Preparation method of charcoal-burning flavor glutinous corn fermented wine

Abstract

This invention discloses a method for preparing a charcoal-roasted flavored fermented glutinous corn wine. It belongs to the field of fermented wine technology. This invention aims to solve the problems of limited product variety and flavor in current low-alcohol fermented wine products on the market, and to develop a fresh glutinous corn fermented wine with a unique charcoal-roasted flavor. The charcoal-roasted flavored fresh glutinous corn fermented wine is light to dark caramel in color, crystal clear, with a uniform texture, and free of suspended matter and sediment. Its aroma is rich and layered, incorporating a unique roasted aroma on the basis of the characteristic sweet grain aroma of fresh glutinous corn, harmoniously unified with the wine aroma.

Description

Technical Field

[0001] This invention relates to the field of fermented wine technology, and more specifically to a method for preparing a charcoal-roasted flavored fermented corn wine. Background Technology

[0002] Waxy corn is a mutant of maize endosperm traits, also known as sticky corn or waxy corn. It is an agricultural product with a unique taste and nutritional value (including carbohydrates, nitrogenous compounds, fats, and reducing sugars), and has broad application potential in the food processing and consumer markets. While there is considerable research on waxy corn germplasm resources and genetic breeding, cultivation physiology and techniques, and its nutritional components and functional characteristics, research on its processing, utilization, and product development in the industry and market is relatively limited, hindering the development of related food products.

[0003] With the continuous development of food culture and the increasingly diverse consumption demands of consumers, low-alcohol fermented beverages (0.5-7% vol), as a historically significant alcoholic drink, are gradually gaining attention. Researchers have conducted in-depth discussions on the production process, quality control, flavor improvement, and health benefits of low-alcohol fermented beverages. However, the current market for low-alcohol fermented beverages still suffers from the following shortcomings: ① Limited product variety, with most being rice wine and no fermented beverages made from glutinous corn being reported; ② Limited flavor profile, particularly the lack of reports on charcoal-flavored fermented beverages.

[0004] Therefore, how to provide a low-alcohol fermented wine with a charcoal-roasted flavor made from glutinous corn is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a method for preparing charcoal-roasted flavored fermented glutinous corn wine.

[0006] This invention provides a charcoal-roasted flavored fermented glutinous corn wine and optimizes the liquefaction, saccharification, and fermentation processes. The technical challenges of this invention include the selection of suitable glutinous corn raw materials and the innovation of new flavor-forming processes. Regarding the selection of suitable glutinous corn raw materials, this invention compares the nutritional content of commercially available fresh glutinous corn from different origins and varieties, and deduces the fermentation flavor formation mechanism to select varieties, including: Zhenghuangnuo 2 from Inner Mongolia Autonomous Region, Meiyu 27 from Guangxi, Nongkeyu 368 from Ningxia, Wannuo 2000 from Shuangyashan, Fuerjinnuo 195 from Qiqihar, Jinnuo 262 from Jilin, and Bainuo 996 from Liaoning. Regarding the innovation of new flavor-forming processes, since the formation of charcoal-roasted flavor requires strict control of the reaction temperature, this invention comprehensively considers the formation of both total nutrition and flavor, and based on this, selects suitable amino acid types and amounts, and optimizes the charcoal roasting process.

[0007] Compared to other raw materials, it is important to note that fresh glutinous corn has a higher content of amylopectin and a lower content of reducing sugars. This requires a more sophisticated liquefaction and saccharification process to improve starch conversion rate and achieve the expected alcohol content of the fermented wine. In addition, some amino acids are relatively lacking in fresh glutinous corn, so the design should consider the dual effects of complete nutrition and the formation of charcoal-roasted flavor.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0009] A method for preparing a charcoal-roasted flavored fermented corn wine includes the following steps: (1) Raw material pretreatment: After the fresh glutinous corn kernels are removed, they are blanched, cooled and frozen to obtain frozen corn kernels; (2) Thawing: The frozen corn kernels are thawed by microwave to obtain thawed corn kernels; (3) Steaming: The thawed corn kernels are steamed to obtain steamed corn kernels; (4) Grinding: The steamed corn kernels are ground with water to obtain corn slurry; (5) Liquefaction: α-amylase is added to the corn slurry to liquefy it, and a liquefied liquid is obtained; Liquefaction parameters: α-amylase addition amount 6~12 U / g, temperature 79~91℃, pH 6.2~6.6, time 75~91min; (6) Saccharification: Add saccharifying enzyme to the liquefied liquid to perform saccharification, and obtain a saccharified liquid; Saccharification parameters: saccharifying enzyme addition of 190~250 U / g, temperature of 70~82℃, pH of 6.2~6.6, and time of 100~180 min; (7) Fermentation: Add brewing yeast to the saccharified liquid for fermentation to obtain fermented base wine; Fermentation parameters: yeast addition 0.6~1.2%, temperature 22~28℃, pH 4.2~4.6, time 40~56h; (8) Charcoal burning: Fructose and complex amino acids are added to the fermented base wine to carry out Maillard reaction, thereby obtaining the charcoal-burnt flavored fresh glutinous corn fermented wine; Charcoal firing parameters: fructose and compound amino acid additions are both 1-3%, temperature is 90-100℃, pH is 5.4-5.8, and time is 3.25-5.25h.

[0010] Furthermore, the scalding parameters in step (1) are: scalding in water at 95~100℃ for 20~25 minutes.

[0011] Furthermore, the thawing parameters in step (2) are: microwave power of 1000~1200w for thawing, and thawing time of 2~3min.

[0012] Furthermore, the steaming parameters in step (3) are: steaming for 15~20 minutes.

[0013] Furthermore, the composite amino acid comprises the following components in parts by weight: 8-9 parts aspartic acid, 6-7 parts threonine, 2-3 parts serine, 8-9 parts glutamic acid, 3-4 parts proline, 6-7 parts glycine, 7-8 parts alanine, 6-7 parts valine, 0.5-1 part methionine, 0.5-1 part isoleucine, 11-12 parts leucine, 1-2 parts tyrosine, 4-5 parts phenylalanine, 8-9 parts lysine, 5-6 parts histidine, and 2-3 parts arginine.

[0014] Furthermore, Liquefaction parameters: α-amylase addition was 9 U / g, temperature was 85℃, pH was 6.4, and time was 85 min; Saccharification parameters: saccharifying enzyme addition of 220 U / g, temperature of 75℃, pH of 6.4, and time of 140 min; Fermentation parameters: yeast addition 0.9%, temperature 25℃, pH 4.4, time 50h; Charcoal firing parameters: fructose and compound amino acid additions are both 2%, temperature is 95℃, pH is 5.6, and time is 4.25h.

[0015] Furthermore, the corn variety mentioned is Bai Nuo 996.

[0016] Furthermore, the brewing yeast is a highly active dry brewing yeast.

[0017] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects: This invention aims to address the current market's problems with low-alcohol fermented beverages, such as limited product variety and flavor diversity, by developing a fresh glutinous corn fermented wine with a unique charcoal-roasted flavor. The charcoal-roasted fresh glutinous corn fermented wine ranges in color from light to dark caramel, is crystal clear, has a uniform texture, and is free of suspended matter and sediment. Its aroma is rich and layered, incorporating a unique roasted flavor on top of the characteristic sweet grain aroma of fresh glutinous corn, harmoniously blending with the overall alcoholic aroma. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0019] Figure 1 This is the charcoal-roasted flavored fermented glutinous corn wine prepared in Example 1 of the present invention.

[0020] Figure 2 This is the charcoal-roasted flavored fermented glutinous corn wine prepared in Example 2 of the present invention.

[0021] Figure 3 The results show the viscosity values ​​of fresh glutinous corn kernels in Experiment 2 of this invention.

[0022] Figure 4 The results show the hardness values ​​of fresh glutinous corn kernels in Experiment 3 of this invention.

[0023] Figure 5 The results show the adhesive properties of fresh glutinous corn kernels after different steaming times in Experiment 4 of this invention.

[0024] Figure 6 This is a stacking curve of volatile aroma components in Experiment 9 of the present invention. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] The yeast used below is commercially available Danboli brewing high-activity dry yeast (heat resistant type).

[0027] Example 1 A method for brewing a charcoal-roasted flavored fermented corn wine, the specific steps of which are as follows: (1) Raw material preservation: Fresh glutinous corn of Liaoning Bainuo 996 was threshed, blanched in 95℃ water for 20 minutes, cooled quickly after blanching, and frozen in a -20℃ cold storage.

[0028] (2) Thawing: Take out the frozen fresh glutinous corn kernels, microwave power is set to 1000w for thawing, and the thawing time is 2min.

[0029] (3) Steaming: Steam for 15 minutes after the steamer is steaming.

[0030] (4) Grinding: After steaming, add water at a ratio of 1:2 (1g of fresh glutinous corn kernels and 2mL of water), and grind the steamed fresh glutinous corn kernels using an 80-mesh filter. Grinding the fresh glutinous corn kernels is a mechanical process that changes the shape of the fresh glutinous corn, so that the amylopectin in the fresh glutinous corn is released from the cells in large quantities and evenly dispersed in the slurry, which can be fully gelatinized in the subsequent liquefaction process.

[0031] (5) Liquefaction process: α-amylase addition amount is 6U / g, temperature is 79℃, pH is 6.2, time is 75min.

[0032] (6) Saccharification process: The amount of saccharifying enzyme added is 190 U / g, the temperature is 70℃, the initial pH is 6.2, and the time is 100 min.

[0033] (7) Fermentation process: The amount of yeast added is 0.6%, the temperature is 22℃, the pH is 4.2, and the time is 40h.

[0034] (8) Charcoal burning process: The amount of fructose and compound amino acids added is 1%, the temperature is 90℃, the pH is 5.4, and the time is 3.25h.

[0035] The compound amino acid comprises the following components in parts by weight: 8 parts aspartic acid, 6 parts threonine, 2 parts serine, 8 parts glutamic acid, 3 parts proline, 6 parts glycine, 7 parts alanine, 6 parts valine, 0.5 parts methionine, 0.5 parts isoleucine, 11 parts leucine, 1 part tyrosine, 4 parts phenylalanine, 8 parts lysine, 5 parts histidine, and 2 parts arginine.

[0036] The charcoal-roasted flavored fermented corn wine is light caramel in color, smooth and glossy, with a uniform texture and no suspended matter or sediment. Figure 1 Its aroma is rich and layered, with a unique caramel aroma that blends in with the sweet grain aroma of fresh glutinous corn, and is harmoniously integrated with the aroma of wine.

[0037] Example 2 A method for brewing a charcoal-roasted flavored fermented corn wine, the specific steps of which are as follows: (1) Raw material preservation: Fresh glutinous corn of Liaoning Bainuo 996 was threshed, blanched in 100℃ water for 25 minutes, cooled quickly after blanching, and frozen in a -20℃ cold storage.

[0038] (2) Thawing: Take out the frozen fresh glutinous corn kernels, microwave power is set to 1200w for thawing, and the thawing time is 3min.

[0039] (3) Steaming: Steam for 20 minutes after the steamer is steaming.

[0040] (4) Grinding: After steaming, add water at a ratio of 1:2 (1g of fresh glutinous corn kernels and 2mL of water), and grind the steamed fresh glutinous corn kernels using an 80-mesh filter. Grinding the fresh glutinous corn kernels is a mechanical process that changes the shape of the fresh glutinous corn, so that the amylopectin in the fresh glutinous corn is released from the cells in large quantities and evenly dispersed in the slurry, which can be fully gelatinized in the subsequent liquefaction process.

[0041] (5) Liquefaction process: α-amylase addition amount is 12U / g, temperature is 91℃, pH is 6.6, time is 91min.

[0042] (6) Saccharification process: The amount of saccharifying enzyme added is 250 U / g, the temperature is 82℃, the initial pH is 6.6, and the time is 180 min.

[0043] (7) Fermentation process: yeast addition amount is 1.2%, temperature is 28℃, pH is 4.6, time is 56h.

[0044] (8) Charcoal burning process: The amount of fructose and compound amino acids added is 3%, the temperature is 100℃, the pH is 5.8, and the time is 5.25h.

[0045] The compound amino acid comprises the following components in parts by weight: 9 parts aspartic acid, 7 parts threonine, 3 parts serine, 9 parts glutamic acid, 4 parts proline, 7 parts glycine, 8 parts alanine, 7 parts valine, 1 part methionine, 1 part isoleucine, 12 parts leucine, 2 parts tyrosine, 5 parts phenylalanine, 9 parts lysine, 6 parts histidine, and 3 parts arginine.

[0046] The charcoal-roasted flavored fermented corn wine is light caramel in color, smooth and glossy, with a uniform texture and no suspended matter or sediment. Figure 2 Its aroma is rich and layered, with a unique caramel aroma that blends in with the sweet grain aroma of fresh glutinous corn, and is harmoniously integrated with the aroma of wine.

[0047] Comparative Example 1 Raw material selection Different nutrient contents have varying effects on the quality of charcoal-roasted fresh glutinous corn fermented wine. Higher starch content allows for liquefaction and saccharification, converting starch into reducing sugars usable by yeast, which are then converted into alcohol and carbon dioxide to achieve the appropriate alcohol content. A suitable amount of nitrogenous compounds facilitates the formation of a charcoal-roasted flavor during the subsequent Maillard reaction process. A suitable fat content helps the fermented wine develop a better flavor. This study compares the effects of commercially available fresh glutinous corn from different origins and varieties on the fermentation of the wine.

[0048] The raw materials were replaced with Liaoning Bainuo 996 glutinous corn, and then with Zhenghuangnuo No. 2 glutinous corn from Inner Mongolia Autonomous Region, Meiyu 27 glutinous corn from Guangxi, Nongkeyu 368 glutinous corn from Ningxia, Wannuo 2000 glutinous corn from Shuangyashan, Fuerjinnuo 195 glutinous corn from Qiqihar, and Jinnuo 262 glutinous corn from Jilin. The remaining operations were the same as in Example 1 (without charcoal roasting).

[0049] Experiment 1 (1) The nutritional components of Zhenghuang Nuo No. 2 from Inner Mongolia Autonomous Region, Meiyu 27 from Guangxi, Nongke Yu 368 from Ningxia, Wannuo 2000 from Shuangyashan, Fuerjin Nuo 195 from Qiqihar, Jinnuo 262 from Jilin, and Bainuo 996 from Liaoning were determined. The determination methods are as follows: Starch content determination: The starch content was determined by the enzymatic hydrolysis method in GB5009.9-2023.

[0050] Nitrogen compound content determination: The nitrogen compound content was determined by the Kjeldahl method in GB5009.5-2025.

[0051] Fat content determination: Fat content was determined by Soxhlet extraction method as specified in GB5009.6-2016.

[0052] Determination of reducing sugar content: The reducing sugar content was determined by the acid hydrolysis-Rhein-Ennon method in GB5009.8-2023.

[0053] Moisture content determination: The moisture content was determined by the direct drying method in GB5009.3-2016.

[0054] Table 1. Nutritional composition of fresh waxy corn from different origins and varieties.

[0055] Based on the results in Table 1, the Bai Nuo 996 variety of fresh glutinous corn was ultimately selected as the raw material for charcoal-roasted fresh glutinous corn fermentation wine. Its starch content (29.93±0.18a%) and reducing sugar content (1.85±0.21a%) were the highest, providing sufficient carbon source for fermentation and accelerating fermentation initiation; the nitrogen compound content (4.14±0.09abc%) and fat content (2.39±0.19a%) were within suitable ranges, ensuring both yeast activity and Maillard reaction substrate supply while reducing the process burden; the moisture content (57.74±0.42bc%) was suitable, resulting in the best nutrient retention rate.

[0056] (2) Determine the alcohol content of the fermented wine (without charcoal burning) prepared in Example 1 and Comparative Example 1.

[0057] Alcohol content determination: The alcohol content was determined using the alcohol meter method in GB5009.225-2023.

[0058] Table 2. Analysis of alcohol content in fermented wine made from fresh glutinous corn of different origins and varieties.

[0059] As shown in Table 2, the fermented wine prepared using Bai Nuo 996 as raw material has the highest alcohol content and can reach the expected alcohol content of the original wine.

[0060] (3) Sensory evaluation of the fermented wines (without charcoal burning) prepared in Example 1 and Comparative Example 1.

[0061] Table 3 Sensory Evaluation Table for Original Flavor Fresh Glutinous Corn Fermented Wine

[0062] Table 4 Scoring Table for Fermented Wine from Fresh Waxy Corn of Different Origins and Varieties

[0063] As shown in Table 4, the fermented wine prepared using Bai Nuo 996 as raw material had the highest sensory score.

[0064] In summary, based on the nutritional composition tables of fresh glutinous corn from different origins and varieties, the alcohol content of fermented wine, and the sensory evaluation results, the raw material variety selected is Bainuo 996.

[0065] Comparative Example 2 Optimization of scalding and bleaching parameters Fresh glutinous corn has a high starch content, and starch is prone to retrogradation. Blanching fresh glutinous corn not only prevents starch retrogradation but also deactivates enzymes. Heat treatment inactivates various enzymes in fresh glutinous corn, preventing the destruction of nutrients during frozen storage. Blanching also sterilizes and kills microorganisms, bacteria, and insect eggs attached to the surface of the corn kernels, ensuring food safety. After blanching, the fresh glutinous corn must be rapidly cooled immediately, quickly lowering its core temperature to below 25°C. This is to quickly terminate the heat treatment process and prevent residual heat from causing the corn to soften excessively.

[0066] Remove the kernels from fresh glutinous corn cobs (white glutinous 996). Then, add an appropriate amount of clean water to a boiler and heat it to 80-100℃. Blanch the fresh glutinous corn kernels for 5-25 minutes, then remove them and quickly cool them with cold water. Specific parameters are: 80℃ for 5 minutes; 80℃ for 10 minutes; 85℃ for 10 minutes; 90℃ for 15 minutes; 95℃ for 25 minutes; 95℃ for 20 minutes; 100℃ for 20 minutes.

[0067] Experiment 2 Sensory evaluation scores and the viscosity of fresh waxy corn were used as evaluation indicators to determine the effects of blanching temperature and time on fresh waxy corn. Using viscosity as an evaluation indicator for the preservation of fresh waxy corn after threshing and blanching essentially transforms the "enzyme inactivation effect" into a quantifiable objective indicator. A suitable viscosity is beneficial for subsequent processing, with an optimal viscosity range of 0.3–0.5 N. The corn used in Comparative Example 2 after blanching was used as the test subject.

[0068] Table 5 Sensory Evaluation Table for Hot and Scalded Products

[0069] Table 6 Sensory Scoring Table for Hot Water Bleaching

[0070] Figure 3 The results show the viscosity values ​​of fresh glutinous corn kernels after blanching.

[0071] Based on sensory evaluation and the viscosity of fresh glutinous corn kernels, the optimal blanching conditions were determined to be a blanching temperature of 95-100℃ and a blanching time of 20-25 minutes.

[0072] Comparative Example 3 Optimization of thawing parameters After blanching, the fresh glutinous corn kernels are rapidly frozen primarily to inhibit microbial activity and prevent quality deterioration. The blanched kernels are then sealed and frozen in a cold storage facility at -20°C to -25°C, with temperature fluctuations within ±1°C, for temporary storage of the raw materials. For frozen glutinous corn, thawing is a crucial pretreatment step. The main purpose of thawing is to improve juice extraction efficiency. By moderately softening the kernels, they become easier to break down during grinding, thus increasing the juice yield. Ideally, the kernels should be slightly soft but still contain a few ice crystals in the center; this state minimizes the loss of juice and flavor compounds. If room temperature is used for thawing, it not only takes a long time but also carries the risk of microbial growth and significant juice loss. Using warm water or running water for thawing will cause the loss of nutrients in the fresh glutinous corn kernels and alter their original flavor. Microwave thawing significantly reduces the thawing time, but the time and power must be strictly controlled. Higher power can easily lead to localized overheating, causing protein denaturation and affecting the uniformity of subsequent processing.

[0073] The thawing method was microwave thawing, and the processing conditions were optimized. Thawing conditions: thawing was performed at a power of 600~1400W for 1~5 minutes. Specific parameters were: 600W for 1 minute; 800W for 3 minutes; 1000W for 5 minutes; 1200W for 2 minutes; 1000W for 3 minutes; 1400W for 4 minutes; and 1400W for 5 minutes. Blanching parameters were the same as in Example 1.

[0074] Experiment 3 Sensory evaluation and the hardness of fresh waxy corn kernels were used as evaluation indicators. Hardness was chosen as the evaluation indicator for thawed frozen fresh waxy corn kernels, essentially quantifying the integrity of cell structure through physicochemical indicators. Selecting a moderate hardness after thawing is beneficial for subsequent processing; the suitable hardness range is 0.7~0.8 N. The tested object was corn from Comparative Example 3 after thawing.

[0075] Table 7 Sensory Evaluation Table for Thawing

[0076] Table 8 Sensory Scoring Table for Thawing

[0077] Figure 4 The results show the hardness of fresh glutinous corn kernels after thawing.

[0078] Using a sensory scoring table and a bar chart of the hardness of fresh glutinous corn kernels, the optimal thawing conditions were determined to be a microwave power of 1000~1200w and a thawing time of 2~3min.

[0079] Comparative Example 4 Steaming parameters optimization The thawed fresh glutinous corn kernels are steamed, primarily to bring them to an optimal processing state through heating, facilitating subsequent liquefaction processes. Impurities are removed from the thawed kernels, and they are steamed for 10-30 minutes after the steam comes into play in the steamer. Specific parameters are: 10 min, 15 min, 20 min, 25 min, and 30 min. Blanching and thawing parameters are the same as in Example 1.

[0080] Experiment 4 Sensory evaluation and the adhesiveness of fresh waxy corn were used as evaluation indicators. Using adhesiveness as the evaluation indicator for steamed fresh waxy corn essentially quantifies the degree of starch gelatinization, molecular structure, and processing fluidity. Moderate adhesiveness is beneficial for subsequent processing, with an optimal adhesiveness range of 0.6–0.7 N. The tested corn was the result of steaming treatment in Comparative Example 4.

[0081] Table 9 Sensory Evaluation Table for Steaming

[0082] Table 10 Sensory Scoring Table for Steaming

[0083] Figure 5 Results of adhesive properties of fresh glutinous corn kernels after different steaming times.

[0084] Based on sensory evaluation and the results of adhesiveness of fresh glutinous corn kernels at different steaming times, a steaming time of 15-20 minutes was selected.

[0085] Comparative Example 5 Optimization of liquefaction process parameters Fresh glutinous corn slurry is rich in amylopectin, and after heating and gelatinizing, it has extremely high viscosity and a thick texture. The liquefaction process can improve the processing performance of fresh glutinous corn slurry, reduce its viscosity, and create conditions for subsequent saccharification processes.

[0086] The liquefaction process conditions were optimized by adding 3~15 U / g of α-amylase and water bathing for 59~91 min at a temperature of 73~97℃ and a pH of 6~6.8. The specific parameters are as follows: ① Enzyme addition 6 U / g, temperature 85℃, pH 6.4, time 75 min; ② Enzyme addition 9 U / g, temperature 85℃, pH 6.4, time 75 min; ③ Enzyme addition 12 U / g, temperature 85℃, pH 6.4, time 75 min; ④ Enzyme addition 9 U / g, temperature 85℃, pH 6.4, time 83 min; ⑤ Enzyme addition 9 U / g, temperature 85℃, pH 6.4, time 91 min; ⑥ Enzyme addition 9 U / g, temperature 79℃, pH 6.4, time 75 min; ⑦ Enzyme addition 9 U / g, temperature 91℃, pH 6.4, time 75 min; ⑧ Enzyme addition 9 U / g, temperature 85℃, pH 6.2, time 75 min; ⑨ Enzyme addition 9 U / g, temperature 85℃, pH 6.6, time 75 min. ⑩ Enzyme addition amount 3U / g, temperature 85℃, pH 6.4, time 75min; Enzyme addition amount 9 U / g, temperature 85℃, pH 6.4, time 59 min; Enzyme addition amount 9 U / g, temperature 73℃, pH 6.4, time 75 min; Enzyme addition amount 9 U / g, temperature 85℃, pH 6, time 75 min; Enzyme addition amount 3 U / g, temperature 97℃, pH 6.8, time 59 min; Enzyme addition was 15 U / g, temperature was 73℃, pH was 6, and time was 91 min. Blanching, thawing, steaming, and grinding parameters were the same as in Example 1.

[0087] Experiment 5 The glucose equivalent value (DE value) was used as the evaluation index. The test object was corn after liquefaction treatment in Comparative Example 5. The optimal DE value was 16%~23%.

[0088] Determination and calculation of DE value: Reducing sugar content: The reducing sugar content was determined using the acid hydrolysis-Rhein-Ennon method in GB5009.8-2023.

[0089] Determination of dry matter content: The dry matter content (°Bx) of the sample was determined by refractive index method.

[0090] The formula for calculating the DE value is as follows: DE value = ( / ) × 100%.

[0091] Table 11 DE values ​​under different liquefaction process conditions

[0092] As shown in Table 11, the optimal liquefaction process conditions after optimization are: α-amylase addition of 6~12 U / g, temperature of 79~91℃, initial pH of 6.2~6.6, time of 75~91 min, and final DE value of 16%~23%.

[0093] Comparative Example 6 Optimization of saccharification process parameters Microorganisms such as yeast cannot directly utilize starch or even dextrin, but they can efficiently ferment monosaccharides or disaccharides such as glucose and maltose. The saccharification process uses saccharifying enzymes to convert the dextrin and residual starch generated in the liquefaction process into glucose, laying the foundation for subsequent alcoholic fermentation.

[0094] The saccharification process conditions were optimized by adding 130~250 U / g saccharifying enzyme and water bathing for 60~220 min at a temperature of 58~82℃ and a pH of 6~6.8. The specific parameters are as follows: ① Enzyme addition 190 U / g, temperature 70℃, pH 6.4, time 140 min; ② Enzyme addition 220 U / g, temperature 70℃, pH 6.4, time 140 min; ③ Enzyme addition 250 U / g, temperature 70℃, pH 6.4, time 140 min; ④ Enzyme addition 190 U / g, temperature 70℃, pH 6.4, time 100 min; ⑤ Enzyme addition 190 U / g, temperature 70℃, pH 6.4, time 180 min; ⑥ Enzyme addition 190 U / g, temperature 76℃, pH 6.4, time 140 min; ⑦ Enzyme addition 190 U / g, temperature 82℃, pH 6.4, time 140 min; ⑧ Enzyme addition 190 U / g, temperature 70℃, pH 6.4, time 140 min; ⑧ Enzyme addition 190 U / g, temperature 70℃, pH 6.4, time 140 min; ☐ 6.2, time 140 min; ⑨ Enzyme addition 190 U / g, temperature 70℃, pH 6.6, time 140 min; ⑩ Enzyme addition 130 U / g, temperature 70℃, pH 6.4, time 140 min; Enzyme addition amount 190 U / g, temperature 70℃, pH 6.4, time 60 min; Enzyme addition amount 190 U / g, temperature 58℃, pH 6.4, time 140 min; Enzyme addition amount 190 U / g, temperature 70℃, pH 6.8, time 140 min; Enzyme addition amount 130 U / g, temperature 82℃, pH 6.8, time 60 min; Enzyme addition was 250 U / g, temperature was 58℃, pH was 6, and time was 220 min. Blanching, thawing, steaming, grinding, and liquefaction parameters were the same as in Example 1.

[0095] Experiment 6 Using total sugar content as the evaluation index, the test subject was corn after saccharification treatment in Comparative Example 6, and the optimal total sugar content was 9.4~13 g / 100g.

[0096] Total sugar content determination: The total sugar content was determined using the acid hydrolysis-Rhein-Ennon method as specified in GB5009.8-2023.

[0097] Table 12 Total sugar content under different saccharification process conditions

[0098] The optimal saccharification process conditions were determined after optimization: the amount of saccharifying enzyme added was 190~250 U / g, the temperature was 70~82℃, the initial pH was 6.2~6.6, and the time was 100~180 min.

[0099] Comparative Example 7 Fermentation process optimization Alcoholic fermentation mainly utilizes the anaerobic metabolism of yeast to break down the reducing sugars in fresh glutinous corn syrup into alcohol and carbon dioxide.

[0100] The alcoholic fermentation process conditions were optimized by adding 0.3-1.5% brewing yeast and fermenting for 24-56 hours at a temperature of 19-31℃ and a pH of 4-4.8. The specific parameters are as follows: ① Yeast addition 0.6%, temperature 25℃, pH 4.4, time 40h; ② Yeast addition 0.9%, temperature 25℃, pH 4.4, time 40h; ③ Yeast addition 1.2%, temperature 25℃, pH 4.4, time 40h; ④ Yeast addition 0.6%, temperature 25℃, pH 4.4, time 40h; ⑤ Yeast addition 0.6%, temperature 25℃, pH 4.4, time 56h; ⑥ Yeast addition 0.6%, temperature 22℃, pH 4.4, time 40h; ⑦ Yeast addition 0.6%, temperature 28℃, pH 4.4, time 40h; ⑧ Yeast addition 0.6%, temperature 25℃, pH 4.2, time 40h; ⑨ Yeast addition 0.6%, temperature 25℃, pH 4.6, time 40h; ⑩ Yeast addition 0.3%, temperature 25℃, pH 4.2, time 40h; ⑨ Yeast addition 0.6%, temperature 25℃, pH 4.6, time 40h; ⑩ Yeast addition 0.3%, temperature 25℃, pH 4.4 ... 4.4, duration 40 hours; Yeast addition amount 0.6%, temperature 25℃, pH 4.4, time 24h; Yeast addition amount 0.6%, temperature 19℃, pH 4.4, time 40h; Yeast addition amount 0.6%, temperature 25℃, pH 4, time 40h; Yeast addition amount 0.3%, temperature 31℃, pH 4.8, time 24h; Yeast addition was 1.5%, temperature was 19℃, pH was 4, and time was 56 hours. The parameters for blanching, thawing, steaming, grinding, liquefaction, and saccharification were the same as in Example 1.

[0101] Experiment 7 Alcohol content was used as the evaluation index, and the test subject was the fermentation broth after fermentation treatment of Comparative Example 7. The optimal alcohol content was 4.9-5.3% vol.

[0102] Alcohol content determination: The alcohol content was determined using the alcohol meter method in GB5009.225-2023.

[0103] Table 13 Alcohol content under different fermentation conditions

[0104] After optimizing the process, the optimal fermentation conditions were determined to be: yeast addition of 0.6-1.2%, temperature of 22-28℃, pH of 4.2-4.6, and fermentation time of 40-56h.

[0105] Comparative Example 8 Charcoal roasting process optimization Charcoal roasting is a key process in the fermentation of charcoal-roasted fresh glutinous corn wine, forming its unique charcoal flavor and determining the product's distinctive light brown color, caramel aroma, and mellow taste. Since fresh glutinous corn lacks lysine, an essential amino acid, and is also low in flavor-related amino acids such as glycine, alanine, and aspartic acid, a compound amino acid (with the same components as in Example 1) was selected for addition.

[0106] The charcoal roasting process conditions were optimized by adding 1-5% fructose and compound amino acids, and reacting at a temperature of 80-100℃ and a pH of 5.2-6 for 1.25-5.25 hours. The specific parameters are as follows: ① 1% addition, 90℃ temperature, pH 5.6, 3.25h time; ② 2% addition, 90℃ temperature, pH 5.6, 3.25h time; ③ 3% addition, 90℃ temperature, pH 5.6, 3.25h time; ④ 3% addition, 90℃ temperature, pH 5.6, 4.25h time; ⑤ 3% addition, 90℃ temperature, pH 5.6, 5.25h time; ⑥ 3% addition, 95℃ temperature, pH 5.6, 3.25h time; ⑦ 3% addition, 100℃ temperature, pH 5.6, 3.25h time; ⑧ 3% addition, 90℃ temperature, pH 5.4, 3.25h time; ⑨ 3% addition, 90℃ temperature, pH 5.8, 3.25h time; ⑩ 5% addition, 90℃ temperature, pH 5.6, 3.25h time. Addition amount 3%, temperature 90℃, pH 5.6, time 1.25h; Addition amount 3%, temperature 80℃, pH 5.6, time 3.25h; Addition amount 3%, temperature 90℃, pH 5.2, time 3.25h; Addition amount 1%, temperature 100℃, pH 6, time 1.25h; The addition amount was 5%, the temperature was 80℃, the pH was 5.2, and the time was 5.25h. The parameters for blanching, thawing, steaming, grinding, liquefaction, saccharification, and fermentation were the same as in Example 1.

[0107] Experiment 8 Sensory evaluation and color difference scale were used as evaluation indicators, with the color difference scale (spectral colorimeter) as the core evaluation indicator. Essentially, it transforms the amount of melanoidins (characteristic products of Maillard reaction) generated and the color state into quantifiable objective parameters. Combined with sensory evaluation, the optimal process parameters were selected. The optimal sensory evaluation score was 72-90, and the optimal color difference value was 65-75.5. The test object was the fermented wine after the charcoal burning process of Comparative Example 8.

[0108] Table 14 Sensory Evaluation Table for Charcoal Roasting Process

[0109] Table 15 Sensory scores and color differences under different charcoal roasting conditions

[0110] The optimal process conditions were determined after optimization: fructose-amino acid addition of 1-3%, temperature of 90-100℃, pH of 5.4-5.8, and time of 3.25-5.25h.

[0111] Experiment 9 Analysis of new flavor components (1) Instruments: HS-20 headspace autosampler (Shimadzu Corporation), GCMS-QP2010 Ultra gas chromatograph-mass spectrometer.

[0112] (2) HS-20 conditions: The headspace sample was automatically injected. The headspace vial equilibration temperature was 80℃; the quantitative loop temperature was 110℃; the transfer line temperature was 120℃; the equilibration time was 60 min; and the injection time was 1 min.

[0113] (3) Gas chromatography-mass spectrometry conditions: GC conditions: The column was a DB-wax (30m × 0.25mm × 0.25µm); derivatized substances were separated using a constant flow of helium at 1 mL / min. 1 mL of sample was added to a 20 mL headspace vial and sealed. The injection port temperature was 255 ℃, initially set at 50 ℃ for 5.5 min, then increased to 220 ℃ at a rate of 5 ℃ / min, and then increased to 255 ℃ at a rate of 20 ℃ / min, held for 2.5 min.

[0114] MS conditions: Ionization mode: EI; Ion energy: 70 eV; Ion source temperature: 220 ℃; Interface temperature: 255℃; Quadrupole temperature: 155℃; Full scan mode; Scan range: 20~400 U.

[0115] The Relative Odor Activity (ROAV) method was used to define the ROAV that contributes most to the volatile flavor components of charcoal-roasted fresh glutinous corn fermented wine. stan The value is 100. Other volatile flavor components are calculated using the following formula: ROAV A =100×(C A / C stan )×(T stan / T A ).

[0116] In the formula: C A The relative content of volatile flavor compounds (%). C stan The threshold (μg / kg) of this volatile flavor compound; T stan The relative content (%) of volatile flavor compounds that contribute the most to the overall flavor. T A The threshold (μg / kg) of volatile flavor compounds that contribute most to the overall flavor.

[0117] (4) Test objects: Charcoal-roasted fresh glutinous corn fermented wine and original fresh glutinous corn fermented wine prepared in Example 1 (without charcoal roasting process, the rest of the operation is the same as in Example 1).

[0118] Figure 6 This is a stacking curve of volatile aroma components.

[0119] This analysis delves into the differences between charcoal-roasted and original-flavor fresh glutinous corn fermented wines from three dimensions: aroma composition, release dynamics, and flavor characteristics. In terms of aroma composition, the charcoal-roasted flavor boasts a richer composition, adding toasty and caramel notes to its fruity aromas of esters and alcohols. Regarding release dynamics, both wines exhibit relatively stable aroma development. As for flavor characteristics, the charcoal-roasted flavor emphasizes a mellow roasted character while maintaining a fresh and distinct fermentation profile.

[0120] Table 16 Composition and relative content of volatile components

[0121] Note: " / " indicates not detected or below the detection limit.

[0122] Fourteen aroma components were identified in the charcoal-roasted fermented wine, including six esters (3.01%), four alcohols (91.7%), and four aldehydes and their derivatives (5.29%). Based on the characteristics of charcoal roasting (caramel, nutty, and roasted aromas) and the results of HS-GC-MS analysis, ethyl acetate, acetaldehyde, 3-methylbutanal (isoamyl), isoamyl acetate, 2-methyl-1-propanol (isobutanol), and 3-methyl-1-butanol (isoamyl alcohol) were identified as key aroma components in the charcoal-roasted fresh glutinous corn fermented wine.

[0123] Table 17 ROAV of volatile flavor compounds in charcoal-roasted fresh glutinous corn fermented wine

[0124] Typically, the intensity of an aroma is expressed as the minimum concentration of aroma compounds required for its formation (called the threshold). In low-alcohol fermented wines made from grains such as glutinous corn and glutinous rice, ethyl acetate is the most stable ester compound with the lowest threshold and the most prominent flavor contribution, making it a "characteristic flavor marker" for this type of wine. Choosing it as a standard substance not only aligns with the actual samples but also conforms to industry research consensus, making the ROAV calculation results more comparable and convincing. Therefore, ethyl acetate is defined as the key flavor compound for charcoal-roasted fresh glutinous corn fermented wine, i.e., ROAV. stan =100. Table 17 lists only 12 substances with ROAV not less than 0.1. Compounds with ROAV ≥ 1 are actually the main flavor components of all analyzed samples; components with 0.1 ≤ ROAV < 1 play a modifying role in aroma.

[0125] As shown in Table 17, ethyl acetate, acetaldehyde, 3-methylbutanal (isopentanal), isoamyl acetate, 2-methyl-1-propanol (isobutanol), and 3-methyl-1-butanol (isoamyl alcohol) have a ROAV of not less than 1, and therefore can all be considered key volatile flavor compounds, exhibiting aromas such as fruity, sweet, green apple, and nutty notes. Six compounds—phenylethanol (2-phenylethanol), ethyl propionate, 1,1-diethoxyethane, ethyl butyrate, ethyl hexanoate, and ethyl octanoate—play an important modifying role in the volatile flavor components of charcoal-roasted fresh glutinous corn fermented wine.

[0126] Aroma analysis results show that ordinary fresh glutinous corn wine is mainly characterized by ester fruit aromas and alcohol aromas, while the key difference of charcoal-roasted fresh glutinous corn fermented wine lies in the formation of 3-methylbutyraldehyde. This component is only produced through the Maillard reaction during high-temperature charcoal roasting pretreatment and is the core marker that distinguishes the flavors of the two. At the same time, the charcoal roasting process increases the formation efficiency of esters and aromatic alcohols, making the flavor richer and more harmonious.

[0127] Comparative Example 9 The yeast was replaced with *Hansenula polymorpha* (Hong-S3), *Lan-S5* (Lan-S5), and Angel Yeast High-Activity Dry Yeast for Brewing, respectively, and the rest of the operation was the same as in Example 1.

[0128] Experiment 10 (1) Determine the alcohol content of the fermented wine prepared in Example 1 and Comparative Example 9.

[0129] Table 18 Analysis of alcohol content in fermented fresh glutinous corn wine made with different yeasts

[0130] (2) Based on the difference in alcohol content, Angel Yeast and Danbaoli high-activity dry yeast (heat-resistant type) were further analyzed. Headspace-gas chromatography-mass spectrometry analysis was performed on their fermented wines. The results are as follows: Table 19 Headspace-Gas Chromatography-Mass Spectrometry Analysis Results

[0131] Advantages of Danbaoli High-Activity Dry Yeast for Brewing (Heat-Resistant Type): ① Formation of characteristic fruity esters: Isoamyl acetate was detected, an important flavor compound generated by yeast through esterification during fermentation, imparting typical banana, pear, and other fruity aromas to the product. This substance was not detected in Angel Yeast's high-activity dry yeast fermented wine. This indicates that Danbaoli's high-activity dry yeast (heat-resistant type) has a more active ester synthesis metabolism, producing a more appealing aroma. ② Optimized alcohol composition: Danbaoli's high-activity dry yeast (heat-resistant type) fermented wine contains fewer higher alcohols and includes 2,3-butanediol, which can soften pungent odors and make the aroma more mellow. ③ Acids contribute to flavor balance: Acetic acid in Danbaoli's high-activity dry yeast (heat-resistant type) fermented wine enhances the refreshing and complex feel of the wine, while Angel Yeast fermented wine contains almost no acids, potentially leading to a monotonous flavor.

[0132] In summary, Danbaoli High-Activity Dry Yeast for Brewing (Heat-Resistant Type) produces a richer variety of esters during fermentation, especially isoamyl acetate, which imparts fruity aromas. Simultaneously, the alcohol and acid compositions are more harmonious, contributing to a richer, more layered flavor profile and a prominent fruity aroma. Therefore, Danbaoli High-Activity Dry Yeast for Brewing (Heat-Resistant Type) was chosen as the brewing yeast for charcoal-roasted fresh glutinous corn fermented wine.

[0133] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0134] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a charcoal-roasted flavored fermented glutinous corn wine, characterized in that, Includes the following steps: (1) Raw material pretreatment: After the fresh glutinous corn kernels are removed, they are blanched, cooled and frozen to obtain frozen corn kernels; (2) Thawing: The frozen corn kernels are thawed by microwave to obtain thawed corn kernels; (3) Steaming: The thawed corn kernels are steamed to obtain steamed corn kernels; (4) Grinding: The steamed corn kernels are ground with water to obtain corn slurry; (5) Liquefaction: α-amylase is added to the corn slurry to liquefy it, and a liquefied liquid is obtained; Liquefaction parameters: α-amylase addition amount 6~12 U / g, temperature 79~91℃, pH 6.2~6.6, time 75~91min; (6) Saccharification: Add saccharifying enzyme to the liquefied liquid to perform saccharification, and obtain a saccharified liquid; Saccharification parameters: saccharifying enzyme addition of 190~250 U / g, temperature of 70~82℃, pH of 6.2~6.6, and time of 100~180 min; (7) Fermentation: Add brewing yeast to the saccharified liquid for fermentation to obtain fermented base wine; Fermentation parameters: yeast addition 0.6~1.2%, temperature 22~28℃, pH 4.2~4.6, time 40~56h; (8) Charcoal burning: Fructose and complex amino acids are added to the fermented base wine to carry out Maillard reaction, thereby obtaining the charcoal-burnt flavored fresh glutinous corn fermented wine; Charcoal firing parameters: fructose and compound amino acid additions are both 1-3%, temperature is 90-100℃, pH is 5.4-5.8, and time is 3.25-5.25h.

2. The method as described in claim 1, characterized in that, The scalding parameters in step (1) are: scalding in water at 95~100℃ for 20~25 minutes.

3. The method as described in claim 1, characterized in that, The thawing parameters in step (2) are: microwave power of 1000~1200w for thawing, and thawing time of 2~3min.

4. The method as described in claim 1, characterized in that, The steaming parameters in step (3) are: steaming for 15~20 minutes.

5. The method as described in claim 1, characterized in that, The compound amino acid comprises the following components in parts by weight: 8-9 parts aspartic acid, 6-7 parts threonine, 2-3 parts serine, 8-9 parts glutamic acid, 3-4 parts proline, 6-7 parts glycine, 7-8 parts alanine, 6-7 parts valine, 0.5-1 part methionine, 0.5-1 part isoleucine, 11-12 parts leucine, 1-2 parts tyrosine, 4-5 parts phenylalanine, 8-9 parts lysine, 5-6 parts histidine, and 2-3 parts arginine.

6. The method as described in claim 1, characterized in that, Liquefaction parameters: α-amylase addition was 9 U / g, temperature was 85℃, pH was 6.4, and time was 85 min; Saccharification parameters: saccharifying enzyme addition of 220 U / g, temperature of 75℃, pH of 6.4, and time of 140 min; Fermentation parameters: yeast addition 0.9%, temperature 25℃, pH 4.4, time 50h; Charcoal firing parameters: fructose and compound amino acid additions are both 2%, temperature is 95℃, pH is 5.6, and time is 4.25h.

7. The method according to any one of claims 1 to 6, characterized in that, The corn variety mentioned is Bai Nuo 996.

8. The method according to any one of claims 1 to 6, characterized in that, The brewing yeast is a highly active dry brewing yeast.

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