillation. The fractions are collected separately by precise control. The initial fraction with an alcohol content of approximately 60% vol is labeled as Distilled Base Spirit A.

[0056] The fraction with an alcohol content of approximately 55% vol is labeled as Distilled Base Spirit B.

[0057] A fraction with an alcohol content of approximately 50% vol is labeled as distilled base spirit C.

[0058] The latter fraction, with an alcohol content of approximately 20% vol, is labeled as distilled base spirit D.

[0059] This multi-effect fractionation process can effectively separate and remove low-boiling-point harmful substances such as methanol.

[0060] S6, Base spirit aging: The eight base spirits obtained in steps 3 and 4 (fermented base spirits a, b, c, d and distilled base spirits A, B, C, D) were transferred to separate stainless steel aging tanks and placed in a constant temperature cellar at 25°C for 30 days of aging. This process allows the flavors of each base spirit to stabilize and blend.

[0061] S7. Blending of finished wines: After aging, the wines are blended according to the following preset proportions (by volume) to prepare three different styles of finished wines, such as... Figure 2 As shown: Honey-flavored (16% vol): Take 50% fermented base wine a, 10% b, 10% c, and 10% d, and 10% distilled base wine C and 10% D, and mix them evenly.

[0062] Smooth type (36% vol): Take 30% fermented base wine b, 20% c, and 10% d, and 20% distilled base wine B and 20% D, and mix them evenly.

[0063] Strong type (58% vol): Take 50% distilled base spirit A and 40% B, and 5% fermented base spirit b and 5% c, and mix them evenly.

[0064] S8. Accelerated aging of finished wine: The three blended finished wines were separately poured into stainless steel storage tanks and placed in a programmable temperature-controlled cellar for alternating hot and cold aging. Figure 3 As shown, the specific procedure is as follows: Phase 1: Store at 0°C for 100 days.

[0065] Second stage: Store at a high temperature of 35℃ for 100 days.

[0066] The above "low temperature-high temperature" storage constitutes a complete cycle, with a total aging time of 400 days, meaning two cycles are performed. This process simulates the natural temperature differences of the four seasons, which can significantly promote the association and redox reactions of molecules such as alcohols, acids, and esters in the wine, accelerate aging, and make the wine taste mellow and smooth in a shorter period of time.

[0067] Inspection and evaluation: After aging, samples of the finished wine are taken for testing.

[0068] Sensory evaluation: The three finished wines exhibit a natural amber to golden-red color, clear and bright. Among them: the honey-flavored wine has a fresh fruity aroma and a smooth taste; the smooth wine has a mellow aroma and a harmonious body; and the robust wine has a rich aroma and a strong but not overpowering taste. All three have distinct navel orange fruity aromas, along with rich fermentation esters and aging aromas, and a pure finish.

[0069] Physicochemical and safety indicators: Tested according to national standards (such as GB / T 15038 "General Analytical Methods for Wine and Fruit Wine"). Alcohol content, total sugar, and total acid meet design requirements. Key safety indicators, methanol and fusel oil content, were found to be far below the limits stipulated in GB 2757 "National Food Safety Standard for Distilled Spirits and Blended Spirits" and GB 2758 "National Food Safety Standard for Fermented Wines and Blended Spirits," demonstrating the effectiveness of the multi-effect distillation technology in this process.

[0070] Nutritional and flavor component analysis: Gas chromatography-mass spectrometry (GC-MS) was used to analyze volatile aroma components, detecting various esters and higher alcohols, including limonene (characteristic aroma of navel orange), ethyl acetate, and ethyl hexanoate, which constitute a complex aroma. Nutritional component analysis showed that the wine retains some vitamin C, potassium, and other minerals, as well as flavonoids (such as hesperidin) from the raw materials.

[0071] Example 3: Blending Experiment with Different Raw Material Ratios Based on Example 1, the process steps remain unchanged, but the blending ratio of the "smooth (36% vol)" finished wine in step S7 is adjusted to conduct a comparative experiment.

[0072] Experimental group 1: Mixed according to the original proportions of Example 1 (b 30%, c 20%, d 10%, B 20%, D 20%).

[0073] Experimental Group 2: The proportions were adjusted to fermented base wine b 35%, c 15%, d 10%, B 25%, and D 15%.

[0074] After aging under the same conditions, the wines in Experimental Group 1 were tasted and found to be more balanced, with harmonious fruit and mellow aromas; while Experimental Group 2 had a more prominent fermentation aroma, but a slightly astringent aftertaste. The results indicate that the blending ratio in Example 1 is an optimal balance point for this formulation.

[0075] Of course, the above description is not limited to the examples above. Technical features not described in this invention can be implemented by or using existing technology, and will not be repeated here. The above embodiments and drawings are only used to illustrate the technical solutions of this invention and are not intended to limit this invention. This invention has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this invention do not depart from the spirit of this invention and should also fall within the scope of protection of the claims of this invention.

Claims

1. A process for brewing navel orange wine, characterized in that: Includes the following steps: S1. Raw material processing: Select fresh, unrotten navel oranges and wash them. S2. Low-temperature freezing: The washed navel oranges are slowly frozen at a temperature of -5℃ to -18℃. S3. Sterilization and disinfection: The slow-frozen navel oranges are subjected to high-voltage electric field treatment and dry ice disinfection in sequence. S4. Segmented temperature-controlled fermentation: The treated fruit is placed in a fermentation tank, and yeast strains isolated from the surface of the navel orange peel are inoculated and sealed for fermentation; the fermentation process is controlled by segmented temperature changes, going through multiple temperature stages in sequence. S5. Multi-stage extraction and distillation: During the fermentation process, the fermentation liquid is collected at different temperature stages to obtain a variety of fermented base wines; after the fermentation cycle is completed, the remaining fermentation liquid is distilled to extract fractions of different alcohol strengths to obtain a variety of distilled base wines. S6. Base wine aging: The various fermented base wines and distilled base wines obtained in step S5 are aged at 25°C. S7. Blending of finished wines: Blending multiple aged base wines in a preset ratio to obtain finished wines with different alcohol contents. S8. Finished wine aging: The blended finished wine undergoes alternating hot and cold aging treatment, first being stored alternately at a low temperature of 0℃ and a high temperature of 35℃ to simulate the natural aging process.

2. The navel orange wine brewing process according to claim 1, characterized in that: In step S2, the temperature program for slow freezing is maintained at -5℃, -10℃, -18℃, and -5℃ sequentially.

3. The navel orange wine brewing process according to claim 1, characterized in that: In step S3, the intensity of the high-voltage electric field treatment is 10 kV / cm; dry ice sterilization involves adding dry ice to a sealed container containing navel oranges, using the low temperature and carbon dioxide gas generated by its sublimation to sterilize and isolate oxygen.

4. The navel orange wine brewing process according to claim 1, characterized in that: In step S3, the temperature program of segmented temperature control is to sequentially control the fermentation temperature at 10℃, 16℃, 20℃, 25℃, 20℃, 16℃, 10℃, and 5℃ for a period of time.

5. The navel orange wine brewing process according to claim 4, characterized in that: The duration of each temperature stage was 24 hours; at the end of the four temperature stages of 20℃, 25℃, 16℃ and 5℃, fermented base wines a, b, c and d were collected respectively.

6. The navel orange wine brewing process according to claim 5, characterized in that: In step S4, the distillation process extracts fractions with alcohol contents of 60 degrees, 55 degrees, 50 degrees, and 20 degrees, respectively, to obtain distilled base spirits A, B, C, and D.

7. The navel orange wine brewing process according to claim 5, characterized in that: In step S7, the mixing includes: The resulting honey-flavored liquor, with an alcohol content of 16% vol, was blended and consisted of: fermented base liquors a 50%, b 10%, c 10%, d 10%, and distilled base liquors C 10% and D 10%. And / or, blending to obtain a smooth finished wine with an alcohol content of 36% vol, the composition of which is: fermented base wine b 30%, c 20%, d 10%, and distilled base wine B 20%, D 20%; And / or, blend to obtain a strong-flavored finished liquor with an alcohol content of 58% vol, the composition of which is: 50% distilled base liquor A, 40% distilled base liquor B, and 5% fermented base liquor b and 5% fermented base liquor c.

8. The navel orange wine brewing process according to claim 1, characterized in that: In step S8, the total duration of the alternating hot and cold aging process is 400 days, with 100 days each at 0℃ and 35℃, and the cycle is repeated twice.

9. A navel orange wine produced by the navel orange wine brewing process described in any one of claims 1 to 7.

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