Preparation method of Dai pottery rose aromatic vinegar based on indigenous microorganism multi-stage fermentation, Dai pottery rose aromatic vinegar and application of Dai pottery rose aromatic vinegar

Abstract

The invention relates to the technical field of food fermentation, in particular to a Dai pottery rose aromatic vinegar preparation method based on indigenous microorganism multi-stage fermentation, Dai pottery rose aromatic vinegar and application thereof.The Dai pottery rose aromatic vinegar preparation method comprises the steps that 1, Dai rice-flavor liquor, handmade brown sugar and Yunnan mountain spring water are mixed according to the volume ratio of 5: 1: 10, vinegar coats and indigenous microorganism agents are added, and the Dai pottery rose aromatic vinegar is prepared; fermenting in a Dai jar at 28-30 DEG C for 45-60 days until the total acidity is 4.0-4.5 g / 100mL; b, mixing the vinegar bran and lactic acid bacteria according to a weight ratio of 1000: 3, adding 0.1% of brown sugar, and fermenting at 22-25 DEG C for 5 days; c, mixing the basic vinegar liquid with the treated vinegar bran according to a volume ratio of 8: 1, adding 8-15% of red rose petals, and performing segmented temperature control fermentation for 12 days; and D, after filtering, aging at 25 DEG C for 10-15 days, carrying out secondary filtering and bottling, adding 1.5 g of lemon grass sections into every 500 mL, and standing in a dark place at 22 DEG C for 5 days, so that efficient utilization of resources and precise regulation and control of product flavor are realized.

Description

Technical Field

[0001] This invention relates to the field of food fermentation technology, specifically to a method for preparing Dai-style rose vinegar based on multi-stage fermentation of indigenous microorganisms, the Dai-style rose vinegar and its applications. Background Technology

[0002] Vinegar, as one of my country's traditional condiments, boasts a long history and profound cultural heritage. Based on different raw materials and processes, traditional Chinese vinegars can be categorized into various types, including grain-brewed vinegars, fruit vinegars, and specialty vinegars. Among them, the traditional vinegar-making techniques of the Dai ethnic group, a precious intangible cultural heritage, have been passed down for a long time in southwestern China, particularly in Yunnan Province, possessing unique ethnic characteristics and cultural value.

[0003] Currently, traditional vinegar brewing techniques have the following main shortcomings:

[0004] 1. Low resource utilization: For example, Chinese patent CN 102146337 B discloses a "method for brewing vinegar from vinegar bran, beer lees and liquor lees". Although it achieves the reuse of vinegar bran, it is mainly aimed at ordinary vinegar and lacks the preparation process of special flavored vinegar. Furthermore, it does not consider the targeted screening and utilization of indigenous microorganisms.

[0005] 2. Limited Flavor: While traditional Dai vinegar-making methods possess a unique flavor, they typically remain at the level of a basic condiment, resulting in a relatively limited flavor profile and low added value. According to existing data, traditional Dai vinegar-making primarily uses homemade Dai white wine (rice-aroma type), Dai handmade brown sugar, and pristine spring water. The process involves long-term fermentation in intangible cultural heritage ceramic jars using a vinegar coat (old vinegar mash containing a complex of indigenous acetic acid bacteria and yeast). This process is cumbersome and inefficient.

[0006] 3. Immature technology in the preparation of floral vinegar: Most floral vinegars on the market are made by blending flavorings or adding flowers directly during a single fermentation process, resulting in a lack of flavor integration and unstable quality. In particular, directly adding flowers such as roses and lemongrass to the fermentation system can easily produce unpleasant flavors such as astringency and bitterness, affecting product quality.

[0007] 4. Insufficient control over fermentation microorganisms: Traditional fermentation processes mainly rely on natural microbial communities, lacking targeted screening and application of functional microorganisms, resulting in unstable product quality and large batch-to-batch differences.

[0008] Therefore, how to develop high-value-added vinegar products with distinctive flavors and stable quality by combining modern biotechnology with the traditional Dai vinegar-making techniques is an important issue currently facing the industry. Summary of the Invention

[0009] The purpose of this invention is to provide a method for preparing Dai pottery rose vinegar based on multi-stage fermentation of indigenous microorganisms, the Dai pottery rose vinegar product obtained by this method, and its application, aiming to solve the technical problems in the prior art such as low resource utilization, single flavor, unnatural floral aroma, and poor product stability.

[0010] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0011] A method for preparing Dai-style rose vinegar based on multi-stage fermentation using indigenous microorganisms includes the following steps:

[0012] A. Basic vinegar fermentation: Mix Dai ethnic rice-fragrant white wine, Dai ethnic handmade brown sugar, and Yunnan spring water in a volume ratio of 5:1:10, add vinegar coating and indigenous microbial compound fermentation agent, and ferment in Dai ethnic pottery jars at 28-30℃ for 45-60 days, stirring once a day, until the total acidity reaches 4.0-4.5g / 100mL;

[0013] B. Vinegar bran treatment: Vinegar bran obtained after fermentation of the basic vinegar solution is mixed with screened lactic acid bacteria at a weight ratio of 1000:3, 1‰ brown sugar is added, and fermentation is carried out at 22-25℃ for 5 days.

[0014] C. Rose Fermentation: The base vinegar solution and the treated vinegar bran are mixed at a volume ratio of 8:1. Dark red rose petals are added, with the amount of petals added being 8-15% of the total weight of the mixture. The fermentation is carried out in stages with temperature control for 12 days. During the first 1-3 days, the mixture is stirred twice a day at 32℃. During the middle 4-8 days, the mixture is stirred once a day at 30℃. During the later 9-12 days, the mixture is left to stand without stirring at 28℃.

[0015] D. Aging and Flavoring: Filter the fermented rose-scented liquid and age it in a Dai-style earthenware jar at 25°C for 10-15 days, shaking it gently every 3 days. After a second filtration, pour it into a glass bottle and add 1.5g of fresh lemongrass pieces per 500mL. Let it stand in the dark at 22°C for 5 days.

[0016] Preferably, the Dai ethnic rice-fragrant liquor has an alcohol content of not less than 30% and an ester content of not less than 1.2 g / L; the Dai ethnic handmade brown sugar has a sucrose content of not less than 80% and a mineral content of not less than 2.5%; and the Yunnan spring water has a pH value of 6.8-7.2 and a hardness of not more than 150 mg / L.

[0017] Preferably, the vinegar coating contains acetic acid bacteria at a quantity of not less than 1×10^6 CFU / g; the indigenous microbial compound fermentation agent is composed of acetic acid bacteria, lactic acid bacteria and yeast in a ratio of 2:2:1, wherein the acetic acid bacteria is *Acetobacter pasteurianus*, the lactic acid bacteria is *Lactobacillus plantarum*, and the yeast is *Saccharomyces cerevisiae*.

[0018] Furthermore, the preparation method of the indigenous microbial composite fermentation agent includes:

[0019] a. Isolating bacterial strains from Dai ethnic vinegar of different years;

[0020] b. Selective culture media were used for initial screening: GYC medium was used for acetic acid bacteria, modified MRS medium was used for lactic acid bacteria, and YPD medium was used for yeast.

[0021] c. Evaluate the function of the screened strains and select strains with strong acid production capacity, good acid resistance and ability to produce aroma substances.

[0022] d. The selected strains were cultured under suitable conditions: acetic acid bacteria and lactic acid bacteria were cultured at 30°C for 48 hours, and yeast was cultured at 28°C for 24 hours.

[0023] e. Prepare a compound fermentation agent by mixing the ingredients in a 2:2:1 ratio, and freeze-dry it to ensure that the bacterial activity is not less than 90%.

[0024] More preferably, the endpoint determination criteria for the fermentation of the basic vinegar solution are a total acidity of not less than 4.0 g / 100 mL and a pH value of not more than 3.2; the detection indicators for the treated vinegar bran are a lactic acid bacteria count of not less than 1×10^7 CFU / g, a pH value of not more than 3.5, and a lactic acid content of not less than 0.8%.

[0025] Preferably, the endpoint criteria for the rose fragrance fermentation are: the rose petals fade to light pink, the vinegar solution turns amber, the total polyphenol content is not less than 45 mg / 100 mL, the 2-phenylethanol content is not less than 25 mg / L, the geraniol content is not less than 15 mg / L, and the rose ketone content is not less than 8 mg / L.

[0026] Furthermore, the Dai pottery jar is unglazed coarse pottery with a microporosity of 8-12% and an air permeability of 0.5-0.8 mL / min·cm²; the filter uses a 100-mesh nylon sieve; and the glass bottle is a dark-colored glass bottle.

[0027] The present invention also provides a Dai pottery rose vinegar, which is prepared by the above method. It has an amber-colored and transparent appearance, a harmonious aroma of rose and lemongrass, a balanced sweet and sour taste, a total acidity of 4.5-5.5g / 100mL, and a rose polyphenol content of not less than 45mg / 100mL.

[0028] The present invention also provides the application of the Dai Tao rose vinegar in the field of condiments, using the Dai Tao rose vinegar as a seasoning vinegar in high-end catering or home cooking, for the preparation of cold dishes, hot stir-fries, soups or sauces, with a dosage of 1-3% of the total weight of the dish.

[0029] The present invention also provides the application of the Dai Tao rose vinegar in the field of functional beverages. The Dai Tao rose vinegar is diluted with purified water at a ratio of 1:5 to 1:10, and 2-5% honey is added to make a functional beverage with antioxidant and beauty-enhancing effects. The daily consumption is 15-30mL.

[0030] The beneficial effects of this invention are:

[0031] 1. Innovative Multi-Stage Fermentation Process: This invention is the first to combine vinegar bran recycling technology with the traditional Dai ethnic group's earthenware jar fermentation process. Through four stages—basic vinegar fermentation, vinegar bran treatment, rose fragrance fermentation, and aging and flavoring—it achieves efficient resource utilization and precise control of product flavor. Compared to traditional processes, raw material utilization is increased by more than 60%, and the production cycle is shortened by approximately 30%.

[0032] 2. Targeted Screening and Application of Indigenous Microorganisms: Functional strains were isolated and screened from Dai ethnic vinegar to establish a stable strain bank, effectively solving the problem of unstable product quality caused by reliance on natural microbial communities in traditional fermentation processes. Simultaneously, the treatment of vinegar bran with specific lactic acid bacteria significantly improved the recycling rate and flavor transformation capabilities of the vinegar bran.

[0033] 3. Segmented temperature-controlled fermentation technology: An innovative "high temperature at the beginning, stable temperature at the end, and low temperature at the end" temperature control strategy was designed for different stages of rose fragrance substance formation, which significantly improved the extraction and conversion efficiency of rose polyphenols and fragrance substances. Compared with traditional constant temperature fermentation, the content of rose fragrance substances increased by about 35-40%.

[0034] 4. Harmoniously Flavored Floral Vinegar Products: Through the synergistic fermentation of rose petals and processed vinegar bran, combined with the post-fermentation of lemongrass, a unique flavor system is created where "floral fragrance does not overpower vinegar fragrance, and floral charm is found in vinegar fragrance," solving the problem of traditional floral vinegar having a single or unharmonious flavor.

[0035] 5. Multi-field application value: The developed Dai pottery rose vinegar can not only be used as a high-end condiment, but can also be extended to multiple fields such as functional beverages and beauty and skin care, which significantly enhances the added value and market competitiveness of the product. Detailed Implementation

[0036] The present invention will be further described in detail below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading this description, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0037] Unless otherwise stated, the raw materials used in the embodiments of the present invention are all commercially available.

[0038] I. Raw Materials and Pretreatment:

[0039] 1.1 Basic Raw Materials:

[0040] In the implementation of this invention, the selection and quality of the basic raw materials are crucial to the flavor and quality of the final product. Preferably, the specific requirements for each basic raw material are as follows:

[0041] Dai ethnic rice-aroma baijiu: Made with glutinous rice wine brewed using traditional techniques in Xishuangbanna, Yunnan Province, with an alcohol content of no less than 30% and an ester content of no less than 1.2g / L, it boasts a rich rice aroma and a refreshing taste. Dai ethnic rice-aroma baijiu not only provides the suitable alcohol content for fermentation, but its abundant esters are also a crucial foundation for the formation of its complex aroma.

[0042] Dai ethnic handmade brown sugar: Made from brown sugar handcrafted in Yunnan, with a sucrose content of no less than 80% and a mineral content of no less than 2.5%. Unlike industrially refined sugar, Dai handmade brown sugar is rich in trace elements and minerals, providing more comprehensive nutrition for microbial fermentation and giving the product a unique sweet aroma.

[0043] Yunnan spring water: Selected high-quality spring water with a pH value of 6.8-7.2 and a hardness not exceeding 150mg / L. The mineral composition of the water has a significant impact on the activity of microorganisms and their metabolic products during fermentation. Suitable water quality can promote the growth of beneficial microorganisms and inhibit the reproduction of harmful bacteria.

[0044] 1.2 Fermentation agent:

[0045] In this invention, the fermentation agent comprises two parts: one part is traditional vinegar coat (old vinegar mash), and the other part is a composite fermentation agent of indigenous microorganisms that has been screened and cultured.

[0046] Vinegar coat: Made from high-quality Dai ethnic vinegar mash aged for more than 3 years, containing no less than 1×10⁻⁶ acetic acid bacteria. 6 CFU / g. The vinegar coating contains a large number of indigenous microbial communities adapted to the local environment, which is an important guarantee for maintaining the traditional flavor characteristics.

[0047] Indigenous microbial compound fermentation agent: composed of acetic acid bacteria, lactic acid bacteria, and yeast in a 2:2:1 ratio, wherein the acetic acid bacteria is *Acetobacter pasteurianus*, the lactic acid bacteria is *Lactobacillus plantarum*, and the yeast is *Saccharomyces cerevisiae*. All three strains were isolated and screened from Dai ethnic vinegar and exhibit significant acid-producing ability, acid resistance, and aroma-generating capacity.

[0048] 1.3 Fragrance ingredients:

[0049] Dark red rose petals: Selected from freshly picked dark red rose petals from the Yunnan plateau region, with a total polyphenol content of no less than 3.5% and a volatile oil content of no less than 0.8%. Dark red roses are rich in various aromatic substances and polyphenolic compounds, which, after microbial fermentation, develop a unique rose fragrance. Before use, the petals should be gently washed and drained of surface moisture, and exposed to direct sunlight to preserve the active ingredients.

[0050] Organic Lemongrass: Fresh organic lemongrass is selected, with a limonene content of no less than 0.5%. Lemongrass contains abundant volatile aromatic components, which can impart a fresh top note to the product during the later flavoring stages, forming a rich and layered aroma structure with the rose fragrance. Before use, lemongrass should be cut into small pieces of about 2cm in length to facilitate aroma release.

[0051] 1.4 Fermentation vessel:

[0052] Dai ethnic intangible cultural heritage pottery jars: These are unglazed coarse pottery jars made using traditional Dai techniques, with a microporosity of 8-12% and an air permeability of 0.5-0.8 mL / min·cm². The microporous structure of the jars creates a unique micro-oxygen environment, which is conducive to the growth of acetic acid bacteria and the formation of esters. At the same time, the microbial biofilm adhering to the inner wall of the jars is also an important factor in maintaining the product's distinctive flavor.

[0053] II. Screening and Enrichment of Indigenous Microorganisms:

[0054] The screening and enrichment of indigenous microorganisms in this invention is a key technical step in achieving stable product quality. The specific steps are as follows:

[0055] 2.1 Strain Isolation:

[0056] Strains were isolated from five different aged Dai vinegar samples (3, 5, 7, 10, and 15 years old). The specific procedure was as follows: 10 mL of aged vinegar sample was taken and serially diluted 10-fold. The sample of the appropriate dilution was spread on a selective medium and incubated at 28°C for 48-72 hours. Single colonies with different morphologies were then picked for purification culture.

[0057] 2.2 Preliminary Screening:

[0058] Different selective culture media are used for initial screening depending on the target bacterial group:

[0059] Acetic acid bacteria: Using GYC medium (5g / L glucose, 10g / L yeast extract, 20g / L calcium carbonate, 20g / L agar, pH 6.8), select colonies with a transparent lysis zone around them.

[0060] Lactic acid bacteria: Using modified MRS medium (standard MRS medium with 0.5% brown sugar and 0.1% ciprofloxacin added), select milky white colonies that can produce acid.

[0061] Yeast: YPD medium (10 g / L yeast extract, 20 g / L peptone, 20 g / L glucose, 20 g / L agar, pH 6.0, with 5% ethanol and 0.01% chloramphenicol added) was used to select colonies with characteristic morphology.

[0062] 2.3 Functional Evaluation:

[0063] The strains obtained from the initial screening were functionally evaluated to select superior strains suitable for vinegar fermentation.

[0064] Acid production capacity: The strain was inoculated into a simulated vinegar fermentation medium (20 g / L glucose, 5 g / L yeast extract, 5% ethanol, pH 4.5), and cultured at 28°C for 48 hours. The total acidity was measured, and strains with a total acidity of not less than 3.5 g / 100 mL were selected.

[0065] Acid resistance: Inoculate the strain into an acidic medium with a pH of 3.0, incubate at 28°C for 24 hours, count the number of viable bacteria, and select strains with a survival rate of not less than 80%.

[0066] Aroma metabolism capacity: Headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) was used to analyze volatile substances in the fermentation broth of the strains, with a focus on detecting rose aroma substances such as 2-phenylethanol and geraniol, and strains that can produce the target aroma substances were selected.

[0067] 2.4 Strain Identification and Preservation

[0068] The selected superior strains were subjected to 16S rDNA (bacteria) or ITS (yeast) sequence analysis to determine their taxonomic position. After identification, three superior strains were finally determined: *Acetobacter pasteurianus*, *Lactobacillus plantarum*, and *Saccharomyces cerevisiae*.

[0069] These three strains were stored in 30% glycerol at -80°C, and their activity was periodically tested to ensure the long-term stability of the strain resources.

[0070] 2.5 Preparation of compound fermentation agent:

[0071] Based on the optimal ratio determined in previous experiments (acetic acid bacteria: lactic acid bacteria: yeast = 2:2:1), a compound fermentation agent was prepared:

[0072] Acetic acid bacteria culture: Acetobacter pasteurianus was inoculated into liquid YGC medium (10 g / L yeast extract, 20 g / L glucose, 5 g / L calcium carbonate, pH 6.8) and cultured at 30°C with shaking at 150 rpm for 48 hours.

[0073] Lactic acid bacteria culture: Lactobacillus plantarum was inoculated into liquid MRS medium and incubated at 30°C for 48 hours.

[0074] Yeast culture: Saccharomyces cerevisiae was inoculated into liquid YPD medium and cultured at 28°C and 150 rpm for 24 hours with shaking.

[0075] Collect the culture medium of each strain, centrifuge (6000 rpm, 10 minutes) to collect the bacterial cells, wash twice with sterile physiological saline, mix in a ratio of 2:2:1, add 10% skim milk powder and 5% sucrose as a protectant, freeze dry, and the final bacterial activity is not less than 90%.

[0076] III. Multi-stage fermentation process:

[0077] One of the core innovations of this invention is the use of a multi-stage fermentation process, which allows for precise control of the product's flavor through process control at different stages. The specific process steps are as follows:

[0078] 3.1 Basic vinegar fermentation:

[0079] The first stage of the entire process is the fermentation of the basic vinegar liquor, the main purpose of which is to form vinegar with a basic acidity and aroma. The specific steps are as follows:

[0080] Ingredients: Mix Dai ethnic rice-fragrant baijiu, Dai ethnic handmade brown sugar, and Yunnan spring water in a volume ratio of 5:1:10. Specific steps: First, dissolve the brown sugar in 65℃ spring water. After cooling to 30℃, add the baijiu and stir well.

[0081] Inoculation: Add 20% vinegar coating and 5% compound fermentation agent to the mixture, mix thoroughly, and pour into a Dai ethnic pottery jar. Cover the mouth of the jar with gauze to prevent impurities from falling in.

[0082] Fermentation: Place the earthenware jar in a constant temperature environment of 28-30℃ and a relative humidity of 60-70% for 45-60 days. During the fermentation process, stir once a day to promote oxygen dissolution and uniform fermentation.

[0083] Monitoring: Samples were taken every 5 days to test pH, total acidity, and microbial count, and the trends during fermentation were recorded. The basic vinegar fermentation stage was completed when the total acidity reached 4.0-4.5 g / 100 mL and the pH dropped below 3.2.

[0084] At this stage, yeast first converts sugar into ethanol, then acetic acid bacteria oxidize the ethanol into acetic acid, producing various esters and organic acids in the process, forming the basic vinegar aroma. Lactic acid bacteria then produce appropriate amounts of lactic acid and other organic acids, enriching the flavor profile of the product.

[0085] 3.2 Processing and Recycling of Vinegar Bran:

[0086] The processing of vinegar bran is one of the key innovations of this invention. Through the action of specific lactic acid bacteria, the utilization value of vinegar bran is significantly improved. The specific steps are as follows:

[0087] Vinegar bran separation: After the basic vinegar liquid has been fermented, the vinegar liquid and vinegar bran are separated. The vinegar bran is taken out and gently squeezed to remove excess liquid, but an appropriate amount of moisture is retained to maintain microbial activity.

[0088] Lactic acid bacteria treatment: Add the screened lactic acid bacteria Lactobacillus plantarum to the isolated vinegar bran at a rate of 0.3% (3‰) of the weight of the vinegar bran, and add 1‰ of brown sugar as a starting nutrient source.

[0089] Fermentation treatment: Place the mixed vinegar bran in an environment of 22-25℃ for 5 days for fermentation, and maintain appropriate humidity during the period to prevent the surface from drying out.

[0090] Quality Inspection: After fermentation, the number of lactic acid bacteria, pH value, and organic acid content in the vinegar bran are tested. Qualified vinegar bran should meet the following standards: lactic acid bacteria count not less than 1×10⁻⁶. 7 CFU / g, pH value not higher than 3.5, lactic acid content not lower than 0.8%.

[0091] During this stage, lactic acid bacteria inhibit the growth of harmful microorganisms by producing lactic acid and antibacterial substances. Simultaneously, they break down polysaccharides and proteins in the vinegar bran, increasing flavor precursors and laying the foundation for subsequent rose-scented fermentation. The processed vinegar bran can be recycled 12-15 times, significantly improving resource utilization.

[0092] 3.3 Rose Fermentation:

[0093] Rose-scented fermentation is a crucial stage in developing its distinctive flavor. Through the synergistic fermentation of dark red rose petals and processed vinegar bran, the efficient transformation of aroma compounds is achieved. The specific steps are as follows:

[0094] Ingredient mixing: Mix the base vinegar liquid with the treated vinegar bran at a volume ratio of 8:1, and then add fresh dark red rose petals. The amount of petals added is 8-15% (preferably 12%) of the total weight of the mixture.

[0095] Segmented temperature-controlled fermentation:

[0096] Early stage (1-3 days): Fermentation at 32℃, stirring twice a day to promote the release and initial transformation of aromatic substances in the petals.

[0097] Mid-stage (4-8 days): Ferment at 30℃, stirring once a day to promote the conversion of aroma precursors by microorganisms.

[0098] Later stage (9-12 days): Static fermentation at 28℃ without stirring to promote the stability and fusion of aroma substances.

[0099] Aroma monitoring: The content changes of key aroma substances in the fermentation broth, including 2-phenylethanol, geraniol, and rose ketone, were monitored regularly using HS-SPME-GC-MS technology. When these key aroma substances reached the predetermined concentrations (2-phenylethanol ≥ 25 mg / L, geraniol ≥ 15 mg / L, rose ketone ≥ 8 mg / L), the rose fragrance fermentation stage was completed.

[0100] During this stage, microorganisms (especially yeasts and lactic acid bacteria) convert glycoside-bound aroma compounds in rose petals into free aroma compounds through the action of enzymes such as β-glucosidase, significantly enhancing the concentration and persistence of the rose aroma. Simultaneously, polyphenols are partially converted into more stable forms under the action of microorganisms, increasing the product's antioxidant activity. The microbial community in the vinegar bran provides a rich enzyme system, accelerating this conversion process.

[0101] 3.4 Aging and Flavoring:

[0102] Aging and flavoring are the final stages in perfecting the product's flavor and enhancing its quality. The specific steps are as follows:

[0103] Filtration: The fermentation broth is filtered through a 100-mesh nylon sieve to remove petal residue and vinegar bran, resulting in a clear vinegar solution.

[0104] Aging: Pour the filtered vinegar back into a clean Dai-style earthenware jar and age it at 25°C for 10-15 days, shaking it gently every 3 days to promote the fusion and mellowing of the aroma.

[0105] Secondary filtration: After aging, the vinegar is filtered again to ensure that the product is clear and transparent, without any suspended matter.

[0106] Flavoring and bottling: Pour the filtered vinegar into dark glass bottles, add 1.5g of fresh lemongrass pieces (about 0.3%) per 500mL, and let it stand in the dark at 22℃ for 5 days to allow the fresh aroma of lemongrass to be slowly released and blend with the vinegar.

[0107] Finished Product Testing: A comprehensive testing process is conducted on the final product, including sensory evaluation, physicochemical analysis, and microbiological safety testing. Qualified products should have a clear, amber-colored appearance, a harmonious blend of rose and lemongrass aromas, a balanced sweet and sour taste, a total acidity of 4.5-5.5 g / 100 mL, and a rose polyphenol content of no less than 45 mg / 100 mL.

[0108] During this stage, the aging process allows various flavor compounds to fully blend, eliminating some harshness and creating a more rounded and full-bodied flavor. The addition of lemongrass, without compromising the basic flavor, adds a refreshing top note, enhancing the product's complexity and complexity.

[0109] Example 1: Preparation of Dai-style Rose Vinegar using Standard Process

[0110] This embodiment demonstrates the complete process for preparing Dai pottery rose vinegar using standard technology.

[0111] Raw material preparation:

[0112] Dai ethnic group rice-fragrant baijiu: 5L (32% alcohol, 1.5g / L ester content);

[0113] Dai ethnic handmade brown sugar: 1kg (85% sucrose content, 2.8% mineral content);

[0114] Yunnan spring water: 10L (pH 7.0, hardness 120mg / L);

[0115] Vinegar coating: 2kg (containing 1.5×10⁻⁶ acetic acid bacteria) 6 CFU / g);

[0116] Compound fermentation agent: 0.5kg (bacterial activity 95%);

[0117] Dark red rose petals: 1.08 kg (total polyphenols 3.8%, volatile oil 0.9%).

[0118] Lemongrass: 25.5g (limonene content 0.6%);

[0119] Operating steps:

[0120] 1. Basic vinegar fermentation:

[0121] Dissolve brown sugar in 65℃ spring water, cool to 30℃, then add white wine and stir thoroughly. Add vinegar coating and compound fermentation agent, mix well, and pour into a 20L Dai-style earthenware jar. Place the jar in a constant temperature environment of 28℃ and relative humidity of 65% for 50 days of fermentation, stirring once a day. At the end of fermentation, the total acidity of the vinegar solution is 4.2g / 100mL, and the pH value is 3.1.

[0122] 2. Processing of vinegar bran:

[0123] 3 kg of vinegar bran was separated from the base vinegar solution, and 9 g of lactic acid bacteria culture (Lactobacillus plantarum) and 3 g of brown sugar were added. After mixing evenly, the mixture was placed in an environment of 22℃ for fermentation for 5 days. The test results of the treated vinegar bran showed that the number of lactic acid bacteria reached 1.5×10^7 CFU / g, the pH value was 3.3, and the lactic acid content was 0.92%.

[0124] 3. Rose fragrance fermentation:

[0125] Mix 8L of base vinegar solution with 1kg of processed vinegar bran, and add 1.08kg of fresh dark red rose petals (12% of the total weight of the mixture). Fermentation is carried out according to a segmented temperature control plan: at 32℃, stir twice daily for the first 3 days; at 30℃, stir once daily for the middle 4-8 days; and at 28℃, allow to stand without stirring for the later 9-12 days, for a total fermentation time of 12 days. At the end of fermentation, the vinegar solution is amber in color, the rose petals have faded significantly to a light pink, and the rose polyphenol content reaches 48mg / 100mL, the 2-phenylethanol content is 32mg / L, the geraniol content is 19mg / L, and the rose ketone content is 10mg / L.

[0126] 4. Aging and Flavoring:

[0127] The fermentation liquid was filtered through a 100-mesh nylon sieve to obtain 8.5L of clear vinegar. The vinegar was then poured back into a clean Dai-style earthenware jar and aged at 25℃ for 12 days, gently shaking it every 3 days. After aging, it was filtered again and dispensed into dark glass bottles. 1.5g of fresh lemongrass was added to every 500mL of the bottle, and the bottles were left to stand in the dark at 22℃ for 5 days.

[0128] Final product test results: The product has a clear amber color, a rich rose fragrance and a fresh lemongrass aroma, a balanced sweet and sour taste, a total acidity of 4.8g / 100mL, a rose polyphenol content of 50mg / 100mL, and microbiological indicators that meet food safety requirements.

[0129] Example 2: Effect of different proportions of vinegar bran added on product quality

[0130] This embodiment investigates the effect of different proportions of vinegar bran addition on the quality of rose balsamic vinegar. The raw material formula and basic process are the same as in Example 1, only the proportion of vinegar bran added after treatment is adjusted.

[0131] Experimental Design:

[0132] Sample A: The volume ratio of base vinegar solution to treated vinegar bran was 10:0.5 (vinegar bran addition was 5%).

[0133] Sample B: The volume ratio of base vinegar solution to treated vinegar bran was 10:1 (vinegar bran addition was 10%).

[0134] Sample C: The volume ratio of base vinegar solution to treated vinegar bran is 8:1 (vinegar bran addition is 12.5%, standard process).

[0135] Sample D: The volume ratio of base vinegar solution to treated vinegar bran was 5:1 (vinegar bran addition was 20%).

[0136] The amount of rose petals added to each sample was 12% of the total weight of the mixture, and other process parameters remained the same.

[0137] Results analysis:

[0138] Each sample was tested after the rose fragrance fermentation stage. The main test indicators included total acidity, rose polyphenol content, key aroma substance content, and sensory evaluation. The results are shown in Table 1.

[0139] Table 1. Effects of different proportions of vinegar bran added on product quality

[0140] sample Total acidity (g / 100mL) pH value Solid content (%) Light transmittance (%) Example 1 4.8 3.1 5.2 92 Comparative Example 1 4.5 3.3 4.8 85 Comparative Example 2 4.3 3.4 5.5 78 Comparative Example 3 4.5 3.3 4.9 88 Comparative Example 4 4.6 3.2 5 85 Comparative Example 5 4.7 3.1 5.1 86

[0141] The results above show that the proportion of vinegar bran added significantly affects the acidity, aroma content, and sensory quality of the product. When the amount of vinegar bran added is 12.5% ​​(sample C), all indicators reach optimal levels. This is mainly because the treated vinegar bran is rich in various active microorganisms and enzymes, which can promote the release and transformation of aroma substances in rose petals. However, when the amount of vinegar bran added is too high (sample D), it may lead to excessive acidity, affecting the sensory balance of the product.

[0142] Therefore, the optimal volume ratio of base vinegar solution to processed vinegar bran is 8:1 (the amount of vinegar bran added is about 12.5%). This ratio can fully utilize the functional role of microorganisms in vinegar bran and maintain the balance of product flavor.

[0143] Example 3: The effect of different amounts of rose petals added on product quality

[0144] This embodiment explores the effect of different proportions of rose petals added on product quality. The raw material formula and basic process are the same as in Example 1, only the proportion of rose petals added is adjusted.

[0145] Experimental Design:

[0146] Sample E: Rose petals were added at 8% of the total weight of the mixture (lower limit of claims).

[0147] Sample F: Rose petals were added at 10% of the total weight of the mixture.

[0148] Sample G: Rose petals were added at 12% of the total weight of the mixture (standard process).

[0149] Sample H: Rose petals were added at 15% of the total weight of the mixture (up to the limit of the claims).

[0150] The volume ratio of the base vinegar solution to the treated vinegar bran was 8:1 for all samples, and other process parameters remained consistent.

[0151] Results analysis:

[0152] Each sample was tested after the rose fragrance fermentation stage. The main test indicators included total acidity, rose polyphenol content, key aroma substance content, and sensory evaluation. The results are shown in Table 2.

[0153] Table 2. Effects of different rose petal addition amounts on product quality

[0154] detection indicators Sample E (8%) Sample F (10%) Sample G (12%) Sample H (15%) Total acidity (g / 100mL) 4.7 4.8 4.8 4.9 Rose polyphenols (mg / 100mL) 40 45 50 58 2-Phenylacetylethanol (mg / L) 24 28 32 38 Geraniol (mg / L) 14 16 19 22 Roserite (mg / L) 8 9 10 12 Sensory rating (out of 10) 8 8.5 9.2 8.8

[0155] The results show that the content of rose polyphenols and aroma compounds in the product increases with the increase of rose petal addition. When the rose petal addition is 12% (sample G), all indicators reach a relatively ideal level, and the sensory score is the highest. Although the content of polyphenols and aroma compounds is higher when the rose petal addition is 15% (sample H), the sensory score actually decreases slightly. This may be because the aroma is too strong, masking the basic flavor of the vinegar and resulting in a decrease in overall balance.

[0156] Therefore, the optimal amount of rose petals to add is 12% of the total weight of the mixture, which allows for a full rose aroma while maintaining the harmony of the product's flavor.

[0157] Example 4: The effect of different temperature control strategies on the formation of rose aroma

[0158] This embodiment explores the effects of different temperature control strategies on the formation of rose aroma. The raw material formula and basic process are the same as in Example 1, except that the temperature control strategy during the rose aroma fermentation stage is adjusted.

[0159] Experimental Design:

[0160] Sample I: Constant temperature of 30℃ throughout (traditional process);

[0161] Sample J: Constant temperature of 32℃ throughout the process (high temperature process);

[0162] Sample K: Constant temperature 28℃ throughout the process (low temperature process);

[0163] Sample L: Segmented temperature control (32℃ in the early stage, 30℃ in the middle stage, and 28℃ in the later stage, according to the standard process of this invention)

[0164] The volume ratio of the base vinegar solution to the treated vinegar bran was 8:1 for all samples, the amount of rose petals added was 12% of the total weight of the mixture, and the total fermentation time was 12 days for all samples.

[0165] Results analysis:

[0166] Each sample was tested after the rose fragrance fermentation stage. The main test indicators included rose polyphenol extraction rate, content of key aroma substances, content of undesirable flavor substances, and sensory evaluation. The results are shown in Table 3.

[0167] Table 3. Effects of different temperature control strategies on rose aroma formation

[0168] detection indicators Sample I (at a constant temperature of 30℃) Sample J (at a constant temperature of 32℃) Sample K (at a constant temperature of 28℃) Sample L (segmented temperature control) Rose polyphenol extraction rate (%) 80 92 75 95 2-Phenylacetylethanol (mg / L) 26 30 22 32 Geraniol (mg / L) 15 18 12 19 Ethyl acetate (mg / L) 180 250 120 150 Aldehydes (mg / L) 25 35 18 20 Sensory rating (out of 10) 8.2 7.8 7.5 9.2

[0169] The results above show that different temperature control strategies have a significant impact on the formation of rose aroma compounds and the generation of undesirable flavor compounds. The segmented temperature control strategy (sample L) performed best in terms of rose polyphenol extraction rate and aroma compound content, while effectively controlling the generation of undesirable flavor compounds, thus achieving the highest sensory score.

[0170] This is mainly because the high temperature in the early stage (32℃) is conducive to the softening of the cell walls of the petals and the initial release of aroma substances; the moderate temperature in the middle stage (30℃) is conducive to the enzymatic transformation of microorganisms, which converts the bound aroma substances into the free state; and the low temperature in the later stage (28℃) is conducive to the stability and fusion of aroma substances, while inhibiting the excessive production of undesirable flavor substances.

[0171] Therefore, the segmented temperature control strategy is the best solution for achieving efficient rose aroma formation and quality control. Compared with the traditional constant temperature process, it can significantly improve the flavor quality of the product.

[0172] Example 5: The effect of different number of vinegar bran cycles on product quality

[0173] This embodiment explores the effect of different number of cycles on product quality of vinegar bran. The raw material formula and basic process are the same as in Example 1, but vinegar bran with different number of cycles is used.

[0174] Experimental Design:

[0175] Sample M: ​​First-time use of treated vinegar bran (0 cycles);

[0176] Sample N: Processed vinegar bran that has been recycled 5 times;

[0177] Sample O: Processed vinegar bran that has been recycled 10 times;

[0178] Sample P: Processed vinegar bran that has been recycled 15 times;

[0179] Sample Q: Processed vinegar bran that has been recycled 20 times;

[0180] The volume ratio of the base vinegar solution to the treated vinegar bran was 8:1 for each sample, and the amount of rose petals added was 12% of the total weight of the mixture. A standard segmented temperature-controlled fermentation process was adopted.

[0181] Results analysis:

[0182] Each sample was tested after the rose fragrance fermentation stage. The main test indicators included total acidity, rose polyphenol content, key aroma substance content, and sensory evaluation. The results are shown in Table 4.

[0183] Table 4. Effects of different number of cycles on product quality of vinegar bran

[0184] detection indicators Sample M (0 times) Sample N (5 times) Sample O (10 times) Sample P (15 times) Sample Q (20 times) Total acidity (g / 100mL) 4.8 4.9 5 4.8 4.5 Rose polyphenols (mg / 100mL) 50 52 55 48 40 2-Phenylacetylethanol (mg / L) 28 32 35 30 25 Geraniol (mg / L) 18 20 22 19 15 Sensory rating (out of 10) 8.6 9 9.2 8.8 8.2

[0185] The results above show that the number of times vinegar bran is recycled has a significant impact on product quality. As the number of recycling cycles increases, product quality first improves and then declines. When recycled 5-10 times (samples N and O), all product indicators are superior to those of vinegar bran used for the first time (sample M). This is mainly because after multiple recycling cycles, the microbial community in the vinegar bran becomes richer and more stable, and enzyme activity is higher, which is beneficial for the conversion of rose aroma compounds.

[0186] However, when the number of cycles exceeded 15 (sample Q), the product quality began to decline significantly. This may be due to the depletion of nutrients in the vinegar bran caused by long-term recycling, reduced microbial activity, and the adverse effects of accumulated metabolic waste on fermentation.

[0187] Therefore, the optimal number of times vinegar bran can be recycled is 10-15 times, at which point its functional benefits can be fully realized while ensuring stable product quality. This discovery provides a scientific basis for the efficient utilization of vinegar bran resources.

[0188] Example 6: Effect of lemongrass addition amount on the flavor of the final product

[0189] This embodiment explores the effect of different lemongrass addition amounts on the flavor of the final product. The raw material formula and basic process are the same as in Example 1, only the amount of lemongrass added is adjusted.

[0190] Experimental Design:

[0191] Sample R: No lemongrass added

[0192] Sample S: The amount of lemongrass added was 0.2% of the vinegar solution (1g per 500mL);

[0193] Sample T: The amount of lemongrass added was 0.3% of the vinegar solution (1.5g per 500mL, standard process).

[0194] Sample U: The amount of lemongrass added was 0.5% of the vinegar solution (2.5g per 500mL);

[0195] All samples were fermented using standard processes in the first three stages, with the amount of lemongrass added only adjusted in the final flavoring stage. The settling time was 5 days for all samples.

[0196] Results analysis:

[0197] After each sample had settled, it was tested. The main test indicators included limonene content, sensory evaluation, and consumer preference. The results are shown in Table 5.

[0198] Table 5. Effects of different lemongrass addition amounts on the flavor of the final product.

[0199] detection indicators Sample R (0%) Sample S (0.2%) Sample T (0.3%) Sample U (0.5%) Limonene content (mg / L) 0 3.5 5.2 8.7 Sensory rating (out of 10) 8.5 8.8 9.3 8 Consumer preference (%) 22 30 38 10

[0200] The results above show that adding an appropriate amount of lemongrass can significantly improve the flavor profile and consumer acceptance of the product. When the lemongrass content was 0.3% (sample T), the product achieved the highest sensory score and consumer preference. This is mainly because an appropriate amount of lemongrass adds a fresh top note, complementing the rose scent and enhancing the overall aroma structure of the product.

[0201] However, when the amount of lemongrass added is too high (sample U), the overly strong lemongrass aroma will mask the basic flavors of rose and vinegar, disrupting the flavor balance of the product and leading to a significant decrease in sensory scores and consumer preference.

[0202] Therefore, the optimal amount of lemongrass to add is 0.3% of the vinegar solution (1.5g per 500mL). This allows the product to have a suitable fresh aroma without compromising its basic flavor, thus enhancing its complexity and appeal.

[0203] To further verify the innovability and superiority of this invention, the following comparative examples were designed:

[0204] Comparative Example 1: Traditional Dai Vinegar Making Process

[0205] This comparative sample uses the traditional Dai vinegar brewing process, without vinegar bran treatment or rose-scented fermentation.

[0206] Raw materials and methods:

[0207] Dai ethnic group rice-fragrant baijiu: 5L (32% alcohol content);

[0208] Dai ethnic handmade brown sugar: 1kg;

[0209] Yunnan spring water: 10L;

[0210] Vinegar coating: 2kg;

[0211] According to traditional methods, baijiu (Chinese liquor), brown sugar, and spring water are mixed, vinegar is added, and the mixture is fermented in a Dai-style earthenware jar at 30°C for 60 days. Then it is filtered and bottled.

[0212] Comparative Example 2: Fermentation Method for Adding Floral Materials in One Go

[0213] This comparative example uses a fermentation method that adds flowers in one go, without vinegar bran treatment or segmented temperature-controlled fermentation.

[0214] Raw materials and methods:

[0215] Dai ethnic group rice-fragrant baijiu: 5L (32% alcohol content);

[0216] Dai ethnic handmade brown sugar: 1kg;

[0217] Yunnan spring water: 10L;

[0218] Vinegar coating: 2kg;

[0219] Dark red rose petals: 1.08 kg;

[0220] Lemongrass: 25.5g

[0221] Mix baijiu (Chinese liquor), brown sugar, and spring water, add vinegar and dark red rose petals, ferment in a Dai-style earthenware jar at 30°C for 60 days, then filter, add lemongrass for flavoring, and bottle after 5 days.

[0222] Comparative Example 3: Fragrance Blending Method

[0223] This comparative example uses the traditional Dai vinegar brewing process, but adds edible flavoring to the finished product.

[0224] Raw materials and methods:

[0225] Dai ethnic group rice-fragrant baijiu: 5L (32% alcohol content);

[0226] Dai ethnic handmade brown sugar: 1kg;

[0227] Yunnan spring water: 10L;

[0228] Vinegar coating: 2kg;

[0229] Edible rose essence: 5mL;

[0230] Edible lemongrass flavoring: 2mL;

[0231] The base vinegar is brewed using traditional methods, and then edible rose essence and lemongrass essence are added to the finished product for flavoring. After stirring evenly, it is bottled.

[0232] Comparative Example 4: No Indigenous Microbial Compound Fermentation Agent

[0233] This comparative example uses the multi-stage fermentation process of the present invention, but does not add indigenous microbial compound fermentation agent, and only uses traditional vinegar coating.

[0234] Raw materials and methods:

[0235] The raw material formula and basic process are the same as in Example 1, but no indigenous microbial compound fermentation agent is added, and only traditional vinegar coating is used for fermentation.

[0236] Comparative Example 5: Non-segmented temperature control strategy

[0237] This comparative example uses the multi-stage fermentation process of the present invention, but does not employ a segmented temperature control strategy; instead, it uses a constant temperature of 30°C for fermentation throughout the entire process.

[0238] Raw materials and methods:

[0239] The raw material formula and basic process are the same as in Example 1, but a constant temperature of 30°C is used in the rose fragrance fermentation stage, without segmented temperature control.

[0240] To comprehensively evaluate the quality and performance of the products of this invention, a systematic test and analysis were conducted on the products of Example 1 and Comparative Examples 1-5, mainly including physicochemical indicators, flavor substances, functional activities and shelf life.

[0241] 6.1 Physicochemical Indicators Testing

[0242] The basic physicochemical properties of each sample were measured, including total acidity, pH value, solids content, and transmittance. The results are shown in Table 6.

[0243] Table 6 Basic physicochemical properties of each sample

[0244] sample Total acidity (g / 100mL) pH value Solid content (%) Light transmittance (%) Example 1 4.8 3.1 5.2 92 Comparative Example 1 4.5 3.3 4.8 85 Comparative Example 2 4.3 3.4 5.5 78 Comparative Example 3 4.5 3.3 4.9 88 Comparative Example 4 4.6 3.2 5 85 Comparative Example 5 4.7 3.1 5.1 86

[0245] As can be seen from the table above, Example 1 performed best in terms of total acidity and light transmittance. This is mainly due to the synergistic effect of the multi-stage fermentation process and indigenous microorganisms, which resulted in more complete fermentation and higher clarity of the product. Comparative Example 2, due to the one-time addition of floral materials, had a high solids content but low light transmittance, affecting the appearance quality of the product.

[0246] 6.2 Aroma Compound Analysis

[0247] The aroma compounds in each sample were qualitatively and quantitatively analyzed using HS-SPME-GC-MS technology, with a focus on rose aroma-related substances and overall aroma complexity. The results are shown in Table 7.

[0248] Table 7. Aroma compound analysis of each sample

[0249] sample 2-Phenylacetylethanol (mg / L) Geraniol (mg / L) Roserite (mg / L) Limonene (mg / L) Aroma complexity (number of detected compounds) Example 1 32 19 10 5.2 78 Comparative Example 1 5 3 2 0 45 Comparative Example 2 18 10 6 3.5 62 Comparative Example 3 45* 28* 15* 8.5* 35 Comparative Example 4 22 14 8 4.8 65 Comparative Example 5 26 15 9 5 70

[0250] Note: The data marked with * in Comparative Example 3 are aroma substances introduced by added flavorings, not produced by natural fermentation.

[0251] As can be seen from the table above, Example 1 demonstrates superior performance in both the content of rose aroma compounds and the complexity of the aroma. Although Comparative Example 3 has a higher content of aroma compounds, this is due to the direct addition of fragrance, resulting in the lowest aroma complexity and a lack of the rich layers produced by natural fermentation. Comparative Example 1, using a traditional process, contains almost no rose aroma compounds; the aroma compound contents of Comparative Examples 2 and 4 are significantly lower than those of Example 1, indicating that segmented temperature control and the indigenous microbial compound fermentation agent play an important role in the formation of aroma compounds.

[0252] 6.3 Functional Activity Test

[0253] To evaluate the functional properties of each sample, its antioxidant activity, polyphenol content, and bioactive peptide content were determined. The results are shown in Table 8.

[0254] Table 8 Functional activity indicators of each sample

[0255] sample Total polyphenol content (mg / 100mL) DPPH free radical scavenging rate (%) FRAP reducing power (mmol Fe²⁺ / L) Bioactive peptide content (mg / L) Example 1 50 65 3.8 285 Comparative Example 1 18 30 1.5 220 Comparative Example 2 35 48 2.6 245 Comparative Example 3 20 32 1.6 225 Comparative Example 4 42 55 3 260 Comparative Example 5 45 58 3.2 270

[0256] As can be seen from the table above, Example 1 showed the best performance in all functional activity indicators, especially with significantly higher total polyphenol content and antioxidant activity compared to other samples. This is mainly due to the efficient extraction and conversion of rose polyphenols during the multi-stage fermentation process, as well as the decomposition of proteins by indigenous microorganisms, resulting in more bioactive peptides. Although Comparative Example 3 added fragrance, its functional activity was similar to that of traditional vinegar (Comparative Example 1), lacking substantial functional improvement.

[0257] 6.4 Shelf life test

[0258] To evaluate the stability and shelf life of each sample, the samples were stored at 25°C for 6 months, and changes in their physicochemical, microbiological, and sensory qualities were periodically monitored. The test results after 6 months are shown in Table 9:

[0259] Table 9. Quality changes of each sample after 6 months of storage

[0260] sample Total acidity change rate (%) Transmittance change rate (%) Aroma retention rate (%) Microbiological pass rate (%) Sensory rating (out of 10) Example 1 2.5 -5 85 100 8.8 Comparative Example 1 4.5 -12 70 95 7.5 Comparative Example 2 5.8 -18 65 90 6.8 Comparative Example 3 4 -10 60 95 6.5 Comparative Example 4 3.5 -8 75 95 7.8 Comparative Example 5 3 -7 80 98 8.2

[0261] As can be seen from the table above, Example 1 exhibited the best storage stability, with minimal changes in various indicators, particularly an aroma retention rate of 85%, far exceeding that of other samples. This is mainly attributed to the thorough conversion and stabilization of aroma substances during the multi-stage fermentation process, as well as the natural preservatives produced by indigenous microorganisms. Comparative Examples 2 and 3 showed the worst storage stability, especially with low aroma retention rates, indicating that while adding flowers or fragrances in a single step can achieve initial aroma, long-term stability is poor.

[0262] To demonstrate the multi-field application value of the product of this invention, the following application examples were studied:

[0263] 7.1 Seasoning Applications:

[0264] The Dai-style rose vinegar of this invention was applied to different types of dishes to evaluate its seasoning effect and consumer acceptance.

[0265] Application method:

[0266] 1. Cold dishes: Take cucumber salad as an example. Add 2% Dai Tao rose vinegar, appropriate amount of salt and sugar to the chopped cucumber strips and marinate for 10 minutes.

[0267] 2. Stir-fried dishes: Take sweet and sour pork as an example, replace traditional vinegar with Dai Tao rose vinegar and add it to the seasoning sauce at a ratio of 3%.

[0268] 3. Soup: Take hot and sour soup as an example, add Dai Tao rose vinegar to the soup at a ratio of 1% for seasoning.

[0269] Evaluation results:

[0270] To compare the effects of Dai Tao rose vinegar and ordinary vinegar on the aforementioned dishes, a blind taste test was conducted by 30 consumers, with a rating scale of 1-10. The results showed that Dai Tao rose vinegar scored higher than ordinary vinegar in all types of dishes, especially in cold dishes and stir-fries, where the scores increased by 2.5-3.0 points. Consumers generally reported that Dai Tao rose vinegar provided a fresher and more layered flavor experience, particularly the harmonious blend of rose aroma and acidity, which enhanced the flavor profile of the dishes.

[0271] 7.2 Application of functional beverages:

[0272] The Dai-style rose vinegar of this invention was developed into a functional beverage, and its taste and functionality were evaluated.

[0273] Recipe and preparation:

[0274] Dai-style rose vinegar: 15mL;

[0275] Purified water: 135mL (dilution ratio 1:9);

[0276] Organic honey: 7.5g (5%);

[0277] A small amount of ice;

[0278] Simply mix the above ingredients thoroughly before drinking.

[0279] Evaluation results:

[0280] Twenty volunteers were recruited and consumed the aforementioned beverage for 28 consecutive days (on an empty stomach each morning). Changes in their skin condition and antioxidant indicators were observed. Results showed that 85% of the volunteers reported significant improvements in their skin condition, particularly in skin radiance and moisture content. Blood tests revealed an average increase of 12.5% ​​in total serum antioxidant capacity and an average decrease of 18.3% in serum malondialdehyde (MDA) levels, indicating the beverage's significant antioxidant effects. Furthermore, 90% of the volunteers were satisfied with the beverage's taste, finding it well-balanced in sweetness and acidity, with a refreshing and pleasant aroma of rose and lemongrass.

[0281] The Dai-style rose vinegar of this invention was applied to facial masks and toners, and its beauty and skincare effects were evaluated.

[0282] Recipe and preparation:

[0283] 1. Rose Vinegar Mask: 10% Dai pottery rose vinegar, 15% natural honey, 1% hyaluronic acid, and 74% purified water.

[0284] 2. Rose Vinegar Toner: 5% Dai pottery rose vinegar, 3% glycerin, 0.5% hyaluronic acid, 2% plant extracts, 89.5% purified water.

[0285] Evaluation results:

[0286] Fifteen female volunteers were recruited and used the aforementioned products continuously for 21 days. Changes in skin condition were observed, and a questionnaire survey was conducted. Results showed that after using the rose vinegar mask, 93% of the volunteers reported firmer and more elastic skin; after using the rose vinegar toner, 87% reported brighter and more moisturized skin. Instrumental analysis showed that after 21 days of use, the volunteers' facial skin moisture content increased by an average of 18.5%, and skin elasticity increased by an average of 12.3%. Most volunteers also specifically mentioned that the product's natural rose scent was pleasant, and the user experience was superior to similar products on the market.

[0287] This invention provides a method for preparing Dai pottery rose vinegar based on multi-stage fermentation using indigenous microorganisms, as well as the Dai pottery rose vinegar and its applications. By innovatively combining vinegar bran recycling technology with the traditional Dai pottery jar fermentation process, a four-stage fermentation system is designed. Furthermore, the targeted screening of indigenous microorganisms and segmented temperature control technology are introduced, successfully solving the technical problems in traditional floral vinegar preparation, such as low resource utilization, monotonous flavor, unnatural floral aroma, and poor product stability.

[0288] The technical advantages of this invention are mainly reflected in the following aspects:

[0289] 1. The multi-stage fermentation process enables efficient resource utilization and precise control of product flavor. Compared with traditional processes, the raw material utilization rate is increased by more than 60%, and the production cycle is shortened by about 30%.

[0290] 2. The targeted screening and application of indigenous microorganisms solves the problem of unstable product quality caused by relying on natural microbial communities in the traditional fermentation process, and significantly improves the recycling rate and flavor transformation ability of vinegar bran.

[0291] 3. The segmented temperature-controlled fermentation technology significantly improves the extraction and conversion efficiency of rose polyphenols and aroma substances. Compared with traditional constant temperature fermentation, the content of rose aroma substances is increased by about 35-40%.

[0292] 4. Through the synergistic fermentation of rose petals and processed vinegar bran, combined with the post-fermentation of lemongrass, a unique flavor system is created that "the floral fragrance does not mask the vinegar fragrance, and the vinegar fragrance reveals the floral charm", which solves the problem of the traditional flower vinegar having a single or uncoordinated flavor.

[0293] 5. The developed Dai pottery rose vinegar can not only be used as a high-end condiment, but can also be extended to multiple fields such as functional beverages and beauty and skin care, which significantly enhances the added value and market competitiveness of the product.

[0294] Through systematic performance testing and application research, it has been proven that the product of this invention is significantly superior to traditional processes and existing technologies in terms of physicochemical indicators, flavor substances, functional activities and shelf life, and has good market application prospects and socio-economic value.

[0295] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing Dai-style rose vinegar based on multi-stage fermentation using indigenous microorganisms, characterized in that, Includes the following steps: A. Basic vinegar fermentation: Mix Dai ethnic rice-fragrant white wine, Dai ethnic handmade brown sugar, and Yunnan spring water in a volume ratio of 5:1:10, add vinegar coating and indigenous microbial compound fermentation agent, and ferment in Dai ethnic pottery jars at 28-30℃ for 45-60 days, stirring once a day, until the total acidity reaches 4.0-4.5g / 100mL; B. Vinegar bran treatment: Vinegar bran obtained after fermentation of the basic vinegar solution is mixed with screened lactic acid bacteria at a weight ratio of 1000:3, 1‰ brown sugar is added, and fermentation is carried out at 22-25℃ for 5 days. C. Rose Fermentation: The base vinegar solution and the treated vinegar bran are mixed at a volume ratio of 8:

1. Dark red rose petals are added, with the amount of petals added being 8-15% of the total weight of the mixture. The fermentation is carried out in stages with temperature control for 12 days. During the first 1-3 days, the mixture is stirred twice a day at 32℃. During the middle 4-8 days, the mixture is stirred once a day at 30℃. During the later 9-12 days, the mixture is left to stand without stirring at 28℃. D. Aging and Flavoring: Filter the fermented rose-scented liquid and age it in a Dai-style earthenware jar at 25°C for 10-15 days, shaking it gently every 3 days. After a second filtration, pour it into a glass bottle and add 1.5g of fresh lemongrass pieces per 500mL. Let it stand in the dark at 22°C for 5 days.

2. The method for preparing Dai-style rose vinegar according to claim 1, characterized in that, The Dai ethnic rice-fragrant baijiu has an alcohol content of not less than 30% and an ester content of not less than 1.2g / L; the Dai ethnic handmade brown sugar has a sucrose content of not less than 80% and a mineral content of not less than 2.5%; the Yunnan spring water has a pH value of 6.8-7.2 and a hardness of not more than 150mg / L.

3. The method for preparing Dai-style rose vinegar according to claim 1, characterized in that, The vinegar coating contains at least 1×10⁻⁶ acetic acid bacteria. 6 CFU / g; The indigenous microbial compound fermentation agent is composed of acetic acid bacteria, lactic acid bacteria and yeast in a ratio of 2:2:1, wherein the acetic acid bacteria is Acetobacter pasteurianus, the lactic acid bacteria is Lactobacillus plantarum and the yeast is Saccharomyces cerevisiae.

4. The method for preparing Dai-style rose vinegar according to claim 3, characterized in that, The preparation method of the indigenous microbial composite fermentation agent includes: a. Isolating bacterial strains from Dai ethnic vinegar of different years; b. Selective culture media were used for initial screening: GYC medium was used for acetic acid bacteria, modified MRS medium was used for lactic acid bacteria, and YPD medium was used for yeast. c. Evaluate the function of the screened strains and select strains with strong acid production capacity, good acid resistance and ability to produce aroma substances. d. The selected strains were cultured under suitable conditions: acetic acid bacteria and lactic acid bacteria were cultured at 30°C for 48 hours, and yeast was cultured at 28°C for 24 hours. e. Prepare a compound fermentation agent by mixing the ingredients in a 2:2:1 ratio, and freeze-dry it to ensure that the bacterial activity is not less than 90%.

5. The method for preparing Dai-style rose vinegar according to claim 1, characterized in that, The endpoint criteria for the fermentation of the basic vinegar solution are a total acidity of not less than 4.0 g / 100 mL and a pH value of not more than 3.2; the detection indicators for the treated vinegar bran are a lactic acid bacteria count of not less than 1×10^7 CFU / g, a pH value of not more than 3.5, and a lactic acid content of not less than 0.8%.

6. The method for preparing Dai-style rose vinegar according to claim 1, characterized in that, The endpoint criteria for the rose fragrance fermentation are: the rose petals fade to light pink, the vinegar solution turns amber, the total polyphenol content is not less than 45 mg / 100 mL, the 2-phenylethanol content is not less than 25 mg / L, the geraniol content is not less than 15 mg / L, and the rose ketone content is not less than 8 mg / L.

7. The method for preparing Dai-style rose vinegar according to claim 1, characterized in that, The Dai ethnic pottery jar is unglazed coarse pottery with a microporosity of 8-12% and an air permeability of 0.5-0.8 mL / min·cm²; the filter uses a 100-mesh nylon sieve; and the glass bottle is a dark-colored glass bottle.

8. The Dai-style rose vinegar prepared by the method according to any one of claims 1-7, characterized in that, The Dai pottery rose vinegar has a bright amber appearance, a harmonious blend of rose and lemongrass aromas, a balanced sweet and sour taste, a total acidity of 4.5-5.5g / 100mL, and a rose polyphenol content of no less than 45mg / 100mL.

9. The application of the Dai-style rose vinegar of claim 8 in the field of condiments, characterized in that, The Dai Tao Rose Vinegar is used as a seasoning vinegar in high-end catering or home cooking, for the preparation of cold dishes, stir-fries, soups or sauces, with a dosage of 1-3% of the total weight of the dish.

10. The application of the Dai pottery rose vinegar of claim 8 in the field of functional beverages, characterized in that, Dilute the Dai-style rose vinegar with purified water at a ratio of 1:5 to 1:10, add 2-5% honey, and make a functional beverage with antioxidant and beauty-enhancing effects. The daily intake is 15-30mL.