Brewing process of novel sweet-scented osmanthus rice wine

Abstract

The invention relates to the field of household kitchens, and discloses a novel sweet-scented osmanthus rice wine brewing process which comprises the following steps: washing glutinous rice, soaking, cooking and spreading for cooling; inoculating a non-saccharomyces cerevisiae group, and adding induced trace ions and a specific low-concentration saccharide precursor; after the first-stage fermentation is finished, inoculating a saccharomyces cerevisiae group, adding an osmanthus fragrans extract and an enzyme preparation, and performing intelligent feedback regulation and control according to real-time online monitoring data; the wine liquid is subjected to primary treatment, an edible aroma embedding matrix is added for microencapsulation or embedding treatment, and then low-temperature ageing and curing are performed. Sequencing batch non-saccharomyces cerevisiae and saccharomyces cerevisiae are adopted for synergistic fermentation, the non-saccharomyces cerevisiae is introduced in the first stage for pre-fermentation, and regulation and control of induced trace ions and specific low-concentration saccharide precursors are supplemented, so that an unprecedented complex flavor substrate is constructed for the rice wine, and the flavor spectrum of the rice wine is widened; the rice wine is different from traditional rice wine fermented by single yeast in simple flavor.

Description

Technical Field

[0001] The invention relates to the technical field of household kitchens, and in particular to a brewing process of a novel osmanthus rice wine. Background Art

[0002] Rice wine, a traditional Chinese brewed beverage, enjoys a long history and is deeply loved by consumers. Its unique flavor and nutritional value have earned it a significant market share. In recent years, with growing consumer demand for healthier and more personalized flavors, the monotonous flavor and limited sensory experience of traditional rice wine have failed to fully meet market expectations. To enhance the added value and market competitiveness of rice wine products, the industry has explored numerous flavor innovations, with the incorporation of floral elements, particularly osmanthus, becoming a key research direction.

[0003] However, existing technologies face multiple challenges in preparing floral-scented rice wine. For one thing, effectively integrating floral aroma into the rice wine matrix and maintaining its stability is a complex problem. Floral aroma components are mostly volatile and unstable. In the complex fermentation and storage environments of rice wine, they are easily lost through volatilization, oxidative degradation, or reactions with other components, resulting in insufficient aroma or an unbalanced flavor profile, seriously affecting the product's sensory quality and shelf life. Simple addition methods often fail to address the stability and durability of aroma components.

[0004] On the other hand, traditional rice wine brewing technology mostly relies on single yeast fermentation, and its flavor generation pathway is relatively simple, making it difficult to construct a flavor spectrum with significant complexity and layering. Although some studies have attempted to introduce non-brewer yeasts to enrich the flavor, the lack of in-depth understanding and refined regulation of the synergistic effects of different yeast species may lead to low fermentation efficiency, product deviation, or the production of undesirable flavor substances. At the same time, the traditional fermentation process is extensively controlled and lacks real-time monitoring and intelligent feedback of key metabolic pathways and environmental parameters. This makes the fermentation process less controllable, the quality of products fluctuates greatly between batches, and it is difficult to achieve high-quality, standardized production.

[0005] Therefore, the current rice wine production industry urgently needs a new brewing technology that can effectively activate and stabilize floral aromas while significantly improving the overall flavor complexity and quality stability of rice wine. This not only involves the effective utilization and protection of aroma components, but also requires systematic optimization and intelligent management of the entire fermentation process, thereby overcoming the shortcomings of existing technologies and providing high-quality floral-scented rice wine products with a unique sensory experience and a longer shelf life. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present invention provides a novel brewing process for osmanthus rice wine, which solves the problems of the existing flower-scented rice wine, such as volatile aroma, single and unharmonious flavor, and poor quality stability during the production process.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: a novel osmanthus rice wine, the rice wine comprising a fermentation product of the following components:

[0008] Glutinous rice: 70%-90% of the total raw material dry weight;

[0009] Non-Saccharomyces fermentation bacteria: accounting for 10%-20% of the total viable bacteria count of the inoculant, with viable bacteria count ≥ 1.0×10 10 CFU / g;

[0010] Saccharomyces cerevisiae fermentation flora: 80%-90% of the total viable bacteria count, viable bacteria count ≥ 1.0×10 10 CFU / g≥1.0×10 10 CFU / g;

[0011] Osmanthus aroma component: added in the form of osmanthus extract, accounting for 0.002%-0.005% of the dry weight of glutinous rice;

[0012] Enzyme preparation: selected from β-glucosidase and / or rhamnosidase, with enzyme activity unit ≥500U / mg, and added in an amount of 100-300U / kg dry glutinous rice;

[0013] Inductive trace ions: selected from zinc sulfate and / or magnesium sulfate, added in an amount of 0.0001%-0.0005% of the dry weight of glutinous rice;

[0014] Specific low-concentration carbohydrate precursor: selected from isomalto-oligosaccharides and / or fructo-oligosaccharides, added in an amount of 0.01%-0.05% of the dry weight of glutinous rice; and

[0015] Edible aroma embedding matrix: selected from β-cyclodextrin and / or gum arabic and / or hydrolyzed casein and / or soy protein isolate, wherein the added amount of edible polysaccharide is 0.5%-1.5% w / v, or the added amount of specific protein is 0.2%-0.8% w / v.

[0016] Preferably, the non-Saccharomyces cerevisiae fermentation flora is selected from one or more of Torulaspora delbrueckii, Pichiakluyveri or Lachanceathermotolerans.

[0017] Preferably, the osmanthus aroma components exist in the form of stable glycosides or esters after enzymatic conversion, and are microencapsulated or embedded in the edible aroma embedding matrix.

[0018] A brewing process for a novel sweet osmanthus rice wine comprises the following steps:

[0019] Glutinous rice pretreatment: wash, soak, steam and cool the glutinous rice to reduce the temperature to 25-30℃;

[0020] The first stage of fermentation: Inoculate a non-Saccharomyces yeast colony, add inducing trace ions and specific low-concentration sugar precursors, and ferment at a temperature of 20-22°C. Simultaneously, the concentration of volatile organic compounds during the fermentation process is monitored online in real time.

[0021] Second stage fermentation: After the first stage fermentation is completed, the brewer's yeast flora is inoculated, and osmanthus extract and enzyme preparation are added. Fermentation is carried out at a temperature of 23-25°C, and intelligent feedback control is carried out based on real-time online monitoring data;

[0022] Aroma microencapsulation and aging: After the second stage of fermentation, the wine is preliminarily treated and an edible aroma embedding matrix is ​​added for microencapsulation or embedding, followed by low-temperature aging.

[0023] Preferably, the soaking time of the glutinous rice is 8-12 hours, and the cooking time is 30-45 minutes.

[0024] Preferably, in the first stage of fermentation, the inoculation amount of the non-brewer's yeast flora accounts for 10%-20% of the total yeast inoculation amount, the inducible trace ions are zinc sulfate and / or magnesium sulfate, and the added amount is 0.0001%-0.0005% of the dry basis mass of glutinous rice, and the specific low-concentration carbohydrate precursors are isomalto-oligosaccharides and / or fructooligosaccharides, and the added amount is 0.01%-0.05% of the dry basis mass of glutinous rice. The first stage of fermentation lasts for 2-3 days.

[0025] Preferably, in the first stage of fermentation, the inoculation amount of the non-brewer's yeast is 1.0×10 6 -5.0×10 6 CFU / g glutinous rice dry basis.

[0026] Preferably, in the second stage fermentation, the inoculation amount of the brewer's yeast community accounts for 80%-90% of the total yeast inoculation amount, the added amount of the osmanthus extract is 0.002%-0.005% of the dry mass of glutinous rice, the enzyme preparation is β-glucosidase and / or rhamnosidase, and the added amount is 100-300 U / kg dry mass of glutinous rice, and the second stage fermentation lasts for 5-7 days.

[0027] Preferably, the intelligent feedback control includes automatically adjusting the fermentation temperature, stirring speed and / or pH value according to the real-time online monitoring of the alcohol concentration, residual sugar content and change trends of the osmanthus aroma components.

[0028] Preferably, the edible aroma embedding matrix is ​​selected from β-cyclodextrin and / or gum arabic, and the addition amount thereof is 0.5%-1.5% w / v; and / or selected from hydrolyzed casein and / or soy protein isolate, and the addition amount thereof is 0.2%-0.8% w / v; the low-temperature aging temperature is 4-8°C, and the aging time is 1-2 weeks.

[0029] The present invention provides a novel brewing process for osmanthus rice wine, which has the following beneficial effects:

[0030] 1. This invention utilizes a sequencing batch fermentation strategy of co-fermentation with non-Saccharomyces yeast. In the first stage, non-Saccharomyces yeast is introduced for pre-fermentation, supplemented by the regulation of inductive trace ions and specific low-concentration sugar precursors. This combination of technologies encourages the non-Saccharomyces yeast to produce a richer and more diverse range of esters, higher alcohols, and terpenes during the initial fermentation phase, creating an unprecedentedly complex flavor base for rice wine and broadening its flavor spectrum, distinguishing it from the simple flavors of traditional rice wine fermented with only one yeast.

[0031] 2. The present invention introduces an enzyme during the second fermentation stage to target and hydrolyze the non-volatile aroma precursor glycosides in osmanthus flowers, releasing characteristic osmanthus aroma components. Subsequently, these activated aroma components are physically protected by microencapsulation or embedding technology assisted by an edible polysaccharide / protein matrix. This combined technology effectively reduces the volatilization loss of osmanthus aroma during brewing, storage, and consumption, and achieves a sustained release of the aroma, ensuring that the rice wine continues to exude osmanthus fragrance while drinking, enhancing the layered sensory experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Flowchart of the present invention. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the present specification. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0034] Example 1:

[0035] Please see the attached Figure 1 The embodiment of the present invention provides a novel brewing process of osmanthus rice wine, comprising:

[0036] This embodiment aims to prepare a new type of osmanthus rice wine through sequencing batch non-brewer's yeast / brewer's yeast collaborative fermentation, enzymatic targeted osmanthus aroma activation-solidification, and polysaccharide / protein matrix-assisted aroma microencapsulation and intelligent fermentation process control technology.

[0037] 1.1 Raw material preparation and pretreatment

[0038] Wash and soak glutinous rice: Weigh 5.00 kg (dry basis) of glutinous rice and rinse repeatedly with purified water three times until the water runs clear. Place the washed rice in a clean soaking tank and add 7.00 kg (rice:water ratio 1:1.4). Soak at 22°C for 10 hours. After soaking, drain the rice.

[0039] Steaming: Spread the drained glutinous rice evenly on the rice steamer tray, about 6 cm thick. Steam for 35 minutes, until the rice grains are puffed up, no hard core remains, and the rice is soft and sticky.

[0040] Cooling: Quickly transfer the cooked rice to a sterilized cooling board, spreading it out to a thickness of approximately 2.5 cm. Cool the rice evenly to 28°C using clean air forced cooling.

[0041] 1.2 First stage fermentation: Non-Saccharomyces yeast-dominated and induced flavor precursor construction

[0042] Inoculation and mixing: After cooling, transfer 5.00 kg of rice into a sterilized fermentation tank. Weigh 0.50 g of activated non-Saccharomyces cerevisiae Torulaspora delbrueckii freeze-dried powder (viable count 2.0 × 10 10 CFU / g) and evenly inoculated it into the rice to ensure that it is fully mixed with the rice.

[0043] Inducible regulation:

[0044] Trace ion addition: Weigh 0.020g zinc sulfate heptahydrate, dissolve it in a small amount of pure water and add it to the fermentation tank.

[0045] Addition of low concentration carbohydrate precursor: Weigh 1.50 g of isomaltooligosaccharide, dissolve it in a small amount of purified water and add it to the fermentation tank.

[0046] Redox potential control: Within the first 8 hours after the start of fermentation, the redox potential of the fermentation system is controlled at -120mV by controlling the airtightness of the fermentation tank.

[0047] Fermentation condition control and online monitoring: The fermentation tank temperature was precisely controlled at 21°C. An online biosensor system was used to monitor the concentration changes of isoamyl acetate and isoamyl alcohol in the fermentation system in real time.

[0048] The first stage of fermentation cycle: This stage of fermentation lasts for 2.5 days until the alcohol content reaches 1.8% (v / v) and online monitoring shows that the accumulation rate of isoamyl acetate tends to be stable.

[0049] 1.3 Second stage fermentation: Saccharomyces cerevisiae-led and enzymatically targeted activation and solidification of osmanthus aroma

[0050] Inoculation of brewer's yeast: After the first stage of fermentation, weigh 4.00 g of activated lyophilized powder of Saccharomyces cerevisiae (viable count 1.5×10 10 CFU / g) and added to the fermenter.

[0051] Addition of osmanthus extract and enzyme preparation: 0.15 g of osmanthus extract was weighed at the same time, mixed with 1.00 g of β-glucosidase (enzyme activity 550 U / mg), and then added to the fermentation tank.

[0052] Intelligent feedback control and fermentation: The fermentation temperature is adjusted and controlled at 24°C. Based on the real-time release profile of alcohol concentration, residual sugar content, and characteristic osmanthus aroma components (such as β-damascenone) monitored by the online biosensor, the intelligent feedback system automatically adjusts the stirring speed to 10 rpm, stirring twice daily for 20 minutes each time, and maintains the pH at 4.0 ± 0.1.

[0053] Second stage fermentation cycle: This stage of fermentation lasts for 6 days until alcohol fermentation is basically completed and the residual sugar content drops to 65g / L.

[0054] 1.4 Aroma Microencapsulation and Ripening

[0055] Microencapsulation / encapsulation of aroma components: After the second stage of fermentation, the wine was initially filtered to remove most of the solid residue. 75.0 g of β-cyclodextrin (1.5% w / v) was added to 5.0 L of wine. The mixture was transferred to a high-speed shear emulsifier and emulsified at 10,000 rpm for 55 minutes. Subsequently, under continuous stirring (300 rpm), 0.1 M citric acid solution was slowly added to adjust the pH to 3.5 to promote complex coacervation and form a microencapsulation system. The entire process was carried out at 28°C for a total stirring time of 45 minutes.

[0056] Low-temperature aging: Transfer the microencapsulated rice wine to a clean aging tank and age it at 6°C for 10 days.

[0057] 1.5 Post-processing and filling

[0058] Clarification and filtration: After aging, the rice wine is precisely filtered using cross-flow filtration equipment to reduce the turbidity of the wine to 0.8NTU.

[0059] Sterilization: Use pasteurization, heat the wine to 72℃ and keep it for 18 minutes.

[0060] Filling and packaging: In a clean and aseptic environment, the sterilized new osmanthus rice wine is filled, sealed, labeled, and packaged. The storage temperature is controlled at 4°C and stored away from light.

[0061] Example 2:

[0062] This example aims to demonstrate the effect of adjusting the non-Saccharomyces yeast strain and the type of inducing substance on the flavor development of the novel osmanthus rice wine. Except for the parameters explicitly stated below, the remaining process steps and parameters are the same as those in Example 1.

[0063] 1.1 Raw material preparation and pretreatment

[0064] Same as Example 1.

[0065] 1.2 First stage fermentation: Non-Saccharomyces yeast-dominated and induced flavor precursor construction

[0066] Inoculation and mixing: After cooling, transfer 5.00 kg of rice into a sterilized fermentation tank. Weigh 0.60 g of activated non-Saccharomyces cerevisiae Pichiakluyveri freeze-dried powder (viable count 1.8 × 10 10 CFU / g) and evenly inoculated into the rice.

[0067] Inducible regulation:

[0068] Trace ion addition: Weigh 0.025g of magnesium sulfate heptahydrate, dissolve it in a small amount of pure water and add it to the fermentation tank.

[0069] Addition of low concentration sugar precursor: Weigh 2.00 g of fructooligosaccharide, dissolve it in a small amount of purified water and add it to the fermentation tank.

[0070] Redox potential regulation: Within the first 10 hours after the start of fermentation, the redox potential of the fermentation system was controlled at -100 mV.

[0071] Fermentation condition control and online monitoring: The fermentation tank temperature was precisely controlled at 20°C, and the concentration changes of phenylethanol and ethyl hexanoate in the fermentation system were monitored in real time using an online biosensor system.

[0072] The first stage of fermentation cycle: This stage of fermentation lasted for 3 days until the alcohol content reached 2.2% (v / v) and online monitoring showed that the accumulation rate of phenylethanol tended to be stable.

[0073] 1.3 Second stage fermentation: Saccharomyces cerevisiae-led and enzymatically targeted activation and solidification of osmanthus aroma

[0074] Same as Example 1.

[0075] 1.4 Aroma Microencapsulation and Ripening

[0076] Microencapsulation / encapsulation of aroma components: After the second stage of fermentation, the wine was initially filtered. 40.0 g of gum arabic (0.8% w / v) and 15.0 g of hydrolyzed casein (0.3% w / v) were added to 5.0 L of wine. The mixture was transferred to a high-speed emulsifier and emulsified at 12,000 rpm for 7 minutes. Subsequently, under continuous stirring (400 rpm), 0.05 M calcium chloride solution was slowly added to promote coagulation. The entire process was carried out at 30°C for a total stirring time of 50 minutes.

[0077] Low-temperature aging: Transfer the microencapsulated rice wine to a clean aging tank and age it at 8°C for 7 days.

[0078] 1.5 Post-processing and filling

[0079] Same as Example 1.

[0080] Example 3:

[0081] This example aims to demonstrate the effects of adjusting the enzyme preparation type and aroma embedding matrix type on the aroma activation and curing effect of the novel osmanthus rice wine. Except for the parameters explicitly stated below, the remaining process steps and parameters are the same as those in Example 1.

[0082] 1.1 Raw material preparation and pretreatment

[0083] Same as Example 1.

[0084] 1.2 First stage fermentation: Non-Saccharomyces yeast-dominated and induced flavor precursor construction

[0085] Same as Example 1.

[0086] 1.3 Second stage fermentation: Saccharomyces cerevisiae-led and enzymatically targeted activation and solidification of osmanthus aroma

[0087] Inoculation of cerevisiae yeast: same as in Example 1.

[0088] Addition of osmanthus extract and enzyme preparation: 0.20 g of osmanthus extract was weighed at the same time, mixed with 0.80 g of rhamnosidase (enzyme activity 520 U / mg), and then added to the fermentation tank.

[0089] Intelligent feedback regulation and fermentation: The fermentation temperature was adjusted and controlled at 23°C. Based on the alcohol concentration, residual sugar content and real-time release curve of osmanthus characteristic aroma components (such as linalool) monitored by the online biosensor, the intelligent feedback system automatically adjusted the stirring speed to 8 rpm, stirred 33 times a day, each time for 15 minutes, and maintained the pH value at 3.9±0.1.

[0090] Second stage fermentation cycle: This stage of fermentation lasts for 5 days until the alcohol fermentation is basically completed and the residual sugar content drops to 70g / L.

[0091] 1.4 Aroma Microencapsulation and Ripening

[0092] Microencapsulation / encapsulation of aroma components: After the second stage of fermentation, the wine was initially filtered. 20.0 g of soy protein isolate (0.4% w / v) was added to 5.0 L of wine. The mixture was transferred to a high-pressure homogenizer and homogenized twice at 100 MPa for emulsification. Subsequently, 0.1 M sodium chloride solution was slowly added under continuous stirring (500 rpm) to promote salting-out and coagulation of the proteins. The entire process was carried out at 25°C for a total stirring time of 60 minutes.

[0093] Low-temperature aging: The microencapsulated rice wine was transferred to a clean aging tank and aged at 4°C for 14 days.

[0094] 1.5 Post-processing and filling

[0095] Clarification and filtration: After aging, the rice wine is precisely filtered using a 0.45μm membrane filtration device to reduce the turbidity of the wine to 0.5NTU.

[0096] Sterilization: Sterilize by filtration using a 0.45 μm membrane.

[0097] Filling and packaging: In a clean and aseptic environment, the sterilized new osmanthus rice wine is filled, sealed, labeled, and packaged. The storage temperature is controlled at 4°C and stored away from light.

[0098] Comparative Example 1: Preparation of traditional osmanthus rice wine

[0099] The differences compared to Example 1 are as follows: only Saccharomyces cerevisiae was used during the fermentation process (non-Saccharomyces cerevisiae yeast was not used in the first stage of fermentation); no inductive trace ions or specific low-concentration carbohydrate precursors were added; no enzyme preparations were added; the osmanthus extract was added directly to the wine after fermentation without microencapsulation or embedding; and real-time online monitoring and intelligent feedback control were not used during the fermentation process. The remaining process steps and parameters were the same as those in Example 1.

[0100] Comparative Example 2: Preparation of Osmanthus Rice Wine Fermented by Single Non-Saccharomyces Yeast

[0101] The differences compared to Example 1 are as follows: only non-Saccharomyces yeast was used during the fermentation process (the second stage of Saccharomyces yeast inoculation and fermentation was omitted); no inducing trace ions or specific low-concentration carbohydrate precursors were added; the osmanthus extract was added directly to the wine after fermentation, without the addition of enzyme preparations or microencapsulation or embedding; and real-time online monitoring and intelligent feedback control were not used during the fermentation process. All other process steps and parameters followed the conventional procedures of Example 1.

[0102] Comparative Example 3: Preparation of Osmanthus Rice Wine without Aroma Embedding Technology

[0103] Compared with Example 1, the difference is that after the second stage of fermentation, no aroma microencapsulation or embedding treatment is performed, that is, no edible aroma embedding matrix is ​​added, and the low-temperature aging step is directly entered. The remaining process steps and parameters are the same as Example 1.

[0104] Test Example 1:

[0105] The purpose of this test example is to compare the differences in aroma, taste, flavor coordination and overall acceptability between the novel osmanthus rice wine prepared in the example and the comparative rice wine through professional sensory evaluation.

[0106] 1.1 Evaluation Method

[0107] Evaluators: A sensory evaluation panel consisting of 12 professional evaluators who have undergone national-level sensory evaluation training for baijiu or huangjiu and possess at least five years of relevant experience will be assembled. All evaluators will undergo taste and olfactory sensitivity tests prior to evaluation to ensure they possess good sensory discrimination abilities.

[0108] Sample Preparation: 50 mL of each rice wine sample prepared in Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, and Comparative Example 3 was placed in a standard sensory evaluation cup. All samples were incubated at 15°C for 30-30 minutes to ensure a consistent evaluation temperature. Samples were coded with three random numbers to prevent evaluators from knowing the true identity of the samples.

[0109] Evaluation Environment: Sensory evaluations are conducted in a professional sensory evaluation room that complies with international standards (ISO8589). The room is odor-free, with soft lighting, a temperature of 20-22°C, and a relative humidity of 60%-70%. Each evaluator conducts their evaluation in an independent booth.

[0110] Evaluation Process: Evaluators tasted each sample in turn. The order of evaluation was randomized to eliminate order effects. After tasting each sample, the evaluators rinsed their mouths with purified water and rested for 2 minutes to eliminate the influence of the previous flavor.

[0111] Evaluation indicators and scale: Evaluators scored each sample according to the following indicators using a 9-point scale (1 = extremely dislike / very weak intensity, 5 = moderate / average, 9 = extremely like / very strong intensity).

[0112] Osmanthus aroma intensity: the richness of the unique aroma of osmanthus.

[0113] Osmanthus aroma persistence: the length of time the osmanthus aroma remains in the mouth or nasal cavity.

[0114] Flavor complexity: In addition to the aroma of osmanthus, the richness and coordination of other flavor substances such as esters and higher alcohols presented in rice wine.

[0115] Body: The full and rich taste experience of rice wine in the mouth.

[0116] Sweet and sour balance: the degree of coordination between sour and sweet taste in rice wine.

[0117] Overall acceptance: the degree to which the evaluators like the overall sensory quality of rice wine.

[0118] 1.2 Sensory evaluation results

[0119] After the sensory evaluation team evaluated the rice wine samples, their average score data are shown in Table 1.

[0120] Table 1. Sensory evaluation results of rice wine samples (average score, 9-point scale)

[0121]

[0122] From the sensory evaluation results in Table 1, it can be seen that the novel osmanthus rice wine prepared in Example 1, Example 2 and Example 3 are significantly better than those in Comparative Example 1, Comparative Example 2 and Comparative Example 3 in various sensory indicators.

[0123] Specifically, the example products show obvious advantages in terms of osmanthus fragrance intensity and osmanthus fragrance persistence. This is mainly attributed to the targeted hydrolysis of aroma precursor glycosides in osmanthus extract by the enzyme preparations (such as β-glucosidase and rhamnosidase) introduced in the present invention, which activates more free aroma components; at the same time, the microencapsulation or embedding treatment of edible polysaccharides or protein matrices (such as β-cyclodextrin, gum arabic, hydrolyzed casein or soy protein isolate) effectively limits the volatilization of these activated aroma components and achieves their slow release during storage and drinking, thereby maintaining the richness and persistence of the osmanthus fragrance. Due to the lack of aroma embedding technology, the osmanthus fragrance persistence score of Comparative Example 3 is significantly lower than that of the example products, verifying the role of aroma embedding in improving aroma retention.

[0124] In addition, the example products also show excellent performance in terms of flavor complexity. This is closely related to the sequencing batch non-brewers yeast and brewer's yeast cooperative fermentation process adopted by the present invention. In the first stage of fermentation, non-brewers yeast (such as Torulaspora delbrueckii, Pichiakluyveri) can produce a wider range of secondary metabolites, such as various esters, higher alcohols and terpenes, under the synergistic effect of inductive trace ions and specific low-concentration sugar precursors. These compounds serve as flavor bases and give rice wine a richer sense of layering. Subsequently, brewer's yeast completes the main alcohol fermentation and further converts flavor substances in the second stage of fermentation, and finally constructs a complex and coordinated overall flavor spectrum. Since Comparative Example 1 and Comparative Example 2 do not adopt sequencing batch cooperative fermentation or inductive regulation of non-brewers yeast, their flavor complexity scores are significantly low, indicating that single yeast fermentation or lack of specific regulation is difficult to achieve the depth of flavor achieved by the present invention.

[0125] The example product also received high marks for body and sweet-sour balance, demonstrating the process's ability to precisely control the fermentation process. The intelligent feedback control system's real-time adjustments to fermentation temperature, stirring speed, and pH ensure optimal yeast metabolism and promote the balanced production of alcohol, organic acids, and sugars. This results in a richer, more balanced sweet-sour rice wine, a more harmonious overall sensory experience, and increased consumer acceptance.

[0126] Test Example 2:

[0127] This test example aims to determine the differences in key physical and chemical indicators such as alcohol content, total sugar / residual sugar, total acidity and pH value between the novel osmanthus rice wine prepared in the example and the comparative rice wine, so as to reflect the influence of the brewing process on the basic composition of the product.

[0128] 1.1 Determination method

[0129] Sample Preparation: 100 mL of each rice wine sample prepared in Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, and Comparative Example 3 was collected. All samples were centrifuged (4000 rpm, 10 min) or filtered to remove suspended matter, resulting in a clear liquor for analysis. Thirty-three replicates were prepared for each sample.

[0130] Alcohol content: Determination is performed using the densimeter method (according to Appendix A, "Determination of Alcohol Content," GB / T 10781.1-2006, Rice Wine). Take 100 mL of sample, distill, and collect the distillate. Read the alcohol content using an alcohol meter at 20°C.

[0131] Total and residual sugars are determined using the anthrone-sulfuric acid colorimetric method (according to the "Determination of Total Sugars" section of GB / T 10345-2007, "Analysis Methods for Liquor"). The sample is diluted and reacted with the anthrone reagent. The absorbance is measured at 620 nm, and the total sugar content is calculated using a glucose standard curve.

[0132] Total acidity: Determine using the acid-base indicator neutralization titration method (according to the "Determination of Total Acidity" section of GB / T 10345-2007, "Analysis Methods for Liquor") Take 10.00 mL of sample and titrate with a standardized sodium hydroxide solution to the endpoint (color change of the phenolphthalein indicator). Calculate the total acidity (as lactic acid).

[0133] pH value determination: Directly measure the pH value using a pH meter (e.g., Mettler-Toledo FE20 pH meter). Before use, calibrate the pH meter at two points (pH 4.00 and pH 6.86 standard buffers).

[0134] 1.2 Physical and chemical index test results

[0135] After the physical and chemical indicators of each rice wine sample were measured, the average values ​​were shown in Table 2.

[0136] Table 2. Determination results of physical and chemical indicators of rice wine samples

[0137] Sample number Alcohol content (% v / v) Residual sugar content (g / L) Total acidity (g / L) pH Example 1 12.3 62.5 2.89 3.98 Example 2 11.8 68.1 3.12 3.92 Example 3 12 69.5 3.05 4.01 Comparative Example 1 13.5 75.8 2.21 4.35 Comparative Example 2 10.5 81.3 3.56 3.78 Comparative Example 3 12.8 66.2 2.75 4.1

[0138] From the results of the physical and chemical index measurements in Table 2, it can be seen that the rice wines prepared in Examples 1, 2 and 3 exhibit different characteristics from those of the comparative example products in terms of alcohol content, residual sugar content, total acidity and pH value, and these differences are directly related to the refined brewing process adopted in the present invention.

[0139] The products of the examples generally show relatively moderate alcohol content and residual sugar content, and the total acidity and pH value are in an optimal balance range. For example, the residual sugar content of Example 1 is 62.5g / L, which is higher than the residual sugar content of Comparative Examples 1 and 2. This reflects the fine control of the brewing yeast fermentation in the second stage of the present invention, ensuring the moderate conversion of sugars, ensuring sufficient alcohol production, and retaining the sweet taste of rice wine. Comparative Example 1 has a higher alcohol content but a lower total acidity, which may be due to its traditional fermentation mode, resulting in a thin flavor and lack of complexity. Comparative Example 2 has the highest residual sugar content, relatively low alcohol content, and high total acidity due to the fermentation of a single non-brewer's yeast, indicating that its fermentation is not thorough and there may be deviations in the metabolites.

[0140] The sequencing batch non-brewers yeast and brewer's yeast collaborative fermentation strategy of the present invention, combined with the intelligent feedback control mechanism, can effectively control the metabolic activity of yeast during the fermentation process. For example, in the first stage, the pre-fermentation of non-brewers yeast can perform preliminary metabolism of the substrate to produce specific organic acids and flavor precursors, laying the foundation for the subsequent fermentation of brewer's yeast. The intelligent online monitoring system senses key parameters (such as residual sugar and pH) in real time and can adjust them according to preset targets, which significantly improves the controllability of the fermentation process, thereby ensuring the balance of alcohol content, residual sugar content and acidity and consistency between batches. This precise control reduces the randomness of fermentation and avoids quality fluctuations caused by insufficient or excessive fermentation.

[0141] Furthermore, the present invention's refined management of the fermentation process indirectly impacts the balance of physical and chemical parameters. For example, controlling the redox potential and adding trace ions facilitates more efficient primary metabolism in non-Saccharomyces yeast, optimizing the substrate environment for subsequent alcohol fermentation and enabling more stable alcohol conversion and secondary metabolite production by Saccharomyces cerevisiae. This multi-dimensional, synergistic regulatory approach ensures that various physical and chemical parameters of the final product remain within ideal ranges, providing a solid foundation for achieving superior sensory quality.

[0142] Test Example 3:

[0143] This test example aims to qualitatively and quantitatively analyze the volatile flavor substances and characteristic osmanthus aroma components in the new osmanthus rice wine prepared in the example and the comparative rice wine through advanced analytical technology, so as to reveal the technical advantages of the present invention in flavor construction and aroma activation.

[0144] 1.1 Determination method

[0145] Sample Preparation: 20 mL of each rice wine sample prepared in Example 1, Example 2, Example 3, Comparative Example 1, Comparative Example 2, and Comparative Example 3 was collected. The samples were centrifuged at 4°C (8000 rpm, 15 min) to remove the precipitate, and the supernatant was collected for subsequent analysis. Three replicates were prepared for each sample.

[0146] Determination of volatile flavor compounds (HS-SPME-GC-MS):

[0147] Headspace solid-phase microextraction (HS-SPME): 5 mL of sample was transferred to a 20 mL headspace vial and 2 g of sodium chloride was added. A 65 μm PDMS / DVB (polydimethylsiloxane / divinylbenzene) solid-phase microextraction tip was inserted into the headspace vial and the extraction was performed at 60°C for 45-45 minutes.

[0148] Gas chromatography-mass spectrometry (GC-MS): After extraction, the extraction head was immediately inserted into the GC-MS inlet (250°C) for desorption for 5 minutes. GC conditions: DB-WAX flexible quartz capillary column (60 m × 0.25 mm, 0.25 μm); temperature program: initial temperature 40°C, hold for 2 minutes, ramp to 180°C at 3°C / min, then ramp to 240°C at 10°C / min, hold for 5 minutes. Carrier gas was high-purity helium at a flow rate of 1.0 mL / min. MS conditions: electron impact ionization (EI) source, ionization energy 70 eV; ionization source temperature 230°C; transfer line temperature 250°C; scan range 35–450 amu. Volatile compounds were identified by spectral matching with the NIST library and retention time comparison with standards. Quantification was performed using an internal standard method (20 μL of 500 mg / L 2-octanol was added as an internal standard) to calculate relative concentrations.

[0149] Quantitative analysis of characteristic aroma components of osmanthus (GC):

[0150] Sample pretreatment: Take 10 mL of sample and concentrate the osmanthus aroma components using liquid-liquid extraction (e.g., extract twice with dichloromethane). Combine the organic phases and concentrate to 1 mL.

[0151] Gas chromatography (GC): Analysis was performed using a gas chromatograph equipped with a flame ionization detector (FID). Column: DB-FFAP flexible quartz capillary column (30 m × 0.25 mm, 0.25 μm). Temperature program: Initial temperature: 60°C, hold for 3 minutes, then increase at 5°C / min to 220°C, hold for 10 minutes. Inlet temperature: 250°C, detector temperature: 280°C. Carrier gas: high-purity nitrogen. Quantification was performed by external standardization with known concentrations of β-damascenone, α-ionone, and linalool standards.

[0152] 1.2 Flavor substance analysis results

[0153] After analyzing the flavor substances of each rice wine sample, the average value data is shown in Table 3.

[0154] Table 3. Contents of main volatile flavor compounds in each rice wine sample (μg / L).

[0155]

[0156] From the flavor substance analysis results in Table 3, it can be seen that the new osmanthus rice wine prepared in Example 1, Example 2 and Example 3 has significantly higher overall volatile flavor substance content and key osmanthus characteristic aroma component content than the comparative example product, which directly confirms the technical effectiveness of the present invention in flavor construction and aroma activation.

[0157] First, in terms of the characteristic aroma components of osmanthus, the β-damascenone content of the example products such as Example 1 is 15.6 μg / L, which is much higher than the 4.1 μg / L of Comparative Example 1 and the 6.5 μg / L of Comparative Example 2. This is due to the enzymatic targeted osmanthus aroma activation technology of the present invention. Osmanthus extract contains a large amount of non-volatile aroma precursors in the form of glycosides. By adding specific glycosidases (such as β-glucosidase and rhamnosidase), these glycosidic bonds can be hydrolyzed to release free, volatile linalool, β-damascenone and α-ionone, etc., which are characteristic aroma components of osmanthus, thereby greatly improving the intensity and complexity of the osmanthus aroma. Comparative Examples 1 and 2 have a low content of characteristic aroma components of osmanthus due to the lack of activation of the enzyme preparation. In addition, the aroma microencapsulation / embedding technology in the present invention (such as using β-cyclodextrin, gum arabic, hydrolyzed casein or soy protein isolate) plays a key protective role in the example products. These encapsulation matrices, through physical coating or complex coacervation, reduce the volatilization loss and oxidative degradation of osmanthus aroma components during fermentation and storage, thereby maintaining a high concentration of these aroma components. Comparative Example 3 also contains osmanthus extract, but due to the lack of encapsulation technology, its content of aroma components (such as α-ionone) is lower than that of the example products. The difference in aroma persistence is particularly significant, demonstrating the importance of encapsulation technology for aroma retention.

[0158] Secondly, in terms of overall volatile flavor substances, the content of major flavor substances such as ethyl acetate, ethyl hexanoate, phenylethyl alcohol and isoamyl alcohol in the example products is higher than that in Comparative Examples 1 and 2. This is directly related to the sequencing batch non-brewer's yeast and saccharomyces cerevisiae collaborative fermentation process adopted by the present invention. Non-brewer's yeast (such as Torulaspora delbrueckii and Pichiakluyveri) can produce diversified esters (such as isoamyl acetate, ethyl hexanoate) and higher alcohols (such as phenylethyl alcohol, isoamyl alcohol) in the first stage fermentation under the synergistic effect of specific inducers (trace ions and low concentrations of carbohydrate precursors). These substances form the basis of the complex flavor of rice wine. Subsequently, the intervention of saccharomyces cerevisiae further transforms the substrate and cooperates with the intermediate metabolites produced by non-brewers yeast to jointly promote the accumulation of flavor compounds. This collaborative fermentation mode optimizes the metabolic pathways of yeast and promotes the synthesis of multiple beneficial flavor compounds, thereby making the rice wine prepared by the present invention have a richer and more coordinated overall flavor spectrum, which has also been confirmed in sensory evaluation. The comparative products failed to fully utilize the metabolic potential of yeast due to their single or non-optimized fermentation mode, resulting in relatively limited types and contents of flavor substances.

[0159] Test Example 4:

[0160] This test example is intended to investigate the stability of osmanthus aroma, total acidity, and microbial indicators of the novel osmanthus rice wine prepared in the example and the comparative rice wine during storage, so as to evaluate the effect of the present invention in extending the shelf life of the product.

[0161] 1.1 Determination method

[0162] Sample Preparation and Storage: The rice wine samples prepared in Examples 1, 2, 3, Comparative Examples 1, 2, and 3 were individually filled into 250 mL glass bottles and sealed. All samples were stored in the dark at 25°C for 6 months to simulate accelerated storage conditions. Samples were taken at the end of the 0th, 1st, 3rd, and 6th month of storage for various parameters. Three replicates were set for each sample and time point.

[0163] Osmanthus aroma retention rate determination: Headspace solid-phase microextraction-gas chromatography (HS-SPME-GC) was used to determine the content of characteristic osmanthus aroma components (such as β-damascenone). Calculate aroma retention rate = (aroma component content at the end of storage period / aroma component content at the beginning of storage period) × 100%. For specific GC conditions, refer to the Quantitative Analysis of Characteristic Osmanthus Aroma Components section in Test Example 3.

[0164] Total acidity determination: Use acid-base indicator neutralization titration method. The determination method refers to the total acidity determination part in Test Example 2.

[0165] Determination of microbial indicators:

[0166] Determination of total colony count: The plate count method (according to GB 4789.2-2016, "Determination of total colony count in food microbiological examination") was used. 1 mL of sample was serially diluted, and the dilutions were spread on nutrient agar medium. The colonies were counted after incubation at 37°C for 48-48 hours.

[0167] Yeast and mold counts: Determine using the plate count method (according to GB 4789.15-2016, "Food Microbiological Examination - Enumeration of Molds and Yeasts"). Serially dilute 1 mL of sample. Spread the dilutions onto rose bengal sodium agar. Incubate at 28°C for 72 hours and count yeast and mold colonies.

[0168] 1.2 Shelf life stability test results

[0169] After the shelf life stability test of each rice wine sample, the average value data are shown in Table 4, Table 5 and Table 6;

[0170] Table 4. Changes in osmanthus aroma retention rate (%) of each rice wine sample with storage time

[0171]

[0172]

[0173] Table 5. Changes in total acidity (g / L) of each rice wine sample with storage time

[0174] Sample number 0 months 1 month 3 months 6 months Example 1 2.89 2.95 3.08 3.15 Example 2 3.12 3.2 3.35 3.42 Example 3 3.05 3.11 3.24 3.3 Comparative Example 1 2.21 2.45 2.88 3.21 Comparative Example 2 3.56 3.68 3.85 4.02 Comparative Example 3 2.75 2.89 3.05 3.18

[0175] Table 6. Changes in microbial counts (CFU / mL) of each rice wine sample over storage time

[0176]

[0177] From the shelf life stability test results in Tables 4, 5 and 6, it can be seen that the new osmanthus rice wine prepared in Examples 1, 2 and 3 showed significantly better stability than the comparative example product during the simulated storage period, especially in terms of retention of osmanthus aroma and microbial control.

[0178] In terms of the retention rate of sweet osmanthus fragrance, the example products can still maintain more than 80% of the fragrance after storage for 6 months. For example, the retention rate of sweet osmanthus fragrance in Example 3 reaches 86.0%. This directly proves the effectiveness of the fragrance microencapsulation / embedding technology adopted by the present invention. The edible embedding matrix (such as β-cyclodextrin, gum arabic, hydrolyzed casein or soy protein isolate) provides a physical barrier to the sweet osmanthus fragrance components (such as β-damascenone and linalool) by forming a microcapsule structure, effectively reducing the volatilization, oxidation and degradation rate of the fragrance substances during storage. In contrast, due to the lack or ineffective use of this technology in Comparative Examples 1, 2 and 3, the retention rate of sweet osmanthus fragrance dropped sharply after storage for 6 months. Among them, the aroma retention rate of Comparative Example 3 was only 50.1%, highlighting the important contribution of microencapsulation to the stability of fragrance.

[0179] In terms of total acidity, the Example products showed a gentle change during storage, with a small increase. This demonstrates that the intelligent fermentation process control technology and post-sterilization treatment employed in this invention effectively inhibit microbial activity and the production of undesirable acids during storage. Precise pH control and fermentation endpoint management ensured stable product acidity before filling. However, the Comparative Examples, particularly Comparative Examples 1 and 2, showed a significant increase in total acidity during the later stages of storage. This may be due to incomplete fermentation, residual microbial activity, or incomplete post-sterilization, resulting in continued microbial metabolism and acidic production during storage.

[0180] More importantly, in terms of microbial indicators, the total colony counts and yeast and mold counts of Example 1, Example 2 and Example 3 were always kept below the detection limit (<10 CFU / mL) during the 6-month storage period. This strongly demonstrates the effectiveness of the pasteurization or precision membrane filtration sterilization technology adopted by the present invention, as well as the strict control of microbial contamination in the overall production process. Comparative Example 1 and Comparative Example 2 showed microbial growth after 1 month of storage, and the total colony count increased significantly after 6 months, indicating that their sterilization effect was poor or that the sanitary control of the production process was insufficient. Although Comparative Example 3 had better microbial control in the early stage, its aroma stability was still significantly different from that of the examples. Based on the above test results, the present invention effectively improved the storage stability of the new osmanthus rice wine through an integrated technical solution, extended the shelf life of the product, and ensured the sensory quality and edible safety of the product throughout its shelf life.

[0181] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A novel sweet-scented osmanthus rice wine, characterized in that: The rice wine comprises a fermentation product of the following components: Glutinous rice: 70%-90% of the total raw material dry weight; Non-Saccharomyces fermentation bacteria: accounting for 10%-20% of the total viable bacteria count of the inoculant, with viable bacteria count ≥ 1.0×10 10 CFU / g; Saccharomyces cerevisiae fermentation flora: 80%-90% of the total viable bacteria count, viable bacteria count ≥ 1.0×10 10 CFU / g≥1.0×10 10 CFU / g; Osmanthus aroma component: added in the form of osmanthus extract, accounting for 0.002%-0.005% of the dry weight of glutinous rice; Enzyme preparation: selected from β-glucosidase and / or rhamnosidase, with enzyme activity unit ≥500U / mg, and added in an amount of 100-300U / kg dry glutinous rice; Inductive trace ions: selected from zinc sulfate and / or magnesium sulfate, added in an amount of 0.0001%-0.0005% of the dry weight of glutinous rice; Specific low-concentration carbohydrate precursor: selected from isomalto-oligosaccharides and / or fructo-oligosaccharides, added in an amount of 0.01%-0.05% of the dry weight of glutinous rice; and Edible aroma embedding matrix: selected from β-cyclodextrin and / or gum arabic and / or hydrolyzed casein and / or soy protein isolate, wherein the added amount of edible polysaccharide is 0.5%-1.5% w / v, or the added amount of specific protein is 0.2%-0.8% w / v.

2. A novel sweet-scented osmanthus rice wine according to claim 1, characterized in that: The non-saccharomyces cerevisiae fermentation flora is selected from one or more of Torulaspora delbrueckii, Pichiakluyveri or Lachanceathermotolerans.

3. A novel sweet-scented osmanthus rice wine according to claim 1, characterized in that: The sweet osmanthus aroma components exist in the form of stable glycosides or esters after enzymatic conversion, and are microencapsulated or embedded in the edible aroma embedding matrix.

4. A brewing process for a novel sweet-scented osmanthus rice wine, applied to the novel sweet-scented osmanthus rice wine according to any one of claims 1 to 3, characterized in that: The following steps are involved: Glutinous rice pretreatment: wash, soak, steam and cool the glutinous rice to reduce the temperature to 25-30℃; The first stage of fermentation: Inoculate a non-Saccharomyces yeast colony, add inducing trace ions and specific low-concentration sugar precursors, and ferment at a temperature of 20-22°C. Simultaneously, the concentration of volatile organic compounds during the fermentation process is monitored online in real time. Second stage fermentation: After the first stage fermentation is completed, the brewer's yeast flora is inoculated, and osmanthus extract and enzyme preparation are added. Fermentation is carried out at a temperature of 23-25°C, and intelligent feedback control is carried out based on real-time online monitoring data; Aroma microencapsulation and aging: After the second stage of fermentation, the wine is preliminarily treated and an edible aroma embedding matrix is ​​added for microencapsulation or embedding, followed by low-temperature aging.

5. The brewing process of a novel sweet-scented osmanthus rice wine according to claim 4, characterized in that: The soaking time of the glutinous rice is 8-12 hours, and the cooking time is 30-45 minutes.

6. The brewing process of a novel sweet-scented osmanthus rice wine according to claim 4, characterized in that: In the first stage of fermentation, the inoculation amount of the non-brewer's yeast flora accounts for 10%-20% of the total yeast inoculation amount, the inducible trace ions are zinc sulfate and / or magnesium sulfate, and the added amount is 0.0001%-0.0005% of the dry basis mass of glutinous rice; the specific low-concentration carbohydrate precursors are isomalto-oligosaccharides and / or fructooligosaccharides, and the added amount is 0.01%-0.05% of the dry basis mass of glutinous rice. The first stage of fermentation lasts for 2-3 days.

7. The brewing process of a novel sweet-scented osmanthus rice wine according to claim 4, characterized in that: In the first stage of fermentation, the inoculation amount of the non-brewer yeast was 1.0×10 6 -5.0×10 6 CFU / g glutinous rice dry basis.

8. The brewing process of a novel sweet-scented osmanthus rice wine according to claim 4, characterized in that: In the second stage of fermentation, the inoculation amount of the brewer's yeast community accounts for 80%-90% of the total yeast inoculation amount, the added amount of the osmanthus extract is 0.002%-0.005% of the dry mass of glutinous rice, the enzyme preparation is β-glucosidase and / or rhamnosidase, and the added amount is 100-300 U / kg dry mass of glutinous rice. The second stage of fermentation lasts for 5-7 days.

9. The brewing process of a novel sweet-scented osmanthus rice wine according to claim 4, characterized in that: The intelligent feedback control includes automatically adjusting the fermentation temperature, stirring speed and / or pH value according to the real-time online monitoring of the alcohol concentration, residual sugar content and change trends of the sweet osmanthus aroma components.

10. The brewing process of a novel sweet-scented osmanthus rice wine according to claim 4, characterized in that: In the aroma microencapsulation and aging, the edible aroma embedding matrix is ​​selected from β-cyclodextrin and / or gum arabic, and the addition amount thereof is 0.5%-1.5% w / v; and / or selected from hydrolyzed casein and / or soy protein isolate, and the addition amount thereof is 0.2%-0.8% w / v; the low-temperature aging and aging temperature is 4-8°C, and the aging time is 1-2 weeks.

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