A production process of yellow rice wine lees flavor extract

Abstract

This invention relates to the field of food by-product processing technology, specifically to a production process for a flavor extract from rice wine lees. The method first involves soaking, fermenting, aging, and separating the solid and liquid components of rice wine lees to obtain a lees slurry. This slurry is then pre-soaked with grafted amylose, followed by ultrasonic-high-pressure homogenization and circulation treatment with grafted amylopectin to obtain an ultrafine lees slurry. Finally, a heat-resistant solvent is constructed using propylene glycol and medium-chain triglycerides, and emulsified and homogenized with the addition of double-grafted starch to obtain the flavor extract. This invention constructs a stepwise synergistic extraction-double grafting encapsulation-oil phase thermal barrier system, effectively solving the problems of insufficient utilization of lees flavor substances and volatilization loss under high-temperature processing. The resulting product has a delicate texture, rich flavor, and excellent heat resistance, greatly enhancing the application value of rice wine lees by-products.

Description

Technical Field

[0001] This invention relates to the field of food by-product processing technology, specifically to a production process for a flavor extract from rice wine lees. Background Technology

[0002] Fermented grain liquor, a traditional Chinese condiment, is beloved by consumers for its unique aroma of alcohol and esters. Traditional processing typically involves soaking, fermenting, aging, and solid-liquid separation of the fermented grains, ultimately yielding a liquid liquor product. However, in this traditional process, the large amount of solid residue (grain) produced after solid-liquid separation is often considered low-value waste and directly used as animal feed or fertilizer. In reality, this residue still contains a large amount of high-value alcohol-soluble and fat-soluble flavor compounds (such as higher esters, phenols, and long-chain fatty acids). These flavor compounds, due to the dense structure of plant cell walls or solubility limitations, cannot be effectively transferred to the liquid liquor, resulting in extremely low overall raw material utilization and significant resource waste.

[0003] The flavor compounds in fermented grains are mainly composed of highly volatile esters and alcohols such as ethyl acetate and ethyl hexanoate, which have extremely poor thermal stability. During the high-temperature sterilization, stir-frying, or baking processes commonly used in modern food industry (usually above 100℃ or even reaching 180℃), these characteristic flavor molecules are prone to explosive volatilization or pyrolysis and deterioration, resulting in a bland flavor, uncoordinated aroma, and even unpleasant off-flavors from steaming or cooking in the final product.

[0004] To address these issues, existing technologies often employ simple physical thickening or the addition of artificial flavorings. However, the former fails to fundamentally resolve flavor loss, while the latter struggles to replicate the complex layers of natural fermented grain aroma and does not align with the trend towards clean labeling. Although microencapsulation technology is widely used for flavor preservation, conventional encapsulation agents (such as maltodextrin and gum arabic) struggle to capture intracellular flavor release in situ during complex grinding and emulsification processes, especially in complex heterogeneous systems like fermented grains. Furthermore, they exhibit poor interfacial stability in high-temperature oil-phase systems, making them prone to demulsification and leakage.

[0005] Therefore, there is an urgent need to develop a production process for fermented grains flavor extract that can make deep use of the lees and build an efficient and stable system to resist the damage caused by high-temperature processing. This is of great significance for increasing the added value of fermented grains resources and promoting the industrial application of traditional flavors. Summary of the Invention

[0006] In view of this, the purpose of this invention is to propose a production process for extracting the flavor of rice wine lees, so as to solve the problems of insufficient extraction of raw material flavor in the existing lees processing, which leads to resource waste, and the subsequent high-temperature heat processing which easily causes flavor volatilization and loss.

[0007] To achieve the above objectives, the present invention provides a production process for a flavor extract from rice wine lees, comprising the following steps:

[0008] S1: Amylose was reacted with 1,4-butanediol diglycidyl ether in sodium hydroxide solution at 25℃-35℃ for 6h-10h. After the reaction was completed, the resulting reaction solution was adjusted to neutral, dialyzed, and freeze-dried to form epoxy-activated amylose. Subsequently, it was stirred with β-cyclodextrin at 55℃-65℃ for 10h-14h under alkaline conditions. After the reaction was completed, the resulting reaction solution was adjusted to neutral, dialyzed, and freeze-dried to obtain β-cyclodextrin-grafted amylose.

[0009] S2: Amylopectin was reacted with 1,4-butanediol diglycidyl ether in sodium hydroxide solution at 25℃-35℃ for 6h-10h. After the reaction was completed, the resulting reaction solution was adjusted to neutral, dialyzed, and freeze-dried to form epoxy-activated amylopectin. Subsequently, it was stirred with β-cyclodextrin at 55℃-65℃ for 10h-14h under alkaline conditions. After the reaction was completed, the resulting reaction solution was adjusted to neutral, dialyzed, and freeze-dried to obtain β-cyclodextrin-grafted amylopectin.

[0010] S3: Mix the rice wine lees with salt, rock sugar and compound spices, then add white wine and soak, ferment and age to form a lees brine system; then add low-alcohol white wine as an extraction medium, stir and filter to separate the lees brine and lees mud.

[0011] S4: Take the sludge, add β-cyclodextrin-grafted amylose and deionized water, and soak it in a closed stirring system to obtain the pre-soaked material;

[0012] S5: Add β-cyclodextrin-grafted amylopectin and deionized water to the obtained pre-soaked material, stir and then perform ultrasonic-homogenization circulation treatment to obtain ultrafine slurry.

[0013] S6: Propylene glycol and medium-chain triglycerides are mixed to obtain a heat-resistant solvent. The resulting ultrafine slurry is heated, and the heat-resistant solvent and Tween 80 are added. At the same time, β-cyclodextrin-grafted amylopectin and β-cyclodextrin-grafted amylose are added. After high-shear emulsification and homogenization, the flavor extract is obtained.

[0014] Preferably, the weight ratio of amylose and 1,4-butanediol diglycidyl ether in step S1 is 4:1.

[0015] Preferably, the amylose in step S1 is derived from potatoes.

[0016] Preferably, the molar concentration of the sodium hydroxide solution in step S1 is 0.1 mol / L.

[0017] Preferably, the adjustment to neutrality in step S1 is performed using 1 mol / L hydrochloric acid.

[0018] Preferably, the weight ratio of epoxy-activated amylose and β-cyclodextrin in step S1 is 1:1.

[0019] Preferably, the dialysis in step S1 is performed in a dialysis bag with a molecular weight cutoff of 8000 Da.

[0020] Preferably, the weight ratio of amylopectin to 1,4-butanediol diglycidyl ether in step S2 is 4:1.

[0021] Preferably, the amylopectin in step S2 is derived from potato starch.

[0022] Preferably, the molar concentration of the sodium hydroxide solution in step S2 is 0.1 mol / L.

[0023] Preferably, the adjustment to neutrality in step S2 is performed using 1 mol / L hydrochloric acid.

[0024] Preferably, the weight ratio of epoxy-activated amylopectin to β-cyclodextrin in step S2 is 1:1.

[0025] Preferably, the dialysis in step S2 is performed in a dialysis bag with a molecular weight cutoff of 8000 Da.

[0026] Preferably, the ratio of rice wine lees, salt, rock sugar, compound spices, and white wine used in step S3 is 800g-1200g: 64g-96g: 40g-60g: 24g-36g: 160mL-240mL.

[0027] Preferably, the rice wine lees mentioned in step S3 are brownish-yellow paste with a moisture content of 62%±2% and a residual starch content of 18%±1%; the raw materials are immediately vacuum-sealed and stored at 4°C after collection.

[0028] Preferably, the compound spice in step S3 is a mixture of star anise, cinnamon, bay leaves, and Sichuan pepper.

[0029] Preferably, the soaking temperature in step S3 is 20℃-30℃ and the soaking time is 18h-30h.

[0030] Preferably, the fermentation temperature in step S3 is 20℃-25℃ and the fermentation time is 7 days, during which the mixture is turned over once a day.

[0031] Preferably, the aging temperature in step S3 is 12℃-18℃ and the aging time is 25d-35d.

[0032] Preferably, the liquor mentioned in step S3 is 52% vol or low-alcohol liquor is 20% vol.

[0033] Preferably, the filtration in step S3 is performed using a 200-mesh nylon filter cloth.

[0034] Preferably, the weight ratio of the sludge and β-cyclodextrin-grafted amylose in step S4 is 6.5:1.

[0035] Preferably, the stirring speed in step S4 is 150 rpm to 250 rpm.

[0036] Preferably, the soaking time in step S4 is 60 min to 120 min.

[0037] Preferably, in step S5, the amount of β-cyclodextrin grafted amylopectin used is 80g-120g based on the total weight of the obtained pre-soaked material.

[0038] Preferably, the ultrasonic frequency in step S5 is 20kHz-30kHz, the power is 500W-700W, and the ultrasonic time is 4-6min.

[0039] Preferably, the homogenization pressure in step S5 is 70MPa-90MPa and the time is 2-3min.

[0040] Preferably, the ultrafine slurry D90 in step S5 is ≤20μm.

[0041] Preferably, the ratio of propylene glycol to medium-chain triglycerides in step S6 is 1:1.

[0042] Preferably, in step S6, the amounts of heat-resistant solvent, Tween 80, β-cyclodextrin-grafted amylopectin, and β-cyclodextrin-grafted amylose, based on the total weight of the obtained ultrafine slurry, are 120g-180g, 4g-6g, 40g-60g, and 40g-60g, respectively.

[0043] Preferably, the high-shear emulsification speed in step S6 is 8000rpm-12000rpm.

[0044] Preferably, the homogenization pressure in step S6 is 130MPa-170MPa.

[0045] The beneficial effects of this invention are:

[0046] This invention significantly improves the utilization rate of rice wine lees and the heat resistance and flavor stability of the final product by constructing a unique "stepwise synergistic extraction-double grafting and embedding-oil phase thermal barrier" technical system. The specific beneficial effects are as follows:

[0047] By introducing β-cyclodextrin-grafted amylose / branched starch as a functional additive and applying it stepwise in the soaking and grinding stages, combined with the physical cell wall disruption effects of high-frequency ultrasonic cavitation and high-pressure homogenization shearing, not only are the lees particles pulverized to the micron level, completely destroying the dense structure of plant cell walls and promoting the full release of deeply bound flavor substances, but more importantly, the cyclodextrin cavities on the grafted starch can achieve in-situ capture of flavor molecules at the moment of release. This molecular-level complexation effectively prevents the escape of highly active flavor substances during processing, thereby significantly improving the flavor transfer efficiency from the raw material end to the product end and realizing the full utilization of lees resources.

[0048] To address the challenge of easily volatile fermented aroma flavor, this invention utilizes medium-chain triglycerides to construct a heat-resistant oil phase and leverages the combined effect of linear and branched starches to stabilize the emulsion interface, effectively blocking the thermal volatilization path under high-temperature conditions. This allows the product to maintain an extremely high retention rate of characteristic flavor even after undergoing a rigorous heat treatment at 180℃, thus solving the technical bottleneck of traditional fermented aroma products being unable to withstand high temperatures.

[0049] In summary, the flavor extract prepared by this process has an extremely narrow particle size distribution and a delicate texture, eliminating the rough taste of traditional fermented grain products, and has a rich and harmonious natural fermented grain aroma and smooth taste. It can be used directly as a high-quality heat-resistant baking filling or cooking sauce, which greatly expands the application scenarios and economic value of fermented grain by-products. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in this invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0051] Figure 1 This is a schematic diagram of the process flow of an embodiment of the present invention;

[0052] Figure 2 This is a test analysis diagram of the electronic nose obtained in Example 2 of the present invention after cold and hot processing. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0054] The sources or properties of the raw materials used in the embodiments and comparative examples of this invention are as follows:

[0055] Amylose: derived from potatoes, type A0512, Sigma-Aldrich; Amylopectin: derived from potato starch, type A8515, Sigma-Aldrich; Rice wine lees: moisture content 62%, residual starch content 18%.

[0056] Example 1: A production process for a flavor extract from rice wine lees, the specific steps of which are as follows:

[0057] (1) Preparation of β-cyclodextrin-grafted amylose:

[0058] 8 g of amylose was added to 80 mL of 0.1 mol / L sodium hydroxide solution, and stirred for 30 min under nitrogen. 2 g of 1,4-butanediol diglycidyl ether was dissolved in 15 mL of isopropanol and added dropwise. The reaction was carried out at 25 °C for 6 h. After the reaction was complete, the pH of the reaction solution was adjusted to 7 with 1 mol / L hydrochloric acid and then transferred to a dialysis bag with a molecular weight cutoff of 8000 Da. Dialysis was performed with purified water for 60 h, with the water changed every 8 h. The resulting product was freeze-dried to obtain epoxy-activated amylose. 8 g of epoxy-activated amylose and 8 g of β-cyclodextrin were added to 200 mL of sodium carbonate solution and the pH was adjusted to 11 with 1 mol / L sodium hydroxide solution. The mixture was stirred at 55 °C for 10 h. The resulting reaction solution was adjusted to pH 7 with 1 mol / L hydrochloric acid and then transferred to a dialysis bag with a molecular weight cutoff of 8000 Da. Dialysis was performed with purified water for 60 h, with the water changed every 8 h. The resulting product was freeze-dried to obtain β-cyclodextrin-grafted amylose.

[0059] (2) Preparation of β-cyclodextrin-grafted amylopectin:

[0060] 8g of amylopectin was added to 80mL of 0.1mol / L sodium hydroxide solution, and stirred for 30min under nitrogen. 2g of 1,4-butanediol diglycidyl ether was dissolved in 15mL of isopropanol and added dropwise. The reaction was carried out at 25℃ for 6h. After the reaction was completed, the pH of the reaction solution was adjusted to 7 with 1mol / L hydrochloric acid and then transferred to a dialysis bag with a molecular weight cutoff of 8000Da. The solution was dialyzed with pure water for 60h, with the water changed every 8h. After freeze-drying, epoxy-activated amylopectin was obtained. 8g of epoxy-activated amylopectin and 8g of β-cyclodextrin were added to 200mL of sodium carbonate solution and the pH was adjusted to 11 with 1mol / L sodium hydroxide solution. The mixture was stirred at 55℃ for 10h. The pH of the resulting reaction solution was adjusted to 7 with 1mol / L hydrochloric acid and then transferred to a dialysis bag with a molecular weight cutoff of 8000Da. The solution was dialyzed with pure water for 60h, with the water changed every 8h. After freeze-drying, β-cyclodextrin-grafted amylopectin was obtained.

[0061] (3) Raw material preparation: Weigh 800g of rice wine lees, 64g of salt, 40g of rock sugar, and 24g of compound spices (star anise: cinnamon: bay leaf: Sichuan pepper in a ratio of 2:2:1:1). Mix them evenly in a mixer and transfer them to a sealed ceramic jar. Add 160mL of 52% vol white wine and 240mL of deionized water. Soak at 20℃ for 18h and then transfer them to a fermentation tank with a breathable valve. Maintain the temperature at 20℃ for 7 days of fermentation, stirring once a day during this period. After fermentation, age them in a sealed container at 12℃ for 25 days to form a lees brine system. Then add 400mL of 20% vol low-alcohol white wine as an extraction medium to the lees brine system. After mechanical stirring for 30min, filter the mixture with a 200-mesh nylon filter cloth to separate the lees brine and lees mud.

[0062] (4) Soaking treatment: Take 520g of sludge, add 80g of β-cyclodextrin-grafted amylose and 400mL of deionized water (45℃), and soak for 60min with closed stirring at 150rpm to obtain pre-soaked material;

[0063] (5) Grinding treatment: Add 80g of β-cyclodextrin-grafted amylopectin and 400mL of deionized water (45℃) to the obtained pre-soaked material, stir for 10min, and then treat with ultrasound at 20kHz and 500W for 4min. Then, use a high-pressure homogenizer to cycle at 70MPa for 2min. Use the ultrasound treatment and high-pressure homogenization treatment as one cycle, repeat 3 cycles, and control the material temperature not to exceed 30℃ during the process to obtain ultrafine slurry with D90≤20μm.

[0064] (6) Emulsification treatment: 60g of propylene glycol and 60g of medium-chain triglycerides were mixed at 45°C to obtain a heat-resistant solvent. The resulting ultrafine slurry was heated to 55°C, and 120g of heat-resistant solvent and 4g of Tween 80 were added. At the same time, 40g of β-cyclodextrin-grafted amylopectin and 40g of β-cyclodextrin-grafted amylose were added. After emulsification at 8000rpm for 4min, the mixture was transferred to a high-pressure microfluidic homogenizer and homogenized twice at 130MPa to form a uniform and stable flavor extract.

[0065] Example 2: A production process for a flavor extract from rice wine lees, the specific steps of which are as follows:

[0066] (1) Preparation of β-cyclodextrin-grafted amylose:

[0067] 10g of amylose was added to 100mL of 0.1mol / L sodium hydroxide solution, and stirred for 30min under nitrogen. 2.5g of 1,4-butanediol diglycidyl ether was dissolved in 20mL of isopropanol and added dropwise. The reaction was carried out at 30℃ for 8h. After the reaction was completed, the pH of the reaction solution was adjusted to 7 with 1mol / L hydrochloric acid and then transferred to a dialysis bag with a molecular weight cutoff of 8000Da. The solution was dialyzed with pure water for 72h, with the water changed every 8h. After freeze-drying, epoxy-activated amylose was obtained. 10g of epoxy-activated amylose and 10g of β-cyclodextrin were added to 200mL of sodium carbonate solution and the pH was adjusted to 11 with 1mol / L sodium hydroxide solution. The mixture was stirred at 60℃ for 12h. The pH of the resulting reaction solution was adjusted to 7 with 1mol / L hydrochloric acid and then transferred to a dialysis bag with a molecular weight cutoff of 8000Da. The solution was dialyzed with pure water for 72h, with the water changed every 8h. After freeze-drying, β-cyclodextrin-grafted amylose was obtained.

[0068] (2) Preparation of β-cyclodextrin-grafted amylopectin:

[0069] 10g of amylopectin was added to 100mL of 0.1mol / L sodium hydroxide solution. After stirring with nitrogen for 30min, 2.5g of 1,4-butanediol diglycidyl ether was dissolved in 20mL of isopropanol and added dropwise. The reaction was carried out at 30℃ for 8h. After the reaction was completed, the pH of the reaction solution was adjusted to 7 with 1mol / L hydrochloric acid and then transferred to a dialysis bag with a molecular weight cutoff of 8000Da. The solution was dialyzed with pure water for 72h, with the water changed every 8h. After freeze-drying, epoxy-activated amylopectin was obtained. 10g of epoxy-activated amylopectin and 10g of β-cyclodextrin were added to 200mL of sodium carbonate solution and the pH was adjusted to 11 with 1mol / L sodium hydroxide solution. The mixture was stirred at 60℃ for 12h. The pH of the resulting reaction solution was adjusted to 7 with 1mol / L hydrochloric acid and then transferred to a dialysis bag with a molecular weight cutoff of 8000Da. The solution was dialyzed with pure water for 72h, with the water changed every 8h. After freeze-drying, β-cyclodextrin-grafted amylopectin was obtained.

[0070] (3) Raw material preparation: Weigh 1000g of rice wine lees, 80g of salt, 50g of rock sugar, and 30g of compound spices (star anise: cinnamon: bay leaf: Sichuan pepper in a ratio of 2:2:1:1). Mix them evenly in a mixer and transfer them to a sealed ceramic jar. Add 200mL of 52% vol white wine and 300mL of deionized water. Soak at 25℃ for 24 hours and then transfer them to a fermentation tank with a breathable valve. Maintain the temperature at 23℃ for 7 days of fermentation, stirring once a day during this period. After fermentation, seal and age at 15℃ for 30 days to form a lees brine system. Then add 500mL of 20% vol low-alcohol white wine as an extraction medium to the lees brine system. After mechanical stirring for 30 minutes, filter with a 200-mesh nylon filter cloth to separate the lees brine and lees mud.

[0071] (4) Soaking treatment: Take 650g of sludge, add 100g of β-cyclodextrin-grafted amylose and 500mL of deionized water (45℃), and soak for 90min with closed stirring at 200rpm to obtain pre-soaked material;

[0072] (5) Grinding treatment: Add 100g of β-cyclodextrin-grafted amylopectin and 500mL of deionized water (45℃) to the obtained pre-soaked material, stir for 10min, and then treat with ultrasound at 25kHz and 600W for 5min. Then, use a high-pressure homogenizer to cycle at 80MPa for 3min. Use the ultrasound treatment and high-pressure homogenization treatment as one cycle, repeat 3 cycles, and control the material temperature not to exceed 30℃ during the process to obtain ultrafine slurry with D90≤20μm.

[0073] (6) Emulsification treatment: 85g of propylene glycol and 85g of medium-chain triglycerides were mixed at 50°C to obtain a heat-resistant solvent. The resulting ultrafine slurry was heated to 60°C, and 150g of heat-resistant solvent and 5g of Tween 80 were added. At the same time, 50g of β-cyclodextrin-grafted amylopectin and 50g of β-cyclodextrin-grafted amylose were added. After emulsification at 10000rpm for 5min, the mixture was transferred to a high-pressure microfluidic homogenizer and homogenized three times at 150MPa to form a uniform and stable flavor extract.

[0074] Example 3: A production process for a flavor extract from rice wine lees, the specific steps of which are as follows:

[0075] (1) Preparation of β-cyclodextrin-grafted amylose:

[0076] 12g of amylose was added to 120mL of 0.1mol / L sodium hydroxide solution, and stirred for 30min under nitrogen. Then, 3g of 1,4-butanediol diglycidyl ether was dissolved in 25mL of isopropanol and added dropwise. The reaction was carried out at 35℃ for 10h. After the reaction was completed, the pH of the reaction solution was adjusted to 7 with 1mol / L hydrochloric acid and then transferred to a dialysis bag with a molecular weight cutoff of 8000Da. The solution was dialyzed with pure water for 84h, with the water changed every 8h. After freeze-drying, epoxy-activated amylose was obtained. 12g of epoxy-activated amylose and 12g of β-cyclodextrin were added to 200mL of sodium carbonate solution and the pH was adjusted to 11 with 1mol / L sodium hydroxide solution. The mixture was stirred at 65℃ for 14h. The pH of the resulting reaction solution was adjusted to 7 with 1mol / L hydrochloric acid and then transferred to a dialysis bag with a molecular weight cutoff of 8000Da. The solution was dialyzed with pure water for 84h, with the water changed every 8h. After freeze-drying, β-cyclodextrin-grafted amylose was obtained.

[0077] (2) Preparation of β-cyclodextrin-grafted amylopectin:

[0078] 12g of amylopectin was added to 120mL of 0.1mol / L sodium hydroxide solution. After stirring with nitrogen for 30min, 3g of 1,4-butanediol diglycidyl ether was dissolved in 25mL of isopropanol and added dropwise. The reaction was carried out at 35℃ for 10h. After the reaction was completed, the pH of the reaction solution was adjusted to 7 with 1mol / L hydrochloric acid and then transferred to a dialysis bag with a molecular weight cutoff of 8000Da. The solution was dialyzed with pure water for 84h, with the water changed every 8h. After freeze-drying, epoxy-activated amylopectin was obtained. 12g of epoxy-activated amylopectin and 12g of β-cyclodextrin were added to 200mL of sodium carbonate solution and the pH was adjusted to 11 with 1mol / L sodium hydroxide solution. The mixture was stirred at 65℃ for 14h. The pH of the resulting reaction solution was adjusted to 7 with 1mol / L hydrochloric acid and then transferred to a dialysis bag with a molecular weight cutoff of 8000Da. The solution was dialyzed with pure water for 84h, with the water changed every 8h. After freeze-drying, β-cyclodextrin-grafted amylopectin was obtained.

[0079] (3) Raw material preparation: Weigh 1200g of rice wine lees, 96g of salt, 60g of rock sugar, and 36g of compound spices (star anise: cinnamon: bay leaf: Sichuan pepper in a ratio of 2:2:1:1). Mix them evenly in a mixer and transfer them to a sealed ceramic jar. Add 240mL of 52% vol white wine and 360mL of deionized water. Soak at 30℃ for 30h and then transfer to a fermentation tank with a breathable valve. Maintain the temperature at 25℃ for 7 days of fermentation, stirring once a day during this period. After fermentation, age the mixture in a sealed container at 18℃ for 35 days to form a lees brine system. Then add 600mL of 20% vol low-alcohol white wine as an extraction medium to the lees brine system. After mechanical stirring for 30min, filter the mixture with a 200-mesh nylon filter cloth to separate the lees brine and lees mud.

[0080] (4) Soaking treatment: Take 780g of sludge, add 120g of β-cyclodextrin-grafted amylose and 600mL of deionized water (45℃), and soak for 120min with closed stirring at 250rpm to obtain pre-soaked material;

[0081] (5) Grinding treatment: Add 120g of β-cyclodextrin-grafted amylopectin and 600mL of deionized water (45℃) to the obtained pre-soaked material, stir for 10min, and then treat with ultrasound at 30kHz and 700W for 6min. Then, use a high-pressure homogenizer to cycle at 90MPa for 3min. Use the ultrasound treatment and high-pressure homogenization treatment as one cycle, repeat 3 cycles, and control the material temperature not to exceed 30℃ during the process to obtain ultrafine slurry with D90≤20μm.

[0082] (6) Emulsification treatment: 90g of propylene glycol and 90g of medium-chain triglycerides were mixed at 55°C to obtain a heat-resistant solvent. The resulting ultrafine slurry was heated to 65°C, and 180g of heat-resistant solvent and 6g of Tween 80 were added. At the same time, 60g of β-cyclodextrin-grafted amylopectin and 60g of β-cyclodextrin-grafted amylose were added. After emulsification at 12000rpm for 6min, the mixture was transferred to a high-pressure microfluidic homogenizer and homogenized 4 times at 170MPa to form a uniform and stable flavor extract.

[0083] Comparative Example 1: The difference from Example 2 is that ultrasonic treatment and high-pressure homogenization circulation treatment are not performed in step (5), while the other conditions are the same as in Example 2.

[0084] Comparative Example 2: The difference from Example 2 is that in step (6), the medium-chain triglycerides are replaced with an equal amount of propylene glycol, while the other conditions remain the same as in Example 2.

[0085] Comparative Example 3: The difference from Example 2 is that β-cyclodextrin grafted with amylose is not added in step (4), β-cyclodextrin grafted with amylopectin is not added in step (5), and neither β-cyclodextrin grafted with amylose nor β-cyclodextrin grafted with amylopectin is added in step (6). The other conditions are the same as in Example 2.

[0086] Comparative Example 4: The difference from Example 2 is that β-cyclodextrin-grafted amylose is not added in step (4), β-cyclodextrin-grafted amylopectin is not added in step (5), and both β-cyclodextrin-grafted amylose and β-cyclodextrin-grafted amylopectin are added in step (6). The other conditions are the same as in Example 2.

[0087] Comparative Example 5: The difference from Example 2 is that β-cyclodextrin-grafted amylose is added only in step (4), β-cyclodextrin-grafted amylopectin is added only in step (5), and β-cyclodextrin-grafted amylose and β-cyclodextrin-grafted amylopectin are not added in step (6). The other conditions are the same as in Example 2.

[0088] Comparative Example 6: The difference from Example 2 is that the β-cyclodextrin grafted amylose in steps (4) and (6) is replaced with an equal amount of β-cyclodextrin grafted amylopectin, while the other conditions are the same as in Example 2.

[0089] Performance testing

[0090] Retention rate of volatile flavor compounds:

[0091] The test subjects were the flavor extracts prepared in Examples 1-3 and Comparative Examples 1-6. Before the test, each group of samples was placed in a sealed container and equilibrated at 4°C for 24 hours. All tests were performed in parallel for 5 times, and the final test results were recorded after taking the average value.

[0092] Sensory evaluation: Samples from Examples 1-3 and Comparative Examples 1-6 were heated at 100℃ for 30 minutes and then cooled to the serving temperature (50℃) for evaluation. The sensory evaluation was conducted according to GB / T 10220-2012 "General Methodology of Sensory Analysis". A group of 10 trained evaluators scored the samples comprehensively on four indicators: aroma intensity, flavor harmony, texture, and absence of bitterness or off-flavors (out of 10).

[0093] Particle size distribution: The flavor extracts prepared in Examples 1-3 and Comparative Examples 1-6 were measured using a laser particle size analyzer. Specifically, 0.5g of sample was added to the sample cell, deionized water was used as the dispersion medium, the ultrasonic dispersion function was turned on (power 40W, time 30s), the pump speed was adjusted to 2000r / min, and the volume average particle size D50 and D90 (μm) of the sample were measured.

[0094] Raw material utilization rate: The sludge obtained after filtration and separation in step (3) of Examples 1-3 and Comparative Examples 1-6 was taken as the raw material end, and the final flavor extracts prepared in step (6) of the corresponding examples and comparative examples were taken as the product end for testing. According to the "National Food Safety Standard for Determination of Volatile Flavor Substances in Food by Gas Chromatography-Mass Spectrometry", the absolute total amount of characteristic flavor substances in the raw material end and product end samples was quantitatively determined by the internal standard method. Ethyl acetate and ethyl hexanoate were selected as representative substances, and the utilization rate was calculated by the mass balance method.

[0095] Raw material utilization rate (%) = ×100%;

[0096] in, The concentration (mg / kg) of a certain flavor substance in the flavor extract; Total yield of flavor extract (kg); The concentration (mg / kg) of a certain flavor substance added to the lees; The mass (kg) of the sludge added is shown in Table 1. The test results are shown in Table 1.

[0097] Retention rate of volatile flavor compounds: The flavor extracts prepared in Examples 1-3 and Comparative Examples 1-6 were used as the pre-treatment group; 50g of each sample was sealed in a heat-resistant retort bag, heated in an oil bath at 180℃ for 20min, and immediately cooled to room temperature in an ice water bath after removal, which was used as the post-treatment group. The determination was performed according to the "National Food Safety Standard for Determination of Volatile Flavor Compounds in Food by Gas Chromatography-Mass Spectrometry". Headspace solid-phase microextraction combined with gas chromatography-mass spectrometry was used for determination. The specific operation was as follows: 2.00g of sample was accurately weighed and placed in a 20mL headspace vial, 1.0g of sodium chloride (saturated salting out) and 5mL of deionized water were added, and 10μL of 50mg / L 2-octanol was added as... As an internal standard, the vial was quickly capped and sealed. The headspace vial was placed in a 60℃ constant temperature water bath for equilibration for 20 min, and then the extraction head was inserted for headspace adsorption for 30 min. Subsequently, desorption was performed at the GC injection port (temperature 250℃) for 5 min. A DB-WAX capillary column was used. The temperature program was set as follows: 40℃ for 3 min, increased to 200℃ at 5℃ / min, and then increased to 230℃ at 10℃ / min for 5 min. The mass spectrometry conditions were electron impact ionization (EI) with an electron energy of 70 eV and an ion source temperature of 230℃. Four characteristic flavor components—ethyl acetate, ethyl hexanoate, ethyl butyrate, and phenylethanol—were selected. The contents of each characteristic flavor component before and after treatment were calculated using the internal standard method, and the retention rate was calculated (retention rate = ...). (×100%), the test results are shown in Table 2.

[0098] Electronic nose sensory array analysis: To visually evaluate the overall flavor stability of the flavor extract prepared in this invention under extreme thermal processing conditions, the flavor extract prepared in Example 2 was selected for electronic nose sensory array analysis. The specific operation is as follows:

[0099] 50g of the flavor extract prepared in Example 2 was stored at room temperature and designated as the cold-processed group. Another 50g of the flavor extract prepared in Example 2 was sealed in a high-temperature resistant retort pouch, heated in an oil bath at 180℃ for 20 minutes, and immediately cooled to room temperature in an ice-water bath after removal; this was designated as the hot-processed group. A portable electronic nose system equipped with a 10-element metal oxide semiconductor sensor array was used for testing. 3.00g of each sample from the cold and hot-processed groups were accurately weighed and placed in 20mL headspace vials. After sealing, the vials were equilibrated in a 60℃ constant-temperature water bath for 30 minutes to allow the volatile components to reach dynamic equilibrium in the headspace. The sensor response values ​​in the stable response region were collected, and principal component analysis (PCA) and the discrimination index (DI) were calculated. The results are shown in [Figure number missing]. Figure 2 .

[0100] Table 1 Performance Test Results

[0101] Sensory evaluation Particle size distribution D50 (μm) Particle size distribution D90 (μm) Raw material utilization rate (%) / ethyl acetate Raw material utilization rate (%) / Ethyl hexanoate Example 1 9.1 5.2 13.8 74.5 76.2 Example 2 9.5 4.6 12.3 76.8 78.5 Example 3 9.0 5.5 14.1 73.9 75.8 Comparative Example 1 6.8 24.5 65.4 55.2 58.4 Comparative Example 2 7.2 5.8 15.2 62.1 64.5 Comparative Example 3 6.2 8.9 22.6 48.5 50.2 Comparative Example 4 8.1 5.1 14.5 60.4 63.1 Comparative Example 5 7.8 7.2 18.6 68.5 70.2 Comparative Example 6 8.6 5.4 14.8 70.1 72.4

[0102] Table 2 Results of volatile flavor compound retention test

[0103] Retention rate (%) / Ethyl acetate Retention rate (%) / Ethyl hexanoate Retention rate (%) / Ethyl butyrate Retention rate (%) / phenylethanol Example 1 90.5 91.2 92.2 93.5 Example 2 91.5 91.8 93.5 95.1 Example 3 90.2 91.5 91.8 93.2 Comparative Example 1 68.5 70.1 72.4 78.2 Comparative Example 2 15.4 18.7 22.6 55.8 Comparative Example 3 28.2 32.3 35.1 60.5 Comparative Example 4 65.6 68.4 71.2 79.1 Comparative Example 5 62.8 65.2 68.5 76.0 Comparative Example 6 70.5 72.6 75.2 80.4

[0104] Data Analysis: As can be seen from the data of Examples 1-3 in Tables 1 and 2, the flavor extract prepared by this invention exhibits excellent comprehensive advantages in all performance indicators. Through the unique "pre-soaking-grinding-emulsification" system, the problem of insufficient raw material extraction in traditional processes is effectively solved, achieving efficient transfer and retention of flavor substances. More importantly, after undergoing rigorous high-temperature treatment at 180℃, the retention rate of the four characteristic flavor substances remains at a high level. This excellent heat resistance and fine texture are presumably due to the stable emulsification system constructed by β-cyclodextrin grafted starch and heat-resistant oil phase, which not only achieves microencapsulation protection of flavor molecules but also prevents volatilization and escape at high temperatures, thus giving the product excellent thermal processing adaptability and high application value.

[0105] As can be seen from the data in Tables 1 and 2 of Example 2 and Comparative Example 1, the ultrasonic treatment and high-pressure homogenization circulation treatment in step (5) have significant beneficial effects. This is mainly due to the cavitation effect of high-frequency ultrasound and the shearing and crushing effect of high-pressure homogenization, which not only pulverizes the sludge particles to the micron level, promoting the dissolution and release of flavor substances, but also provides more uniform binding sites for the subsequent encapsulation of grafted starch. This deep refinement and reconstruction of the physical structure is a prerequisite for fully utilizing the flavor and constructing a stable emulsion system to resist high-temperature volatilization.

[0106] As can be seen from the data in Examples 2 and Comparative Example 2 in Tables 1 and 2, the high-temperature flavor retention rate dropped sharply when the heat-resistant solvent system was changed. This is mainly due to the high boiling point and non-polar environment of medium-chain triglycerides, which may have formed an oil-starch composite interfacial film with β-cyclodextrin-grafted starch. This film provides a denser hydrophobic protective layer for fat-soluble and volatile flavor molecules, thereby effectively blocking the thermal volatilization pathway at high temperatures.

[0107] As can be seen from the data in Tables 1 and 2 of Example 2 and Comparative Example 3, the lack of functional additives at each stage of the system led to the complete collapse of product performance. The main reason is that simple physical mixing cannot form an effective host-guest encapsulation structure, and flavor substances are in a free state, which is very easy to volatilize and be lost during processing. Example 2 utilizes the β-cyclodextrin cavity on the grafted starch to capture flavor molecules and constructs a three-dimensional network structure through the starch long chain, achieving the dual effect of "molecular-level encapsulation and macroscopic emulsification stabilization", thereby ensuring efficient flavor control throughout the entire process from raw material extraction to finished product heat resistance.

[0108] As can be seen from the data in Tables 1 and 2 of Example 2 and Comparative Example 4, changing the addition sequence of β-cyclodextrin-grafted amylose and β-cyclodextrin-grafted amylopectin (adding only in step 6) still cannot achieve the optimal effect. The main reason may be that the role of grafted starch is not only in the final emulsification and stabilization, but also in the step-by-step synergy of the whole process. Adding grafted starch in steps is conducive to the gradual combination and modification of grafted starch with sludge particles, forming a denser interface layer.

[0109] As can be seen from the data in Tables 1 and 2 of Example 2 and Comparative Example 5, adding grafted starch only at the front end and not adding it during the emulsification stage in step (6) will cause a decrease in product stability and heat resistance. This indicates that the addition operation in step (6) is crucial for building the final stable emulsification system. It is speculated that this is because the front-end addition achieves the initial extraction and protection of flavor, and the addition of grafted starch during the emulsification stage can encapsulate the newly formed micro oil droplets, further strengthening the ternary stable system of "flavor-oil-starch", ensuring that the external protective layer remains intact and effective in the subsequent extreme 180°C heat environment, and preventing the leakage of flavor substances.

[0110] As can be seen from the data in Tables 1 and 2 of Example 2 and Comparative Example 6, the matrix structure of grafted starch also has a subtle influence on performance. It is speculated that this is because the combination of amylose and amylopectin may have taken into account the high-strength encapsulation ability of amylose and the excellent dispersion stability of amylopectin, thus achieving the best synergistic effect.

[0111] like Figure 2 As shown, principal component 1 (PC1) contributed 65.1%, principal component 2 (PC2) contributed 21.9%, and the total cumulative contribution of the first two principal components reached 87.0%, indicating that the model effectively extracted the main flavor characteristics of the samples. In addition, the DI value in the figure is less than 80%, indicating that there is a certain similarity between the two groups of samples. In summary, the electronic nose PCA analysis shows that the odor fingerprints of the samples before and after heat treatment are somewhat different but still maintain the same flavor type / profile. This indicates that although there is a trace amount of physical volatilization, the overall flavor profile and aroma balance of the samples have not undergone qualitative changes, which strongly confirms the excellent thermal protection performance of the microcapsule system of this invention for aroma quality.

[0112] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in detail for the sake of brevity.

Claims

1. A production process for a flavor extract from rice wine lees, characterized in that, Includes the following steps: S1: Amylose was reacted with 1,4-butanediol diglycidyl ether in sodium hydroxide solution at 25℃-35℃ for 6h-10h. After the reaction was completed, the resulting reaction solution was adjusted to neutral, dialyzed, and freeze-dried to form epoxy-activated amylose. Subsequently, it was stirred with β-cyclodextrin at 55℃-65℃ for 10h-14h under alkaline conditions. After the reaction was completed, the resulting reaction solution was adjusted to neutral, dialyzed, and freeze-dried to obtain β-cyclodextrin-grafted amylose. S2: Amylopectin was reacted with 1,4-butanediol diglycidyl ether in sodium hydroxide solution at 25℃-35℃ for 6h-10h. After the reaction was completed, the resulting reaction solution was adjusted to neutral, dialyzed, and freeze-dried to form epoxy-activated amylopectin. Subsequently, it was stirred with β-cyclodextrin at 55℃-65℃ for 10h-14h under alkaline conditions. After the reaction was completed, the resulting reaction solution was adjusted to neutral, dialyzed, and freeze-dried to obtain β-cyclodextrin-grafted amylopectin. S3: Mix the rice wine lees with salt, rock sugar and compound spices, then add white wine and soak, ferment and age to form a lees brine system; then add low-alcohol white wine as an extraction medium, stir and filter to separate the lees brine and lees mud. S4: Take the sludge, add β-cyclodextrin-grafted amylose and deionized water, and soak it in a closed stirring system to obtain the pre-soaked material; S5: Add β-cyclodextrin-grafted amylopectin and deionized water to the obtained pre-soaked material, stir and then perform ultrasonic-homogenization circulation treatment to obtain ultrafine slurry. S6: Propylene glycol and medium-chain triglycerides are mixed to obtain a heat-resistant solvent. The resulting ultrafine slurry is heated, and the heat-resistant solvent and Tween 80 are added. At the same time, β-cyclodextrin-grafted amylopectin and β-cyclodextrin-grafted amylose are added. After high-shear emulsification and homogenization, the flavor extract is obtained.

2. The production process according to claim 1, characterized in that, In step S1, the weight ratio of amylose to 1,4-butanediol diglycidyl ether is 4:1; the weight ratio of epoxy-activated amylose to β-cyclodextrin is 1:

1.

3. The production process according to claim 1, characterized in that, In step S2, the weight ratio of amylopectin to 1,4-butanediol diglycidyl ether is 4:1; the weight ratio of epoxy-activated amylopectin to β-cyclodextrin is 1:

1.

4. The production process according to claim 1, characterized in that, The compound spice mixture mentioned in step S3 is a mixture of star anise, cinnamon, bay leaves, and Sichuan pepper.

5. The production process according to claim 1, characterized in that, The rice wine lees mentioned in step S3 are brownish-yellow paste with a moisture content of 62%±2% and a residual starch content of 18%±1%. The raw materials are immediately vacuum-sealed and stored at 4℃ after collection.

6. The production process according to claim 1, characterized in that, The weight ratio of the sludge and β-cyclodextrin-grafted amylose in step S4 is 6.5:

1.

7. The production process according to claim 1, characterized in that, The high-shear emulsification speed in step S6 is 8000rpm-12000rpm.

Images